Evaluation of Picralima nitida hypoglycemic activity, toxicity and analytical standards

WHO Expert Committee on diabetes encourages further investigation into traditional methods of treatment and also emphasizes the need to ensure safety and quality control of ingredients used. Picralima nitida Stapf (Apocynaceae) seeds used in the treatment of hepatitis, worms, sleeping sickness and malaria in Ihiala town, Anambra state of Nigeria, have been shown to have hypoglycemic effects [1]. Hypoglycemic activity was confirmed, recorded as an index of blood glucose with a glucometer in normal and intraperitonially induced alloxan diabetic albino rats with glibenclamide as reference standard and normal saline as control. Toxicity studies included the evaluation of acute and sub-acute (15 days) tests. The animals were observed for toxic signs and symptoms, body weight changes recorded and LD₅₀ calculated. Analytical standards were moisture content, ash and extractive values for quality assurance. 100mg/kg, 300mg/kg and 900mg/kg of the extracts to normal rats resulted in significant (P<0.01) lowering of fasting blood sugar after eight hours. Extract maintained hypoglycemic action throughout the 24hours of study indicating a long duration of action. In normal rats, pulp extract (100mg/kg) produced a maximum percentage reduction of 38.35%, rind extract (900mg/kg) 46.19% and seed extract (100mg/kg) 36.81%. Alloxan induced rats were pulp 85.85% (300mg/kg), seed 83.26% (300mg/kg) and rind 80.25% (900mg/kg) respectively. Order of activity recorded as pulp > seed > rind. Acute toxicities (LD₅₀) of pulp, seed and rind were 7071.06mg/kg, 948.68mg/kg and 1364.91mg/kg respectively.

Reference: 1. Aguwa, C.N. et al. (2001), J. Natural Remed. 1: 135–139.