Ninety-Day Toxicological Assessment of Preparation of the Medicinal Plant Newbouldia laevis (P. Beauv.) Seem. (Bignoniaceae) in Rats

Abstract

Objectives To investigate the safety profile of subchronic oral administration of hydroethanol leaf extract of Newbouldia laevis (NL) in rats. Methods NL was administered orally (20, 100, and 500 mg/kg) to groups of rats for 90 days. Distilled water served as control. Some rats were spared for an extra 30 days with no extract administration (reversibility study). Blood, urine and selected vital organs were collected for analyses. Results In male rats, NL (20, 500 mg/kg) irreversibly increased ( P˂.05) bodyweight and feeding pattern with opposite trend of results in females. NL (20 mg/kg) elicited irreversible decrease ( P˂0.05) in RBC in male rats; a reversible decrease in RBC and Hb, and an irreversible increase (500 mg/kg) in WBC and neutrophils in females. In male rats, NL irreversibly decreased ( P˂.01) HDL-c and increased uric acid; in female rats, it elicited a reversible increase ( P˂.05, 500 mg/kg) in AST. NL (500 mg/kg) irreversibly decreased ( P˂.05) sperm motility and count, and produced an irreversible increase ( P˂.01) in testosterone levels in male rats (100 mg/kg). It reversibly decreased (20-500 mg/kg) luteinizing hormone levels (both sexes). Conclusions NL is fairly safe at lower doses. However, it could cause anemia at lower doses, infertility (both sexes), liver and kidney injuries at high doses.