Anti-Inflammatory Effect of Wogonin on RAW 264.7 Mouse Macrophages Induced with Polyinosinic-Polycytidylic Acid

Wogonin (5,7-dihydroxy-8-methoxyflavone) is an active flavonoid compound originally isolated from Scutellaria radix, which has been used to treat lung inflammation in Korea, China, and Japan. Wogonin has been known to inhibit inducible nitric oxide synthase and have the anti-tumor properties. However, the effects of wogonin on virus-induced macrophages are not fully reported. In this study, the anti-inflammatory effect of wogonin on double-stranded RNA (dsRNA)-induced macrophages was examined. Wogonin restored the cell viability in dsRNA [polyinosinic-polycytidylic acid]-induced RAW 264.7 mouse macrophages at concentrations of up to 50 μM. Wogonin significantly inhibited the production of nitric oxide, IL-1α, IL-1β, IL-6, IL-10, IP-10, G-CSF, GM-CSF, LIF (IL-6 class cytokine), LIX/CXCL5, MCP-1, M-CSF, MIP-1α, MIP-1β, MIP-2, RANTES/CCL5, TNF-α, and VEGF as well as calcium release and mRNA expression of signal transducer and activated transcription 1 (STAT1) and STAT3 in dsRNA-induced RAW 264.7 cells (P < 0.05). In conclusion, wogonin has anti-inflammatory properties related with its inhibition of nitric oxide, cytokines, chemokines, and growth factors in dsRNA-induced macrophages via the calcium-STAT pathway.