Antidiabetic potential of methanol bulb extracts of bulbinenatalensisand leaf extract of eucomisautumnalis: carbohydrate metabolizing enzymes and pancreatic lipase inhibition:- Nwabuisi, Vincent C

ABSTRACT

 Diabetes mellitus is a metabolic disorder of glucose metabolism. The management of blood glucose level is the hallmark in the treatment ofthis disease. This may be achieved through the use of oral hypoglycemic drugs such as sulfonylureas, metformin, insulin secretagogues, and alpha amylase, alpha glucosidase and pancreatic lipase inhibitors. The purpose ofthe present study was to investigate the inliibitory effect of methanol bulb extract of Bulbine natalensis and leaf extract of Eucomis autumnalis on the activities of alpha amylase, alpha glucosidase and pancreatic lipase. This was performed using porcine pancreatic alpha amylase from Aspergillus oryzae, alpha glucosidase from Saccharomyces cerevisiae and pancreatic lipase. Highest concentration of methanol bulb extract of B. natalensis and leaf extract of E. autumnalis possesses the highest percentage inliibitory activity against amylase (B.N Img/ml (70.15±2.14%), E.A Img/ml (71.19±0.85%), alpha glucosidase (B.N 0.2mg/ml (73.24±1.05%), E.A 0.2mg/ml (62.1l±0.18%) and pancreatic lipase (B.N Img/ml (49.69±2.37%), E.A Img/ml (38.44±2.86%) comparable to the standard drugs, acarbose (80.34±0.18%) and orlistat (60.22±1.68%). Kinetic analysis revealed that the methanol extract of both plants inhibited the alpha amylase uncompetitively but displayed mixed noncompetitive mode of inhibition towards alpha glucosidase and pancreatic lipase. It can be concluded that methanol extracts of B. natalensis bulb and E. autumnalis leaves exhibited a potent inhibitory activity on the three enzymes studied.