Resveratrol and quercetin protect from Benzo(a)pyrene-induced autophagy in retinal pigment epithelial cells.

Abstract

This study aims to investigate the role of Resveratrol (RES) and quercetin (QR) treatments against Benzo(a)pyrene (B(a)p)-induced autophagy in retinal pigment epithelial cells. The IC50 doses of B(a)p, RES and QR in retinal pigment epithelial cells were determined by MTT assay and the relevant agents were administered singly or in combinations to ARPE-19 cells for 24h. Occurrence of autophagy in the cells was verified by detection of autophagosomes using fluorescence microscope. Also, the mRNA expression levels of LC3 and Beclin 1 genes were analyzed by RT-PCR to collect further data on autophagy. Caspase-3 and IL-1β levels in lysed cells were analyzed by ELISA. Autophagosomes were detected in B(a)p-treated ARPE-19 cell lines, as well as a 1.787-fold increase in LC3 mRNA expression levels. No autophagosome occurred in RES and QR treatments, and a significant decrease in their percentage amounts were observed in B(a)p + RES and B(a)p + QR. The mRNA expression levels of LC3 and Beclin 1 also supported these findings. B(a)p had no effect on Caspase-3 levels in ARPE-19 cells, but combined with RES and QR, it increased Caspase-3 levels significantly.IL-1β levels were higher in B(a)p, B(a)p + QR, B(a)p + RES, RES and QR than control group. This rise in IL-1β levels was correlated with suppression of mRNA expression levels of Beclin 1. B(a)p exposure caused autophagy in ARPE-19 cells, but did not induce apoptosis. RES and QR treatments prevented B(a)p-induced autophagy. Therefore, RES and QR treatments showed protective effect against potential degenerative diseases caused by chronic exposure to B(a)p.