In vitro Hypoglycemic and Antioxidant Activities of Litsea cubeba (Lour.) Pers. fruits, Traditionally used to Cure Diabetes in Darjeeling Hills (India)

Introduction: Fruits of Litsea cubeba (Lour.) Pers. has been reported to be used traditionally in the treatment of diabetes in Darjeeling Himalayan region of India; though the hypoglycemic potential of the fruit has not been assessed till now, and the active constituents are yet to be discovered. Therefore, there is a necessity for the appraisal and characterization of the hypoglycemic properties of the fruits. Methods: Fresh fruits were collected and sequentially extracted with solvents of gradient polarity. In vitro antidiabetic activity was performed by α-amylase and α-glucosidase inhibitory assays. Free radical scavenging activity was performed by DPPH, ABTS, TPTZ (FRAP assay), NO and OH radical scavenging assays. To identify the bioactive components, GC-MS analysis was also performed. Result: Phytochemical screening of secondary metabolites in different solvent extracts showed the presence of phenols, flavonoids, alkaloids, cardiac glycosides, tannins, saponins, and anthocyanins. Methanolic extract exhibited highest antidiabetic potential with IC50 values of 514.9 μg/ml and 1435.7 μg/ml in α-amylase and α-glucosidase inhibition assay respectively followed by ethanol extract. Significant free radical scavenging activities were also found in the alcohol extracts. GC-MS analysis revealed the presence of principle compounds like oleic acid, morin, apigenin etc. which might be responsible for hypoglycemic activity. Conclusion: Here we report the appraisal of traditional usage of L. cubeba (Lour.) Pers. fruits based on in vitro antidiabetic and antioxidant assays along with GC-MS characterization of potent molecules. Our study confirms the traditional knowledge of the people of Darjeeling Hills regarding the use of the fruit of this plant in curing diabetes.