Toxicological profile of hydro-ethanolic extract of the leaf of Solenostemon monostachyus (P. Beauv.) (Lamiaceae) in rats

Abstract

The rapid increase in consumption of herbal remedies worldwide has been stimulated by several factors, including the notion that all herbal products are safe and effective. However, over the past decade, several news-catching episodes in developed communities indicated adverse effects, sometimes life-threatening, allegedly arising as a consequence to taking herbal products or traditional medicines from various ethnic groups. Therefore, this present study aimed to carry out extensive toxicological evaluation of hydro-ethanolic extract of the leaf of Solenostemon monostachyus (P. Beauv.) Lamiaceae. In an acute toxicity tests of five groups of mice (n = 5/group), male albino mice were orally treated with aqueous extract of S. monostachyus up to 25000 mg/kg and general behavioral activity, adverse effects, and mortality were recorded for up to 14 days. A sub-chronic toxicity test was performed by daily administration with the extract at 75, 112.5 and 225 mg/kg orally (n = 6/group) for 49 days, while control rats received distilled water. Haematological and biochemical (liver enzymes, proteins and bilirubin) parameters were determined and histopathological examination was carried out. The LD⁵⁰ was estimated to be 22500 mg/kg, with acute behavioural manifestations of reduced locomotion and calmness. The extract showed statistical significant difference (P ≤ 0.05) in haematological and biochemical parameters in the treated rats compared to the control in subchronic treatment. While, subchronic administration of the extract affected some vital organs evident by slight distortion in histo-architecture, degeneration and fat deposits. Results obtained in this study suggest hydro-ethanolic extract of the leaf of S. monostachyus is relatively safe when administered orally in traditional medicine.

Keywords: Solenostemon monostachyus, haematology, liver and biochemical function, sub-chronic toxicity.