Open Access

Chinese medicines as a resource for liver fibrosis treatment

  • Yibin Feng1,
  • Kwok-Fan Cheung2,
  • Ning Wang1,
  • Ping Liu3,
  • Tadashi Nagamatsu4 and
  • Yao Tong1Email author
Chinese Medicine20094:16

DOI: 10.1186/1749-8546-4-16

Received: 2 April 2009

Accepted: 20 August 2009

Published: 20 August 2009

Abstract

Liver fibrosis is a condition of abnormal proliferation of connective tissue due to various types of chronic liver injury often caused by viral infection and chemicals. Effective therapies against liver fibrosis are still limited. In this review, we focus on research on Chinese medicines against liver fibrosis in three categories, namely pure compounds, composite formulae and combination treatment using single compounds with composite formulae or conventional medicines. Action mechanisms of the anti-fibrosis Chinese medicines, clinical application, herbal adverse events and quality control are also reviewed. Evidence indicates that some Chinese medicines are clinically effective on liver fibrosis. Strict quality control such as research to identify and monitor the manufacturing of Chinese medicines enables reliable pharmacological, clinical and in-depth mechanism studies. Further experiments and clinical trials should be carried out on the platforms that conform to international standards.

Background

Liver fibrosis is a condition of abnormal proliferation of connective tissue due to various types of chronic liver injury often caused by viral infection and chemicals. Hepatitis B viral (HBV) infection is the major cause of liver fibrosis in China, whereas hepatitis C viral (HCV) infection and alcohol are the main causes in the United States, Europe and Japan [14]. Liver fibrosis may progress into liver cirrhosis and other complications coupled with carcinogenesis [5, 6]. The pathogenesis of liver fibrosis involves the activation of hepatic stellate cells (HSCs), the over-expression and over-secretion of collagens, and consequently an excessive accumulation of extracellular matrix (ECM) proteins [7]. Research has been focused on the management of liver fibrosis including the elimination of primary diseases, immunomodulation, suppression of hepatocyte inflammation, prevention of death and damage of hepatocytes, inhibition of over-secretion and accumulation of ECM proteins, promotion of ECM degradation, improvement of microcirculation and metabolism of liver and reduction of complications [8]. The reversal of liver fibrosis and even cirrhosis has been documented [9].

Complementary and alternative treatments of liver fibrosis have been under active research worldwide [1012]. In Chinese medicine, liver fibrosis is thought to be caused by 'poor blood circulation, toxin stagnation and a deficiency of healthy energy' (dysregulated metabolism). Thus, Chinese medicine therapy to treat liver fibrosis is mainly based on reducing blood stagnation, resolving stasis, eliminating toxins and enhancing body immunity.

This review aims to provide an overview on the types of Chinese medicines used to treat liver fibrosis.

Chinese medicines used to treat liver fibrosis

Compounds and extracts

Around 20 compounds or extracts from Chinese medicines have been reported to have liver protective and anti-fibrotic effects. Various studies on their chemistry and pharmacology as well as clinical trials have been carried out to study these compounds or extracts. Table 1 summarizes those with liver protection and anti-fibrotic effects demonstrated in various research reports [1368].
Table 1

Anti-fibrosis effect of compounds or extracts derived from Chinese medicines

Compounds or extracts and major references

Pharmacological actions and clinical indications

Botanic source

Salvia miltiorrhiza

Extract & SA-B [1318]

Reduce ALT and AST activities, inhibit protein expressions of TGF-β1, type I collagen and Smad3, anti-oxidation, down- regulate TGF-β1, TIMP-1 gene expression and MAPK activity, anti-nitric oxide, anti-apoptosis, apply to CHB patients

Root of Salviae miltiorrhiza Bge.

Glycyrrhizin [1926]

Reduce ALT and AST activities, inhibit NF-κB binding activity, down-regulate smurf2 gene expression, apply to CHC patients and prevent hepatocarcinoma in patients with HCV-associated cirrhosis

Rhizome of Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Batal. or Glycyrrhiza glabra L.

Tetrandrine [2732]

Down-regulate c-fos and c-jun gene expression, anti-nitric oxide, up-regulate Smad7 gene expression, apply to CHB patients, down-regulate NF-κB signalling cascade and biomarker such as ICAM-1 and α-SMA

Root of Stephaniae tetrandrae S. Moore

Matrine & Oxymatrine [3335]

Inhibit PDGF and TGF-β1 actions, inhibit HBV-DNA, improve liver function in patients with CHB or CHC patients

Root of Sophorae flavescentis Ait

Taurine [36, 37]

Inhibit TGF-β1 action, collagen formation in M cell culture system, reduce oxidative stress

Calculus Bovis

Tetramethylpyrazine

(Chuanxiongzine) [38]

Anti-oxidation, synergic anti-hepatic fibrosis effect with rehin, apply to CHB patients

Rhizome of Ligusticum chuanxiong Hort.

Rehin, emodin [3941]

Inhibit TGF-β1 expression, anti-HSC proliferation

Root and Rhizome of Rheum palmatum L., Rheum tanguticum Maxim. Ex Balf. or Rheum officinale Baill.

Curcumin [42, 43]

Anti-oxidative effect, activate PPARgamma to reduce cell proliferation, induce apoptosis and suppress ECM gene expression in vitro and in vivo

Rhizome of Curcumae longa L.

Panax Notoginseng saponin

and its water-extract [4446]

Reduce AST and ALT, increase liver and serum SOD, reduce serum liver fibrosis markers levels, prevent liver fibrosis and hepatic microvascular dysfunction in liver fibrosis rats

Root of Panax notoginseng (Burk)F.H. Chen

Cordyceps polysaccharide [47, 48]

Increase CD4/CD8 T lymphocytes ratio and decrease HA and PC III, inhibit TGF-β1 and PDGF expressions, reduce AST and ALT, apply to CHB patients

The complex of the stroma of the fungus Cordceps sinensis (berk.)Sacc. and larva of caterpillar on which the fungus grows

Ginkgo biloba extract [49, 50]

Reduce ALT and AST, anti-oxidation, suppress NF-κB activation, inhibit TGF-β1 and collagen gene expression in rats

Leaves of Ginkgo bioba L.

Artemisinin/artesunate [51]

As inhibitors of hepatitis B virus production

Aerial part of Artemesia annua L.

Berberis aristata fruit extract and berberine [5262]

Reduce AST and ALT, anti-oxidation, suppress expression of NF-κB, α-SMA, TGF-β1, anti-liver cancer, induce apoptosis in cancer cell lines and animal models

Rhizome of Coptis chinensis French., Coptis teeta Wall., Coptis japonica Makino., other genus Berberis

Aucubin [63, 64]

Reduce AST and ALT, against HBV replication, suppress NF-κB activation in cell or animal models.

Ripe seed of Plantago asiatica L.

Ganoderma lucidum extract & Ganoderma polysaccharide [65, 66]

Reduce AST, ALT, ALP, Tbil and the collagen content in rats with cirrhosis induced by biliary obstruction in rats, inhibit HSCs cells proliferation through blocking PDGFβR phosphorylation

Ganoderma lucidum

Gypenoside [67]

Inhibits HSCs proliferation, arrest HSC cells at G1 phase, inhibit the signal pathway of PDGF-Akt-p70 and down-regulate of cyclin D1 and D3 expression

Gynostemma pentaphyllum

Solanum nigrum Linn extract [68]

Reduce AST, ALT, ALP, Tbil, modulate GSTs and SOD, repress the production of free radicals

Solanum nigrum Linn

Composite formulae

More than ten composite formulae for liver fibrosis have been reported [69108]. Table 2 summarizes traditional composite formulae such as Yinchenhao Tang, Xiao Chaihu Tang, Buzhong Yiqi Tang and Renshen Yangrong Tang as well as modern formulae such as Fufang Jinsane, Danshen Taoxiong Tang, Ershen Zezhu Tang, Buqi Jianzhong Tang, Fangji Tang, Handan Ganle, Ganzhifu and Fuzheng Huayu.
Table 2

Anti-fibrosis effect of composite formulae

Composite formulae and major references

Pharmacological actions and clinical indications

Compositions of formulae

Yinchenhao Tang [6978]

Induce HSCs apoptosis, inhibit HSCs activation, reduce collagen deposition and α-SMA and decrease the serum level of HA, apply to postoperative biliary atresia patients and icteric patients with cirrhosis

Herba Artemisiae Scopariae, Radix et Rhizoma Rhei, Fructus Gardeniae

Xiao Chaihu Tang[7990]

Inhibit TGF-β1 and PDGF expressions, regulate MMPs/TIMPs balance, increase IL-12 production, suppress HSC activation, apply to CHC and CHB patients

Radix Bupleuri, Radix Scutellariae, Rhizoma Pinelliae, Radix Ginseng, Fructus Jujubae, Radix Glycyrrhizae

Buzhong Yiqi Tang[91, 92]

Immunoregulation, inhibit TGF-β1 and IL-13 production, apply to CHC patients

Radix Astragali, Radix Glycyrrhizae, Radix Ginseng, Radix Angelicae Sinensis, Pericarpium citri reticulatae, Rhizoma Cimicifugae, Radix Bupleuri, Rhizoma Atractylodis macrocephalae

Renshen Yangrong Tang[9294]

Immunoregulation, inhibit TGF-β1 and IL-13 production, apply to CHC patients

Radix Astragali, Radix Angelicae sinensis, Cortex Cinnamomi, Radix Glycyrrhizae, Pericarpium citri reticulatae, Rhizoma Atractylodis macrocephalae, Radix Ginseng, Radix Paeoniae alba, Radix Rehmanniae, Fructus Schisandrae chinensis, Poria, Cortex et Radix Polygalae

