The aim of our study was to examine the effects of crocin (0.5 (C0.5), 1 (C1) and 1.5 (C1.5) mM) and naringenin (50 (N50), 100 (N100) and 150 (N150) μM) in cryopreservation extender for freezing rooster semen. Sperm motility, viability, abnormalities, membrane functionality, active mitochondria, apoptosis status, lipid peroxidation (LP), GPX, SOD, TAC, the mRNA expression of pro-apoptotic (CASPASE 3) and anti-apoptotic (Bcl-2) genes, fertile eggs, hatched eggs and hatching rate were investigated following freeze-thawing. C1 and N100 resulted in higher (P < 0.05) total motility and progressive motility in comparison to the control group. The C1 and N100 groups improved viability, membrane functionality and reduced lipid peroxidation. We found higher values for active mitochondria with C1 and N100 compared to control group. The C1 and N100 groups showed lower percentages of early apoptosis when compared with control group. Also, C1 and N100 had higher TAC, compared to the control group. The mRNA expressions of BCL-2 in the C1 and N100 groups were significantly higher than that of other treatments. The expression of CASPASES 3 was significantly reduced in C1 and N100 group (P < 0.05) when compared to control group. Significantly higher percentages of fertile eggs, hatched eggs and hatching rate were observed in C1 and N100 compared to the control group. In conclusion, crocin at 1 mM and naringenin at 100 μM seem to improve the post-thawing rooster semen quality, fertility and could protect the sperm by reducing the pro-apoptotic (CASPASE 3) and increasing anti-apoptotic (Bcl-2) genes.
