The effects of CAPE (caffeic acid phenethyl ester) addition on spermatological parameters, oxidative stress and DNA damage after frozen-thawed process in ram semen

The aim of this study is to investigate the effects of different doses caffeic acid phenethyl ester (CAPE) adding to extender on some spermatological parameters, oxidative stress and DNA damage during post-thawed of ram semen. Ejaculates were collected from five Merino rams using an artificial vagina ones a week and this process was repeated six times. Ejaculates were split into four aliquots and diluted to a final concentration of 150x106 spermatozoa/ml with the base extender containing antioxidant (10 µg/ml, 50 µg/ml and 100 µg/ml)and no additive (control). All samples were cooled to 4°C and equilibrated for 3 h then were loaded into 0.25 ml straws and frozen using a liqued nitrogen vapour and plunged into liquid nitrogen. In terms of subjective motility, the groups containing 50 and 100 μg / ml were found to be significantly superior (P <0.05) compared to the control group. In addition, in terms of mid-piece anomalies and total abnormal spermatozoon rate, the decrease in the group containing 100 μg / ml compared to the control group and in the groups containing 50 and 100 μg / ml in terms of tail anomalies was found to be significant (P <0.05). The increase in all antioxidant groups in terms of H + / E- ratio compared to the control group, decreases in the group containing 100 μg / ml CAPE compared to the control group in terms of tail length, tail DNA and tail moment, and the spermatozoon TAS levels in the groups containing 10 and 100 μg / ml CAPE compared to the control group. the increase was statistically significant (P <0.05). In conclusion, in our study, it was observed that the 100 μg / ml dose of CAPE in different doses added to the sperm in the storage of ram semen provided the best protection compared to the control group and other groups in terms of spermatozoon motility, abnormal spermatozoon rate, HOST-Eosin test rate, oxidative stress and DNA damage.