The LD50 of the interface portion of ethyl acetate and n-hexane extract from antidiabetic Anogeissus leiocarpus stem bark was greater than 2000mg/kg.bd.wt., with a wide range of safety value. In addition it caused no death 24hours and thereafter and had no effects on pregnancy, gestation, parturition, reproductive performance with no teratogenic effects on pups of Wistar-rats. This led to investigation of the effects of the extract on ovarian functions of adult female Wistar-rats but strategically optimized to obtain appropriate therapeutic hypoglycaemic-dose.
On day 0, 20 adult-female Wistar-rats weighing between 155 and 235 g were separated, at random, into 4 cages (A-D) of 5 rats each, unadministered A (normal control), administered B (5 mg/kg.bd.wt.), C (10 mg/kg.bd.wt.) and D (20 mg/kg.bd.wt.); to each group, an adult male Wistar-rat was added. They were on feeds (superstarter chow) and water ad libitum. Groups B and C were reduced to 4 rats each due to exclusion criteria. On day0, baseline parameters, were collected from all rats. Thereafter, from day0 to day12, each female rat received the optimized dose of the interface and samples were collected for random blood glucose (RBG), vaginal cytology and assay for oestrogen and progesterone. Blood samples were collected after day 12 for clinical biochemistry analyses.
At day 1, mean RBG values were significantly (P<0.05) higher (129.5±57.7 mg/dl) in group B than values of groups A,C&D which were 99.0±13.2, 101.8±3.2 and 102.0±11.9 mg/dl, respectively.
From days 2 to 12, the mean RBG values significantly (P<0.05) decreased to 98.3±15.6 in group B. The mean bodyweights of group B decreased from day 2 to14. In group D, mean values of body weights equally decreased on day14, but after increase on day7
Conclusion: Daily administration of 5 mg/kg/bd.wt. of the extract (interface) of A. leiocarpus stem-bark is therapeutically hypoglycaemic as it reduced RBG significantly (P<0.05) up to day12. The clinical application of lower doses is suggested to maintain normoglycaemia for a while after “crashing” down the hyperglycaemia of DM with a much higher dose. The shelf-life of extract (interface) of A. leiocarpus stem bark is greater than 17 months, when stored at room temperature