Puerarin, an isoflavone extracted from Radix puerariae, is a 5-HT2C receptor antagonist. In Vitro: Puerarin inhibits the expression of LPS-induced iNOS, COX-2 and CRP proteins and also suppresses their mRNAs from RT-PCR experiments in RAW264.7 cells. The inhibition of iNOS, COX-2 and CRP expression is due to a dose-dependent inhibition of phosphorylation and degradation of I-κB, which resulted in the reduction of p65NF-κB nuclear translocation. The effect of puerarin-mediated inhibition of LPS-induced iNOS, COX-2 and CRP expression is attributed to suppressed NF-κB activation at the transcriptional level^[1]. Puerarin is a novel open-channel blocker of IK1, which may underlie the antiarrhythmic action of puerarin. Puerarin competes with barium, an open-channel blocker of IK1, to inhibit IK1 currents^[2]. In Vivo: Both genistein and puerarin effectively alleviate hepatic damage induced by chronic alcohol administration through potential antioxidant, anti-inflammatory, or anti apoptotic mechanisms. However, genistein is more effective than puerarin in decreasing levels of malondialdehyde (1.05±0.0947 vs. 1.28±0.213 nmol/mg pro, p< 0.05), tumor necrosis factor α (3.12±0.498 vs. 3.82±0.277 pg/mg pro, p < 0.05), interleukin-6 (1.46±0.223 vs. 1.88±0.309 pg/mg pro, p < 0.05), whereas puerarin is more effective than genistein in ameliorating serum activities or levels of alanine transaminase (35.8±3.95 vs. 42.6±6.56 U/L, p < 0.05) and low-density lipoprotein cholesterol (1.12±0.160 vs. 1.55±0.150 mmol/L, p < 0.05) ^[3]. Early-stage renal damages can be significantly improved by puerarin, possibly via its suppression of ICAM-1 and TNF-α expression in diabetic rat kidneys^[4].