Reactive Oxygen Species (ROS) are required for intact spermatogenesis and sperm function,
but excessive levels will cause oxidative stress, impairing sperms and sperm function
due to membrane damage and DNA fragmentation.Theoretically, antioxidant supplementation
may act as a protecting system against free radicals. Since infertile males have higher
levels of ROS, nutritional supplements are widely used for protecting sperms. In the
recent review authors summarize the most recent data regarding the effect of antioxidant
treatment and draw an attention of the limitations of antioxidant use in male infertility.The
recent review gives an update of antioxidant treatment in male infertility.Improvement
of sperm parameters was reported in the majority of studies. Comparing different antioxidants
versus placebo showed low certainty of evidence with a serious risk of bias, and there
is a lack regarding certain doses, pregnancy rate, and live birth rate outcomes. Various
clinical studies and randomized control trials reported even negative outcomes. Conflicting
findings lead the attention to the study of biochemical features of the oxidant vs.
antioxidant equilibrium. Higher exposure to antioxidants will result in "reductive
stress", which has harmful effects on sperm function, moreover can negatively influence
embryo development. Reductive stress is as dangerous as oxidative stress and may act
as a cause of different human pathologies.An intact balance of oxidant and antioxidant
systems is required to normal sperm function. No guideline exists for the antioxidant
dose regimen and treatment duration. Overdosing can result in reductive stress, which
is also harmful to fertility and can cause several diseases. Assessment of the pre-treatment
redox status can be recommended before the administration of exogenous antioxidants.
