Effect of Xiaoyaosan on major depressive disorder
Chinese Medicinevolume 10, Article number: 18 (2015)
This study aims to evaluate the efficacy of Xiaoyaosan (XYS) for treatment of major depressive disorder (MDD) and to review the studies on antidepressant mechanisms of XYS.
The China Knowledge Resource Integrated Database (1998–2014), VIP Journal Integration Platform (1989–2009), and PubMed (1950–2014) were used to search for and collect scientific publications related to XYS and MDD. Clinical trials for “MDD” and “xiaoyao” were screened. Papers that used the original prescription of XYS for treatment and in combination with Western medicines were included, while papers describing modified XYS were excluded. Four investigators read and screened the resulting publications independently, evaluated the associated scientific results and evidence.
There were no conclusive results to support the efficacy of XYS for treatment of MDD, owing to limited sample sizes, flaws in blinding and randomization, and lack of multi-centered clinical trials. Among the experimental studies on the effects of XYS possible involvement of 5-hydroxytryptamine, hypothalamic–pituitary–adrenal axis function, and neuroinflammation were possibly involved demonstrated.
The effectiveness of XYS for treatment of MDD is uncertain.
Major depressive disorder (MDD) affects ~16% of the world population . In China, the MDD prevalence is 9% in the general population, and 15–30% of all adolescents are estimated to be affected by the disease . Observations from 245,404 subjects in 60 countries revealed that the 1-year prevalence of ICD-10 depressive episodes alone is 3.2% . The depression comorbidity rate of participants with one or more chronic physical diseases ranges from 9.3 to 23.0% . Common antidepressants include selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors. The slow onset of action and limited efficacy of these antidepressants have limited their use and prompted the search for novel strategies or alternative methods to combat the illness .
Xiaoyaosan (XYS) is a Chinese medicinal formula that comprises Radix Bupleuri, Radix Angelicae Sinensis, Radix Paeoniae Alba, Rhizoma Atractylodis Macrocephalae, Poria, Rhizoma Zingiberis Recens, Herba Menthae, and Radix Glycyrrhizae. XYS alone or combined with antidepressants has been used to treat MDD in China. However, the action mechanisms of XYS on MDD are still unknown.
This study aims to evaluate the efficacy of Xiaoyaosan (XYS) for treatment of major depressive disorder (MDD) and to review the studies on antidepressant mechanisms of XYS.
Literature searches were performed with the terms “depression” and “xiaoyao” in the China Knowledge Resource Integrated Database (1998–2014), VIP Journal Integration Platform (1989–2009), and PubMed (1950–2014). After reports describing basic research were excluded, a total of 110 papers on clinical trials were assessed for eligibility. Papers about modified XYS were eliminated from the analysis, because of the difficulty in comparing the efficacies of medicinal formulas based on the incommensurability of the reports . Reports on depression comorbidities, such as postpartum, post-stroke, and post-cancer depression, were also excluded. Papers that used the original prescription of XYS for treatment and/or in combination with Western medicines were included. A total of 15 reports on unmodified XYS and MDD met the inclusion criteria and were evaluated in the present study (Figure 1).
Records of basic research were excluded according to the standard of meta-analysis of evidence-based medicine. The full texts on modified XYS were eliminated for the incommensurability of the reports and papers on depression comorbidities were also excluded for our focus on MDD.
Efficacy of XYS
Efficacy of XYS in ameliorating MDD
Regarding the efficacy of XYS in ameliorating MDD, the disease showed significant improvement according to the traditional Chinese medicine curative index . XYS also significantly decreased the Hamilton depression scores in MDD patients . Controlled, randomized, and double-blinded trials showed that the total effective rate of XYS in treating MDD was 91.38% in 58 patients, being significantly higher than the value of 32.69% for the placebo in 52 patients . XYS treatment was associated with a significantly decreased depression inventory score  (Table 1).
