Toxicological and Antidiabetic Investigation of <i>Albizia zygia</i> (D.C.) Macbr

Background of the study The global increase in the number of diabetes cases reported yearly is alarming, especially in developing countries. The study assessed the toxicological and antidiabetic effects of the leaf extract of Albizia zygia , examined the antihyperglycaemic activity of the partitioned fractions and identified the phytocompounds in the most active fraction. Methodology The acute and sub-chronic toxicity tests of extract of A. zygia were carried out and followed by histopathological, haematological and biochemical analysis of vital organs of the experimental animals. Antihyperglycaemic and streptozotocin-induced antidiabetic studies of the extract were carried out and followed by antihyperglycaemic activity of the partitioned fractions. The most active fraction was subjected to spectroscopic analysis using GC-MS to identify its constituents. Results A . zygia extract elicited no signs of acute toxicity in the animals up to the dose of 5000 mg/kg. In the heamatological and biochemical studies, the extract significantly improved the recruitment of white blood cells (WBC) at 1000 mg/kg extract with 11.4 (10 3 /μL) WBC compared to control group with 5.2 (10 3 /μL) WBC. The extract also demonstrated a pronounced biphasic effect on the expression and activity of aspartate transaminase enzyme (AST) at 250 and 500 mg/kg. Additionally, the A. zygia extract elicited a 60% reduction in the blood glucose level after four hours in the antihyperglycaemic studies and an 85% reduction in the streptozotocin-induced antidiabetic studies. Furthermore, the n -hexane fraction gave the highest percentage blood glucose level reduction among the partitioned fractions, while 6-(4-ethoxyphenyl)-3-methyl-4-oxo-4,5,6,7-tetrahydro-isopropyl-1H-Indole-2-carboxylic acid was identified as the most abundant compound in the non-polar fraction. Conclusion The results of the antidiabetic activity of Albizia zygia leaf extract confirmed its potency and safety and therefore justified its ethnomedicinal use in the management of type II diabetes.