Fufang Jinsan E[95]

Inhibit TGF-β1 and Smad3, Up-regulate Smad7 in liver fibrotic rats

Radix Curcumae, Rhizoma Sparganii, Rhizoma Curcumae

Denshen Taoxiong Tang[96]

Anti-ascites, regulate urine sodium concentration in liver fibrotic mouse

Radix Salviae Miltiorrhizae, Semen Persicae, Rhizoma Chuanxiong

Ershen Zezhu Tang[96]

Anti-ascites, regulate urine sodium concentration in liver fibrotic mouse

Radix Codonopsis, Radix Salviae miltiorrhizae, Rhizoma Atractylodis macrocephalae, Rhizoma Alismatis

Buqi Jianzhong Tang[97, 98]

Diuretic effect, increase excretion Na+, reduce GPT and GOT, apply to cirrhosis ascites

Largehead Atractyloidis Rhizoma, Hoelen, Aurantii Nobilis Pericarpium, Radix Ginseng, Radix Scutellariae, Magnolia Bark, Alisma Rhizoma, Radix Ophiopogonis, Atractylodis Rhizoma

Fangji Tang[97, 98]

Diuretic effect, increase excretion Na+, reduce GPT and GOT, apply to cirrhosis ascites

Sinomeni Claulis Et Rhizoma, Mori Contex, Hoelen

Preilla Herba, Saussurae Radis

Handan Ganle[99102]

Anti-oxidatation, collagenolytic effect, regulate MMPs/TIMPs balance, apply to CHB patients

Radix Sophorae Flavescentis, Radix Salviae miltiorrhizae, Radix Paeoniae, Radix Astragali, Folium Ginkgo

Ganzhifu[103]

Anti-oxidation, reduce collagens, anti-liver fibrosis in liver fibrotic rats

Rhizoma Zingiberis, Ramulus Cinnmomi, Radix Aconiti Lateralis preparata, Radix Astragali, Radix Bupleuri, Fructus Aurantii, Rhizoma Atractylodis macrocephalae, Radix Glycyrrhizae

Fuzheng Huay[104108]

Significantly decrease HA, LM, P-III-P and IV-C content, improve serum Alb, ALT, AST, GGT, LM, HA, Hyp and ration of BCAA/AAA in animals and CHB patients. Inhibit HSCs activation via FN/integrin signaling.

Radix Salvia miltiorrhizae, Cordyceps mycelia extract, Semen Persicae, Gynostemma Pentaphyllammak, Pollen Pini, Fructus schisandrae chinensis

Combination therapy

Studies [109118] show that combination therapy improves clinical anti-fibrotic effects by using a single compound with composite formulae or Chinese medicines with conventional medicines (Table 3).
Table 3

Anti-fibrosis effect of combinations of single compound and formulae or Chinese medicines and conventional medicines

Combination of drugs and major references

Clinical indications and pharmacological actions or side effects

ITF-α. injection + glycyrrhizin (Stronger Neo Minophagen C) injection [109]

CHC patients. With IFN therapy, ALT levels did not decrease more than 50%, while with IFN combined with SNMC therapy, ALT levels decreased approximately 70% in all patients (one became normal), but no other parameters were changed.

Ursodeoxycholic acid P.O + glycyrrhizin P.O [110]

CHC patients belong to interferon-resistant or unstable patients. Improving liver-specific enzyme abnormalities: AST, ALT and gamma-glutamyl transpeptidase, no change HCV-related factors or liver histology compared with control.

Matrine injection + Xiao Chaihu Tang P.O [111]

Liver fibrosis patients. Combination therapy improves AST, ALT and reduces HA, LN, CIV, TGF-β1 and TNF-α.

IFN-γ or IFN-α. injection + Xiao Chaihu Tang (Sho-saiko-to) P.O [112115]

CHB patients. Combination therapy improves AST, ALT, Tbil and has synergistic anti-fibrosis in biochemical parameters, but IFN and/or Sho-saiko-to may also induce acute interstitial pneumonitis.

Tiopronin P.O + Xiao Chaihu Tang P.O [116]

CHB patients. Synergistic effects in improving liver functions and fibrotic factors.

Lamivudine + Radix Salviae Miltiorrhizae [117]

CHB patients. Treatment with both drugs was better than one and more effective than the control group in parameters of liver function and liver fibrosis.

Bushen Granule (BSG) P.O + Marine Injection (MI) [118]

CHB patients. Combined treatment of BSG and MI was better than Lamivudine group in one year therapeutical course.

Action mechanisms of Chinese medicines in treating liver fibrosis

Inhibition of viral replication

HBV and HCV infections account for most liver cirrhosis and primary liver cancer worldwide [6]. Certain Chinese medicines are anti-HBV and anti-HCV. Berberine markedly reduces viral production in vitro but is toxic to host cells [51]. Artemisinin and artesunate strongly inhibit viral production at concentrations that do not affect host cell viability; artesunate and lamivudine exhibit synergistic anti-HBV effects [51]. Another study shows that ascucubin inhibits HBV replication [63]. Nobiletin, the active ingredient of Citrus unshiu peel, has anti-HCV effects [94]. Clinical studies show that oxymatrine [28] is effective in reducing hepatitis B viral replication in patients with chronic hepatitis B. Xiao Chaihu Tang enhances production of interferon-gamma (IFN-γ) and antibodies against hepatitis B core and e antigen by peripheral blood mononuclear cells (PBMC) in patients with chronic hepatitis [82]. Handan Ganle inhibits viral DNA replication in patients with decompensated cirrhosis thereby leading to clinical improvement [102].

Immunomodulation action

Buzhong Yiqi Tang and Renshen Yangrong Tang demonstrate immunomodulation effects [91]. In a study on porcine serum-induced liver fibrosis in rats [92], Interleukin 13 (IL-13) levels are positively correlated with hydroxyproline (Hyp) contents in the liver. Buzhong Yiqi Tang and Renshen Yangrong Tang significantly suppress the increase of hepatic Hyp, while Xiao Chaihu Tang does not. Short-term and long-term studies [93] show that Renshen Yangrong Tang is effective in liver fibrosis. Further studies find that Renshen Yangrong Tang inhibits HCV infection, and that Gomisin A, an active component in the formula's Schisandra fruit, exhibits protective effects on immunological hepatopathy [94].

Anti-oxidation and anti-inflammation actions

Salvia miltiorrhizae (Danshen) extract [13] improves serum superoxide dismutase (SOD) activity and reduces malondialdehyde (MDA) content in both carbon tetrachloride (CCl4) and dimethylnitrosamine (DMN) induced hepatic fibrosis rat models. Salvia miltiorrhizae extract [18] increases hepatic glutathione levels and decreases peroxidation products in a dose-dependent manner. Taurine [27, 28] reduces oxidative stress and prevents progression of hepatic fibrosis in CCl4-induced hepatic damaged rats and inhibits transformation of the hepatic stellate cell (HSC). In chronic ethanol-induced hepatotoxicity or CCl4-induced rat liver fibrosis, Panax notoginseng (Tianqi) extract or total saponin extracted from Panax notoginseng reduces the generation of MDA, scavenges free radicals, increases liver and serum SOD content and reduces the accumulation of body lipid peroxide [4446]. Ginkgo biloba (Yinxing) extract [49, 50] and berberine [54, 55, 60] exhibit anti-oxidation effects and suppress nuclear factor κB (NF-κB) in rats or cell culture. Yinchenhao Tang is used to treat liver fibrosis and portal hypertension through suppressing the activated HSC function by genipin, an absorbed form of its component, in CCl4-or pig-serum- induced rat liver fibrosis [72]. Lin et al. [68] find that the hepatoprotective effect of Solanum nigrum Linn extract on CCl4-induced liver fibrosis is achieved through blocking oxidative stress. Xiao Chaihu Tang [76, 83, 85] whose active components baicalin and baicalein function as a potent fibrosis suppressant via the inhibition of the oxidative stress in hepatocyte and HSC. Handan Ganle [99] is effective in protecting against liver fibrosis by inhibiting lipid peroxidation in hepatocytes and HSC in vivo.

Regulation of cytokines, collagen metabolism and inhibition of HSC

The fibrogenic process is regulated by TGF-β1 and the specific blockade of TGF-β1/Smad3 signalling may therapeutically intervene in the fibrosis of various tissues [119]. Most of the Chinese medicines listed in Tables 1 and 2 exhibit in vitro and in vivo inhibitory effects on TGF-β1. Salvianolic acid B (SA-B) inhibits HSC proliferation and collagen production and decreases the cellular TGF-β1 autocrine and Mitogen-Activated Protein Kinase (MAPK) activity, which may be the anti-fibrosis mechanism of SA-B [14, 17]. Paclitaxel, a compound isolated from Taxus brevifolia, suppresses the TGF-β1 signalling pathway between biliary epithelium cells and myofibroblasts and reduces collagen synthesis [120]. Yinchenhao Tang [71] regulates platelet-derived growth factor (PDGF)-BB-dependent signalling pathways of HSC in primary culture and attenuates the development of liver fibrosis induced by thioacetamide in rats. Among the components of Yinchenhao Tang, 3-methyl-1,6,8-trihydroxyanthraquinone (emodin) derived from Rhei rhizoma is the most active compound [72]. Genipin, a metabolite derived from Yinchenhao Tang, suppresses wound-induced cell migration and proliferation and decreases collagen type I, TGF β1 and α-smooth muscle actins (α-SMA) mRNA and protein expression [76]. Chen et al. [67] demonstrate that Gypenosides inhibits PDGF-induced HSCs proliferation through inhibiting the signalling pathway of PDGF-Akt-p70S6K and down-regulating cyclin D1 and D3 expression. Another study shows that ganoderic acids and ganoderenic acids in Ganoderma lucidum (Lingzhi) extract significantly inhibit the proliferation of HSCs by attenuating the blockade of PDGFβR phosphorylation [66]. Chen et al. [88] show that 0.5 g/kg/day of Xiao Chaihu Tang significantly reduces the serum level of the N-terminal pro-peptide of collagen type III (PIII NP) and the mRNA expression of TGF-β1 and PDGF in a rat bile duct ligated model.