Analysis of XYS-induced efficacy of antidepressants
The total effective rate of XYS–antidepressant combinations in 12 trials was not significantly improved compared with those of other antidepressants in seven trials. However, the cure rate was increased in one of the seven trials. The five remaining trials exhibited improved effective rates in the combination groups. Nine trials demonstrated that XYS reduced side effects, four trials revealed decreased relapse rates, and four trials showed delays in onset time (Table 2).
XYS exhibited fewer side effects than antidepressants, but similar effectiveness. The combinations of XYS and antidepressants advanced the onset time and reduced adverse side effects in most of the trials. The methodological quality of most included trials was generally “poor”. So, defects in sample sizes, blindness, and randomization were observed in most of the trials evaluated. Therefore, biases including performance and detection biases could not be ignored  (Table 3).
Mechanism of XYS as an integrated model
Hypotheses for MDD and functions of XYS
5-HT deficiency was the prevailing hypothesis for MDD [22, 23]. SSRIs were widely used, and accounted for about 60–80% of the total market share of antidepressants . XYS upregulated the 5-HT contents in the cerebral cortex of a chronic restraint stress (CRS)-induced rat depression model , and increased the 5-HT contents in the hippocampus of rats with postpartum depression . XYS could be a regulator of monoamine neurotransmitters .
The hypothalamic–pituitary–adrenal (HPA) axis is governed by secretion of corticotropin-releasing hormone (CRH) from the hypothalamus to activate secretion of adrenocorticotropic hormone (ACTH) from the pituitary gland. Corticoids (cortisol in humans and corticosterone in rodents) are stimulated from the adrenal cortex and interact with their receptors, such as glucocorticoid receptors, for negative feedback control . HPA hyperactivity results from deficits in the negative feedback regulation of the axis based on the failure of glucocorticoid receptor activation to decrease plasma levels of cortisol . XYS downregulated CRH-1 and upregulated CRH-2 expression in the hypothalamus of a CRS-induced depressive rat model . XYS decreased the expression of CRH-1 mRNA in paraventricular nuclei and increased GR expression in the hippocampus of a chronic unpredictable mild stress-induced depressive rat model . Therefore, homeostasis of CRH receptors might be involved in improvement of the disequilibrium in the HPA system.
HPA hyperactivity was observed in 30–50% of all acutely depressed patients . Mitochondrial dysfunctions affected important functions in MDD pathogenesis . Small deletions of mitochondrial DNA were observed in muscles from patients with MDD . Alterations in nuclear DNA-encoded mitochondrial mRNA and proteins in the cerebellum of MDD patients were also reported . MDD patients with serious somatic complaints exhibited low ATP production rates in biopsied muscles . These studies provide concrete evidence for the clinical relevance of an association between low ATP supply arising through mitochondrial dysfunction and MDD. XYS was reported by our group to ameliorate depressive-like behaviors in rats by regulating mammalian target of rapamycin (mTOR), suggesting that XYS may exert its anti-depressive effects through regulation of energy metabolism .
Inflammatory pathways were suggested to be involved in the pathophysiology of MDD through increased blood and cerebrospinal fluid concentrations of pro-inflammatory cytokines as well as acute phase proteins and their receptors . Cytokines interact with mitochondria to increase the production of reactive oxygen species (ROS). Increased expressions of pro-inflammatory mediators, neurotoxic factors, and ROS contributed to the development of MDD . XYS has been widely used for treating inflammatory diseases and depression comorbidities in hepatitis . Recently, we found that XYS significantly reduced the serum levels of tumor necrosis factor-α and interleukin-6 in rats with depressive-like behaviors induced by chronic unpredictable mild stress (unpublished data). MDD was associated with neuronal atrophy and neuronal cell loss, especially in the hippocampus and cerebral cortex . Decreased brain-derived neurotrophic factor (BDNF) was strongly associated with an increased risk for MDD . A clinical meta-analysis showed that BDNF levels were associated with changes in depression . BDNF was downregulated in the hippocampus of a CRS-induced rat depression model . Reports from our group and others indicated that XYS increased BDNF expression in the hippocampus [36, 42, 43]. These results suggest that XYS improves MDD by upregulating BDNF in specific encephalic regions.
