In vitro and In vivo experimental study of Aqueous and Ethanolic Extracts of Selected Medicinal Plants for Free Radical Scavenging and Hypoglycemic Activity

Abstract

Background Diabetes mellitus (DM) is a condition affecting metabolism characterized by a high level of glucose in the bloodstream, either due to failure of the Islets of Langerhans of the pancreatic beta cell to produce enough insulin (Type I diabetes) or when there is insulin resistance in body cells (Type II diabetes). Oxidative stress caused by the free radicals produced during the oxidation of glucose, protein glycation by non-enzymatic pathway, and the gradual breakdown of glycated protein by oxidation, is a significant factor in the pathogenesis of diabetic complications. This study was designed for the qualitative and quantitative phytoconstituent determination, free radical lowering activity, and in-vitro and in-vivo glucose-lowering effect of selected parts of five medicinal plants of Nepal using two solvents, i.e., methanol and water of different polarity. The selected plant species are Artocarpus heterophyllus Lam., Dendrocalamus hamiltoni, Fagopyrum megacarpumH. Hara., Somallanthus sonchifolius (poepp)H. Rob., Urtica parvifloraRoxb. Results The result from the study revealed that among the tested samples, A. heterophyllus, F. megacarpum, and S. sonchifoliushave higher Total Phenolic Content (TPC) and Total Flavonoid Content (TFC), conclusively showing significant free radical scavenging properties. The in-vitrostudy for the hypoglycemic activity of plant samples showed that ethanolic and water extracts of S. sonchifolius have potent alpha-amylase inhibitory effect showing the half-maximal inhibitory concentration as 0.136 mg/ml and 0.168 mg/ml respectively. In vivo hypoglycemic activity study of S. sonchifolius depicted the blood glucose lowering effect in a dose-dependent manner having a comparative release profile to standard Metformin. S. sonchifolius with the dose of 500 mg/kg showed the optimal decrement in blood glucose level in normal mice by 17.99%, while the same dose of S. sonchifolius diminished the glucose level in blood by 15.74% in glucose-loaded hyperglycemic mice in 120 minutes. Conclusion The results from the study outlined that the positive qualitative and quantitative phytoconstituent determination and the ability to eliminate free radicals align with the in vitro and in vivohypoglycemic activity test.