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


OBJECTIVE
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.


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.


CONCLUSIONS
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.
Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.
Charline Florence
CF
Awounfack
Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.
Sylvin Benjamin
SB
Ateba
Laboratory of Physiology, Department of Life and Earth Sciences, Higher Teachers' Training College, University of Maroua, P.O. Box 55, Maroua, Cameroon.
Stéphane
S
Zingue
Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon.
Oumarou Riepouo
OR
Mouchili
Laboratory of Animal Physiology, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, P.O. Box 812, Yaounde, Cameroon. Electronic address: dnjamen@gmail.com.
Dieudonné
D
Njamen
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology* / Q000633:toxicity; D018515:Plant Leaves / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D023382:Toxicity Tests, Acute; D059551:Toxicity Tests, Subacute; D027003:Urticaceae / Q000737:chemistry*
D010936:Plant Extracts
Acute toxicity; Aqueous extract; Myrianthus arboreus; Sub-acute toxicity; Wistar rats