Epigenetic alterations were found in the frontal cortex of suicide victims with depression . Antidepressants exerted some of their effects by causing epigenetic alterations . Observed dysfunctions of biological clocks were related to MDD . Patients with depression often showed altered circadian rhythms, sleep disturbances, and variations in diurnal moods . The degree of circadian misalignment was correlated with the severity of depressive symptoms . The actions of XYS on epigenetic modifications and circadian rhythms are significant, because this medicinal formula is efficacious in the treatment of sleeping and mood disorders.
Integrated hypothesis for MDD as a unified mechanism of XYS
Hypotheses for MDD include 5-HT depletion, neurotrophin deficiency, neuroinflammation, mitochondrial dysfunction, HPA hyperactivity, epigenetic variation, and circadian dysrhythmia. However, the pathophysiology of MDD has rarely been studied and the published hypotheses are far from mutually exclusive.
The theory of inadequate monoamine neurotransmission, in which antidepressants increase monoamine availability and produce long-term adaptive changes in monoaminergic receptor sensitivity , is insufficient to explain MDD. Lowered plasma tryptophan reduced 5-HT synthesis and aggravated MDD symptoms . N-acetylserotonin, an intermediate product of melatonin formation from 5-HT, is a specific agonist of BDNF receptors, and 5-HT is a substrate for melatonin biosynthesis. Melatonin deficiency contributed to primary and depression-associated insomnia as well as disturbances in circadian rhythms .
Neuroinflammation, which is characterized by increased production of interferon-γ, interleukin-6, and tumor necrosis factor-α, and induction of indoleamine 2,3-dioxygenase (IDO) in the blood and brain, plays a role in depression . Activation of IDO reduces plasma tryptophan and brain 5-HT and increases the levels of tryptophan catabolites (TRYCATs), such as quinolinic and picolinic acids. Inflammation increases CRH and ACTH secretion. Cortisol levels are increased to activate liver tryptophan 2,3-dioxygenase, which further decreases plasma tryptophan and increases TRYCAT production. TRYCATs generate ROS, cause mitochondrial dysfunctions, and interfere with energy metabolism. They also potently activate NMDA receptors and induce pro-inflammatory responses and neuron apoptosis. These findings imply a shift from tryptophan and 5-HT depletion toward the detrimental effects of TRYCATs. IDO links the neuroinflammation and neurotoxicity of TRYCATs, which jointly promote the development of depressive symptoms .
Psychosocial stresses arising from life events can potentially induce continuous increases in stress hormones, which impair negative-feedback mechanisms and lead to continuous hyperactivity of the HPA axis. Pro-inflammatory cytokines are also potential activators of the HPA axis, thereby increasing the secretion of glucocorticoids, which are markers of glucocorticoid resistance. Glucocorticoids augment the alternative pathway for IDO-catalyzed tryptophan and decrease the amount of 5-HT available in synapses by increasing the expression of the serotonin transporter gene. Prolonged increases in glucocorticoids desensitize their receptors on immune cells, such as macrophages. Activation of macrophages in the periphery and brain occurred and pro-inflammatory cytokines were released in MDD patients . Psychosocial stresses decrease the levels of BDNF and other neurotrophic/growth factors, while increasing the glucocorticoid concentration. Multiple interaction pathways exist between pro-inflammatory immune functions, brain and neuronal structures, brain serotonergic systems, and the HPA axis. The HPA axis is a key integrative component that links primary biological and psychosocial theories .
Dysfunction of the hippocampus, cerebellum, insula, frontal cortex, and temporal cortex could eventually contribute to the pathogenesis of MDD. The integrated model conjectures a general-purpose co-processor, whose effects depend on the specific brain centers to which individual modules are connected . The disparate modules and different ideas on MDD emphasize the internal relationships among the different hypotheses (Figure 2).
