The effects of some antioxidant additives on spermatological parameters, oxidative stress and DNA damage after frozen-thawed process in ram semen

The aim of this study was to determine the effect of the addition of antioxidants on the post thawed sperm, CASA, oxidative stress parameters and the DNA damage. Semen were collected from 2-3 years of age ten Pirlak rams under Afyonkarahisar conditions and these semen were divided in the five equal aliquots and diluted with the tris base extender containing with taurine, trehalose, trolox, lipoic acid and no antioxidant (control). Diluted samples were submitted to three hour equilibration at 5 oC and frozen 0,25 ml French straws in liquid nitrogen vapour and storage in liquid nitrogen (-196 oC). In thawed semen according to subjective motility (54.6 ± 2.25 %) and CASA motility (24.2±1.84 %), VAP (98.2 ± 2.20 µm/s) and VSL (80.1 ± 1.88 µm/s) taurine group indicated the highest value. Abnormal spermatozoon, head, middle piece and acrosome rate comparing with control group (1.2 ± 0.2 % 1, 1.2 ± 0.21 % and 13.3 ± 0.70 %) taurine (0.8 ± 0.15 %, 0.2 ± 0.08 % and 10.7 ± 0.51 %), trehalose (0.5 ± 0.07 %, 0.1 ± 0.04 % and 5.2 ± 0.26 %), lipoic acid (1.0 ± 0.12 %, 0.2 ± 0.07 % and7.1 ± 0.41 %) and trolox (0.4 ± 0.08 %, 0.1 ± 0.04 % and 3.6 ± 0.21 %) in these groups the lowest value were found. In the increases H+/E- type spermatozoon which one of spermatozoon HE-test parameters compared with control group (22.3 ± 0.72 %) then taurine, (32.6 ± 1.31 %), trehalose (30.2 ± 1.52 %) and lipoic acid (28.1 ± 1.25 %) groups were found significantly (P<0.05). In DNA damage, the lowest value trehalose (43.5 ± 4.51 AU) ve lipoic acid (48.4 ± 5.27 AU) were observed in compared control group (68.7 ± 4.09 AU). According to MDA which is one of the oxidative stress parameters, lipoic acid (3.7 ± 0.22 nmol/ml) and trolox (3.6 ± 0.24nmol/ml) indicated the lowest value that provided preservation.In conclusion that the effects of antioxidants such as taurine, trehalose, lipoic acid and trolox for frozen of ram semen is found to be significant at differences in effectiveness whereas lipoic acid is more effective on reducing oxidative stress and damage in DNA. However in order to understand the positive effects of antioxidants, it is essential to test in different dosages on spermatalogic parameters, CASA, oxidative stres parameters ve DNA damage together with fertility result on large number of animals.Key Words: Antioxidant, DNA damage, H-E test, Ram Semen, Oxidative stress