Extraction, purification, content analysis and hypoglycemic effect of mulberry marc anthocyanin

Background: Mulberry marc (MM) which as a wasted residue contains many available resources and one of the valuable nutrients is anthocyanin. In this study, the extraction, purification, content analysis, and hypoglycemic effect of anthocyanin from MM were studied. Materials and Methods: The total anthocyanin and cyanidin-3-O-glucoside of the purified anthocyanin of mulberry marc (MMA) were determined using pH differential method and high-performance liquid chromatography. The hypoglycemic effects were studied by streptozotocin and high-fat diet-induced type 2 diabetic rats. The rats were given MMA for 4 weeks and at the end of experiment; the blood was collected for determination serum indexes; the tissue of liver, kidney, pancreas, and spleen was removed for weighting and observing pathological changes. Results: The content of total anthocyanin and cyanidin-3-O-glucoside of MMA was 39.72% and 18.63%, respectively. The fasting blood glucose of rats in the MMA treatment groups was decreased. The lipid metabolites (triglycerides and total cholesterol) and malondialdehyde were decreased and superoxide dismutase was increased of type 2 diabetes rats after MMA treated; the pathological changes were alleviated in various degrees. Conclusion: The content of anthocyanin in mulberry marc is higher than mulberry juice, and the MMA has a good hypoglycemic effect.