An Overview on Assay Methods to Quantify ROS and Enzymatic Antioxidants in Erythrocytes and Spermatozoa of Small Domestic Ruminants

Abstract

The present review aims to provide an overview of the assay methods for the quantification of ROS and principal enzymatic antioxidants as biomarkers of oxidative stress in erythrocytes and spermatozoa of small domestic ruminants. A complete literature search was carried out in PubMed, Scopus and the World Wide Web using relevant keywords and focusing on the last five years (2018–2023). Among spectrophotometry, fluorometry and chemiluminescence, the most widely used method for ROS assay is fluorometry, probably because it allows to simultaneously assay several ROS, using different probes, with greater economic advantages. Regarding intracellular antioxidant enzymes, recent literature reports only spectrophotometric methods, many of which use commercial kits. The use of a less sensitive but cheapest method is suitable because both erythrocytes and spermatozoa samples are highly concentrated in domestic ruminant species. All methods considered in this review have been found to be appropriate; in general, the differences are related to their costs and sensitivity. Quantification of ROS and enzymatic antioxidant activity in erythrocytes and spermatozoa may find application in the study of the welfare and health status of small domestic ruminants for monitoring livestock production.

Advancements in Understanding and Enhancing Antioxidant-Mediated Sperm Cryopreservation in Small Ruminants: Challenges and Perspectives

“…Spermatozoa are highly susceptible to the detrimental effects of reactive oxygen species (ROS) primarily due to the substantial presence of unsaturated fatty acids in their cell membranes. ROS promote the peroxidation of lipids, leading to a loss of membrane integrity and subsequently increasing permeability [ 20 ]. Additionally, spermatozoa are particularly vulnerable to oxidative attacks because their cellular membranes contain a high quantity of polyunsaturated fatty acids (PUFAs), which are highly sensitive to lipid peroxidation.…”

“…O’Flaherty et al [ 28 ] have reported that these reactions are associated with impaired sperm function, leading to infertility and alterations in sperm motility in ruminants and equines, as well as affecting sperm capacitation. Within proteins, the specific ratio of oxidized to reduced thiol groups (SS/SH) is essential to ensure proper protein functions, but this balance can be affected by ROS [ 20 , 29 ]. Therefore, the quantification of total thiols and/or glutathione (GSH) in cells is critical for monitoring the level of OS.…”