Anti-apoptosis in hepatocyte and inducement of apoptosis in HSC

Yamamoto et al. [73] find that Yinchenhao Tang inhibits hepatocyte apoptosis induced by TGF-β1 in vitro. Another study [74] demonstrates that pre-treatment with Yinchenhao Tang markedly suppresses liver apoptosis/injury. Genipin, which is a principal ingredient of Yinchenhao Tang, suppresses Fas-mediated apoptosis in primary-cultured murine hepatocytes in vitro [73]. The resistance to Ca2+-induced mitochondrial permeability transition (MPT) is enhanced in liver mitochondria of genipin-treated mice [74]. These results suggest that the anti-apoptotic activity of genipin via the interference with MPT is a possible mechanism for the therapeutic effects of Yinchenhao Tang and that Yinchenhao Tang and its ingredient genipin protect hepatocyte from liver apoptosis/injury. Conversely, activated HSC plays a pivotal role in hepatic fibrosis, HSC apoptosis is involved in the mechanisms of spontaneous resolution of rat hepatic fibrosis, and the agent that induces HSC apoptosis has been shown to reduce experimental hepatic fibrosis in rats [121]. Considerable interest has been generated in uncovering the molecular events that regulate HSC apoptosis and discovering drugs that can stimulate HSC apoptosis in a selective manner. Ikeda et al. [75] find that Yinchenhao Tang induces HSC apoptosis in a time- and concentration-dependent manner as judged by the nuclear morphology, quantitation of cytoplasmic histone-associated DNA oligonucleosome fragments and caspase-3 activity. Thus, the induction of HSC apoptosis may be the mechanism whereby Yinchenhao Tang treats hepatic fibrosis. Tetrandrine [29] also induces apoptosis of T-HSC/Cl-6 cells and induces the activation of caspase-3 protease and subsequent proteolytic cleavage of poly (ADP-ribose) polymerase.

Synergistic effects on liver fibrosis and carcinogenesis

Berberine derived from berberis markedly reduces viral production in vitro [51]. In liver damage induced by paracetamol or CCl4, Berberis aristata fruit extract and berberine, its principal ingredient, show hepato-protective action [52, 53]. Berberine also exhibits antioxidative effects on tert-butyl hydroperoxide-induced oxidative damage in rat liver [54] and in the lipopolysaccharide (LPS) plus ischemia-reperfusion model [55]. Berberine abolishes acetaldehyde-induced NF-κB activity and cytokine production in a dose dependent manner, suggesting the potential role of berberine to treat alcoholic liver disease (ALD) [56]. In the rat liver fibrosis induced by multiple hepatotoxic factors (CCl4, ethanol and high cholesterol), the serum levels of ALT and AST and the hepatic content of MDA and Hyp are markedly decreased, while the activity of hepatic SOD is significantly increased in berberine-treated groups in a dose-dependent manner. In addition, histopathological changes, such as steatosis, necrosis and myofibroblast proliferation, are reduced and the expression of α-SMA and TGF-β1 is significantly down-regulated in the berberine-treated groups [57].

Clinically, berberine has been used in Japan to alleviate hypertyraminemia in patients with liver cirrhosis [58]. Berberine possesses anti-tumor effects in rats and mice with chemical-induced liver cancer [59] and anti-invasion in human lung cancer cell lines [60]. The mechanism may be related to its anti-inflammation effects [60, 61]. The inhibitory effects of two different doses of berberine in human liver cancer HepG2 cell lines display different effects: in HepG2 cells treated with 24.0 mg/L of berberine, an increase in the sub G0 phase that indicates cell death is observed in cell cycle analysis with flow cytometry, however, there is no significant increase in sub G0 in HepG2 cells treated with 4.0 mg/L of berberine [62]. These results demonstrate that the dosage of berberine is a meaningful factor in liver diseases treatment. Composite formulae, such as Xiao Chaihu Tang, not only inhibit viral replication, ameliorate inflammation and enhance regeneration of hepatic cells, but also inhibit HSC proliferation, suppress intra- and extra-cellular secretion, decrease the secretion of collagen and promote its degradation and re-absorption [7990]. Shimizu et al. [83] show that Xiao Chaihu Tang functions as a potent anti-fibrosis agent via the inhibition of oxidative stress in hepatocytes and HSCs and that its active components are baicalin and baicalein. It should be noted that baicalin and baicalein are flavonoids with chemical structures very similar to silybinin which possess anti-fibrogenic activities. Several composite formulae have been used to improve ascites induced by hepatic cirrhosis in chronic hepatitis B (CHB) or chronic hepatitis C (CHC) patients. We demonstrate that Buqi Jianzhong Tang and Fangji Tang increase Na+ excretion and urine volume and reduce GOT and GPT in rats with CCl4- induced liver damage [89, 98]. Most of the Chinese medicines in Tables 1 and 2 reduce serum enzymes, i.e. aspartate transaminase (AST) and alanine transaminase (ALT). A study with multivariate analysis demonstrates that the mode of therapy and ALT levels are significant factors affecting HCC development [26]. Glycyrrhizin administered as Stronger Neo Minophagen C (SNMC) and Xiao Chaihu Tang exhibit this effect [2426, 90] in long-term clinical trials. Considered to possess anti-carcinogenic properties, Xiao Chaihu Tang inhibits chemical hepatocarcinogenesis in animals, acts as a biological response modifier and suppresses the proliferation of hepatoma cells by inducing apoptosis and arresting the cell cycle. Among the active components of Xiao Chaihu Tang, baicalin, baicalein and saikosaponin have the ability to inhibit cell proliferation [90].

Efficiency and safety of Chinese medicines in treating liver fibrosis

Efficacy

Some anti-fibrosis Chinese medicines, such as Salvianolic acid B (SA-B), tetrandrine and oxymatrine, are clinically effective. SA-B reverses liver fibrosis in chronic hepatitis B patients. SA-B reduces the serum HA content and decreases the overall serum fibrosis markers better than IFN-γ [14]. A multi-centre, randomized, double-blind, placebo-controlled clinical trial shows that oxymatrine effectively reduces the DNA replication of HBV [34, 35] and the therapeutic effect is even stronger when used together with Xiao Chaihu Tang [110]. A double-blind, randomized, placebo-controlled phases I/II trial of intravenous glycyrrhizin for the treatment of chronic hepatitis C shows that glycyrrhizin lowers serum ALT and that the treatment has no effect on the RNA levels of HCV [23]. Long-term clinical trials in Japan and the Netherlands demonstrate that interferon non-responder patients with chronic hepatitis C and fibrosis stage 3 or 4 have a reduced incidence rate of HCC after glycyrrhizin therapy normalizes ALT levels [24, 25].

In China and Japan, many composite formulae are used to treat liver fibrosis and cirrhosis (Table 2) and the pharmacological effects and mechanisms have been demonstrated [6994]. Experimental and clinical studies show that Handan Ganle is effective [99102]. Fuzheng Huayu, another modern formula, has also been intensively studied [104107]. The results suggest that Fuzheng Huayu's anti-fibrosis effects may be associated with the inhibition of liver collagen production [104]. Further study reveals that the conditioned medium from activated HSC stimulates the quiescent HSC proliferation and type I collagen secretion and that the drug serum inhibits this stimulating action and vascular endothelial growth factor (VEGF) secretion from the activated HSC. Fuzheng Huayu acts effectively against the autocrine activation pathway of HSC [105].

A recent study demonstrates the action of Fuzheng Huayu against HSC activation via the fibronectin/integrin-5β1 signalling pathway [107]. Another study shows that Fuzheng Huayu alleviates liver fibrosis without any adverse events [106]. A systematic review analyzes the efficacy and safety of Fuzheng Huayu in treatment of CHB fibrosis [108] based on clinical trials with placebo and/or random control (other positive Chinese medicines and conventional drugs). Seven studies on Fuzheng Huayu in the treatment of CHB fibrosis (total 590 cases) are included in the systematic review. This systematic review concludes that Fuzheng Huayu has significant improvement of serum fibrosis index and pathology of liver biopsy (class S in fibrosis) without observable adverse events, although some included studies are of low quality and are small randomized clinical trials.

The combined therapy with ursodeoxycholic acid and glycyrrhizin is safe and effective in improving liver-specific enzyme abnormalities, and may be an alternative to interferon in chronic hepatitis C viral infection, especially for interferon-resistant or unstable patients [110]. The antiviral efficacy of Bushen granule (BSG) coupled with marine injection (MI) to treat chronic hepatitis B was more effective than lamivudine treatment [118]. Other reports of therapeutic value gained through combining conventional and Chinese medicines can be found in Table 3[112117].

