Abstract
Yichun Blue Honeysuckle (YBHS) is reported to have a broad range of health benefits including protection against a number of chronic diseases. The objective of our study was to determine whether YBHS exhibits antioxidant activity, and if so, determine how it provides protection against oxidative stress. Eight-week old mice (25 male and 25 female) were randomized into five groups (n = 10 per group). YBHS extract (at 6.25%, 12.5%, or 25%) was administrated via intra-gastric tube to mice at 0.1 mL/10 g body weight once daily for 7 days. On the 8th day, all animals except for the controls received 250 mg/kg of CCl&sub4; through an intra-gastric tube. The animals were sacrificed 6 h after CCl&sub4; administration. Liver samples obtained from these mice were analyzed for the levels of Thiobarbituric Acid Reactive Substances (TBARS) and glutathione and the activities of Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione Peroxidase (GPx), using biochemical assay kits. Our results showed that YBHS indeed reduces lipid peroxidation, suggesting that YBHS decreases the Reactive Oxygen Species (ROS) levels. We also found that YBHS activated the endogenous antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase and its co-enzyme glutathione reductase. In addition, we showed that glutathione levels were increased by YBHS treatment. Furthermore, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay revealed that YBHS has potent free radical scavenging activity. Based on the results from our study, we conclude that YBHS scavenges ROS by enhancing the activity of the endogenous antioxidant defense system activity for conferring liver protective effects.