ABSTRACT
Objective: This study sought to determine the antioxidant activities of African birch leaf, to assess its interaction with key enzymes relevant to type 2 diabetes [aamylase and alpha-glucosidase] and to evaluate its effect on acarbose in vitro
Methods: One milligram per milliliter of aqueous extract of African birch and acarbose were separately prepared. At the same time, both the African extract and acarbose solution [50:50 v/v] were thoroughly mixed until homogeneity was attained. The phenolic phytoconstituents and antioxidant properties of African birch leaf were subsequently determined. Finally, the effects of African birch extract, acarbose solution and a mixture of acarbose and African birch extract on alpha-amylase and alpha-glucosidase activities were assessed in vitro
Results: The results showed that African birch extract demonstrated a remarkable antioxidant effect, as exemplified by its radical scavenging abilities, Fe2þ chelating ability and prevention of lipid peroxidation. Acarbose had significantly [p < 0.05] higher alpha-amylase [IC[50] = 11.77 mg/ml] and alpha-glucosidase [IC[50] = 9.05 mg/ml] activities compared to African birch extract [alpha-amylase [IC[50] = 242.17 mg/ml]; aglucosidase [IC[50] = 196.35 mg/ml]]. However, the combination of acarbose and African birch extract showed an additive effect on alpha-amylase inhibition, while a resultant synergistic action was observed against alpha-glucosidase inhibition