Future directions and implications
Although XYS is a widely used medicinal formula in China, the research results are not commensurable among the various modifications of XYS, i.e., different ingredients because of their origins, and forms of prescriptions, such as powders, decoctions, and pills. A new strategy for Chinese medicine quality control called formulomics was proposed to analyze XYS . This strategy emphasizes strict extract quality control for XYS by liquid chromatography/mass spectrometry for chemical characterization and chemical fingerprinting , and recommends a fixed material origin and basis, and a standard extraction protocol. Targets for XYS in MDD must be screened with omics approaches and repeatedly confirmed using transgenic knockdown or knockin mice.
The effectiveness of XYS for treatment of MDD is uncertain.
major depressive disorder
selective serotonin reuptake inhibitors
reactive oxygen species
brain-derived neurotrophic factor
Kessler RC, Berglund P, Demler O, Jin R, Koretz D, Merikangas KR et al. (2003) The epidemiology of major depressive disorder: results from the National Comorbidity Survey Replication (NCS-R). JAMA 289(23):3095–3105
Ryder AG, Sun J, Zhu X, Yao S, Chentsova-Dutton YE (2012) Depression in China: integrating developmental psychopathology and cultural-clinical psychology. J Clin Child Adolesc Psychol 41(5):682–694
Moussavi S, Chatterji S, Verdes E, Tandon A, Patel V, Ustun B (2007) Depression, chronic diseases, and decrements in health: results from the World Health Surveys. Lancet 370(9590):851–858
Cao X, Li LP, Wang Q, Wu Q, Hu HH, Zhang M et al (2013) Astrocyte-derived ATP modulates depressive-like behaviors. Nat Med 19(6):773–777
Qin XB, Li P, Han M, Liu ZJ, Liu JP (2010) Systematic review of randomize controlled trials of xiaoyaopowder in treatment of depression. J Tradit Chin Med 51(6):500–505
Xian H, Tang QS, Zhao J (2008) Treatment of depression of liver-qi stagnation and spleen-deficiency type with therapy of soothing liver and invigorating spleen. J Beijing Univ Tradit Chin Med 31(12):856–859
Feng GM, Tian JS, Wu YF, Zhao SJ, Zhang LZ, Qin XM (2014) Clinical study of Xiaoyao powder in treatment of depression. Liaoning J Tradit Chin Med 41(3):512–516
Zhang MZ, Zhang QY, Cui GB (1998) Clinical study of xiaoyaosan on treatment of depressive disorder. J Shandong Univ TCM 22(1):34–37
Wang HY, Zhang BJ, Liu X, Tao YD (2013) Clinical observation on treatment of first—episode depression by duloxetine combined with Xiaoyaowan mixture. Sichuan Ment Health 26(1):32–34
Wang WA, Liu QZ, Liu WG, Liu CZ, Chen HL (2005) The efficacy of doxepin & Xiaoyao pills combination and fluoxetine on elderly depression. Chin J Behav Med Sci 14(3):248
Nan HC, Nan H (2004) Treatment of 30 cases of depressive neurosis with traditional Chinese medicine and western medicine. Jilin J Tradit Chin Med 24(6):31
Li J, Liu CL, Lan SZ, Li L, Cai JM (2008) Clinical observation on imipramine and xiaoyao pills on treatment of depression. Sichuan Ment Health 21(2):79
Du XB, Han GL, Song ZJ, Liu GL, Jian YL, Li PS et al (2005) Comparative study of fluoxetine and Chinese traditional medicine in the treatment of senile depression in altiplano. J High Alt Med 15(2):14–17
Ma C (2007) Controled study of citalopram and xiaoyao pills on treatment of depression. Health Vocat Educ 25(1):139–140
Chen J (2003) Treatment of depressive neurosis combined with traditional Chinese medicine and western medicine. J Pract Tradit Chin Med 19(7):368
Zhai XZ, Dong L, Zhang JZ (2001) Controled study on doxepin and xiaoyao pills on latent depression. Chin J Behav Med Sci 10(4):368
