Impact of seminal trace element and glutathione levels on semen quality of Tunisian infertile men

Abstract

BackgroundGrowing evidence indicates that oxidative stress can be a primary cause of male infertility. Non-enzymatic antioxidants play an important protective role against oxidative damages and lipid peroxidation. Human seminal plasma is a natural reservoir of antioxidants. The aim of this study was to determine glutathione (GSH) concentrations, trace element levels (zinc and selenium) and the lipid peroxidation end product, malondialdehyde (MDA), in the seminal plasma of men with different fertility potentials.MethodsSemen samples from 60 fertile men (normozoospermics) and 190 infertile patients (74 asthenozoospermics, 56 oligozoospermics, and 60 teratozoospermics) were analyzed for physical and biochemical parameters. Zinc (Zn) and selenium (Se) levels were estimated by atomic absorption spectrophotometry. Total GSH (GSHt), oxidized GSH (GSSG), reduced GSH (GSHr) and MDA concentrations were measured spectrophotometrically.ResultsZn and Se concentrations in seminal plasma of normozoospermics were more elevated than the three abnormal groups. Nevertheless, only the Zn showed significant differences. On the other hand, Zn showed positive and significant correlations with sperm motility (P = 0.03, r = 0.29) and count (P < 0.01, r = 0.49); however Se was significantly correlated only with sperm motility (P < 0.01, r = 0.36). GSHt, GSSG and GSHr were significantly higher in normozoospermics than in abnormal groups. We noted a significant association between seminal GSHt and sperm motility (P = 0.03). GSSG was highly correlated to sperm motility (P < 0.001) and negatively associated to abnormal morphology (P < 0.001). GSHr was significantly associated to total sperm motility (P < 0.001) and sperm count (P = 0.01). MDA levels were significantly higher in the three abnormal groups than in normozoospermics. Rates of seminal MDA were negatively associated to sperm motility (P < 0.01; r = -0.24) and sperm concentration (P = 0.003; r = -0.35) Meanwhile, there is a positive correlation between seminal lipid peroxidation and the percentage of abnormal morphology (P = 0.008).ConclusionsThis report revealed that decreased seminal GSH and trace element deficiencies are implicated in low sperm quality and may be an important indirect biomarker of idiopathic male infertility. Our results sustain that the evaluation of seminal antioxidant status in infertile men is necessary and can be helpful in fertility assessment from early stages.

Effects of reduced seminal enzymatic antioxidants on sperm DNA fragmentation and semen quality of Tunisian infertile men

“…ROS are highly reactive oxidizing agents belonging to the class of free radicals containing one or more unpaired electrons which are continuously being generated through metabolic and physiopathologic processes. Unlike other cells, spermatozoa are more vulnerable to OS because their plasma membrane is rich of polyunsaturated fatty acids (PUFAs) and membrane-bound nicotinamide adenine dinucleotide phosphate (NADPH) oxidase [6,7].…”

“…In effect, ROS have been shown to correlate with reduced male fertility by causing membrane lipid peroxidation (LPO) and affecting sperm concentration, morphology and motility [6,7]. LPO in the sperm cell membranes is an autocatalytic, self-propagating reaction, which can cause cell dysfunction associated with the loss of the membrane function, integrity and finally leads to decreased fertilizing ability of spermatozoa [5].…”

“…These enzymes are constitutively expressed in human semen [1,27]. The free radical scavenging activity of SOD, GPX and CAT protects the sperm membrane against the LPO, preserving its integrity and hence maintaining the normal sperm parameters of motility and morphology [6,7]. Studies by [2,8] have also implicated the role of antioxidants in protecting the sperm nuclear genome from oxidative strand breaks and base modifications.…”

“…LPO in the sperm cell membranes is an autocatalytic, self-propagating reaction, which can cause cell dysfunction associated with the loss of the membrane function, integrity and finally leads to decreased fertilizing ability of spermatozoa [5]. Malnodialdehyde acid (MDA) is the major product of LPO and studies have implicated increased MDA levels with poor sperm parameters in infertile men [6,7]. Moreover, it was reported that ROS react with sperm DNA leading to oxidative base modifications and high frequencies of DNA fragmentation [3].…”

“…To protect spermatozoa from the ROS-induced damage, seminal plasma is well equipped with an array of antioxidant systems comprising natural antioxidants (Vitamines A, C, E, ascorbate and glutathione) and enzymatic antioxidants [6,7]. The enzymatic antioxidants include the following components: superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT).…”