Safety evaluations of the aqueous extract of Acacia karroo stem bark in rats and mice

The aqueous extract from the shoot of Acacia karroo was evaluated for its acute toxicity by the oral route in mice and for the sub acute effect on haematological, biochemical and histological parameters in rats. In the acute toxicity test, A. karroo extract caused death in animals that received 1600 and 3200 mg/kg doses. Oral treatments in rats with this extract at 800 mg/kg did not cause any significant change in the red blood cell count (RBC), packed cell volume (PCV), haemoglobin concentration (HB), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular haemoglobin (MCH), white blood cells and its differentials. It, however, caused a significance decrease in the levels of platelets. In the biochemical parameters, the extract caused a significant decrease in the levels of total protein, albumin, globulin, aspartate amino transferase (AST), alanine amino transferase (ALT), total and unconjugated bilirubin. Changes were also noted in the body weights but no significant changes were observed in the levels of some electrolytes (sodium, potassium and chloride). Clinico-pathologically, starry hair coat, respiratory distress and mortality were recorded. Lung with multiple abscess, kidney and liver with mild congestion were also observed histopathologically. The study concluded that caution must be exercised in the use of the plant for medicinal purposes .