Wogonin Suppresses IL-10 Production in B Cells via STAT3 and ERK Signaling Pathway.

Wogonin (5,7-dihydroxy-8-methoxyflavone) is an ingredient of the extracts from Scutellaria baicalensis, which has documented a wide spectrum of anti-inflammatory and antitumor activities, including inhibiting regulatory T cells, regulating effector T cell functions, and mediating macrophage immunity. However, the potential effect of Wogonin on B cells has not been fully understood. Here, our results showed that Wogonin inhibited IL-10 secretion in B cells. When purified B cells were activated by lipopolysaccharide (LPS) in vitro, the amount of IL-10 production in supernatant was decreased by Wogonin significantly. The protective role of B cells on dextran sulfate sodium- (DSS-) induced colitis was alleviated after exposure to Wogonin. Furthermore, administration of Wogonin on LPS-treated B cells suppressed phosphorylation of STAT3 and ERK, but not AKT. Interestingly, among those IL-10 signaling-associated transcription factors, mRNA and protein levels of Hif-1 were specifically decreased by Wogonin. Overall, our study indicates that Wogonin suppresses potentially IL-10 production in B cells via inhibition of the STAT3 and ERK signaling pathway as well as inhibition of mRNA and protein levels of the transcription factor Hif-1. These results provide novel and potential molecular targets of Wogonin in B cells and help us further understand its mechanism of action, which could potentially improve its clinical application in the future.