Protective effect of procyanidin A-type dimers against HO-induced oxidative stress in prostate DU145 cells through the MAPKs signaling pathway.

It has been reported that B-type procyanidins can alleviate oxidative damage of prostatic cells, but there has been limited information on the similar role of A-type procyanidins. This study investigated the protective effect of procyanidin A-type dimers from peanut skin against HO-induced oxidative stress damage in prostate cancer DU145 cells. According to the UPLC-Q-TOF-MS/MS analysis and comparison with standards, the fourth fraction of peanut skin procyanidin (PSP-4) was identified as procyanidin A-type dimers, namely, procyanidin A and A. Results revealed that PSP-4 treatment prior HO exposure increased cell activity and attenuated the cell cycle arrest and apoptosis rate. The HO-induced increase in intracellular reactive oxygen species (ROS) was remarkably inhibited by PSP-4. PSP-4 treatment enhanced the activity of catalase (CAT) and total super oxide dismutase (T-SOD) and restored glutathione (GSH) content, compared with the HO treatment. Furthermore, the results indicated that PSP-4 protected DU145 cells by attenuating phosphorylation of the mitogen-activated protein kinases (MAPKs), by increasing the Bcl-2/Bax ratio, and by reducing the activation of caspase-3 and caspase-9 by cascade reactions. This study reveals that procyanidin A-type dimers from peanut skin have the potential function in preventing oxidative stress damage of prostatic cells.