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Dspace de universite Djillali Liabes de SBA >
Thèse de Doctorat de 3ème cycle (LMD) >
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http://hdl.handle.net/123456789/1013
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Titre: | Effet de l’exposition chronique aux alcaloïdes totaux du
tabac sur la fonction reproductrice chez les rats mâles
wistar: effet preventif de la fraction d’acetate d’ethyle de l’extrait de the vert |
Auteur(s): | BENALIA, Abdelkrim Encadreur: BENDAHMANE, Malika |
Mots-clés: | tabac thé vert rats mâles reprotoxicité stress oxydatif antioxydants |
Date de publication: | 26-mai-2016 |
Résumé: | Tobacco is one of the most susceptible agents that can induce male infertility. However, its effects on reproductive system, apart from pregnancy, embryonic and fetal development, are not well evaluated. The principal aim of our study is to assess tobacco total alkaloids (TTA) effects on the histological structure of testes, sperm parameters and on sexual hormones, and to highlight the relationship between these effects and oxidative stress supposed to be a major mechanism of their induction. A second part of this study was carried out to assess the in vivo green tea protective effects. Before that, an in vitro phytochemical study was conducted in order to optimize the green tea use as antioxidants source. First of all, two groups of male WISTAR rats aged of two months (n=5) received during 30 days by gavage, TTA at 2,5 mg/kg and 5mg/kg of bodyweight (G1 and G2 respectively), while, for green tea protective effect assessment, animals received the ethyl acetate fraction of green tea extract (EAF) at 50mg/kg combined with TTA at either low (G3) or high dose (G4), whereas the animals of the fifth group (G5) were treated by the EAF alone, in order to assess its safety. For control group (G6), animals received the vehicle of different extracts (TTA and EAF). Results obtained from the phytochemical study showed that EAF possesses the most powerful antioxidant activity as compared to green tea total extract and its other fractions. The in vivo study results showed a dose-dependent reprotoxic effect of TTA on all studied parameters. TTA induced a dose-dependent decrease in sperm count, motility and viability of sperm cells. These observations were associated with a histological alteration of testes with interstitial tissue hypotrophy, reduced sperm cells number in the lumens and a deterioration of spermatogenesis within seminiferous tubules. These effects seem to be more pronounced at high dose of TTA, with ruptured blood-testis barrier and a reduced number of Sertoli cells. The hormonal study showed reduced levels of testosterone and FSH related to a significant increase in LH level at only high dose. These findings were associated with a decrease of blood plasma, testes and epididymis total antioxidant activity and high levels of lipid peroxidation. It is to note that EAF treatment has significantly decreased TTA reprotoxiciy in particular on testes histological structure, sexual hormone levels and sperm parameters. Furthermore, no related toxic repercussions of EAF has been observed in G5. In conclusion, TTA exposure can involve a considerable oxidative stress-dependent reproductive toxicity, which can be reduced using green tea phenolic compounds. |
Description: | Doctorat |
URI/URL: | http://hdl.handle.net/123456789/1013 |
Collection(s) : | Sciences Biologiques
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