Phytochemical screening and hypoglycaemic activity of Lasianthera africana Beauv. (Aquifoliales: Stemonuraceae) leaf extract on diabetic rats

Lasianthera africana Beauv. (Aquifoliales: Stemonuraceae) is a native leafy vegetable used in traditional medicine for control and management of problems associated with complications of diabetes mellitus. The study was aimed to evaluate the phytochemical and hypoglycaemic properties for effective control of diabetes. Phytochemical analyses were conducted using standard methods. The rats were divided into four groups of six rats each of which Group 1 received distilled water (1 mL); Group 2 received aqueous extract (doses of 500 mg/kg, 1,000 mg/kg and 1,500 mg/kg); Group 3 received ethanolic extract (doses of 500 mg/kg, 1,000 mg/kg and 1,500 mg/kg); Group 4 received synthetic drug (dose of 10 mg/kg) for seven consecutive days. The phytochemical showed the presence of alkaloids, glycosides, saponins, tannins, phlobatannins, flavonoid and terpenes. Hypoglycaemic studies of 1,000 mg/kg body weight of the ethanolic extract administered intraperitoneally significantly reduced the blood sugar level (p < 0.05) from 239.71 +/- 4.26 mg/dL (fasting hour) to 51.42 +/- 2.19 mg/dL within 4 h post administration. The aqueous extract also significantly lowered the blood sugar from 230.29 +/- 5.54 mg/dL to 88.57 +/- 4.88 mg/dL within 3 h. The percentage decrease in blood sugar level of ethanolic extract at 1,000 mg/kg was more significant (p < 0.05) than glibenclamide. Acute toxicity showed that L. africana was non toxic because 5,000 mg extract/kg body weight did not produce visible toxic sign or mortality within 24 h. The study has shown that L. africana leaf possesses some useful medicinal potential for therapeutic purposes and that the hypoglycaemic activity of the leaf could be utilized by diabetic patients as supplement. This may contribute greatly to the management of their health conditions. The evaluation of hypoglycaemic activity in this study validates the claims that the plant leaf is useful in controlling and management of diabetes mellitus.