Diabetes affects 422 million people in the world and caused 1.5 million deaths. The Psydrax genus has been reported to have various pharmacological activities. Based on ethno-pharmacological information, Psydrax horizontalis Schum. & Thonn. (Bridson) locally known as “Akata-ike” in Nsukka is used in the management of diabetes in South-eastern Nigeria. However, as at the time of this research, no previous work has been done to investigate the anti-diabetic activity of leaves of P.horizontalis. The aim of this study is to investigate the phytochemical constituents in the leaves of P. horizontalis and scientifically validate the anti-diabetic activity in the traditional management of diabetes in Nsukka, South-eastern Nigeria. The methanol extract (ME) obtained by maceration was analyzed for phytochemicals present using standard procedures. Alloxan monohydrate at 150 mg/Kg was used to induce diabetes. The acute toxicity test was done using Lorke’s method. The normoglycemic and alloxan-induced groups of twenty animals each were treated orally with 100, 200 and 400 mg/Kg of ME; 5 mg/Kg of glibenclamide and 2 mL/kg of 3% Tween 80 as the controls. The fasting blood glucose concentrations were monitored at 0, 1, 3 and 6 h, as well as 1st, 3rd and 5th day. Phytochemical screening revealed the presence of glycosides, alkaloids, tannins, flavonoids, steroids, saponins and terpenoids. The median lethal dose was above 5000 mg/kg. In the alloxan-induced diabetic rats, significant activity at p<0.01 on the 6th hour was recorded at doses 100, 200 and 400 mg/Kg ME on day 3. Our findings suggest that ME of Psydrax horizontalis possesses significant anti-diabetic activity and validates its trado-medical use in the management of diabetes. Isolation of bioactive compounds responsible for the anti-diabetic activity is recommended.

Keywords: Psydrax horizontalis methanol extract, Anti-diabetic activity, phytochemical analysis