Safety

There have been reports on adverse events and hepatotoxicity caused by herbal medicines [122]. Xiao Chaihu Tang, used alone or in combination with interferon, may induce acute interstitial pneumonia in patients with chronic active hepatitis [113, 114]. Glycyrrhizin injection may induce fatal biliary cirrhosis [123]. A one-year study demonstrates that Chinese medicines caused hepatotoxicity in patients with chronic hepatitis B [124]. Some of hepatic veno-occlusive diseases have been ascribed to toxicity of herbs; however, the toxic compounds remain to be determined. Hepatic veno-occlusive disease may result from pyrrolizidine alkaloids which are found in numerous plants worldwide. Systematic toxicological knowledge of Chinese medicines is available [125].

Adverse events in the cases of herbal toxicity are in fact very complex. The fatal biliary cirrhosis case [123] was a 50-year-old woman suffering from a diffuse skin rash, high fever and jaundice immediately after a second injection of glutathione and stronger neo-minophagen C, which contains glycyrrhizin. It is difficult to determine the cause of the adverse events to be indeed glycyrrhizin (which is extracted from Glycyrrhiza uralensis) for the following reasons: (1) no literature has shown the hepatotoxicity of glycyrrhizin until now; (2) stronger neo-minophagen C includes 0.1% cysteine and 2.0% glycine in physiological saline solution as well as 0.2% glycyrrhizin, and is also combined with glutathione; and (3) the clinical indication of glycyrrhizin was clear enough (glycyrrhizin is only used in chronic liver hepatitis without bile duct obstruction, which is Yinchenhao Tang's indication in Chinese medicine clinical practice), and glycyrrhizin has no anti-fibrotic effect in rats with fibrosis induced by bile duct ligation and scission [65].

Evidence against Chinese medicines

While ample evidence supports Chinese medicines in treating liver fibrosis, some recent reviews on clinical trials did not find significant effects. Levy et al. [126] review the use of silymarin, glycyrrhizin, Xiao Chaihu Tang, Phyllanthus amarus, Picrorrhiza kurroa, Compound 861, CH-100 and LIV.52 used to treat chronic liver diseases. Dhiman et al. [127] review Phyllanthus, Silybum marianum (milk thistle), glycyrrhizin and LIV.52 used to treat liver diseases. However, neither review recommends the use of herbal medicines to treat chronic liver diseases.

SA-B, Glycyrrhizin, Xiao Chaihu Tang and Yinchenhao Tang are used to treat chronic liver diseases in China and Japan. The major active herb is coptis, of which berberine is the major active component [128]. According to Chinese medicine theory, we use coptis to treat various liver diseases and cancer in Hong Kong [129]. We also propose to replace bear bile with coptis in Chinese medicine practice [130].

Further studies on pharmacological actions and clinical efficacies of the anti-fibrosis effects of Chinese medicines are warranted. Systematic reviews to evaluate clinical studies on the efficacy and safety of Chinese medicines are also necessary. An exemplifying strategy for these studies is demonstrated in Figure 1.
https://static-content.springer.com/image/art%3A10.1186%2F1749-8546-4-16/MediaObjects/13020_2009_Article_50_Fig1_HTML.jpg
Figure 1

Research chart of Chinese medicines for liver fibrosis. The re-evaluation involved in pharmaceutical and medical research including herb quality control, mechanism study and clinical trial will be carried out on standardized international platforms.

Conclusion

Evidence indicates that some Chinese medicines are clinically effective in treating liver fibrosis. Strict quality control of Chinese medicines is critical [131] for pharmacological, clinical and in-depth mechanism studies [132]. Experiments and clinical trials should be carried out on the platforms that conform to international standards [133].

Abbreviations

ECM: 

extracellular matrix

HSC: 

hepatic stellate cell

CAM: 

complementary and alternative medicine

SA-B: 

salvianolic acid B

HBV: 

hepatitis B virus

HCV: 

hepatitis C virus

CHB: 

chronic hepatitis B

CHC: 

chronic hepatitis C

AST (= GOT): 

aspartate aminotransferase

ALT (= GPT): 

alanine aminotranferease

TGF-β1: 

transforming growth factor beta1

Smad3: 

SMAD family member 3

Smad7: 

SMAD family member 7

smurf2: 

Smad ubiquitination regulatory factor 2

TIMP: 

tissue inhibitors of metalloproteases

MMP: 

matrix metalloproteinase

MAPK: 

mitogen-activated protein kinase

NF-κB: 

nuclear factor-κB

PDGF: 

platelet-derived growth factor

PPARgamma: 

proliferator-activated receptor gamma

SOD: 

superoxide dismutase

Hyp: 

hydroxyproline

HA: 

hyaluronic acid

α-SMA: 

α-smooth muscle actins

IFN-γ: 

interferon-gamma

IFN-α: 

interferon-alfa

LN: 

laminin

PCIII: 

type III procollagen

CIV: 

type IV collagen

Tbil: 

total bilirubin

TNF-α: 

tumor necrosis factor alfa

PIIINP: 

the N-terminal pro-peptide of collagen type III

MPT: 

mitochondrial permeability transition

Alb: 

albumin

BCAA: 

branched chain amino acid

AAA: 

aromatic amino acid

FN/integrin: 

fibronectin (FN)-integrin-5β1 complex.

Declarations

Acknowledgements

The study was financially supported by grants from the Research Council of the University of Hong Kong (Project Codes: 10208005 and 10400413), the University Grants Committee (UGC) of Hong Kong (Project Code: 764708M), the Pong Ding Yuen Endowment Fund for Education and Research in Chinese-Western Medicine (Project Code: 20005274) and the Government-Matching Grant Scheme (4th Phase, Project Code: 20740314). The authors would like to thank Prof SP Lee and Dr GKK Lau for their assistance in revising the manuscript.

Authors’ Affiliations

(1)
School of Chinese Medicine, The University of Hong Kong
(2)
Department of Medicine, The University of Hong Kong
(3)
Department of Cell Biology, Shanghai University of Traditional Chinese Medicine
(4)
Department of Pharmacobiology and Therapeutics, Faculty of Pharmacy, Meijo University

