Acute and Sub-chronic Toxicity Evaluation of the Ethanolic Extract of Coula edulis B., (Olacaceae) Stem Bark

Aims: Coula edulis Baill., (Olacaceae) is a non-lignified forest product not well known and widely used in sub-Saharan Africa as a phytomedicine or food additive. However, the toxicity of this plant remains unknown. This study aimed to assess the safety of the ethanolic extract of C. edulis stem bark (CEE).

Study Design: Pharmacological study.

Place and Duration of Study: Laboratory of Nutrition and Nutritional Biochemistry, Department of Biochemistry, University of Yaounde 1 (Cameroon), between June 2018 and July 2022.

Methodology: Studies on the assessment of acute and subchronic toxicity were carried out by guidelines 423 of the Organization for Economic Co-operation and Development (OECD). Subacute toxicity of the sample was assessed over 28 days using repeated doses by OECD Guideline 407.

Results: No cases of death and clinical signs of toxicity were observed in the treated rats, suggesting that the LD50 of C. edulis ethanolic extract is greater than 2000 mg/kg bw. Regarding the subacute toxicity study, the administration of CEE also did not result in any changes in the course of body weight. Only a significant decrease in the relative weight of the ovaries in females at the highest dose of 600 mg/kg was observed. In males and females, CEE did not affect lipid profile markers or transaminase levels (AST, ALT). In addition, a small but non-significant (p> 0.05) increase in creatinine was observed without kidney dysfunction. In males, CEE induced an increase in mean corpuscular volume number at 600 mg/kg, while at the same time, mean corpuscular hemoglobin concentration decreased at the 300 mg/kg dose. In females, a significant increase in the number of monocytes, red blood cells, and hemoglobin level were observed. No difference in the levels of urea, glucose, and lipid markers was observed nor histological changes in the organs studied.

Conclusion: As would be expected, exposure to CEE did not cause significant toxic effects in treated rats. Therefore, this plant extract can be safely recommended for therapeutic use.