Schisandrin C (Wuweizisu-C) is a phytochemical lignan isolated from Schizandra chinensis Baill; shows anticancer-effects in human leukemia U937 cells.

Schisandrin C inhibited cell growth in a dose-dependent manner, which was associated with the induction of G1 arrest of the cell cycle and apoptosis. Schisandrin C induced G1 arrest was correlated with down-regulation of cyclin D1, cyclin E, cyclin-dependent kinase (Cdk) 4 and E2Fs expression, inhibition of phosphorylation of retinoblastoma protein (pRB), and up-regulation of the Cdk inhibitor p21(WAF1/CIP1). In addition, schisandrin C-induced apoptosis was associated with down-regulation of expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, proteolytic activation of caspase-3 and -9, and a concomitant degradation of poly(ADP-ribose) polymerase (PARP). Furthermore, schisandrin C-induced apoptosis was significantly inhibited by a caspase-3 specific inhibitor z-DEVD-fmk . Schisandrin C was found to reduce nitric oxide (NO) production from LPS-stimulated Raw 264.7 cells. Pre-treatment of Raw 264.7 cells with gomisin J, gomisin N, or schisandrin C reduced the expression of mRNA and the secretion of pro-inflammatory cytokines .