Acute toxicity, oxidative stress response and clinicopathological changes in Wistar rats exposed to aqueous extract of Uvaria chamae leaves

Acute toxicity, oxidative stress damage and clinicopathological changes were investigated in Wistar rats exposed to the aqueous extract of Uvaria chamae leaves because of the widespread ethnomedicinal use of the plant in many parts of the world. The acclimatized rats were administration 10 mgkg−1, 100 mgkg−1 and 1000 mgkg−1 (Phase I) and 1600 mgkg−1, 2900 mgkg−1 and 5000 mgkg−1 of the extract (Phase II). We observed rats for signs of toxicity within the first 30 min, 1-h, 2-h, 3-h, 4-h, 12-h, 24-h and thereafter daily for 14 days. Body and organ weights of rats were also monitored and used as measures of toxicity. We evaluated the haematological, biochemical, antioxidant and lipid peroxidation as well as histopathological effects of the extract in experimental rats after day 14th of the exposure. Exposed rats showed no signs of toxicity. The median lethal dose of the extract was estimated to be above 5000 mgkg−1. We observed significant (p < 0.05) weight gain in pooled body weights of rats at the end of the experiment but this was significant (p < 0.05) in Phase I only. There were no significant (p > 0.05) differences in the haematological and biochemical profiles as well as in the antioxidant and lipid peroxidative activities of the extract in exposed rats. Similarly, no obvious histopathological changes were observed in exposed rats. Although the aqueous extract of U. Chamae leaves was apparently non-toxic to the exposed rats as demonstrated, there is still a need for further investigations of its prolonged use and at sub-chronic extract concentrations.