Potential Regulatory Roles of Zinc in Normal and Nano Forms in Balancing Redox Homeostasis and Antioxidant Capacity of Rabbit Buck Semen

Ghanem, Nasser; Dessouki, Sherif Mohamed; Mehsien, Gamal Kamel; AboEl-Hassan, Amira; Abu Elnaga, Nehal; Farid, Omar; AbdElKhalek, Amira Salem; Khalil, Beshoy; Khfagy, Rana; Abou-Hashim, Fatma

doi:10.21608/ejvs.2025.349628.2588

Potential Regulatory Roles of Zinc in Normal and Nano Forms in Balancing Redox Homeostasis and Antioxidant Capacity of Rabbit Buck Semen

Articles in Press

Document Type : Original Article

Authors

¹ Cairo University,Faculty of Agricultur

² Faculty of Agriculture, Cairo University

³ Faculty of Agriculture - Cairo University

⁴ Embryology Department, Faculty of Science, ElAzhar University

⁵ National Organization for Drug Control and Research

⁶ Department of Genetics, Faculty of Agriculture, Cairo University

⁷ Department of Animal Production, Faculty of Agriculture, Cairo University

10.21608/ejvs.2025.349628.2588

Abstract

This research work was performed to investigate the actions of zinc - when supplemented to rabbit male (buck) semen in nano or in normal forms - on the post-freezing spermatozoa physical quality (motion, viability, DNA fragmentation and acrosome integrity), and biochemical profile (TAC, SOD, GPX and MDA). In addition, molecular characteristics of selected genes were profiled using Real-time PCR. Bucks (n=16) were trained and used for semen collection. Collected semen ejaculates were evaluated using computer assisted semen analysis (CASA) software. Semen ejaculates that showed sperm progressive motion of at least ≥ 70% were pooled for cryopreservation. The pooled semen was divided into three equal aliquots that were supplemented either with zinc oxide (ZnO) at the level of 10^-6M either in nanoparticles (nano Zn) or with normal form of zinc (Zn), in addition to a control group of the pooled semen without adding any supplementations. Morphological characteristics of sperms such as viability, acrosome integrity as well as CASA parameters were assessed before and after freezing. Moreover, biochemical analysis of cryopreserved buck semen was used to assay enzymatic activity and total antioxidant capacity. The transcriptional profile of genes controlling mitochondrial activity, antioxidant capacity and redox homeostasis was assessed by Real-Time PCR. Our results demonstrated a significant post-freezing enhancement of some measurements of CASA parameters such as Distance Straight Line (DSL), Velocity Average Path (VSL), Distance Curved Line (LIN) and Wobble (WOB) in both Zn supplemented groups compared to control group. Additionally, the percentage of live sperm was greater (P ≤0.05) in both Zn supplemented groups than control group. The percentage of DNA fragmentation found to be higher in control group than both Zn supplemented groups. Some of the antioxidants (TAC, CAT and GPX) were improved (P ≤0.05) in semen groups supplemented with ZnO and nano Zn compared to the control group. Key genes regulating redox and antioxidant balance (NRF2 and GPX) were upregulated in both Zn supplemented semen groups compared to control group. Furthermore, the transcript abundance of SOD1 and PRDX6 genes was higher in the Zn supplemented groups than that in the control group. However, the expression of two mitochondrial transcripts (ND1 and CPT2) was enhanced in ZnO supplemented group compared to nano Zn and control groups. In conclusion, the findings of this research work showed an improvement in physical and biochemical characteristics following cryopreservation of rabbit buck semen which was supplemented with Zn in normal form. This enhancement in semen quality was caused by sustaining both enzymatic and transcriptional activities of genes regulating redox-antioxidant sperm capacity. Nonetheless, the addition of Zn in nano form has a partial improvement in semen quality which requires further studies to get real insights into its action in semen cryopreservation.

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