Acute and Sub-acute Toxicity Evaluation of Commelina benghalensis (Commelinacaea) and Newbouldia laevis (Bignoniaceae) Ethanol Leaf Extracts in Wistar Rats

Abstract

Acute and Sub-acute Toxicity Evaluation of Commelina benghalensis (Commelinacaea) and Newbouldia laevis (Bignoniaceae) Ethanol Leaf Extracts in Wistar Rats Aim: Commelina benghalensis and Newbouldia laevis are tropical plants which are widely used in ethnomedicine. Acute and subacute toxicity profiles of both plants were herein studied. Place and Duration Study: This study was conducted at the Department of Pharmacology, Faculty of Basic Medical Sciences, University of Port Harcourt, Nigeria; between January and July, 2017. Methodology: Median lethal doses (LD50) of both extracts were determined using Lorke’s method. Forty-two rats were used for the subacute toxicity study. They were divided into 7 equal groups (n=6) and administered C. benghalensis extract (50, 200 or 500 mg/kg) or N. laevis extract (50, 200 or 500 mg/kg) daily by oral gavage for 28 days. The seventh group was given vehicle (distilled water) and used as the control. Blood serum levels of biochemical parameters- aspartate transaminase (AST), alkaline phosphatase (ALP), alanine transaminase (ALT), albumin, total protein, urea, creatinine, sodium, potassium, chloride and bicarbonate were quantified by ELISA technique. The kidney, liver and heart were removed and histologically analyzed. Results: The oral LD50 of C. benghalensis and N. laevis extracts were >5000 mg/kg. Both plants caused reductions of AST and ALP, without having effect on total protein. N. laevis extract also reduced ALT at the highest dose. Serum levels of urea, creatinine, chloride and bicarbonate ions were not affected by both plant extracts. Additionally, sodium ion was reduced by N. laevis, whereas C. benghalensis reduced both sodium and potassium ions. Furthermore, C. benghalensis and N. laevis did not cause histological changes in liver, kidney and heart tissues. Conclusion: The results indicate that the plant extracts have high levels of safety and will cause no harmful effect on the kidney, liver or heart tissues.