In this study, it was aimed to investigate the likelihood of detrimental effects of carbon tetrachloride (CCl4 ) on male reproductive system through oxidative stress mechanism and also protective effects of cinnamon bark oil (CBO). For this purpose, 28 healthy male Wistar rats were divided into four groups, seven rats in each. Group 1 received only olive oil daily; group 2 was treated with 100 mg kg(-1) CBO daily; group 3 was treated with only 0.25 ml kg(-1) CCl4 weekly; and group 4 received weekly CCl4 + daily CBO. All administrations were made by intragastric catheter and maintained for 10 weeks. Body and reproductive organ weights, sperm characteristics, testicular oxidative stress markers and testicular apoptosis were examined. CCl4 administration caused significant decreases in body and reproductive organ weights, testicular catalase (CAT) activity, sperm motility and concentration, and significant increases in lipid peroxidation (LPO) level, abnormal sperm rate and apoptotic index along with some histopathological damages compared with the control group. However, significant improvements were observed in absolute weights of testis and epididymis, all sperm quality parameters, LPO level, apoptotic index and testicular histopathological structure following the administration of CCl4 together with CBO when compared to group given CCl4 only. The findings of this study clearly suggest that CBO has protective effect against damages in male reproductive organs and cells induced by CCl4 .

This study was designed to determine the effects of propolis on the sperm quality, antioxidant and histological parameters in the testicular tissues of male Sprague Dawley rats exposed to excessive copper (Cu). In this aim, 24 rats were randomly divided into four groups as follows: the control, Cu, Propolis and Cu+Propolis. When compared to control group, Cu administration significantly decreased sperm motility and concentration, increased total abnormal sperm rate. It caused a significant induction the malondialdehyde (MDA), and reduction the superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) in testicular tissues. Also, it caused loss, disorganisation and vacuolation of the germinal epithelium, oedema of the interstitial tissues, proliferation of the interstitial cells, spilled immature spermatogenic cells in the lumen of some seminiferous tubules. A large number of active caspase‐3‐positive stained apoptotic cells and a significant decrease in Johnsen's testicular score were determined. However, significant ameliorations were observed in all sperm characteristics, MDA, SOD, CAT, GSH, seminiferous tubules, number of apoptotic cells and Johnsen's testicular score in Cu+Propolis group. Our results showed that oral supplementation of propolis had curative effect on the sperm quality, antioxidant and histological parameters in the testicular tissues of male Sprague Dawley rats exposed to Cu.

This study was carried out to investigate the effect of the semen freeze–thawing process on the functionality and molecular structure of ram spermatozoa. The temperature of pooled and diluted semen at 38°C (group 1, control) was lowered to 5°C (group 2), and it was subjected to glycerolisation–equilibration (group 3), frozen and thawed (group 4). Compared to the control, deterioration in spermatological parameters and significant increases in lipid peroxidation and global DNA methylation levels were observed in groups 3 and 4. When compared with the control, significant downregulation in the levels of miR-485 of group 2, miR-29a of group 3 and let-7a, miR-485 and miR-29a of group 4, and significant upregulation in the levels of miR-107 of group 3 and miR-127 of groups 3 and 4 were detected. In comparison to the control, significant upregulation in the levels of CatSper1, CatSper2, CatSper3, CatSper4, ANO1 and TRPM3 of group 2, CatSper4, ANO1 and TRPM3 of group 3 and KCNJ11 of group 4, and significant downregulation in the CatSper 3 level of group 4 were determined. As a result, the semen freeze–thawing process causes motility and morphological disorders in rams. This may be due to molecular changes associated with lipid peroxidation in spermatozoa.

This study was conducted to investigate the effect of quercetin on carbon tetrachloride (CCl4 )-induced sperm damages, testicular apoptosis and oxidative stress in male rats. Group 1 served as control, group 2 was treated with only quercetin, group 3 was treated with only CCl4 and group 4 received CCl4 + quercetin. All administrations were performed by gavage and maintained for 10 weeks. CCl4 administration caused significant decreases in absolute and relative reproductive organ weights, sperm motility, concentration and testicular glutathione peroxidase (GSH-Px) and catalase (CAT) activities, and significant increases in lipid peroxidation (LPO) level, abnormal sperm rate and testicular apoptotic cell index, along with some histopathological damages when compared to the control group. However, administration of CCl4 together with quercetin provided statistically significant improvements in LPO level, abnormal sperm rate, the degree of histopathological lesions and testicular apoptotic cell index when compared to only CCl4 group. In addition, improvements observed in absolute and relative weights of reproductive organs, sperm motility and concentration, and testicular GSH-Px and CAT activities in group 4 were statistically insignificant when compared to only CCl4 group. In conclusion, quercetin has antiperoxidative effect, and its oral administration attenuates the CCl4 -induced some damages in male reproductive organs and cells by decreasing the LPO.

Supplementation of natural antioxidants to diets of male poultry has been reported to be effective in reducing or completely eliminating heat stress (HS)-induced reproductive failures. In this study, the aim is to investigate whether rosemary oil (RO) has a protective effect on HS-induced damage in spermatozoa production, testicular histologic structures, apoptosis, and androgenic receptor (AR) through lipid peroxidation mechanisms in growing Japanese quail. Male chicks (n=90) at 15-days of age were assigned to two groups. The first group (n=45) was kept in a thermo-neutral (TN) room at 22°C for 24h/d. The second group (n=45) was kept in a room with a greater ambient temperature of 34°C for 8h/d (from 9:00 AM to 5:00 PM) and 22°C for 16h/d. Animals in each of these two groups were randomly assigned to three subgroups (RO groups: 0, 125, 250ppm), consisting of 15 chicks (six treatment groups in 2×3 factorial design). Each of subgroups was replicated three times with each replicate including five chicks. The HS treatment significantly reduced the testicular spermatogenic cell counts, amount of testicular Bcl-2 (anti-apoptotic marker) and amount of AR. In addition, it significantly increased testicular lipid peroxidation, Bax (apoptotic marker) immunopositive staining, and the Bax/Bcl-2 ratio in conjunction with some histopathologic damage. Dietary supplementation of RO to diets of quail where the HS treatment was imposed alleviated HS-induced almost all negative changes such as increased testicular lipid peroxidation, decreased numbers of spermatogenic cells, and decreased amounts of Bcl-2 and AR, increased ratio of Bax/Bcl-2 and some testicular histopathologic lesion. In conclusion, dietary supplementation of RO for growing male Japanese quail reared in HS environmental conditions alleviates the HS-induced structural and functional damage by providing a decrease in lipid peroxidation.