Toxicological Evaluation of Methanol Leaf Extract of Cola hispida doi.org/10.26538/tjnpr/v5i10.25

Abstract

Cola hispida is a plant that has been employed in African folkloric medicine as an analgesic plant and to prevent premature labor. The aim of the research is to assess the acute and sub-acute oral toxicity of the methanol leaf extract of Cola hispida in mice and rats, respectively. Pulverized leaf was extracted by maceration in 6 L of methanol (98% purity) for 72 hours, filtered and concentrated at 40ºC using a rotary evaporator. In the acute toxicity test, the extract at 10, 100, 1000, 1600, 2900, and 5000 mg/kg was administered orally to mice, while, 200, 400, 600, and 800 mg/kg doses of the extract were administered orally for 28 days in the sub-acute toxicity test. No behavioural signs of toxicity nor lethal effect were observed in the acute toxicity test indicating that the LD50 is greater than 5000 mg/kg. In the sub-acute toxicity evaluation, the extract showed neither mortality nor treatment-related adverse effects with regards to the cardiac, hepatic, renal, and antioxidant parameters. The histopathological examination of liver sections, however, revealed mild congestion of blood vessels and haemorrhage at 800 mg/kg indicating potential unfavorable effect on long-term administration at higher doses. The findings imply that the methanol extract of Cola hispida leaves is relatively safe. However, long-term use at higher doses should be avoided.