Zhang LN (2004) Observation of fluoxetine and xiaoyao pills on treatment of depression. Med J Indus Enterp 17(3):43
Zhang XZ, Feng SL, Lin SZ, Wang ZY (2003) A clinical study on treating depressive neurosis with xiaoyao infusion mixed with baiyoujie. J Beijing Univ TCM (Clin Med). 10(1):15–17
Xia XY, Tan XY, Wang DJ, Meng QM. The efficacy observation of xiaoyaosan combined with escitalopram in the treatment of depression. China Med Herald 8(24):71–72
Xiang Q (2012) Treatment of depression with xiaoyao pills and paroxetine. J Tradit Chin Med 58(18):1594–1595
Zhang Y, Han M, Liu Z, Wang J, He Q, Liu J (2012) Chinese herbal formula xiao yao san for treatment of depression: a systematic review of randomized controlled trials. Evid Based Complement Alternat Med 2012:931636
Vaswani M, Linda FK, Ramesh S (2003) Role of selective serotonin reuptake inhibitors in psychiatric disorders: a comprehensive review. Prog Neuropsychopharmacol Biol Psychiatry 27(1):85–102
Gardner A, Boles RG (2011) Beyond the serotonin hypothesis: mitochondria, inflammation and neurodegeneration in major depression and affective spectrum disorders. Prog Neuropsychopharmacol Biol Psychiatry 35(3):730–743
Chen Y, Kelton CM, Jing Y, Guo JJ, Li X, Patel NC (2008) Utilization, price, and spending trends for antidepressants in the US Medicaid Program. Res Soc Adm Pharm 4(3):244–257
Bao L, Chen J, Huang L, Chen W, Lin Q, Yao XS et al (2008) Effects of Xiaoyao Wan on the behavioral despair and stress depression mice. Zhong Yao Cai 31(9):1360–1364
Wang T, Qin F (2010) Effects of Chinese herbal medicine Xiaoyao Powder on monoamine neurotransmitters in hippocampus of rats with postpartum depression. Zhong Xi Yi Jie He Xue Bao 8(11):1075–1079
Kong M, Xing CY, Shu XC (2010) Influence of ease powder decoction on expression of hippocampus 5-HT1A Receptor and 5-HT2A receptor in rat model of sleep deprivation depression. Chin J Exp Med Formulae 16(14):157–160
Hauger RL, Risbrough V, Oakley RH, Olivares-Reyes JA, Dautzenberg FM (2009) Role of CRF receptor signaling in stress vulnerability, anxiety, and depression. Ann N Y Acad Sci 1179:120–143
Massart R, Mongeau R, Lanfumey L (2012) Beyond the monoaminergic hypothesis: neuroplasticity and epigenetic changes in a transgenic mouse model of depression. Philos Trans R Soc Lond B Biol Sci 367(1601):2485–2494
Chen JX, Tang YT (2004) Effect of Xiaoyao powder on changes of relative brain zone CRF gene expression in chronic restrained stress rats. Zhongguo Ying Yong Sheng Li Xue Za Zhi 20(1):71–74
Ao HQ, Xu ZW, Fu WJ, Su JF, Sun Q, Huang J et al (2010) Primary research on the mechanisms of Xiaoyao powder influences hypothalamus–pituitary–adrenal axis of chronic stress rats. Chin J Behav Med Brain Sci 19(8):680–682
Schule C, Baghai TC, Eser D, Rupprecht R (2009) Hypothalamic–pituitary–adrenocortical system dysregulation and new treatment strategies in depression. Expert Rev Neurother 9(7):1005–1019
Gardner A, Johansson A, Wibom R, Nennesmo I, von Dobeln U, Hagenfeldt L et al (2003) Alterations of mitochondrial function and correlations with personality traits in selected major depressive disorder patients. J Affect Disord 76(1–3):55–68
Ben-Shachar D, Karry R (2008) Neuroanatomical pattern of mitochondrial complex I pathology varies between schizophrenia, bipolar disorder and major depression. PLoS One 3(11):e3676
Gardner A, Boles RG (2008) Mitochondrial energy depletion in depression with somatization. Psychother Psychosom 77(2):127–129
Zhu X, Xia O, Han W, Shao M, Jing LL, Fan Q et al (2014) Xiao Yao San improves depressive-like behavior in rats through modulation of beta-arrestin 2-mediated pathways in hippocampus. Evid Based Complement Alternat Med 2014:902516
