Manassantin A and B from Saururus chinensis inhibit interleukin-6 - Induced signal transducer and activator of transcription 3 activation in Hep3B cells

Inhibition of interleukin-6 (il-6) has been postulated to be an effective therapy in the pathogenesis of several inflammatory diseases. the current study was performed to examine potential effects of manassantin a and b isolated from saururus chinensis on the il-6-induced response to human hepatoma cells. we found that manassantin a and b inhibit signal transducer and activator of transcription 3 (stat3) activity stimulated by il-6. we also found that both compounds decreased il-6-induced stat3 phosphorylation and nuclear translocation. both compounds blocked suppressor of cytokine signaling 3 (socs-3)-mrna expression induced by il-6. in addition,we found that stat3 inhibitory effects of these compounds could be related to protein tyrosine phosphatase. these findings suggest that manassantin a and b could be useful remedies for treatment of inflammatory diseases by inhibiting il-6 action. © the japanese pharmacological society.