Metabolite profiling and antidiabetic attributes of ultrasonicated leaf extracts of Conocarpus lancifolius

Objective: To profile the secondary metabolites and to evaluate the antidiabetic potential of hydroethanolic leaf extracts of Conocarpus lancifolius. Methods: The various hydroethanolic extracts of Conocarpus lancifolius leaf were prepared by ultrasonication assisted freeze- drying. Total phenolic contents, flavonoid contents, antioxidant activity, alpha-glucosidase and alpha-amylase inhibitions of leaf extracts were determined. The metabolite profiling was accomplished by UHPLC-Q-TOF-MS/MS analysis. The antidiabetic assessment of the most potent extract was carried out by measuring the hypoglycemic and hypolipidemic effect in the high fat diet-fed diabetic albino mice. The blood glucose level, haemoglobin, total cholesterol, high-density lipoproteins (HDL) and low-density lipoproteins (LDL) were determined. Results: The 60% ethanolic extract exhibited the highest phenolic and flavonoid contents of (349.39 +/- 2.13) mg GAE/g dry extract and (116.95 +/- 2.34) mg RE/g dry extracts, respectively, and the highest DPPH scavenging activity with an IC50 value of (32.87 +/- 1.11) mu g/ mL. The IC50 values for alpha-glucosidase and alpha-amylase inhibitions were (38.64 +/- 0.93) mu g/mL and (44.80 +/- 1.57) mu g/mL, respectively. UHPLC-Q-TOF-MS/MS analysis confirmed the presence of gallic acid, ellagic acid, corilagin, kaempherol-3-O-rutinoside, caffeic acid derivative, isorhamnetin and galloyl derivatives in the 60% ethanolic extract. Plant extract at a dose of 450 mg/kg body weight reduced blood glucose level, total cholesterol, LDL and HDL, and increased haemoglobin in alloxan-induced diabetic mice, Conclusions: Conocarpus lancifolius leaves are proved as a good source of biologically functional metabolites and possess antidiabetic activity which may be further explored to treat diabetes.