References

  1. Yuen MF, Lai CL: Natural history of chronic hepatitis B virus infection. J Gastroenterol Hepatol. 2000, 15 (Suppl): E20-4. 10.1046/j.1440-1746.2000.02123.x.PubMedGoogle Scholar
  2. Seeff LB, Hoofnagle JH: The national institutes of health consensus development conference management of hepatitis C 2002. Clin Liver Dis. 2003, 7: 261-87. 10.1016/S1089-3261(02)00078-8.PubMedGoogle Scholar
  3. Koike K: Antiviral treatment of hepatitis C: present status and future prospects. J Infect Chemother. 2006, 12: 227-32. 10.1007/s10156-006-0460-0.PubMedGoogle Scholar
  4. Tsukamoto H, Lu SC: Current concepts in the pathogenesis of alcoholic liver injury. FASEB J. 2001, 15: 1335-49. 10.1096/fj.00-0650rev.PubMedGoogle Scholar
  5. Heidelbaugh JJ, Bruderly M: Cirrhosis and chronic liver failure: part I. Diagnosis and evaluation. Am Fam Physician. 2006, 74: 756-62.PubMedGoogle Scholar
  6. Perz JF, Armstrong GL, Farrington LA, Hutin YJ, Bell BP: The contributions of hepatitis B virus and hepatitis C virus infections to cirrhosis and primary liver cancer worldwide. J Hepatol. 2006, 45: 529-38. 10.1016/j.jhep.2006.05.013.PubMedGoogle Scholar
  7. Wells RG: The role of matrix stiffness in hepatic stellate cell activation and liver fibrosis. J Clin Gastroenterol. 2005, 39: 158-61. 10.1097/01.mcg.0000155516.02468.0f.Google Scholar
  8. Friedman SL: Liver fibrosis–from bench to bedside. J Hepatol. 2003, 38 (Suppl 1): 38-53. 10.1016/S0168-8278(02)00429-4.Google Scholar
  9. Friedman SL: Reversibility of hepatic fibrosis and cirrhosis–is it all hype?. Nat Clin Pract Gastroenterol Hepatol. 2007, 4 (5): 236-7. 10.1038/ncpgasthep0813.PubMedGoogle Scholar
  10. Schuppan D, Jia JD, Brinkhaus B, Hahn EG: Herbal products for liver diseases: a therapeutic challenge for the new millennium. Hepatolog. 1999, 30 (4): 1099-104. 10.1002/hep.510300437.Google Scholar
  11. Shimizu I: Antifibrogenic therapies in chronic HCV infection. Infect Disord Drug Targets. 2001, 1 (2): 227-40. 10.2174/1568005014606053.Google Scholar
  12. Seeff LB, Lindsay KL, Bacon BR, Kresina TF, Hoofnagle JH: Complementary and alternative medicine in chronic liver disease. Hepatology. 2001, 34 (3): 595-603. 10.1053/jhep.2001.27445.PubMedGoogle Scholar
  13. Xie HM, Hu YY, Gu HT, Nagano Y, Ji G, Liu P: Study of Salviae miltiorrhizae on liver fibrosis in rats induced by CCl4 and DMN. Zhongxiyi Jiehe Ganbing Zazh. 1999, 9: 16-8.Google Scholar
  14. Liu P, Hu YY, Liu C, Zhu DY, Xue HM, Xu ZQ, Xu LM, Liu CH, Gu HT, Zhang ZQ: Clinical observation of salvianolic acid B in treatment of liver fibrosis in chronic hepatitis B. World J Gastroenterol. 2002, 8: 679-85.PubMedGoogle Scholar
  15. Lee TY, Wang GJ, Chiu JH, Lin HC: Long-term administration of Salvia miltiorrhiza ameliorates carbon tetrachloride-induced hepatic fibrosis in rats. J Pharm Pharmacol. 2003, 55: 1561-8. 10.1211/0022357022098.PubMedGoogle Scholar
  16. Wang H, Chen XP, Qiu FZ: Salviae miltiorrhizae ameliorates cirrhosis and portal hypertension by inhibiting nitric oxide in cirrhotic rats. Hepatobiliary Pancreat Dis Int. 2003, 2: 391-6.PubMedGoogle Scholar
  17. Zhao JF, Liu CH, Hu YY, Xu LM, Liu P, Liu C: Effect of salvianolic acid B on Smad3 expression in hepatic stellate cells. Hepatobiliary Pancreat Dis Int. 2004, 3: 102-5.PubMedGoogle Scholar
  18. Lee TY, Chang HH, Wang GJ, Chiu JH, Yang YY, Lin HC: Water-soluble extract of Salvia miltiorrhiza ameliorates carbon tetrachloride-mediated hepatic apoptosis in rats. J Pharm Pharmacol. 2006, 58: 659-65. 10.1211/jpp.58.5.0011.PubMedGoogle Scholar
  19. Yamamura Y, Kotaki H, Tanaka N, Aikawa T, Sawada Y, Iga T: The pharmacokinetics of glycyrrhizin and its restorative effect on hepatic function in patients with chronic hepatitis and in chronically carbon-tetrachloride-intoxicated rats. Biopharm Drug Dispos. 1997, 18: 717-25. 10.1002/(SICI)1099-081X(199711)18:8<717::AID-BDD54>3.0.CO;2-U.PubMedGoogle Scholar
  20. Wang JY, Guo JS, Li H, Liu SL, Zern MA: Inhibitory effect of glycyrrhizin on NF-kappaB binding activity in CCl4- plus ethanol-induced liver cirrhosis in rats. Liver. 1998, 18: 180-5.PubMedGoogle Scholar
  21. Iino S, Tango T, Matsushima T, Toda G, Miyake K, Hino K, Kumada H, Yasuda K, Kuroki T, Hirayama C, Suzuki H: Therapeutic effects of stronger neo-minophagen C at different doses on chronic hepatitis and liver cirrhosis. Hepatol Res. 2001, 19: 31-40. 10.1016/S1386-6346(00)00079-6.PubMedGoogle Scholar
  22. Cai Y, Shen SZ, Wang JY: Effects of glycyrrhizin on genes expression during the process of liver fibrosis. Zhonghua Yixue Zazhi. 2003, 83: 1122-5.PubMedGoogle Scholar
  23. Rossum Van TGJ, Vulto AG, Hop WC, Brouwer JT, Niesters HG, Schalm SW: Intravenous glycyrrhizin for the treatment of chronic hepatitis C: a double blind, randomised, placebo controlled phase I/II trial. J Gastroenterol Hepatol. 1999, 14: 1093-9. 10.1046/j.1440-1746.1999.02008.x.Google Scholar
  24. Veldt BJ, Hansen BE, Ikeda K, Verhey E, Suzuki H, Schalm SW: Long-term clinical outcome and effect of glycyrrhizin in 1093 chronic hepatitis C patients with non-response or relapse to interferon. Scand J Gastroenterol. 2006, 41: 1087-94. 10.1080/00365520600641365.PubMedGoogle Scholar
  25. Ikeda K, Arase Y, Kobayashi M, Saitoh S, Someya T, Hosaka T, Sezaki H, Akuta N, Suzuki Y, Suzuki F, Kumada H: A long-term glycyrrhizin injection therapy reduces hepatocellular carcinogenesis rate in patients with interferon-resistant active chronic hepatitis C: a cohort study of 1249 patients. Dig Dis Sci. 2006, 51: 603-9. 10.1007/s10620-006-3177-0.PubMedGoogle Scholar
  26. Rino Y, Tarao K, Morinaga S, Ohkawa S, Miyakawa K, Hirokawa S, Masaki T, Tarao N, Yukawa N, Saeki H, Takanashi Y, Imada T: Reduction therapy of alanine aminotransferase levels prevent HCC development in patients with HCV-associated cirrhosis. Anticancer Res. 2006, 26 (3B): 2221-6.PubMedGoogle Scholar
  27. Wang ZR, Chen XM, Li DG: Tetrandrine inhibits expressions of c-fos and c-jun mRNA in fibrosis liver of rats. Shanghai Yixue. 2003, 26: 332-4.Google Scholar
  28. Wang H, Chen XP, Qiu FZ: Tetrandrine increased hepatic expression of nitric oxide synthase type II in cirrhotic rats. World J Gastroenterol. 2004, 10: 1923-7.PubMed CentralPubMedGoogle Scholar
  29. Zhao YZ, Kim JY, Park EJ, Lee SH, Woo SW, Ko G, Sohn DH: Tetrandrine induces apoptosis in hepatic stellate cells. Phytother Res. 2004, 18: 306-9. 10.1002/ptr.1435.PubMedGoogle Scholar
  30. Chen YW, Li DG, Wu JX, Chen YW, Lu HM: Tetrandrine inhibits activation of rat hepatic stellate cells stimulated by transforming growth factor-beta in vitro via up-regulation of Smad 7. J Ethnopharmacol. 2005, 100: 299-305. 10.1016/j.jep.2005.03.027.PubMedGoogle Scholar
  31. Hsu YC, Chiu YT, Lee CY, Wu CF, Huang YT: Anti-fibrotic effects of tetrandrine on bile-duct ligated rats. Can J Physiol Pharmacol. 2006, 84: 967-76. 10.1139/Y06-050.PubMedGoogle Scholar
  32. Hsu YC, Chiu YT, Cheng CC, Wu CF, Lin YL, Huang YT: Antifibrotic effects of tetrandrine on hepatic stellate cells and rats with liver fibrosis. J Gastroenterol Hepatol. 2007, 22: 99-111. 10.1111/j.1440-1746.2006.04361.x.PubMedGoogle Scholar
  33. Zhang JP, Zhang M, Zhou JP, Liu FT, Zhou B, Xie WF, Guo C: Antifibrotic effects of matrine on in vitro and in vivo models of liver fibrosis in rats. Acta Pharmacol Sin. 2001, 22: 183-6.PubMedGoogle Scholar
  34. Chen YX, Mao BY, Jiang JH: Relationship between serum load of HBV-DNA and therapeutic effect of oxymatrine in patients with chronic hepatitis B. Zhongguo Zhongxiyi Jiehe Zazhi. 2002, 22: 335-6.PubMedGoogle Scholar
  35. Mao YM, Zeng MD, Lu LG: Capsule oxymatrine in treatment of hepatic fibrosis due to chronic viral hepatitis: a randomized, double blind, placebo-controlled, multicenter clinical study. World J Gastroenterol. 2004, 10: 3269-73.PubMed CentralPubMedGoogle Scholar
