Effets de l’extrait aqueux des feuilles de Graptophyllum glandulosum Turrill (Acanthaceae) en traitement curatif contre quelques altérations de la fonction de reproduction induites par la nicotine chez le rat

Abstract

Smoking is Associate with a deterioration in sperm quality in terms of motility, concentration and morphology, which are the most fréquent used parameters in clinical settings to assess male fertility. The management of these disorders involves hormone therapy and vitamins. Some of these treatments induce adverse effects, hence the need to explore other therapeutic alternatives such as phytotherapy. Graptophyllum glandulosum is a plant traditionally used to treat infertility. The objective of this study was to evaluate the effects of the aqueous extract of G. glandulosum leaves as a curative treatment on some nicotine-induced alterations in reproductive function in rats. To do this, 35 rats aged 8 to 10 weeks were divided into 2 groups : group 1 received NaCl 0.9% and group 2 received nicotine solution (1mg/kg) daily for 28 days. After 28 days of administration of the solutions, 5 normal rats and 5 diseased rats underwent the breeding test. They were then sacrificed for the verification of the installation of the pathology. Once pathology had set in, the animals were divided into 7 groups of 5 rats each and were treated for 28 days as follows: the normal control group received distilled water (10 ml/kg) and 0.9% NaCl ; the positive control group received clomiphene citrate (1 ml/kg) and nicotine (1 mg/kg) ; the negative control group received nicotine (1 mg/kg) and NaCl 0.9% ; 3 tests groups received the extract at doses of 75 ; 150 and 300 mg/kg and nicotine (1mg/kg). The reversible control group received distilled water for the duration of treatment. The extract and distilled water were administered orally while nicotine and 0.9% NaCl were administered subcutaneously. The breeding test was carried out in three series (on day 0, day 28 and day 56) with ovariectomized females whose estrus has been chemically induced. On day 57, the animals were sacrificed, blood was collected, testes, epididymis, prostates, seminal vesicles, and penises were collected, and their relative masses were détermine. Epididyme spermatozoa were counted and some biochemical (testosterone, proteins, nitrites, MDA, CAT) and histological (testes, epididymis) analyses were performed. Aqueous extract of G. glandulosum increased sexual motivation and performance in rats. Serum testosterone levels were not significantly increased (p > 0.05) at 150 mg/kg by 36.81%. Testicular protein and penile nitrite levels significantly increased (p < 0.001) by 44.85% and 32.17% respectively. MDA levels and testicular catalase activity were signifiant increased at 300 mg/kg 1-fold (p<0.001) and 3-fold (p<0.05) at 150 mg/kg, respectively. The 150 mg/kg dose resulted in a significant increase (p < 0.001) in sperm count and viability by 2- fold and 1-fold respectively. Sperm motility increased at 75 mg/kg by 3-fold (p < 0.001). These results suggest that G. glandulosum extract may have aphrodisiac and antioxidant properties, which would justify its empirical use for the treatment of some alterations in male reproductive function.