Polyphenol-Rich Extract of Hibiscus Sabdariffa Linn. Prevents Oxidative Damage of Aorta in Diabetic Rats

Abstract

Chronic hyperglycemia in diabetic condition induce free radicals production and oxidative stress, which are associated with numerous diabetic complications. Hibiscus sabdariffa Linn. or roselle is a popular traditional herb used to treat various diseases. Previous studies have shown roselle to have high antioxidant properties. This study was aimed to investigate the supplementation effects of Hibiscus sabdariffa polyphenol-rich extract (HPE) of calyx on the biochemical changes towards aorta of Streptozotocin (STZ)-induced diabetic rats. Twenty-four male Sprague Dawley rats weighing 250-300 g were randomly divided into three groups (n=8) namely the control group (NDM), diabetes mellitus group (DM) and diabetes mellitus plus HPE group (DM + HPE). Diabetes was induced using STZ at 60 mg/kg through a single intraperitoneal injection. HPE was administered through oral gavage at 100 mg/kg daily for 28 consecutive days. At the end of the experiment period, the rats were sacrificed and thoracic aorta was isolated and prepared for homogenate. Results showed that the glucose level in DM + HPE was significantly (p<0.05) lower compared with DM group, indicating its potential as antidiabetic. Conversely, the level of glutathione (GSH), catalase (CAT), HDL-C and HDL-C/LDL-C ratio as well as the enzyme activity of superoxide dismutase (SOD) in DM + HPE group were significantly higher (p<0.05) compared with DM group. The level of malondialdehyde (MDA), protein carbonyl (PC), triglyceride, total cholesterol, LDL-C and total cholesterol/HDL-C ratio in DM + HPE group were significantly lower (p<0.05) in comparison with DM group. In conclusion, this study suggests that HPE may give positive effect as antihyperlipidemic agent while protecting thoracic aorta in STZ-induced diabetic rats from oxidative damage.