Safety evaluation (acute and sub-acute studies) of the aqueous extract of the leaves of Myrianthus arboreus P. Beauv. (Cecropiaceae) in Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Myrianthus arboreus P. Beauv (Cecropiaceae) is a medicinal plant distributed in forests and damp places of tropical Africa. Its leaves are widely used as food and/or for the treatment of various ailments including dysmenorrhoea, female infertility, tumors and diarrhea. However, to the best of our knowledge, no safety assessment of this plant has been reported yet. AIM OF STUDY: The present study aimed at evaluating the safety of the aqueous extract of leaves of Myrianthus arboreus (MAA) in Wistar rats through an acute and sub-acute oral administration. MATERIAL AND METHODS: In acute oral toxicity, the test was performed according to the Organization for Economic Cooperation and Development (OECD) guidelines Nr. 423 (acute toxicity class method, ATC) with slight modifications. Female Wistar rats were orally treated with the aqueous extract of M. arboreus at the doses of 2000 and 5000mg/kg. In sub-acute toxicity study, using the OECD guidelines Nr. 407, the extract was administered by gavage at the doses of 20, 110 and 200mg/kg/day for 28 consecutive days. RESULTS: A single oral administration of 2000 or 5000mg/kg of the extract induced neither mortality nor exterior signs of toxicity indicating a LD50 >5000mg/kg. In sub-acute study, the extract decreased triglycerides, total cholesterol/high density lipoproteins ratio and atherogenic index of plasma in both sexes at all tested doses. Alanine transaminase decreased in both sexes at 200mg/kg and serum creatinine levels decreased at all tested doses in females. Moreover, significant increases in ovarian and uterine wet weights, red blood cell count, hematocrit, mean corpuscular hemoglobin and hemoglobin were observed at 200mg/kg in females. In males, this extract decreased white blood cell count, lymphocytes and relative weight of seminal vesicles and ventral prostate at 200mg/kg. CONCLUSION: The aqueous extract of Myrianthus arboreus leaves was non-toxic in acute administration and exhibited a relatively low toxicity potential on accessory sex organs in both sexes, and leukocytes in males following the repeated 28-days oral administration of the dose 200mg/kg.

Safety assessment of the methanol extract of the stem bark of Amphimas pterocarpoides Harms: Acute and subchronic oral toxicity studies in Wistar rats.

Amphimas pterocarpoides Harms (Leguminosae) is widely used traditionally in Central and West Africa for the treatment of various ailments. However, no data regarding its safety have been published until now. Thus, the present study aimed to investigate the potential toxicity of the methanol extract of the stem bark of Amphimas pterocarpoides (AP) in Wistar rats following the OECD guidelines. In acute oral toxicity, female rats received a single dose of 2000 mg/kg of AP and were observed for 14 days. In subchronic toxicity, doses of 150, 300, 600 mg/kg/day of AP were given per os to rats (males and females) for 28 days. No death and abnormal behaviors were observed in acute toxicity and the LD50 was estimated higher than 5000 mg/kg. In the subchronic study, AP induced no significant variation in body weight and relative weight of organs, whereas a delayed decrease of white blood cell count and granulocytes was observed. Inconsistent increase of the total cholesterol/high density lipoprotein was observed at 600 mg/kg in males. Such variation (not dose dependent) and without biological relevance indicate a wide margin of safety for the traditional use of AP.