Short-term storage is a crucial strategy in aquaculture, associated with oxidative stress that leads to a decline in sperm function, as observed in coho salmon (Oncorhynchus kisutch). In this study, creatine is proposed as a potential antioxidant. Thus, the aim was to assess the potential antioxidant effect of creatine on intratesticular sperm extracted by testicular maceration from coho salmon, through sperm quality parameters for subsequent studies on oxidative stress. Treatments included different concentrations of creatine monohydrate: 0 (control), 0.1, 0.2, and 0.4 mM (n=12). Samples were placed in an incubation chamber with constant agitation (30 rpm) at 4°C in darkness for 1 h. Motility (Mot) was determined by computer-assisted sperm analysis (CASA), while plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), superoxide anion level (O), mitochondrial superoxide anion level (MS), and DNA fragmentation (DNAF) were evaluated by flow cytometry and fluorescence microscopy. Statistical analyses were performed using the R statistical program (version 4.2.3), employing Kruskal-Wallis ANOVA followed by Dunn’s test for multiple mean comparisons or Wilcoxon test depending on the amount of data compared. In Figure 1, it is observed that for the 0.4 mM creatine treatment, PMI significantly decreased compared to the control (36%). On the contrary, MMP significantly increased with the addition of 0.2 mM creatine, rising by 121%.
In Figure 2, Intracellular Superoxide Anion (O) production in the creatine-added treatments showed no significant differences compared to the control. The addition of creatine decreased MS, being significant only with the highest dose. DNA fragmentation (DNAF) significantly decreased with the incorporation of creatine.
It is concluded that the addition of creatine to the testicular macerate of coho salmon had an antioxidant potential effect at low concentrations.