Fig. 5

Effect of curcumin and piperine alone and in combination in LPS-induced RAW 264.7 macrophage cells. (A, B) Cytotoxicity profile of curcumin (A) and piperine (B) in RAW 264.7 macrophage cells. (C) Concentration–response curves for NO inhibitory effects of curcumin, piperine, and combination in LPS-induced RAW 264.7 macrophage cells. (D) Fa-CI plot, representing the interaction between curcumin and piperine in NO inhibition. (E) Normalized isobologram, representing NO inhibitory effects of curcumin, piperine, and their combination at 25%, 50%, and 90% effect levels. (F, G) Effect of curcumin, piperine, and their combination on LPS-induced IL-6 (F) and TNF-α (G) production in RAW 264.7 macrophage cells. Data are expressed as means ± S.E.M (n = 3). The difference between the treatment and control groups was analyzed using ANOVA followed by Dunnett’s post hoc test for cell viability assay. ***p < 0.001, *p < 0.05, compared to the control group. For the cytokine expression, the differences between the groups were analyzed using one-way ANOVA followed by the Bonferroni post hoc test. ^$p < 0.05, compared to the control group, ^#p < 0.05, compared to the LPS group. *p < 0.05, compared to the respective individual concentration of curcumin, and ^&p < 0.05, compared to the respective individual concentration of piperine