Prodelphinidin B-2 3,3'-di-O-gallate from Myrica rubra inhibits proliferation of A549 carcinoma cells via blocking cell cycle progression and inducing apoptosis.

In this study, the antiproliferative activity of prodelphinidin B-2 3, 3'-di-O-gallate (PB233'OG) isolated from the bark of Myrica rubra (Myricaceae) was investigated. The results showed that PB233'OG inhibited the proliferation of A549 by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. Enzyme-linked immunosorbent assay (ELISA) showed that the G0/G1 phase arrest is due to increase the expression of p21/WAF1. An enhancement in Fas/APO-1 and its two form ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by PB233'OG. Our study reports here for the first time that the induction of p21/WAF1 and activity of the Fas/Fas ligand apoptotic system may participate in the anti-proliferative activity of PB233'OG in A549 cells.