Effect of Oral Zinc Supplementation on the Thiol Oxido-Reductive Index and Thiol-Related Enzymes in Seminal Plasma and Spermatozoa of Iraqi Asthenospermic Patients

Abstract

A thiol group plays an essential role in sperm metabolism and the antioxidative defense state. Zinc is the second most abundant element in the human body, following iron. The present study was conducted to study the effect of zinc supplementation on the characteristics of semen along with thiol and thiol-related enzymes in semen of asthenospermic patients. Semen samples were obtained from 60 fertile and 60 asthenospermic men, from couples who had consulted the infertility clinic of Babil Hospital (Hillah city, Iraq). The subfertile group was treated with zinc; every participant took two 220 mg capsules of zinc sulfate per day for 3 months. Semen samples were obtained (before and after zinc supplementation). The levels of reduced thiol, oxidized thiol, thiol oxido-reductive index, and thiol-related enzymes activities were determined in spermatozoa and seminal plasma of patients and healthy groups. Oxidized thiol levels were significantly higher in the infertile patients compared to that in the fertile group. Conversely, reduced thiol level, sulfhydryl oxidase activity, and glutathione peroxidase activity significantly decreased in the infertile patients compared to that in the fertile group. Oxidized thiol levels, reduced thiol levels, and thiol-related enzymes activities of the infertile patients were restored to normal values after treatment with zinc. However, reduced and oxidized thiol levels in spermatozoa did not change significantly in the group treated with zinc. The quantitative values for RSH/RSSR and thiol-related enzymes may provide useful means to qualitatively express the oxidant/antioxidant balance in clinical and epidemiologic studies. ClinicalTrials.gov Identifier: NCT02985905.

Oxidative Stress Indexes for Diagnosis of Health or Disease in Humans

“…In this review, we found sixty-six studies that refer them. All the studies, except one [72], were carried out in Turkey in a variety of age groups and clinical situations since 2015. The thiols can be measured in serum/plasma, but semen sample [72] and aqueous humor [73] also have been used, and they are applicable to evaluate the oxidative state in a variety of clinical events, from alterations during pregnancy, cardiovascular, psychiatric, neurological, hereditary, infectious diseases, etc.…”

“…All the studies, except one [72], were carried out in Turkey in a variety of age groups and clinical situations since 2015. The thiols can be measured in serum/plasma, but semen sample [72] and aqueous humor [73] also have been used, and they are applicable to evaluate the oxidative state in a variety of clinical events, from alterations during pregnancy, cardiovascular, psychiatric, neurological, hereditary, infectious diseases, etc. Although the information is abundant, the analysis result has not shown substantial differences among the studies, because all agree in recommending the thiol ratios to their use in clinical events; therefore, we only did a descriptive analysis of the information (Table 5) and presented references found in a supplementary file in case of any reader is interested in consulting the information.…”

An impact of selected micronutrients on fertility

“…Other study, conducted by Camejo et al [26] on normozoospermic man and those who had varicocele, showed that higher doses of zinc can positively affect sperm concentration. According to Alsalman [27] et al the sperm motility, sperm count and volume of semen increase after Zn completion in asthenospermic patients. Ajina et al…”

The Role of Zinc in Male Fertility

“…Thus, it is possible that a significant proportion of unexplained infertility is, in fact, caused by spermatozoon failure to perform proper capacitation. It was shown that zinc deficiency is correlated with a decrease in male fertility [ 25 , 26 ], and the presence of zinc in the diets of humans [ 27 ] and domestic animals [ 28 , 29 , 30 ] is required for the achievement of an optimal fertility rate. The addition of Zn 2+ to semen extenders before freezing reduces reactive oxygen species (ROS) [ 31 ]; however, excess Zn 2+ can act as a pro-oxidant, leading to mitochondrial oxidative stress [ 32 ].…”

“…Zinc-deficient nutrition causes a low quality of sperm and male infertility [ 11 ], and the presence of zinc in the diets of humans [ 27 ] and domestic animals [ 28 , 29 , 30 , 147 ] is required for the achievement of an optimal fertility rate. Nevertheless, recent clinical studies investigated the effect of dietary supplements containing zinc and showed that zinc supplementation does not appear to improve pregnancy rates, sperm counts or sperm function [ 148 ].…”