  36. Kato J, Ido A, Hasuike S, Uto H, Hori T, Hayashi K, Murakami S, Terano A, Tsubouchi H: Transforming growth factor-beta-induced stimulation of formation of collagen fiber network and anti-fibrotic effect of taurine in an in vitro model of hepatic fibrosis. Hepatol Res. 2004, 30: 34-41. 10.1016/j.hepres.2004.04.006.PubMedGoogle Scholar
  37. Miyazaki T, Karube M, Matsuzaki Y, Ikegami T, Doy M, Tanaka N, Bouscarel B: Taurine inhibits oxidative damage and prevents fibrosis in carbon tetrachloride-induced hepatic fibrosis. J Hepatol. 2005, 43: 117-25. 10.1016/j.jhep.2005.01.033.PubMedGoogle Scholar
  38. Chen ZZ, Wang H: Inhibitory Effects of tetramethylpyrazine on experimental hepatic fibrosis in rats. Zhong Xiyi Jiehe Ganbing Zazhi. 1997, 7: 156-8.Google Scholar
  39. Tan LX, Li XS, Liu ZQ, Liu LY: Effects of combination therapy of rehin and tetramethylpyrazine on experimental hepatic fibrosis induced by tetrachloride. Zhonghua Ganzangbing Zazhi. 2004, 12: 692-3.PubMedGoogle Scholar
  40. Zhan Y, Li D, Wei H, Wang Z, Huang X, Xu Q, Lu H: Emodin on hepatic fibrosis in rats. Chin Med J (Engl). 2000, 113: 599-601.Google Scholar
  41. Zhan YT, Liu B, Li DG, Bi CS: Mechanism of emodin for anti-fibrosis of liver. Zhonghua Ganzangbing Zazhi. 2004, 12: 245-6.PubMedGoogle Scholar
  42. Yang W, Chen H, Jiang Y: Inhibitive effect of curcumin and amiloride on the fibrosis of rat hepatic stellate cells induced by oxidative stress. Zhongyaocai. 2003, 26: 795-8.PubMedGoogle Scholar
  43. Zheng S, Chen A: Activation of PPARgamma is required for curcumin to induce apoptosis and to inhibit the expression of extracellular matrix genes in hepatic stellate cells in vitro. Biochem J. 2004, 384: 149-57. 10.1042/BJ20040928.PubMed CentralPubMedGoogle Scholar
  44. Lin CF, Wong KL, Wu RS, Huang TC, Liu CF: Protection by hot water extract of Panax notoginseng on chronic ethanol-induced hepatotoxicity. Phytother Res. 2003, 17: 1119-22. 10.1002/ptr.1329.PubMedGoogle Scholar
  45. Shii XF, Liu Q, Liu L, Xu M: Effect of total saponin of Panax Notoginseng on liver fibrosis in rats. Zhongyao Yaoli yu Linchuang. 2004, 20: 12-4.Google Scholar
  46. Park WH, Lee SK, Kim CH: A Korean herbal medicine, Panax notoginseng, prevents liver fibrosis and hepatic microvascular dysfunction in rats. Life Sci. 2005, 76 (15): 1675-90. 10.1016/j.lfs.2004.07.030.PubMedGoogle Scholar
  47. Gong HY, Wang KQ, Tang SG: Effects of cordyceps sinensis on T lymphocyte subsets and hepatofibrosis in patients with chronic hepatitis B. Hunan Yike Daxue Xuebao. 2000, 25: 248-50.PubMedGoogle Scholar
  48. Liu YK, Shen W: Inhibitive effect of cordyceps sinensis on experimental hepatic fibrosis and its possible mechanism. World J Gastroenterol. 2003, 9: 529-33.PubMedGoogle Scholar
  49. Ding J, Yu J, Wang C, Hu W, Li D, Luo Y, Luo H, Yu H: Ginkgo biloba extract alleviates liver fibrosis induced by CCl4 in rats. Liver International. 2005, 25: 1224-32. 10.1111/j.1478-3231.2005.01169.x.PubMedGoogle Scholar
  50. Liu SQ, Yu JP, Chen HL, Luo HS, Chen SM, Yu HG: Therapeutic effects and molecular mechanisms of Ginkgo biloba extract on liver fibrosis in rats. Am J Chin Med. 2006, 34: 99-114. 10.1142/S0192415X06003679.PubMedGoogle Scholar
  51. Romero MR, Efferth T, Serrano MA, Castano B, Macias RI, Briz O, Marin JJ: Effect of artemisinin/artesunate as inhibitors of hepatitis B virus production in an "in vitro" replicative system. Antiviral Res. 2005, 68: 75-83. 10.1016/j.antiviral.2005.07.005.PubMedGoogle Scholar
  52. Gilani AH, Janbaz KH: Preventive and curative effects of berberis aristata fruit extract on paracetamol- and CCl4-induced hepatotoxicity. Phytotherapy Res. 1995, 9: 489-94. 10.1002/ptr.2650090705.Google Scholar
  53. Janbaz KH, Gilani AH: Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia. 2000, 71: 25-33. 10.1016/S0367-326X(99)00098-2.PubMedGoogle Scholar
  54. Hwang JM, Wang CJ, Chou FP, Tseng TH, Hsieh YS, Lin WL, Chu CY: Inhibitory effect of berberine on tert-butyl hydroperoxide-induced oxidative damage in rat liver. Arch Toxicol. 2002, 76: 664-70. 10.1007/s00204-002-0351-9.PubMedGoogle Scholar
  55. Yokozawa T, Ishida A, Kashiwada Y, Cho Ej, Kim Hy, Ikeshiro Y: Coptidis Rhizoma: protective effects against peroxynitrite-induced oxidative damage and elucidation of its active components. J Pharm Pharmacol. 2004, 56: 547-56. 10.1211/0022357023024.PubMedGoogle Scholar
  56. Hsiang CY, Wu SL, Cheng SE, Ho TY: Acetaldehyde-induced interleukin-1beta and tumor necrosis factor-alpha production is inhibited by berberine through nuclear factor-kappaB signaling pathway in HepG2 cells. J Biomed Sci. 2005, 12: 791-801. 10.1007/s11373-005-9003-4.PubMedGoogle Scholar
  57. Zhang BJ, Xu D, Guo Y, Ping J, Chen LB, Wang H: Protection by and anti-oxidant mechanism of berberine against rat liver fibrosis induced by multiple hepatotoxic factors. Clin Exp Pharmacol Physiol. 2008, 35 (3): 303-9. 10.1111/j.1440-1681.2007.04819.x.PubMedGoogle Scholar
  58. Watanabe A, Obata T, Nagashima H: Berberine therapy of hypertyraminemia in patients with liver cirrhosis. Acta Med Okayama. 1982, 36 (4): 277-81.PubMedGoogle Scholar
  59. Anis KV, Rajeshkumar NV, Kuttan R: Inhibition of chemical carcinogenesis by berberine in rats and mice. J Pharm Pharmacol. 2001, 53: 763-8. 10.1211/0022357011775901.PubMedGoogle Scholar
  60. Peng PL, Hsieh YS, Wang CJ, Hsu JL, Chou FP: Inhibitory effect of berberine on the invasion of human lung cancer cells via decreased productions of urokinase-plasminogen activator and matrix metalloproteinase-2. Toxicol Appl Pharmacol. 2006, 214: 8-15. 10.1016/j.taap.2005.11.010.PubMedGoogle Scholar
  61. Kuo CL, Chi CW, Liu TY: The anti-inflammatory potential of berberine in vitro and in vivo. Cancer Lett. 2004, 203: 127-37. 10.1016/j.canlet.2003.09.002.PubMedGoogle Scholar
  62. Tan Yl, Goh D, Ong ES: Investigation of differentially expressed proteins due to the inhibitory effects of berberine in human liver cancer cell line HepG2. Mol Biosyst. 2006, 2: 250-8. 10.1039/b517116d.PubMedGoogle Scholar
  63. Chang IM: Liver-protective activities of aucubin derived from traditional oriental medicine. Res Commun Mol Pathol Pharmacol. 1998, 102: 189-204.PubMedGoogle Scholar
  64. Park KS, Chang IM: Anti-inflammatory activity of aucubin by inhibition of tumor necrosis factor-alpha production in RAW 264.7 cells. Planta Med. 2004, 70: 778-9. 10.1055/s-2004-827211.PubMedGoogle Scholar
  65. Park EJ, Ko G, Kim J, Sohn DH: Antifibrotic effects of a polysaccharide extracted from Ganoderma lucidum, glycyrrhizin, and pentoxifylline in rats with cirrhosis induced by biliary obstruction. Biol Pharm Bull. 1997, 20: 417-20.PubMedGoogle Scholar
  66. Wang GJ, Huang YJ, Chen DH, Lin YL: Ganoderma lucidum extract attenuates the proliferation of hepatic stellate cells by blocking the PDGF receptor. Phytother Res. 2008, 23: 833-9. 10.1002/ptr.2687.Google Scholar
  67. Chen MH, Chen SH, Wang QF, Chen JC, Chang DC, Hsu SL, Chen CH, Sheue CR, Liu YW: The molecular mechanism of gypenosides-induced G1 growth arrest of rat hepatic stellate cells. J Ethnopharmacol. 2008, 117: 309-17. 10.1016/j.jep.2008.02.009.PubMedGoogle Scholar
  68. Lin HM, Tseng HC, Wang CJ, Lin JJ, Lo CW, Chou FP: Hepatoprotective effects of Solanum nigrum Linn extract against CCl4-induced oxidative damage in rats. Chem Biol Interact. 2008, 171: 283-93. 10.1016/j.cbi.2007.08.008.PubMedGoogle Scholar
  69. Kobayashi H, Horikoshi K, Yamataka A, Lane GJ, Yamamoto M, Miyano T: Beneficial effect of a traditional herbal medicine (inchin-ko-to) in postoperative biliary atresia patients. Pediatr Surg Int. 2001, 17: 386-9. 10.1007/s003830000561.PubMedGoogle Scholar
