Oxidative Stress and Role of Natural Plant Derived Antioxidants in Animal Reproduction

The experimental knowledge on the role of oxidative stress, and beneficial and detrimental effects of plant derived antioxidants in male and female animal reproduction are reviewed in this article. Free radical-induced oxidative stress in animal reproduction causes great loss to livestock industry. Antioxidant therapy has been implicated to be effective in preventing diseases resulted from oxidative stress. Considering the advantages of lower side effects of natural antioxidants than those of synthetic antioxidants, plants or their extracts have been extensively utilized in animals. Although many advances have been gained on application of plant derived antioxidants in alleviating oxidative stress, debatable issues still exist. Because many opposite effects were observed even using plant extracts containing similar bioactive substances in the same animal species. Therefore, plant derived antioxidants, like free radicals, are double-edged swords in animal reproduction, representing that they may exhibit beneficial or detrimental effects in animal reproduction, including spermatogenesis, semen functions, estrous cycles, ovulation, ovary functions, endometrium, embryo development, and pregnancy. Besides dose-dependent manner as an explanation of plant extracts' dual function, future studies are needed to investigate the mechanism of double-edged actions of plant derived antioxidants in different animal reproduction systems.