Inhibitory activity of leaf extract on alpha-amylase and alpha-glucosidase: and approach.

Objectives: In food ingestion, alpha-glucosidase (α-glucosidase) and alpha-amylase (α-amylase) are enzymes that are responsible to convert a carbohydrate into glucose. Inhibition of both enzyme activities can prolong absorption of glucose in intestine and reduce post-prandial increase of blood glucose concentration, thus, it is beneficial for type-2 diabetes treatment. Traditionally, () has been used to manage diabetes, but the scientific proof of this claim remains scarce. Therefore, the objective of this study to examine the anti-diabetic potential of leaf extract through inhibition of α-amylase and α-glucosidase.

Methods: leaf extract was obtained through extraction process using ethanol and the chemical compounds in the extract were analyzed by liquid chromatography-mass spectra (LC-MS). The inhibitory activity of on α-glucosidase and α-amylase was evaluated by using docking server, whereas enzymatic assays were using nitrophenyl-α-d-glucopyranoside (α-NPG) and starch as substrates. The data were presented as mean ± SD and the IC value was calculated using SPSS.

Results: leaf extract showed inhibitory activity on α-glucosidase and α-amylase with the IC value was 43.73 and 83.73 μg/mL, respectively, meanwhile, acarbose as standard has IC value at 1.14 and 0.08 μg/mL. Molecular docking study indicated β-sitosterol and stigmasterol from extract have a huge inhibitory activity both on α-amylase and α-glucosidase based on inhibition constant (Ki) value.

Conclusions: Ethanolic extract of showed inhibition activity on α-glucosidase stronger than on α-amylase as antidiabetic.