Evaluation of sub-acute oral toxicity effects of Phaulopsis falcisepala C.B. Clarke (Acanthaceae) in rats

Phaulopsis falcisepala is a herb or undershrub found in forest zone of West Africa and used for a wide range of ethnomedicinal purposes. Despite the ethnomedicinal importance of P. falcisepala, detailed data about its safety and toxicity is lacking. This study was done to evaluate sub-acute toxicity of P. falcisepala in rats. Whole plant of P. falcisepala was extracted with methanol. Wistar rats (n = 6/group) were administered orally with P. falcisepala extract at doses of 250, 500 and 1000 mg/kg/day for 28 days. Control group received distilled water. Physical observations were recorded daily and weights of animals were recorded weekly. After 28 days, samples of blood, serum and vital organs were obtained for haematological, biochemical and histological evaluations. Results showed that daily oral doses of P. falcisepala extract up to 1000 mg/kg for 28-days did not cause any behavioral changes or mortality. The plant extract did not induce significant alterations in body-weights, haematological, hepatic and renal parameters and serum levels of sodium, potassium, and chloride ions. No significant differences (p > 0.05) were recorded in relative weights of ovaries, testes, heart and kidneys of experimental groups compared to control group. Changes were observed in lipid profile (p < 0.05) and histology of kidneys and liver of rats treated with plant extract, particularly at highest dose, 1000 mg/kg. These findings suggest that extract of P. falcisepala could be safely applied for its medicinal properties at low to medium doses. However, sub-acute administration of doses up to 1000 mg/kg/day could pose deleterious risk to liver and kidneys.