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 5000 mg/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 200 mg/kg/day for 28 consecutive days. Results: A single oral administration of 2000 or 5000 mg/kg of the extract induced neither mortality nor exterior signs of toxicity indicating a LD50 > 5000 mg/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 200 mg/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 200 mg/kg in females. In males, this extract decreased white blood cell count, lymphocytes and relative weight of seminal vesicles and ventral prostate at 200 mg/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 200 mg/kg. (C) 2016 Elsevier Ireland Ltd. All rights reserved.