Background: Acalypha wilkesiana (Euphorbiaceae) is highly accepted for traditional treatment of human plasmodiasis in Africa.
Methods: The toxicological effects of the aqueous leaf extract of A. wilkesiana were studied in 45 male and female Wistar albino rats. An acute toxicity testing was done using 21 rats divided into seven groups and LD50 determined. In the sub-chronic toxicity study, the extract was administered orally over a period of 28 days to rats in three groups with doses of 400 mg kg-1, 800 mg kg-1 and 1,600 mg kg-1, respectively, and the fourth group administered with water served as control. Blood samples were collected for hematological and serum biochemical analysis; organs of the animals were harvested for histopathological examination.
Results: The acute toxicity testing showed that the extract was non-toxic at doses up to 3,000 mg kg-1 and the LD50 was calculated to be 2,828.34 mg kg-1. The study showed that at 1,600 mg kg-1 dose, the extract caused a decrease in the level of neutrophils (NEUT) while lymphocytes (LYMP) were statistically significantly increased. The administration of the extract also resulted in varying significant dose dependent increase in the levels of aspartate amino transferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP). There were also significant increases in the level of total protein (TP), urea (URN) and albumin (GLB) especially at 1,600 mg kg-1 dosage. Histopathology showed that the extract caused mild to severe significant lesions that are dose dependent in the liver and kidney when compared with the control group.
Conclusions: Prolonged administration of high dose of A. wilkesiana extract has tendency to cause organ toxicity.