Inhibitory activity against α-amylase and glucose adsorption capacity of the aqueous decoctate of Chamaecrista nigricans (Vahl) Greene

Abstract

Diabetes management involves preventing its risk factors. Inhibition of glucosidases and adsorption of excess free glucose are approaches to the prevention of postprandial hyperglycemia. The objective of the present study was to evaluate the antioxidant activity, glucose adsorption capacity, and α-amylase inhibitory activity in vitro of the aqueous extract of Chamaecrista nigricans. Determination of phenolic compounds content was performed using the Folin-Ciocalteu reagent and the aluminum chloride method was used for total flavonoids one. The glucose oxidase peroxidase kit was used to determine the adsorption capacity of glucose while the 3,5-dinitrosalicylic acid method was used to assess the inhibitory activity against α-amylase. Levels ranging from 33.87 ± 2.48 mg GAE/100 mg dry extract (DE) for total phenolic compounds and 1.98 ± 0.51 mg QE/100 mg DE for total flavonoids were observed. The adsorption capacity was correlated with the glucose concentration of the solution (r = 0.95) and was up to 36.61 μmol/g DE for a glucose concentration of 30 mM. The extract from the November collection was most active against α-amylase with IC50 = 0.17 mg DE/mL. Observations confirm the traditional use of this species as a preventive measure in recipes for the treatment of diabetes. This data provides a basis for future pharmaceutical prospecting.

Keywords

• Diabetes, phenolic compounds, adsorption, α-amylase, Chamaecrista nigricans.