Ameliorative potential of Operculina turpethum against streptozotocin-induced diabetes in rats: biochemical and histopathological studies

The study aimed to investigate the acute toxicity, antidiabetic potential (in-vitro and in-vivo) of the Operculina turpethum (L.) Silva Manso at fraction level. The plant was fractionated into different fractions, i.e., flavonoid fraction (OTFF), tannin fraction (OTTF), saponin fraction (OTSF). In-vitro alpha-amylase inhibition assay revealed that OTFF was found to be more potent than standard Acarbose. The plant fractions were evaluated by MTT assay at different concentrations ranging from 100 to 1000 mu g/ml. All the fractions were further evaluated for their safety profile, and the biochemical, hematology and histopathology result exhibits that the OTFF fraction produces mild toxicity at organ level at a concentration of 2000 mg/kg in albino mice. The in-vivo antidiabetic study was carried out on Sprague-Dawley rats using high-fat diet (HFD) feeding streptozotocin (STZ) diabetic model, and the biochemical, histopathology research findings represent that OTFF at a concentration of 500 mg/kg, p.o. was found to be highly significant among all the fractions and found to be more potent than the standard Acarbose. LC-MS characterization of the bioactive fraction OTFF showed the presence of rutin with m/z 610.52 in 50.50% and Apigenin 7-O-6'' acetyl-glucoside with m/z 475.42 in 24.10%; from molecular docking study, it is predicted that the fraction primarily acts as an alpha-amylase inhibitor and PPAR gamma agonist. In conclusion, the plant's OTFF fraction acts as a potential therapeutic agent for Type II diabetes mellitus.