A simple and rapid method for the preparation of pure delphinidin-3-O-sambubioside from Roselle and its antioxidant and hypoglycemic activity

The present study aimed to establish a simple and rapid method for the preparation of pure delphinidin-3-O-sambubioside (D3S) from Roselle and then investigate its antioxidant and hypoglycemic activity. According to our results, 60 mg of D3S with the purity of 96.1% was finally isolated from 500 g of Roselle by combination of macroporous resins and C18 Sep-Pak cartridge techniques. Further studies revealed that D3S could significantly attenuate H2O2-induced oxidative stress by inhibiting H2O2-induced ROS overproduction, GSH depletion, mitochondrial membrane potential decrease and mitochondrial membrane peroxidation. In addition, we also found that D3S at the concentrations of 20 μg/mL and 40 μg/mL are able to promote glucose consumption and increase glycogen content in human liver HepG2 cells. These results indicated that D3S possesses potent antioxidant activity and hypoglycemic activity. Overall, our studies suggest that D3S could be a valuable material for designing functional foods against oxidative stress-related diseases and diabetes.