  70. Sakaida I, Tsuchiya M, Kawaguchi K, Kimura T, Terai S, Okita K: Herbal medicine Inchin-ko-to (TJ-135) prevents liver fibrosis and enzyme-altered lesions in rat liver cirrhosis induced by a choline-deficient L-amino acid-defined diet. J Hepatol. 2003, 38: 762-9. 10.1016/S0168-8278(03)00094-1.PubMedGoogle Scholar
  71. Imanishi Y, Maeda N, Otogawa K, Seki S, Matsui H, Kawada N, Arakawa T: Herb medicine Inchin-ko-to (TJ-135) regulates PDGF-BB-dependent signaling pathways of hepatic stellate cells in primary culture and attenuates development of liver fibrosis induced by thioacetamide administration in rats. J Hepatol. 2004, 41: 242-50. 10.1016/j.jhep.2004.04.005.PubMedGoogle Scholar
  72. Inao M, Mochida S, Matsui A, Eguchi Y, Yulutuz Y, Wang Y, Naiki K, Kakinuma T, Fujimori K, Nagoshi S, Fujiwara K: Japanese herbal medicine Inchin-ko-to as a therapeutic drug for liver fibrosis. J Hepatol. 2004, 41: 584-91. 10.1016/j.jhep.2004.06.033.PubMedGoogle Scholar
  73. Yamamoto M, Ogawa K, Morita M, Fukuda K, Komatsu Y: The herbal medicine Inchin-ko-to inhibits liver cell apoptosis induced by transforming growth factor beta 1. Hepatology. 1996, 23: 552-9.PubMedGoogle Scholar
  74. Yamamoto M, Miura N, Ohtake N, Amagaya S, Ishige A, Sasaki H, Komatsu Y, Fukuda K, Ito T, Terasawa K: Genipin, a metabolite derived from the herbal medicine Inchin-ko-to, and suppression of Fas-induced lethal liver apoptosis in mice. Gastroenterology. 2000, 118: 380-9. 10.1016/S0016-5085(00)70220-4.PubMedGoogle Scholar
  75. Ikeda H, Nagashima K, Yanase M, Tomiya T, Arai M, Inoue Y, Tejima K, Nishikawa T, Watanabe N, Kitamura K, Isono T, Yahagi N, Noiri E, Inao M, Mochida S, Kume Y, Yatomi Y, Nakahara K, Omata M, Fujiwara K: The herbal medicine inchin-ko-to (TJ-135) induces apoptosis in cultured rat hepatic stellate cells. Life Sci. 2006, 78: 2226-33. 10.1016/j.lfs.2005.09.024.PubMedGoogle Scholar
  76. Kitano A, Saika S, Yamanaka O, Ikeda K, Reinach PS, Nakajima Y, Okada Y, Shirai K, Ohnishi Y: Genipin suppresses subconjunctival fibroblast migration, proliferation and myofibroblast transdifferentiation. Ophthalmic Res. 2006, 38 (6): 355-60. 10.1159/000096231.PubMedGoogle Scholar
  77. Lee TY, Chang HH, Chen JH, Hsueh ML, Kuo JJ: Herb medicine Yin-Chen-Hao-Tang ameliorates hepatic fibrosis in bile duct ligation rats. J Ethnopharmacol. 2007, 109: 318-24. 10.1016/j.jep.2006.07.042.PubMedGoogle Scholar
  78. Lee TY, Chang HH, Kuo JJ, Shen JJ: Changes of hepatic proteome in bile duct ligated rats with hepatic fibrosis following treatment with Yin-Chen-Hao-Tang. Int J Mol Med. 2009, 23: 477-84.PubMedGoogle Scholar
  79. Miyamura M, Ono M, Kyotani S, Nishioka Y: Effects of sho-saiko-to extract on fibrosis and regeneration of the liver in rats. J Pharm Pharmacol. 1998, 50: 97-105.PubMedGoogle Scholar
  80. Sakaida I, Matsumura Y, Akiyama S, Hayashi K, Ishige A, Okita K: Herbal medicine Sho-saiko-to (TJ-9) prevents liver fibrosis and enzyme-altered lesions in rat liver cirrhosis induced by a choline-deficient L-amino acid-defined diet. J Hepatol. 1998, 28: 298-306. 10.1016/0168-8278(88)80017-5.PubMedGoogle Scholar
  81. Kayano K, Sakaida I, Uchida K, Okita K: Inhibitory effects of the herbal medicine Sho-saiko-to (TJ-9) on cell proliferation and procollagen gene expressions in cultured rat hepatic stellate cells. J Hepatol. 1998, 29: 642-9. 10.1016/S0168-8278(98)80161-X.PubMedGoogle Scholar
  82. Yamashiki M, Nishimura A, Huang XX, Nobori T, Sakaguchi S, Suzuki H: Effects of the Japanese herbal medicine "Sho-saiko-to" (TJ-9) on interleukin-12 production in patients with HCV-positive liver cirrhosis. Dev Immunol. 1999, 7: 17-22. 10.1155/1999/62564.PubMed CentralPubMedGoogle Scholar
  83. Shimizu I, Ma YR, Mizobuchi Y, Liu F, Miura T, Nakai Y, Yasuda M, Shiba M, Horie T, Amagaya S, Kawada N, Hori H, Ito S: Effects of Sho-saiko-to, a Japanese herbal medicine, on hepatic fibrosis in rats. Hepatology. 1999, 29 (1): 149-60. 10.1002/hep.510290108.PubMedGoogle Scholar
  84. Ono M, Miyamura M, Kyotani S, Saibara T, Ohnishi S, Nishioka Y: Effects of Sho-saiko-to extract on liver fibrosis in relation to the changes in hydroxyproline and retinoid levels of the liver in rats. J Pharm Pharmacol. 1999, 51: 1079-84. 10.1211/0022357991773429.PubMedGoogle Scholar
  85. Kusunose M, Qiu B, Cui T, Hamada A, Yoshioka S, Ono M, Miyamura M, Kyotani S, Nishioka Y: Effect of Sho-saiko-to extract on hepatic inflammation and fibrosis in dimethylnitrosamine induced liver injury rats. Biol Pharm Bull. 2002, 25 (11): 1417-21. 10.1248/bpb.25.1417.PubMedGoogle Scholar
  86. Kitade Y, Watanabe S, Masaki T, Nishioka M, Nishino H: Inhibition of liver fibrosis in LEC rats by a carotenoid, lycopene, or a herbal medicine, Sho-saiko-to. Hepatol Res. 2002, 22: 196-205. 10.1016/S1386-6346(01)00132-2.PubMedGoogle Scholar
  87. Sakaida I, Hironaka K, Kimura T, Terai S, Yamasaki T, Okita K: Herbal medicine Sho-saiko-to (TJ-9) increases expression matrix metalloproteinases (MMPs) with reduced expression of tissue inhibitor of metalloproteinases (TIMPs) in rat stellate cell. Life Sci. 2004, 74: 2251-63. 10.1016/j.lfs.2003.09.059.PubMedGoogle Scholar
  88. Chen MH, Chen JC, Tsai CC, Wang WC, Chang DC, Tu DG, Hsieh HY: The role of TGF-beta 1 and cytokines in the modulation of liver fibrosis by Sho-saiko-to in rat's bile duct ligated model. J Ethnopharmacol. 2005, 97 (1): 7-13. 10.1016/j.jep.2004.09.040.PubMedGoogle Scholar
  89. Kakumu S, Yoshioka K, Wakita T, Ishikawa T: Effect of TJ-9 Sho-saiko-to (Kampo medicine) on interferon gamma and antibody production specific for hepatitis B virus antigen in patients with type B chronic hepatitis. Int Immunopharmacol. 1991, 13: 141-6. 10.1016/0192-0561(91)90091-K.Google Scholar
  90. Shimizu I: Sho-saiko-to: Japanese herbal medicine for protection against hepatic fibrosis and carcinoma. J Gastroenterol Hepatol. 2000, 15 (Suppl): D84-90. 10.1046/j.1440-1746.2000.02138.x.PubMedGoogle Scholar
  91. Abe S, Ishibshi H, Tansho S, Hanazawa R, Komatsu Y, Yamaguchi H: Protective effect of oral administration of several traditional Kampo-medicines on lethal Candida infection in immunosuppressed mice. Nippon Ishinkin Gakkai Zasshi. 2000, 41: 115-9.Google Scholar
  92. Ochi T, Kawakita T, Nomoto K: Effects of Hochu-ekki-to and Ninjin-youei-to, traditional Japanese medicines, on porcine serum-induced liver fibrosis in rats. Immunopharmacol Immunotoxicol. 2004, 26: 285-98. 10.1081/IPH-120037726.PubMedGoogle Scholar
  93. Cyong JC, Ki SM, Iijima K, Kobayashi T, Furuya M: Clinical and pharmacological studies on liver diseases treated with Kampo herbal medicine. Am J Chin Med. 2000, 28: 351-60. 10.1142/S0192415X00000416.PubMedGoogle Scholar
  94. Suzuki M, Sasaki K, Yoshizaki F, Oguchi K, Fujisawa M, Cyong JC: Anti-hepatitis C virus effect of citrus unshiu peel and its active ingredient nobiletin. Am J Chin Med. 2005, 33: 87-94. 10.1142/S0192415X05002680.PubMedGoogle Scholar
  95. Song SL, Gong ZJ, Zhang QR: Therapeutic effect and mechanism of traditional Chinese compound decoction of Radix Curcumae, Rhzoma Sparganii, Rhizoma Zedoariae on fibrotic liver in rats. Zhong Caoyao. 2004, 35: 293-6.Google Scholar
  96. Lu ZL, Li JC, Liu JD: Experimental study of effects of TCM formulas on regulation of peritoneal lymphatic stomata and urine sodium in liver fibrosis mouse model. Zhongguo Zhongyiyao Xinxi Zazhi. 2000, 7: 25-6.Google Scholar
  97. Feng Y, Nagamatu T, Suzuki Y, Kawata T, Koike T: The diuretic effects of Wakan-yaku prescription on normal rats and various pathological models. Wakan Iyakugaku Zasshi. 1996, 13: 484-485.Google Scholar
  98. Feng Y, Nagamatu T, Suzuki Y, Kawata T, Feng YG, Kobayashi S, Koike T: Pharmacological studies of diuretic Wakan-yaku formulations: its application and evaluation of Pharmacological screening. Wakan Iyakugaku Zasshi. 2000, 17: 122-30.Google Scholar
