Effects of Dietary Pomegranate Peel on Antioxidant Gene Expression and DJ-1 Protein Abundance in Ram Testes

Background: Pomegranate is an ancient fruit containing Punicalagin, which has known as an effective antioxidant. Pomegranate peel was recognized as a phenol and tannin source, and pomegranate seed contains unique fatty acid (Punicic acid). Limited information exists about the influences of pomegranate peel and seed on antioxidant enzymes and proteins in the male reproduction system. This study was performed to determine the pomegranate peel and seed effects on the expression of antioxidant genes and DJ-1 protein in ram's testis. Materials and Methods: In this experimental study, twenty-one mature Iranian rams were randomly divided into three groups (n=7 in each group), and fed experimental diets consisted of a control diet (C), a diet containing city pomegranate seed pulp (S), and a diet containing pomegranate peel (P) for 80 days. All rams were offered isoenergetic and isonitrogenous rations. Testicular tissue samples were collected, and expression of Gpx1, Gpx4, Prdx4, Prdx5, and Sod2 genes was quantified by real-time polymerase chain reaction (RT-PCR). In addition, western blotting was used to evaluate DJ-1 expression at the protein level. Results: Gpx1 and Sod2 mRNA levels in the peel group were significantly (P<0.05) higher than control. Prdx5 mRNA level was increased (P<0.05) in the seeds group than in the control group. Gpx4 and Prdx4 expression were statistically not affected significantly by the experimental diet. Data analysis showed a significant (P<0.05) increase (1.5-fold) in the expression level of DJ-1 in peel groups than in control. Conclusion: The expression of antioxidant genes and DJ-1 protein in ram testes are more influenced by pomegranate peel than seed.