Inhibitory Effect of Tanshinone IIA on Inflammatory Mediator Production

Objective: Activated macrophages generate tumor necrosis factor- a (TNF- a), interleukin-1 (IL-1), interleukin-6 (IL-6), as well as nitric oxide (NO) via the inducible form of nitric oxide synthesis (iNOS). Tanshinone IIA is one of the major diterpene from Salvia miltiorrhiza Bunge (S. miltiorrhiza). The compound is known to exhibit antitumor activity, and scavenge lipid radicals. However, little is known that tanshinone IIA alters production of pro-inflammatory cytokine and iNOS expression in macrophages. In this study, we clearly demonstrate that tanshinone IIA inhibited the production of NO, TNF- a, IL-1 and IL-6 and suppressed the expression of iNOS in activated RAW 264.7 cell Methods: The inhibitory effects of tanshinone IIA, a diterpene isolated from S. miltiorrhiza root, on production of NO, IL-1, IL-6 and TNF- a, and expression of iNOS were investigated in activated RAW 264.7 cells. Results: Tanshinone IIA markedly inhibited the production of NO, IL-1 and TNF- a, and suppressed the expression of iNOS in a dose-dependent manner. Conclusion: In conclusion, tanshinone IIA from S. miltiorrhiza strongly inhibited the production of NO, TNF- a, IL-1and IL-6, and expression of iNOS in activated RAW 264.7 cells. These results suggest that the traditional use of S. miltiorrhiza as an anti-inflammatory regimen may be explained, in part, by the inhibition of NO, IL-1, IL-6 and TNF- a production, and expression of iNOS.