  99. Li CX, Li L, Lou J, Yang WX, Lei TW, Li YH, Liu J, Cheng ML, Huang LH: The protective effects of traditional Chinese medicine prescription, han-dan-gan-le, on CCl4-induced liver fibrosis in rats. Am J Chin Med. 1998, 26: 325-32. 10.1142/S0192415X98000361.PubMedGoogle Scholar
  100. Li C, Luo J, Li L, Cheng M, Huang N, Liu J, Waalkes MP: The collagenolytic effects of the traditional Chinese medicine preparation, Han-Dan-Gan-Le, contribute to reversal of chemical-induced liver fibrosis in rats. Life Sci. 2003, 72: 1563-71. 10.1016/S0024-3205(02)02448-7.PubMedGoogle Scholar
  101. Yang Q, Xie RJ, Geng XX, Luo XH, Han B, Cheng ML: Effect of Danshao Huaxian capsule on expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in fibrotic liver of rats. World J Gastroenterol. 2005, 11: 4953-6.PubMed CentralPubMedGoogle Scholar
  102. Cheng ML, Lu T, Yao YM, Geng XX: Danshao huaxian capsule in treatment of decompensated cirrhosis resulting from chronic hepatitis B. Hepatobiliary Pancreat Dis Int. 2006, 5: 48-51.PubMedGoogle Scholar
  103. Wang LC, Zhao LS, Tang H: Experimental study of liver fibrosis reversal effect of warming-yang compound formula ganzhifu. Zhongguo Zhongxiyi Jiehe Zazhi. 2006, 26: 63-7.PubMedGoogle Scholar
  104. Liu C, Liu P, Liu CH, Zhu XQ, Ji G: Effects of Fuzhenghuayu decoction on collagen synthesis of cultured hepatic stellate cells, hepatocytes and fibroblasts in rats. World J Gastroenterol. 1998, 4: 548-549.PubMedGoogle Scholar
  105. Liu C, Jiang CM, Liu CH, Liu P, Hu YY: Effect of Fuzhenghuayu decoction on vascular endothelial growth factor secretion in hepatic stellate cells. Hepatobiliary Pancreat Dis Int. 2002, 1: 207-10.PubMedGoogle Scholar
  106. Liu P, Hu YY, Liu C, Xu LM, Liu CH, Sun KW, Hu DC, Yin YK, Zhou XQ, Wan MB, Cai X, Zhang ZQ, Ye J, Zhou RX, He J, Tang BZ: Multicenter clinical study on Fuzhenghuayu capsule against liver fibrosis due to chronic hepatitis B. World J Gastroenterol. 2005, 11: 2892-9.PubMed CentralPubMedGoogle Scholar
  107. Liu CH, Hu YY, Xu LM, Liu C, Liu P: Effect of Fuzheng Huayu formula and its actions against liver fibrosis. Chin Med. 2009, 4: 12-10.1186/1749-8546-4-12.PubMed CentralPubMedGoogle Scholar
  108. He Q, Yang DG, Li L, Zhong BL, Zeng XM: The 24 week effectiveness of Fuzheng Huayu capsule for CHB liver fibrosis: a systematic assessment. Zhongguo Xunzheng Yixue Zazhi. 2008, 8: 892-7.Google Scholar
  109. Okuno T, Arai K, Shindo M: Efficacy of interferon combined glycyrrhizin therapy in patients with chronic hepatitis C resistant to interferon therapy. Nippon Rinsho. 1994, 52: 1823-7.PubMedGoogle Scholar
  110. Tsubota A, Kumada H, Arase Y, Chayama K, Saitoh S, Ikeda K, Kobayashi M, Suzuki Y, Murashima N: Combined ursodeoxycholic acid and glycyrrhizin therapy for chronic hepatitis C virus infection: a randomized controlled trial in 170 patients. Eur J Gastroenterol Hepatol. 1999, 11: 1077-83. 10.1097/00042737-199910000-00002.PubMedGoogle Scholar
  111. Sun WH, Song MQ, Liu ZJ: Combination therapy for hepatic fibrosis in 64 patients with hepatitis using Xiao-chai-hu-tang and Matrine injection. Zhongxiyi Jiehe Ganbing Zazhi. 2003, 13: 41-2.Google Scholar
  112. Li Z, Liao HH, Wu MJ, Lin ZH: Study of combination therapy of Interferon-gamma and Xiao-chai-hu-tang for patients with liver fibrosis. Zhongxiyi Jiehe Ganbing Zazhi. 2001, 11 (Suppl): 95-Google Scholar
  113. Xiong F, Sun J, Xiong W: Clinical observation of combination therapy of Interferon and Xiao-chai-hu-tang for patients with liver fibrosis. Hubei Zhongyi Zazhi. 2003, 25: 10-11.Google Scholar
  114. Nakagawa A, Yamaguchi T, Takao T, Amano H: Five cases of drug-induced pneumonitis due to Sho-saiko-to or interferon-alpha or both. Nihon Kyobu Shikkan Gakkai Zasshi. 1995, 33 (12): 1361-1366.PubMedGoogle Scholar
  115. Ishizaki T, Sasaki F, Ameshima S, Shiozaki K, Takahashi H, Abe Y, Ito S, Kuriyama M, Nakai T, Kitagawa M: Pneumonitis during interferon and/or herbal drug therapy in patients with chronic active hepatitis. Eur Respir J. 1996, 9: 2691-6. 10.1183/09031936.96.09122691.PubMedGoogle Scholar
  116. Liu AL, Wei M, Zeng ZG, Sun JX, Yang M, Yan SY: Combination therapy of Xiao-chai-hu-tang and Tiopronin for patients with liver fibrosis. Shaanxi Zhongyi. 2005, 26: 873-4.Google Scholar
  117. Chen YS: The efficacy of combining Lamivudine with Salvia miltiorrhiza on the treatment of chronic hepatitis B liver fibrosis. Redai Yixue Zazhi. 2003, 3: 207-9.Google Scholar
  118. Chen JJ, Tang BX, Wang LT, Chen XR: Clinical study on effect of bushen granule combined with marine injection in treating chronic hepatitis B of Gan-shen deficiency with damp-heat syndrome type. Zhongguo Zhongxiyi Jiehe Zazhi. 2006, 26: 23-7.PubMedGoogle Scholar
  119. Liu X, Hu H, Yin JQ: Therapeutic strategies against TGF-beta signalling pathway in hepatic fibrosis. Liver Int. 2006, 26: 8-22. 10.1111/j.1478-3231.2005.01192.x.PubMedGoogle Scholar
  120. Choi HS, Savard CE, Choi JW, Kuver R, Lee SP: Paclitaxel interrupts TGF-beta1 signaling between gallbladder epithelial cells and myofibroblasts. J Surg Res. 2007, 141: 183-91. 10.1016/j.jss.2006.12.558.PubMed CentralPubMedGoogle Scholar
  121. Elsharkawy AM, Oakley F, Mann DA: The role and regulation of hepatic stellate cell apoptosis in reversal of liver fibrosis. Apoptosis. 2005, 10: 927-39. 10.1007/s10495-005-1055-4.PubMedGoogle Scholar
  122. Stickel F, Patsenker E, Schuppan D: Herbal hepatotoxicity. J Hepatol. 2005, 43: 901-10. 10.1016/j.jhep.2005.08.002.PubMedGoogle Scholar
  123. Ishii M, Miyazaki Y, Yamamoto T, Miura M, Ueno Y, Takahashi T, Toyota T: A case of drug-induced ductopenia resulting in fatal biliary cirrhosis. Liver. 1993, 13: 227-31.PubMedGoogle Scholar
  124. Yuen MF, Tam S, Fung J, Wong DK, Wong BC, Lai CL: Traditional Chinese medicine causing hepatotoxicity in patients with chronic hepatitis B infection: a 1-year prospective study. Aliment Pharmacol Ther. 2006, 24: 1179-86. 10.1111/j.1365-2036.2006.03111.x.PubMedGoogle Scholar
  125. Feng Y: Basic and Clinical Toxicology of Chinese Medicines. 2009, Hong Kong: Commercial Press,Google Scholar
  126. Levy C, Seeff LD, Lindor KD: Use of herbal supplements for chronic liver diseases. Clin Gastroenterol Hepatol. 2004, 2: 947-56. 10.1016/S1542-3565(04)00455-0.PubMedGoogle Scholar
  127. Dhiman RK, Chawla YK: Herbal medicines for liver diseases. Dig Dis Sci. 2005, 50: 1807-12. 10.1007/s10620-005-2942-9.PubMedGoogle Scholar
  128. Ye X, Feng Y, Tong Y, Ng KM, Tsao SW, Lau GKK, Sze C, Zhang Y, Tang J, Shen J, Kobayashi S: Hepatoprotective effects of Coptidis rhizoma aqueous extract on carbon tetrachloride-induced acute liver hepatotoxicity in rats. J Ethnopharmacol. 2009, 124: 130-6. 10.1016/j.jep.2009.04.003.PubMedGoogle Scholar
  129. Feng Y, Luo WQ, Zhu SQ: Explore new clinical application of Huanglian and corresponding compound prescriptions from their traditional use. Zhongguo Zhongyao Zazhi. 2008, 33: 1221-5.PubMedGoogle Scholar
  130. Feng Y, Siu K, Wang N, Ng KM, Tsao SW, Nagamatsu T, Tong Y: Bear bile: dilemma of traditional medicinal use and animal protection. J Ethnobiol Ethnomed. 2009, 5: 2-10.1186/1746-4269-5-2.PubMed CentralPubMedGoogle Scholar
  131. Zhao ZZ, Hu YN, Liang ZT, Yuen JPS, Jian ZH, Lueng KSY: Authentication is fundamental for standardization of Chinese Medicines. Planta Medica. 2006, 72: 1-10. 10.1055/s-2006-947209.Google Scholar
  132. Geerts A, Rogiers V, Sho-saiko-to : the right blend of Traditional oriental medicine and liver cell biology. Hepatology. 1999, 29: 282-3. 10.1002/hep.510290129.PubMedGoogle Scholar
  133. Angell M, Kassirer JP: Alternative medicine-the risks of untested and unregulated remedies (Editorial). N Engl J Med. 1998, 339: 839-41. 10.1056/NEJM199809173391210.PubMedGoogle Scholar

Copyright

© Feng et al; licensee BioMed Central Ltd. 2009

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.