Effets de l’extrait aqueux de l’écorce du tronc de Baillonella toxisperma Pierre (Sapotaceae) sur quelques modèles de dysfonctions du système reproducteur chez le rat Wistar

Abstract

Infertility in couples is often the cause of marital frustration, violence and divorce or polygamy. This inability to procreate can be attributed to men in 50% of cases. In addition, chronic exposure to stressors, excessive consumption of psychoactive substances and exposure to many xenobiotics (endocrine disruptors) are among the major causes of male infertility. Treatment with synthetic androgens, although they improve male fertility, in some cases have drawbacks such as the risk of cardiovascular or hepatic damage. Faced with this situation, due to their availability and minimal side effects, herbal remedies provide an alternative treatment source for many infertile couples. The objective of this work was to evaluate the effects of the aqueous extract of Baillonella toxisperma stem barks on some models of reproductive system dysfunction in Wistar rats. In the first experiment, the effectiveness of the aqueous extract of B. toxisperma in stimulating copulatory activity was evaluated in normal, sexually inexperienced rats. To do this, the extract at doses of 75, 150 and 300 mg/kg was administered to the animals for 8 days and copulation tests were performed on days 1 and 8 of the experiment. Subsequently, three infertility models were used to assess the efficacy of the extract at the same doses in protecting/restoring the reproductive functions of animals subjected to the stress of immobilization (6 hrs/day for 35 days); or subjected to excessive consumption of ethanol (42 days) or subjected to maneb (60 days). The endpoints were sexual behavior, fertility parameters, androgen levels, oxidative stress parameters, testicular histology and the toxicological profile of the extract. At the end of the first experiment, the extract (150 and 300 mg/kg) showed aphrodisiac properties by significantly reducing (p < 0.05) latencies of mount and intromission and by increasing significantly (p < 0.05) frequencies of mount, intromission and ejaculation. In the stress induced infertility model, the results show that stressed animals exhibited a significant decrease in sexual performance (p < 0.05) and motivation (p < 0.01) as well as an alteration in sperm parameters compared to the normal control, the extract restored spermatogenesis and boosted copulatory activity in stressed animals. In the model of infertility induced by excessive ethanol consumption, inhibition of copulatory activity, a significant decrease (p <0.05) in sperm and androgenic parameters were observed in animals receiving only ethanol compared to the normal control. Co-treatment of animals with the extract significantly (p <0.05) counteracted this alteration in reproductive function induced by ethanol. In the maneb-induced infertility model, animals receiving only maneb (4 mg/kg) showed a significant reduction (p < 0.01) in serum total testosterone level, with impaired copulatory activity and a decrease in the assessed fertility parameters. Treatment with the extract restored fertility in animals subjected to maneb. Normal animals treated with the extract showed decreased reproductive parameters with a decrease in serum total testosterone. The oral LD50 of B.toxisperma is estimated to be greater than 5000 mg/kg b.w, which makes it possible to classify the toxicity of this extract in category 5 of the globally harmonized classification system: low toxicity. The extract administered at a therapeutic dose of 150 mg/kg showed no major signs of toxicity on certain biochemical and hematological parameters evaluated. In summary, the results obtained could justify the use of B. toxisperma in the treatment of male infertility in several regions of Central Africa.