Antioxidant effect of hydroxytyrosol on human sperm quality during in vitro incubation.

The aim of the study was to evaluate the antioxidant potential of hydroxytyrosol (HT) on human sperm quality during incubation in vitro. Semen samples collected from men attending the Laboratory of Histology-Embryology of Sfax Faculty of Medicine (Tunisia) for infertility investigations were evaluated for initial sperm parameters. Only normal selected ejaculates (n = 15) were centrifuged and incubated further with or without HT (200ug ml-1 ) at room temperature for 45 min. After incubation, sperm motility and viability, DNA oxidation and reactive oxygen species (ROS) production were assessed. The results showed that centrifugation significantly influenced sperm motility and viability. The supplementation of HT in incubating media improved (P = 0.01) significantly sperm viability and decreased sperm DNA oxidation (P < 0.001) and ROS levels (P = 0.03) following centrifugation. It can be concluded that supplementation of HT might be helpful to maintain the human spermatozoon after centrifugation.

Antioxidant supplementations in vitro improve rat sperm parameters and enhance antioxidant enzyme activities against dimethoate-induced sperm damages.

Organophosphorus compounds are currently among the most frequently used pesticides worldwide, and therefore, the potential for human exposure to man is considerable. Their toxicity results in negative effects on many organs and systems such as the male reproductive system. So, vitamins that can offer spermatozoa protection are of great importance. This study was designed to investigate (i) the possibility of dimethoate, an organophosphate insecticide, to induce oxidative stress response in rat spermatozoa in vitro and its effect on antioxidant defence system and (ii) the role of vitamin C and vitamin E in alleviating the cytotoxic effects of dimethoate Epididymal spermatozoa were incubated for 3 h at 37 °C with different concentrations of dimethoate (50, 100 and 200 µm) without vitamins or pre-incubated with 20 mm of vitamin C or 2 mm of vitamin E. Sperm parameters, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) levels were performed. Dimethoate caused a significant induction of oxidative damage in spermatozoa at different concentrations as evidenced by increased MDA levels. However, a significant decrease in sperm mobility, viability and activities SOD, CAT and GPx was observed. Vitamins pre-treated spermatozoa showed a significant protection against the cytotoxic effects induced by dimethoate on studied parameters.

Antioxidative potential of Quercetin against hydrogen peroxide induced oxidative stress in spermatozoa in vitro.

This study was carried out to test the antioxidant effects of Quercetin on sperm parameters and antioxidant enzymes in male rats assessed in vitro after H(2) 0(2) -mediated sperm oxidative damage. Spermatozoa were incubated with Quercetin (10, 100 and 200 µm), H(2) O(2) alone (100 µm) and Quercetin (100, 200 µm) + H(2) O(2) (100 µm) repectively, for 3 h at 32 °C. After that, sperm parameters (motility, viability and abnormal morphology), malondialdehyde, superoxide dismutase, catalase and glutathione peroxidase levels were determined. We found that exposure to H(2) O(2) let to significant increase in lipid peroxidation (LP) and abnormal morphology associated with significant decrease in sperm motility, viability and antioxidant enzymes activities. When Quercetin was added in culture medium, it improved activities of antioxidant enzymes and protected spermatozoa against the deleterious effect of H(2) O(2) on sperm parameters and LP. This study demonstrated that supplementation with Quercetin could protect spermatozoa against H(2) O(2) -mediated sperm damage.

[Prevalence of Toxoplasma gondii infection in Tunisian sheep]. / Prévalence d'infection des ovins par Toxoplasma gondii en Tunisie.

The aim of this study is to estimate the prevalence of Toxoplasma gondii infection in 527 sheep from 4 governorates of Tunisia by Elisa (350 animals) and PCR (177 animals). The seroprevalence in sheep was estimated to be 1.8% (N = 166) in the governorate of Siliana (North Tunisia) and 19% (N = 184) in the governorate of Kasserine (Central Tunisia) with a commercial Elisa kit. T. gondii DNA was extracted from the apex of the heart in 25.5% (N = 106) of sheep from the Sidi-Bouzid governorate (Central Tunisia) and 12.7% (N = 71) from the Ben-Arous governorate (North Tunisia). There was no statistically significant difference between different age categories' prevalence within each locality. Our results indicate that T. gondii infection is frequent in Tunisian sheep. The implementation of a national control programme against toxoplasmosis should not neglect sheep as a frequently infected intermediate host.