Antiproliferative and Anti-invasion Effects of Carvacrol on PC3 Human Prostate Cancer Cells through Reducing pSTAT3, pAKT, and pERK1/2 Signaling Proteins

Background: One of the most effective parameters in the progression of the prostate cancer is interleukin (IL)-6 through affecting pSTAT3, pERK1/2, and pAKT cell signaling proteins. Carvacrol is an herbal antioxidant with antitumor effects. The purpose of this study was to investigate the effects of carvacrol on IL-6 gene expression, pSTAT3, pAKT, pERK1/2 cellular signaling proteins, and invasion in human prostate cancer PC3 cells. Methods: PC3 cell viability was evaluated by MTT assay with different concentrations of carvacrol (0–800 µM). IL-6 gene expression and cellular concentration of pSTAT3, pERK1/2, and pAKT were investigated using the real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blotting technic, respectively. PC3 cell invasion was determined by invasion assay test. Results: Carvacrol IC50 for PC3 prostate cancer cells was 360 µM. Carvacrol led to a significant reduction (P < 0.05) for IL-6 gene expression in a dose-dependent manner compared to control. IL-6 protein reduced 41.5% and 52.7% when compared with control cells at 360 and 420 µM of carvacrol, respectively. Carvacrol led to a decline in pSTAT3, pAKT, and pERK1/2 above 360 µM compared to control. PC3 potential invasion was significantly reduced after treatment with carvacrol in a dose‑dependent manner. Conclusions: Decreased IL-6 protein level by carvacrol resulted in diminishing of pSTAT3, pERK1/2, and pAKT signaling proteins, which leads to the reduction of the cell survival, proliferation, and invasion in PC3 cells.