Abstract: The present study aimed to investigate the protective effect of ethanol extract from sesame sauce (SSE) on 2,2’-azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative stress in pig renal epithelial LLC-PK1 cells. LLC-PK1 cells were incubated with different concentrations of SSE (10–100 μg/mL) for 24 h, and then exposed to AAPH (1 mmol/L) for 4 h. Cell viability was determined by methyl thiazolyl tetrazolium assay. The levels of malondialdehyde (MDA) and reactive oxygen species (ROS) were determined by thiobarbituric acid reactive substances assay (TBARS) and DCFHDA assay, respectively. The activities of cellular antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), γ-glutamylcysteine synthetase (γ-GCS) and glutathione (GSH) were measured by colorimetric assay. In addition, the mRNA levels of these antioxidant enzymes (SOD, GSH-Px and CAT) were determined by quantitative real-time polymerase chain reaction assay. SSE was able to increase cell viability, and decrease ROS and MDA level, as well as increase the activities and mRNA expression of antioxidant enzymes (CAT、SOD and GSH-Px) compared with the control group. SSE treatment also increased the activity of γ-GCS and GSH levels in AAPH-treated LLC-PK1 cells. These results suggested that SSE showed a protective effect against AAPH-induced oxidative stress in LLC-PK1 cells through inhibiting lipid peroxidation, deceasing ROS levels, and increasing the activity of the endogenous antioxidant system.

Key words: sesame sauce, oxidative damage, antioxidant, LLC-PK1 cells