Catena-Dell’Osso M, Rotella F, Dell’Osso A, Fagiolini A, Marazziti D (2013) Inflammation, serotonin and major depression. Curr Drug Targets 14(5):571–577
Wang Q, Shen D, Xu L (2007) Treatment of 72 cases of chronic viral hepatitis B combined with anxiety and depression. Henan Tradit Chin Med 27(4):66
Duman RS, Malberg J, Nakagawa S, D’Sa C (2000) Neuronal plasticity and survival in mood disorders. Biol Psychiatry 48(8):732–739
Erickson KI, Miller DL, Roecklein KA (2012) The aging hippocampus: interactions between exercise, depression, and BDNF. Neuroscientist 18(1):82–97
Brunoni AR, Lopes M, Fregni F (2008) A systematic review and meta-analysis of clinical studies on major depression and BDNF levels: implications for the role of neuroplasticity in depression. Int J Neuropsychopharmacol 11(8):1169–1180
Zhang QL, Yue GX, Wang ZF, Zhao X, Yue LF, Ding J et al (2010) Changes of BDNF in different encephalic region of rats of chronic immobilization stress model and effect of xiaoyaosan. Liaoning J Tradit Chin Med 37(1):162–165
Li W, Chen JX (2005) Changes of BDNF TrkB NT3 in hippocampus of rats of chronic immobilization stress model and effect of xiaoyaosan. Chin Achiv Tradit Chin Med 23(7):1205–1208
Schroeder M, Krebs MO, Bleich S, Frieling H (2010) Epigenetics and depression: current challenges and new therapeutic options. Curr Opin Psychiatry 23(6):588–592
Menke A, Klengel T, Binder EB (2012) Epigenetics, depression and antidepressant treatment. Curr Pharm Des 18(36):5879–5889
Monteggia LM, Kavalali ET (2012) Circadian rhythms: depression brought to light. Nature 491(7425):537–538
Germain A, Kupfer DJ (2008) Circadian rhythm disturbances in depression. Hum Psychopharmacol 23(7):571–585
Hamon M, Blier P (2013) Monoamine neurocircuitry in depression and strategies for new treatments. Prog Neuropsychopharmacol Biol Psychiatry 45:54–63
Maes M, Leonard BE, Myint AM, Kubera M, Verkerk R (2011) The new ‘5-HT’ hypothesis of depression: cell-mediated immune activation induces indoleamine 2,3-dioxygenase, which leads to lower plasma tryptophan and an increased synthesis of detrimental tryptophan catabolites (TRYCATs), both of which contribute to the onset of depression. Prog Neuropsychopharmacol Biol Psychiatry 35(3):702–721
Oxenkrug G (2011) Interferon-gamma—inducible inflammation: contribution to aging and aging-associated psychiatric disorders. Aging Dis. 2(6):474–486
D’Angelo E, Casali S (2012) Seeking a unified framework for cerebellar function and dysfunction: from circuit operations to cognition. Front Neural Circuits 6:116
Sun XG, Lv ZP (2011) Formulomics:a strategy for translational medicine research of traditional Chinese medicine based on formula extraction quality control. Pharmacol Clin Chin Materia Medica 27(3):120–122
Lam W, Bussom S, Guan F, Jiang Z, Zhang W, Gullen EA et al (2010) The four-herb Chinese medicine PHY906 reduces chemotherapy-induced gastrointestinal toxicity. Sci Transl Med 2(45):1–8
XS conceived and designed the study. LJ and XZ searched and analyzed the literature, and performed the data analysis. ZL and XS wrote the manuscript. All authors read and approved the final manuscript.
This work was supported by the National Science Foundation of China (81230085, 81173168), the Research Program jointly sponsored by the Department of Science and Technology and the Academy of Traditional Chinese Medicine of Guangdong Province and the Planned Science (2014A020221011), Technology Project of Guangzhou, China (12C32121551).
Compliance with ethical guidelines
Competing interests The authors declare that they have no competing interests.