Antitumor Activity of Garcinol in Human Prostate Cancer Cells and Xenograft Mice

Garcinol, which is isolated from fruit rinds of Garcinia indica, is a polyisoprenylated benzophenone. It has been studied for its antitumor activity by inducing apoptosis and inhibiting autophagy in human prostate cancer cells. The Bax/Bcl-2 ratio increased when garcinol was applied to PC-3 cells indicating a presence of apoptosis. Meanwhile, procaspases-9 and -3 were suppressed with attenuating PARP and DFF-45. Autophagy was inhibited through activating p-mTOR and p-PI3 Kinase/AKT by garcinol, which as a result induced the cells to apoptosis directly. In addition, the apoptosis effect of garcinol in a xenograft mouse model was also tested, suggesting a consistent result with PC-3 cell model. The tumor size was reduced more than 80 percent after the mouse accepted the garcinol treatment. Garcinol was demonstrated to have a strong antitumor activity through inhibiting autophagy and inducing apoptosis, which was discovered for the first time. Based on these findings, our data suggests that garcinol deserves further investigation as a potent chemopreventive agent.