Cryopreservation is common in small ruminant breeding to conserve genetics and facilitate artificial insemination. On the other hand, oxidative stress occurring during the freezing and thawing process remains a major factor contributing to reduced sperm function and fertility. In this regard, the natural polyphenolic antioxidant agent resveratrol (RES) has been proposed as an additive to semen extenders. This study summarizes in vitro experimental studies assessing the impact of RES supplementation on sperm quality and oxidative status during semen cryopreservation (at −196 °C) and liquid storage at 5 °C in rams and bucks. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist, ten peer-reviewed articles from 2010 to 2025 were selected for the analysis based on the experimental method, extender composition, RES dosage, preservation protocols, and measured parameters. The synthesis indicates that moderate RES concentrations (25–75 µM) are generally associated with improvements in total and progressive motility, plasma and acrosomal membrane integrity, and mitochondrial function, along with reductions in oxidative stress markers such as reactive oxygen species (ROS), malondialdehyde (MDA), and lipid peroxidation. The observed effects may be associated with enhanced cellular redox balance and mitochondrial function. Concentrations above 100 µM have been reported to exert potential adverse effects, suggesting a relatively narrow optimal dosage range. In general, the current data suggest that RES may improve sperm preservation efficiency. Nevertheless, additional standardized and in vivo studies are needed to verify its practical use in small ruminant production systems.

Formaldehyde is a highly reactive one‑carbon aldehyde that induces cytotoxicity through DNA–protein crosslinks, RNA adduct formation, and disruption of cellular redox homeostasis. Because all living cells must counteract these lesions to survive, elucidating formaldehyde detoxification and tolerance mechanisms is essential for understanding formaldehyde stress biology. The budding yeast Saccharomyces cerevisiae provides a genetically tractable model for dissecting formaldehyde‑induced molecular damage and the pathways that mitigate it. This review summarizes key mechanisms of formaldehyde tolerance in budding yeast, including glutathione‑dependent formaldehyde detoxification, aldehyde and alcohol metabolic networks, DNA and RNA repair pathways, and other protective mechanisms. As many of these mechanisms are evolutionarily conserved, insights gained from budding yeast offer a valuable framework for understanding formaldehyde toxicity across eukaryotes and may contribute to the development of strategies to mitigate formaldehyde‑related cellular damage.