Effects Of Epigallocatechin Gallateon Quality Of Boar Semen During Normal Temperature Preservation

Artificial insemination technology is a key link in pig breeding,and high quality semen is required to be stored at room temperature,and the dilution stored at room temperature has a great impact on semen quality.One of the factors affecting semen quality is the production of excessive reactive oxygen species(Reactive oxygen species,ROS).Excessive ROS production can lead to oxidative stress in sperm,damage to organelles and plasma membrane and even damage to sperm DNA,and affect sperm fertilization ability and reproductive performance of sows after artificial insemination.Current studies have shown that adding appropriate antioxidants to the diluent can effectively prevent oxidative damage to sperm,thus improving the quality of stored semen at room temperature.Therefore,this test by adding in boar sperm normal temperature preservation diluent natural antioxidants-table gallic acid ester gallic catechins(Epigallocatechin gallate,EGCG),and through to the 17 ? under normal temperature preservation of 1?5 d boar live sperm rate,rate of plasma membrane integrity,acrosome intact rate,total antioxidant capacity(T-AOC),malondialdehyde(MDA)content,reactive oxygen species(ROS)content,superoxide dismutase(SOD),catalase(CAT)and ATP content and mitochondrial membrane potential(MMP)and succinate dehydrogenase(SDH)activity index were determined,To study the antioxidant properties of EGCG and analyze the effect of adding EGCG in diluent on the quality of stored boar semen at room temperature,so as to provide theoretical basis for the application of EGCG as an antioxidant in stored boar semen at room temperature.This experiment mainly obtains the following research results:1.EGCG of different concentrations(10 ?mol/L,20 ?mol/L,30 ?mol/L,40 ?mol/L and 50 ?mol/L)was added to the diluted solution of boar semen at room temperature,which had positive protective effect on the storage of boar semen at room temperature.The optimal results were achieved when diluent was added to 20 ?mol/L and 30 ?mol/L EGCG.And the difference between the two groups is not significant(P > 0.05),the sperm viability rate,plasma membrane integrity rate and acrosome integrity rate of semen which diluted solution with 30 ?mol/L EGCG,stored at 17 ? on day 5 reached 78.36%,74.17% and 63.09%,respectively,which were significantly higher thanother groups(P < 0.05);however,there was no significant difference in sperm motility of the group with 50 ?mol/L EGCG diluted solution compared with the control group(P > 0.05).When diluent was added to 20 ?mol/L and 30 ?mol/L EGCG,there was no significant difference in sperm motility(P > 0.05).2.The addition of EGCG of different concentrations to the room temperature storage diluents of boar semen could improve the activity of T-AOC,SOD,CAT,and reduce the content of MDA and ROS,and the difference was significant compared with the control group(P < 0.05).The activity of T-AOC,SOD and CAT in sperm treated with 20 ?mol/L EGCG diluted solution was significantly higher than that of other groups(P < 0.05),and the MDA content and ROS level were significantly lower than that of other groups(P < 0.05).The ROS level and CAT activity of 50 ?mol/L EGCG treatment group were not significantly different from that of the control group(P > 0.05),but the activity of T-AOC and SOD were significantly increased and the content of MDA was decreased(P < 0.05).There were no significant differences in T-AOC activity,MDA content and SOD activity between 30,40 and 50 ?mol/L EGCG treatment groups(P > 0.05).In addition,after adding EGCG to diluent at room temperature for 1 day,the preservation effect was significantly different from that of the control group(P < 0.05),but the effect difference between the third and fifth day was not significant(P > 0.05).Therefore,the optimal concentration of EGCG in the room temperature storage diluent of boar semen is 20 ?mol/L,and its effective storage time can reach 5 days.3.Adding EGCG to the dilution of boar semen at room temperature can enhance the mitochondrial function and energy metabolism of sperm to varying degrees.However,as the amount of EGCG added increased,the semen preservation effect decreased instead.Adding 20 ?mol/L EGCG to the diluent has the best preservation effect.The ATP content,mitochondrial membrane potential,and SDH activity of the spermatozoa reached 4.4 ?mol/m L,3.1 ??m,and 69.2 U/m L when stored at room temperature for 5 days,which were significantly higher Control group(P < 0.05).Compared with the 20 ?mol/L EGCG treatment group,there was no significant difference in sperm mitochondrial membrane potential and SDH activity at 1 and 5 days of storage at an EGCG concentration of 30 ?mol/L(P > 0.05).SDH activity was significantly lower than that of the 20 ?mol/L EGCG group(P < 0.05),but both were superior to the control group(P < 0.05).When the concentration of EGCG was 10 ?mol/L,there was no significant difference in SDH activity after 5 days of storage compared with the control group(P > 0.05),and the ATP content,mitochondrial membrane potential,SDH activity for 1 day and 3 days after storage were higher than those in the control group(P < 0.05).When the concentration of EGCG was 50 ?mol/L,there was no significant difference in SDH activity and sperm ATP content at 1 d and 5 d storage compared with the 40 ?mol/LEGCG treatment group(P > 0.05).Mitochondrial membrane potential and sperm ATP storage at 3 d Compared with other treatment groups,the content was significantly different(P < 0.05),both were better than the control group(P < 0.05).Therefore,this study proved that adding EGCG to the room temperature storage diluent of boar semen could effectively improve the quality of semen preservation,and the optimal concentration was 20 mol/L.The addition of EGCG can significantly improve the sperm viability,plasma membrane integrity,acrosome integrity,T-AOC,SOD activity,CAT activity,ATP content,mitochondrial membrane potential and SDH activity after storage at room temperature,and reduce MDA content and ROS level.The addition of a certain concentration of EGCG in diluent has a positive effect on sperm and is of great significance to the study of room temperature storage of boar semen.