Protective effect of makrut lime leaf (Citrus hystrix) in HepG2 cells: Implications for oxidative stress

摘要

The objective of the present study was to examine fresh and processed (boiled or fried) leaves of Citrus hystrix in terms of total phenolic content, malondialdehyde content, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl radicals scavenging activities, the baseline levels of glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase in HepG2 cells. The results indicated that fresh C. hystrix leaves possess the higher hydroxyl radical scavenging activity (22 mg/ml). Pretreatment of C. hystrix leaf extracts decreases GST, SOD, or catalase activity induced by H_2O_2, rendering them unsuitable for cancer chemoprevention, superoxide scavenging, or hydrogen peroxide detoxification. A linear relation between the total phenolic content and DPPH or hydroxyl radical activities of the extract was not observed. This study showed that C. hystrix leaf may exert its antioxidative stress by scavenging hydroxyl radicals and inhibiting lipid peroxidation that causes oxidative damage to HepG2 cells.