Phytochemical and Pharmacological Basis for the Ethnomedicinal Use of Root Extracts from Anogeissus leiocarpus as an Antidiabetic in Eastern Nigeria

Purpose: To obtain and validate evidence for or against the continued traditional use of A. leiocarpus root extract as an antidiabetic.

Methods: Aqueous methanol, ethanol, trona-treated ethanol extracts of the plant whole root, were screened for antidiabetic activity using alloxan-induced diabetic rats at three different oral dose levels (100-500 mg kg-1day-1) against standards. Phytochemical and acute toxicity tests were also carried out on the extracts.

Results: Tannins, saponins, carbohydrates occurred in very high amounts while steroids, terpenoids alkaloids, flavonoids and resins were moderate. The extracts exhibited a dose-dependent potent and statistically significant (p<0.05, ANOVA) antidiabetic activities up to the dose of 200 mg kg-1 compared to the untreated group with a glucose reduction values of 52.69±5.99% and 66.61±5.79%, respectively, at 12 and 24 h compared to 24.39±1.54% and 38.79±4.06% recorded for the positive control. Above 200 mg/kg dose, the extract did not produce additional activity. The calculated LD50 values of all the extracts were above 10,000 mg kg-1 in mice.

Conclusion: This study validates the traditional use of root extracts of A. leiocarpus as a potent, cheap and alternative antidiabetic remedy.