Antioxidants in Fish Sperm and the Potential Role of Melatonin

Abstract

In recent years, the effects of novel antioxidants have played an important role in the research focusing on fish cell protection. As food demand grows, aquaculture production becomes more intensive, and fish are more exposed to oxidative stress conditions, like high densities, temperature shifting, frequent fish handling and samplings, and prophylactic or disease treatments, which expose fish to a different environment. Particularly in reproduction, germ cells lose antioxidant capacity with spermatogenesis, as spermatozoa are more prone to oxidative stress. Antioxidants have been used in a variety of fish physiological problems including in reproduction and in the establishment of cryopreservation protocols. From the most used antioxidants to natural plant food and herbs, and endogenously produced antioxidants, like melatonin, a review of the literature available in terms of their effects on the protection of fish spermatozoa is presented here in a classified structure. Several direct and indirect approaches to improve gamete quality using antioxidants administration are mentioned (through feed supplementation or by adding in cryopreservation media), as well as factors affecting the efficiency of these molecules and their mechanisms of action. Special attention is given to the unclear melatonin pathway and its potential scavenger activity to prevent and counteract oxidative stress damage on fish spermatozoa.

Dimeric Histidine as a Novel Free Radical Scavenger Alleviates Non-Alcoholic Liver Injury

“…Collectively, H-bihistidine is composed of two histidines where the N-1 atom of the imidazole group in histidine and N-1 atom of the other histidine imidazole group are connected by a hemi-protonated intramolecular hydrogen bond (N-H + •••N) (Figure 1D). The compound remains stable at experimental pH (3)(4)(5)(6)(7)(8)(9) and temperature (−20-100 • C).…”

“…Recently, there has been a growing interest in amino acids with antioxidant activity that can prevent the deleterious effects of reactive oxygen species (ROS) in the liver [5]. It is known that histidine is a conditionally essential amino acid for mammals, and the previous report suggests that histidine supplementation can reduce the level of oxidative stress in obese women and obese rats caused by high-fat diets [6].…”

Evaluation of Current Antioxidant Profile in Semen

“…Antioxidants can be anti-ROS antioxidants (metal chelators or binding proteins such as lactoferrin) or antioxidants that eliminate existing ROS (such as vitamins C and E) (Hussain et al, 2018). It is classified into two groups according to its chemical properties: enzymatic antioxidants and non-enzymatic antioxidants (Félix et al, 2021). Enzymatic antioxidants are known as natural antioxidants; glutathione, glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase (SOD).…”

How We Can Change Clinical Practice Using Antioxidant Molecules?

“…Félix et al [ 10 ] summarized in a review article the several direct and indirect approaches to reduce the spermatozoa oxidative processes reporting also the factors affecting the efficiency of antioxidant molecules and their mechanisms of action. Special attention was given to the melatonin pathway and its potential activity in preventing oxidative stress damage on fish spermatozoa.…”