Hydroxytyrosol effectively improves the quality of pig sperm at 17 °C.

Artificial insemination (AI) is a proven breeding technology which has been widely used in pig reproduction. Low temperature can cause very serious damage to pig sperm below 15 °C and the situation is even more serious at lower temperature. Besides, the preservation of pig sperm is mainly carried out at 17 °C because of its outstanding performance in pig reproduction. However, the accumulation of a large amount of reactive oxygen species (ROS) during the preservation process is the main reason for the deterioration of sperm quality. In our research, by adding different concentrations of hydroxytyrosol to the diluent during the storage of pig sperm at 17 °C, we compared them with the traditional diluent to study the sperm motility, the cumulative amount of ROS, the extent of sperm membrane damage, the sperm acrosome integrity, the sperm DNA damage and the activity of antioxidant enzymes (CAT, T-AOC, SOD, GSH-PX, MDA) to evaluate the effect of hydroxytyrosol on the sperm quality during storage. We used proteomics sequencing technology to monitor difference in sperm protein between the control samples and the addition of 120 µmol/L hydroxytyrosol samples (optimum concentration) after three days storage. Ultimately, we selected the control samples and the addition of 120 µmol/L hydroxytyrosol samples to test the effect of AI. The results of our research showed that during storage of pig sperm at 17 °C, the sperm quality and antioxidant capacity of the hydroxytyrosol-treated samples significantly improved (HT 120 µmol/L) (P < 0.05). Proteomics sequencing analysis proved that the addition of 120 µmol/L hydroxytyrosol treatment samples had potential value in improving sperm quality. The significant increase in sow pregnancy rate and piglet birth weight proved that hydroxytyrosol had important practical value in pig reproduction. Based on our results, we demonstrated that the addition of hydroxytyrosol to the diluent could improve the quality of pig sperm and the efficiency of AI.

Boar sperm quality and oxidative status as affected by rosmarinic acid at 17 °C.

Peroxidation damage induces sublethal injury to boar sperm during preservation. Rosmarinic acid (RA) has already been verified to efficiently protect cells from oxidant-induced injury and to produce significant effect on cryopreservation of semen. Through our experiments, we aim at investigating whether RA has a positive effect on the preservation of pig semen at room temperature. The semen collected from sexually mature Large White boars were preserved at 17 °C in Beltsville thawing solution (BTS) supplied. The boar sperm were exposed to 0, 25, 50, 75, 100, 125 and 150 µM RA in vitro and the sperm functions were examined. The sperm motility, the acrosome and plasma membrane integrity, the catalase activity (CAT), the total antioxidative capacity (T-AOC) activity and the malondialdehyde content (MDA) were examined at 0, 1, 3 and 5 days. The BTS diluent containing RA improved the sperm quality during the process of liquid preservation compared with the control treatment. After 5 days of liquid preservation, the addition of RA at 100 µM produced an optimal effect on the survival time as well as on the maintenance of motility, acrosome and plasma membrane integrity; T-AOC activity; CAT activity; and the MDA content. Besides, our results in the reproductive experiments showed that the addition of RA at 100 µM to the BTS diluent increased the pregnancy rate. These results suggest that the proper concentration of RA in boar semen extenders possibly improves the artificial insemination efficiency by reducing the sperm damage and the subsequent dysfunction during liquid preservation in swine production systems.

Bifenthrin Induces Fat Deposition by Improving Fatty Acid Uptake and Inhibiting Lipolysis in Mice.

Chemical residues in the environment are considered to be important factors that cause obesity. Bifenthrin is one of the pyrethroid pesticides and is widely used worldwide. However, its effect on adipose tissue is ill-defined. Here, we administered bifenthrin/corn oil to adult C57BL/6 mice by gavage. After 6 weeks, the bifenthrin treatment significantly increased their body weight (P = 0.015) and fat mass (P < 0.001). Then we identified 246 differently expressed proteins by proteomic analysis, and they were highly involved in fatty acid uptake and lipid metabolism processes. Interestingly, protein hormone-sensitive lipase and adipose triacylglyceride lipase were downregulated while lipoprotein lipase is upregulated after bifenthrin treatment. Similar effects in 3T3-L1 cells treated with bifenthrin validated the in vivo results. Thus, this study suggests that long-term exposure to low-dose bifenthrin induces fat deposition in mice by improving fatty acid uptake and inhibiting lipolysis, and it may cause obesity in humans.

Supplementation of salvianic acid A to boar semen extender to improve seminal quality and antioxidant capacity.

The purpose of this test was to investigate the effect of salvianic acid A (SAA, CAS No. 76822-21-4) on the quality of boar semen during liquid storage at 17°C. The effects of different concentrations of SAA on semen quality and antioxidant capacity were analyzed. Boar semen was diluted with Beltsville Thawing Solution (BTS) containing different concentrations (0, 15, 30, 45, 60, 75 µM of SAA). During the storage period, sperm activity was measured every 24 hr, and plasma membrane integrity, acrosome integrity, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, and catalase (CAT) activity were measured at 0, 1, 3, and 5 days. The results from our study suggest that different concentrations of SAA have different effects on semen preservation. Semen samples supplemented with SAA showed reduced effects of oxidative stress on sperm compared to the control samples. Supplementation of 30 µM of SAA significantly improved sperm motility, plasma membrane integrity, acrosome integrity, and antioxidant capacity. However, the addition of SAA to the extender was scarcely beneficial to the improvement of results of artificial insemination with boar semen after liquid preservation. Further studies are necessary in order to demonstrate that SAA has good effects on the liquid preservation of semen.

Supplemental effect of different levels of taurine in Modena on boar semen quality during liquid preservation at 17°C.

Peroxidation damage induces sublethal injury to boar sperm during the storage process. Taurine has already been demonstrated to protect cells effectively from oxidant-induced injury. This study was aimed to evaluate the effect of different concentrations of taurine (0.5, 1, 5 and 10 mmol/L) in Modena diluent on boar sperm quality during liquid storage at 17°C. Ejaculates from sexually mature Duroc pigs were collected, pooled and preserved in the Modena containing different concentrations of taurine. Sperm motility, plasma membrane integrity, acrosome integrity, total antioxidative capacity (T-AOC) activity and malondialdehyde content (MDA) were examined every 24 h. Modena diluent containing taurine suppressed the reduction in sperm qualities during the process of liquid preservation compared with those of the control group. After 5 days of liquid preservation, the addition of taurine at 5 mmol/L had the optimal effect on survival time as well as maintenance of motility, plasma membrane integrity, acrosomal integrity, T-AOC activity and MDA content. These results may suggest the possibility that the proper addition of taurine to the semen extender improves the swine production system using artificial insemination by the suppressing of sperm damage and subsequent dysfunction during liquid preservation.