Toxicological Studies on the Ethanol Extract of Acalypha torta (Muell) Leaves in Mice and Rats.

Abstract

Herbal pharmaceuticals and nutraceuticals are now popularly used worldwide.These herbal remedies, although natural, can cause some serious damaging effects on the vital organs of the body due to inadequacy in standardization and safety regulations. Ethanol extract of Acalypha torta was obtained after defatting dried pulverized leaves of the plant with chloroform : methanol ( 2 : 1). A 24 h – acute-toxicity study of the extract in mice was carried out to ascertain the risk of acute toxicty by selected doses (200 to 8,000 mg/kg body weight) administered intraperitoneally. The median lethal dose (LD₅₀) as well as other signs of toxicity were determined. Toxicity to the vital organs in rats was also assessed following intraperitoneal administration of doses less than 50% of the LD₅₀ for 28 days . Results of acute toxicity studies gave LD₅₀ of 562.30 mg/kg body weight. All the tested doses of ethanol extract of A. torta administered reduced appetite in all the experimental rats used whereas high doses, above 2000 mg/kg body weight triggered increase in respiratory rate,and convulsion before the animals died. Observed pathological changes in vital organs after the 28 days of treatment in rats were necrosis, follicular disorganization, inflammatory reactions ,fibrosis and bronchial dilatation. These changes were seen in the liver, spleen, brain, heart, kidney and lung sections, but at low frequencies (i.e number of lesions per slide). These findings may suggest that prolonged use of the extract at doses higher than recommended therapeutic dose could precipitate organ damage.

Keywords: Acalypha torta, medicinal plants, toxicology, inflammation, necrosis.