US EPA

1098272 

Journal Article 

Role of reactive oxygen species in female reproduction. Part I. Oxidative stress: a general overview 

Agarwal, A; Gupta, S 

2005 

16 

1 

English 

Oxidative stress occurs when there is an elevated concentration of intracellular reactive oxygen species in a steady state condition. When the balance between reactive oxygen species and antioxidants is tied towards overabundance of ROS, oxidative stress results. Oxidative stress has been implicated in the etiology of multiple diseases like atherosclerosis, Alzheimer's and ageing. This article addresses and reviews the literature on the role of free radicals in female reproduction. Free radicals influence the entire reproductive span of a woman' life and even during menopause. Review of the literature emphasizes that oxidative stress acts as a mediator in the modulation of important ovarian functions, endometrial cyclical changes, embryo development, tubal functions, pregnancy, and its complications such as abortions, recurrent pregnancy losses, preeclampsia, and gestational diabetes. Oxidative stress influences the outcome of natural and assisted fertility and plays a role in the etiopathogenesis of various causes of infertility i.e. endometriosis. Infertility is a problem with huge magnitude, and multiple etiological factors. The etiology of unexplained infertility and recurrent pregnancy loss remains unclear and is a scientific challenge. The treatment is mainly empirical. Oxidative stress may be a piece in this puzzle. Pregnancy is a state of oxidative stress as revealed by number of studies demonstrating elevated levels of the oxidative stress biomarkers. The redox state, influences the maintenance of uterine quiescence in pregnancy via the paracrine effects of nitric oxide radical on the myometrium, inhibiting uterine contractions. Oxidative stress at parturition up regulates the antioxidant reserves of the neonate, but its role in initiation of labor is not known. Preterm fetuses are susceptible to free radical induced injuries, retinopathy and bronchopulmonary dysplasia. Currently available studies on antioxidant supplementation have been reviewed. In this paper we will discuss the role of various antioxidants both in-vivo and in-vitro, in overcoming oxidative stress affecting female reproductive tract pathologies. Clinical evidence on the role of antioxidants in modulating disease outcomes in female reproduction is equivocal. Trials investigating combination intervention strategy of vitamin E and vitamin C supplementation in preventing preeclampsia are highlighted. There is ongoing research investigating the exact mechanisms by which oxidative stress causes pathological processes affecting female reproduction i.e. infertility abortions, preeclampsia and fetal embryopathies and to design strategies for surmounting oxidative stress.