Evaluation of in vitro and in vivo safety profile of the Indian traditional medicinal plant Grewia tiliaefolia.

Grewia tiliaefolia Vahl., is a subtropical tree used in Ayurvedic formulations and also by tribal communities in India for treatment of wounds, urinary infection and skin diseases. Despite of its medicinal use, the plant has not been previously tested for its safety. This study evaluated the toxicological profile of the methanolic extract of G. tiliaefolia leaves (MEGT) through in vitro (cytotoxic, mutagenic, genotoxic) and in vivo (acute and sub-acute) studies. In vitro assays conclude that there is no significant (p<0.05) level of cytotoxicity and genotoxicity at the tested concentrations (250-2000 μg/ml) in peripheral blood mononuclear cells. Ames assay in the tested Salmonella typhimurium strains revealed no significant (p<0.05) increase in the mutagenic index both in the presence and absence of metabolic activation. Alternatively, no change in mortality, physiological, behavioural, haematological and biochemical parameters were observed under in vivo acute (250, 500, 1000, 2000 mg/kg b.w) and sub-acute (100, 200, 1000 mg/kg b.w) toxicity studies in Wistar rats. Histopathological examinations of the animals did not reveal any treatment related changes and showed normal architecture, even at the highest concentration (1000 mg/kg b.w) following 28 days treatment. Overall, the results show that MEGT is non-toxic at the tested concentrations and is safe to be used as herbal medicine.