BIOACTIVITIES OF THE ETHYL ACETATE EXTRACT OF RHODOCOCCUS QINGSHENGII STRAIN BJC15-A38 AN ENDOPHYTE OF AZADIRACHTA INDICA A. JUSS

Abstract

Objective: This study evaluated the antidiabetic activities of the ethyl acetate-methanol (4:1) extract (EA) of Rhodococcus qingshengii strain BJC15-A38 supernatant.Methods: In vitro alpha-amylase and alpha-glucosidase inhibitory assays, were used to determine the antidiabetic activity of EA (100, 250, 500, 750 and 1000 μg/ml). Also, the total phenol content of the extract was determined, followed by understanding the mode of α-amylase inhibition.Results: The crude extract from Azadirachta indica A. Juss. endophytic actinomycete Rhodococcus qingshengii strain BJC15-A38 was found to have significant inhibition against α-amylase (IC50 = 65.93 µg/ml) and α-glucosidase (IC50 = 929.56 µg/ml). The total phenol content of the crude was found to be 97.25±6.47 and 15.40±0.43 mg/g of the extract in terms of catechol and gallic acid equivalents respectively. Purification of the extract was carried out using silica gel column chromatography. Kinetic analysis revealed the mixed competitive with mixed competitive of inhibition towards α-amylase.Conclusion: The findings suggest that the extract of Rhodococcus qingshengii strain BJC15-A38 possesses antidiabetic effects.