Acute and sub-acute oral toxicity studies of crude aqueous and ethanolic extracts of Tapinanthus preussii leaf in normal adult male wistar albino rats

Abstract

Tapinanthus preussii (African mistletoe), is widely used in ethno medicine for the prevention and management of numerous diseases. Hence this study was aimed at evaluating the acute and sub-acute toxicological effects of its crude aqueous and ethanolic leaf extracts in Wistar albino rats. Acute toxicity tests were conducted in two phases by a single oral administration of both extracts at increasing dosages: 10, 100, 1000, 1600 2,900 and 5000 mg/kg body weight of the rats. This resulted in no clinical signs or symptoms of toxicity within 24h, 72h and 14 days revealing that both extracts were safe up to 5000 mg/kg. In the sub-acute toxicity study, the rats received increasing dosages of both aqueous and ethanolic extracts (200, 350 and 500 mg/kg body weight) p. o. daily for 28 days. The absolute bodyweight, liver function markers (serum aspartate amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase (ALP), bilirubin, albumin and total proteins) and kidney function indices (urea, creatinine and electrolytes) were not significantly (p>0.05) different in all the extracts treated groups compared to the control. This indicates that both extracts were safe since they were neither hepatotoxic nor nephrotoxic. Histopathological studies revealed no lesions in the liver and kidney of extract treated groups further confirming the safety of both extracts. Therefore these results validate the safety of this medicinal plant use indigenously to alleviate various diseases, optimize health and useful in pharmacological studies.