In Vitro α-Amylase and α-Glucosidase Inhibitory Potential of Green Banana Powder Extracts

This study investigated the proximate composition and inhibitory potential of hot water and ethanolic extracts of the pulp, peel and whole fruit of green banana (Musa sapientum) on α-amylase and α-glucosidase. Bioactive compounds were identified using GC-MS analysis. In addition, the cytotoxic effect on human gingival fibroblast (hGF) was evaluated using the sulphorhodamine B (SRB) assay. The results showed that the peel of green banana had the highest amount of ash (10.05%), fat (2.83%), protein (3.64%) and total dietary fibre (36.62%). The carbohydrate content of the whole fruit (81.79%) and pulp (81.50%) was higher than that of the peel (71.90%). The moisture content of the pulp (13.08%) was higher than that of the peel (11.58%) and whole fruit (11.30%). The ethanolic green banana peel extract showed a good inhibitory effect of α-amylase and α-glucosidase with the concentration necessary for 50% inhibition (IC₅₀) of 0.512 and 0.100 mg·mL^-1, respectively. The α-glucosidase inhibitory effect of the ethanolic green banana peel extract and the hot water green banana peel extract was not significantly different from that of acarbose (IC₅₀ 0.108 mg·mL^-1). GC-MS analysis of the ethanolic green banana peel extract revealed fatty acids and fatty acid ester (9-octadecenamide (Z), octadecanamide and other compounds). The ethanolic peel extract exhibits a significant noncytotoxicity effect on hGF cells at concentrations ranging from 0.0001 to 1.0 mg·mL^-1.