Sub-acute Toxicity of Aqueous Extracts of Tephrosia vogelii, Vernonia amygdalina and Senna occidentalis in Rats

摘要

There is an intense search for new plant-derived medicines to match the ever increasing prevalence of drug resistance. Toxicity profiles of three commonly used plants against helminthosis in Uganda will support their optimum use.Objective: To evaluate the sub-acute toxicity of aqueous leaf extracts of Tephrosia vogelii (TV), Vernonia amygdalina (VA) and Senna occidentalis (SO).Methods: One hundred Wistar white albino rats in 10 groups were dosed orally daily with 200, 400 and 600 mg/kg of TV, VA and SO for 28 days or Goodwin’s physiological solution. Daily changes in behaviour, feed/water intake and weight (weekly) were monitored. On day 29, blood for haematology, serum for biochemical analysis and organs (lungs, liver, kidney, heart and small intestines) for histopathology were collected.Results: Continued exposure of rats to 600 mg/kg doses of SO and VA extracts led to elevation of ALT, AST and ALP and cholesterol in the treatment groups. SO and VA at 600 mg/kg elevated urea and uric acid; depressed bilirubin while VA and TV 600 mg/kg caused the reverse. Histopathology findings (villi sloughing, pneumonitis, liver and kidney degeneration) further supported these results.Conclusion: The very low toxicity of the aqueous leaf extracts of TV, VA and SO at high doses makes them safe at currently non-standardised doses used for animal treatment.