The line of defense employed against oxidative insult consists of antioxidants which are agents that reduce the level of OS by breaking oxidative chain reactions and can be classified according to two subsets: enzymatic or "natural" such as superoxide dimutase, catalase, and glutathione peroxidase, and nonenzymatic or "synthetic" chain-breaking antioxidants for example pyruvate, glutathione, and carnitine, all of which can offer protection to spermatozoa against hazardous OS produced by the leukocytes [1, 2, 10, 77, 78].

These defensive compounds against free radical-induced OS can be regarded in two categories: preventative and scavenging antioxidants [ 43] In human semen, examples of the three main antioxidants present are urate, thiols, and ascorbate [77]. Antioxidative action effective in offering protection to spermatozoa below a critical threshold of ROS can be considered to consist of two stages. The primary step may be viewed as preventative, whereby the ROS are scavenged directly by the antioxidative compounds present in the seminal plasma [1]. Following this initial response initiated by antioxidative reactions is the secondary stage which encapsulates the influence that antioxidants may have on the actions that the ROS have already initiated. This step is regarded as interception which includes interruptions of chain reactions, for example the process of lipid peroxidation [1] The cytoplasm of the spermatozoa also contain a low concentration of antioxidants such as catalase and superoxise dimutase, which are capable of offering additional protection against ROS [10, 79]. However, due to the small volume of cytoplasm in each spermatozoa, this defensive approach against extracellular free radicals is less effective compared to the antioxidants abundantly present in seminal plasma [80] .

Despite the antioxidative system to provide protection against OS, this pathway can be easily overwhelmed. The rapid increase in the production of leukocyte-derived ROS can overpower the antioxidative capabilities of the seminal plasma and spermatozoa [57], The effect of leukocytospermia is highly effective in causing potential DNA damage towards spermatozoa at varying stages of maturation which can decrease the chances of successful oocyte fertilization [6, 39]. Damaging effects on the sperm genome that can arise from OS include: chromatin cross-linkage, base modification, and strand breakages in spermatozoa [31]. These DNA damages work in a cascade-like manner [ 7] and abnormal spermatozoa from leukocytospermic samples have more than doubled levels of impaired DNA under the influence of OS when compared to similar forms of irregular spermatozoa in samples that are not leukocytospermic [81].

Pregnancy Guide

Pregnancy Guide

A Beginner's Guide to Healthy Pregnancy. If you suspect, or know, that you are pregnant, we ho pe you have already visited your doctor. Presuming that you have confirmed your suspicions and that this is your first child, or that you wish to take better care of yourself d uring pregnancy than you did during your other pregnancies; you have come to the right place.

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