Anti-Hyperglycaemic And Antioxidant Studies On Azanza Garckeana Aqueous Leaf Extract

Abstract

Azanza garckeana is an African medicinal plant with various medicinal values and it is traditionally used for the management and treatment of diabetes, edema, liver problems and among others. Persistent hyperglycaemia is a forerunner of various complications (damage and failure of different organs such as heart, kidney, eyes, nerve etc). Current drugs used for its control have various side effects hence the need for safer alternatives. Therefore, this research investigated anti-hyperglycaemic and antioxidative abilities of Azanza garckeana aqueous leaf extracts. The study was conducted to investigate the in vitro anti-hyperglycaemic activity using α-amylase and glucosidase inhibition assay while DPPH and FRAP were used to evaluate the antioxidant potential of the aqueous extract of the leaves. Acarbose was used as the standard drug for the hyperglycaemic assay while vitamin C was used as standard for the antioxidant assay. In vivo blood glucose lowering activity of Azanza garckeana aqueous leaf extract (AGALE) in type II model diabetic rats was also investigated. For the in vitro studies, the extract exhibited alpha-amylase inhibitory activity of 2.2±0.02 mg/mL and alpha-glucosidase inhibitory of 2.3±0.03 mg/mL showing a higher IC₅₀ value than the control drug acarbose which had IC₅₀ values of 1.3±0.08 and 2.0±0.03 mg/mL for alpha amylase and alpha glucosidase respectively. The DPPH scavenging activity was found to have IC₅₀ values of 1.4±0.07 mg/mL and 3.2±0.08 mg/mL for FRAP both higher than the control. For the in vivo studies, twenty rats (20) were grouped into four (4), each group comprising of five (5) rats each. Diabetes mellitus was induced by intraperitoneal injection of STZ (60 mg/kg). Group A was normal control, Group B Diabetic control, Group C  Diabetic rats given 150 mg/kg b.w. AGALE and Group D Diabetic rats given 100 mg/kg b.w. AGALE. Blood glucose levels were recorded weekly AGALE exerted potent blood glucose lowering activity in STZ-induced diabetic rats, it was observed that the diabetic control group experienced a steady elevation in blood glucose levels. Conversely, the oral administration of AGALE extract exhibited a noteworthy decline in blood glucose levels. The dosage of 150 mg/kg resulted in a considerable reduction in blood glucose levels starting from the second week of the experiment. The present study demonstrated that AGALE exerted potent anti-hyperglycaemic activity by lowering blood glucose levels, exhibiting appreciable inhibition against alpha amylase and glucosidase as well as having antioxidant activity hence its use in the management of diabetes mellitus may be justified.