Reactive oxygen species and sperm cells

The effect of dietary supplementation with blueberry, α-tocopherol or astaxanthin on oxidative stability of Arctic char (Salvelinus alpinus) semen

The objective was to determine the oxidative stability of Arctic char (Salvelinus alpinus) semen following dietary supplementation with lowbush blueberry (Vaccinium angustifolium) product, alpha-tocopherol, alpha-tocopherol+blueberry product, or alpha-tocopherol+astaxanthin. Sperm lipid peroxidation was initiated by challenging with ferrous sulphate/ascorbic acid (Fe(++)/Asc) at level of 0.04/0.2 mmol/L. Addition of blueberry, alpha-tocopherol, or both to char diets inhibited semen lipid peroxidation by: (a) decreasing the rate of sperm lipid peroxidation, an effect which was more pronounced with alpha-tocopherol treatments; and (b) increasing the antioxidant potential of seminal plasma, based on the lipid peroxidation process of sperm and an in vitro chicken brain tissue model. Dietary supplementation with astaxanthin and alpha-tocopherol had the same effect as the supplementation with alpha-tocopherol alone on inhibiting the lipid peroxidation process of sperm and chicken brain. Catalase-like activity increased significantly in sperm of fish fed alpha-tocopherol, blueberry, or both. There was a negative correlation (r= -0.397, P < 0.05) between catalase-like activity in sperm cells and the rate of sperm lipid peroxidation. Seminal plasma alpha-tocopherol levels increased significantly in fish supplemented with alpha-tocopherol alone or in combination with blueberry or astaxanthin. There were negative correlations between seminal plasma alpha-tocopherol levels and lipid peroxidation rates of sperm cells (r= -0.625, P < 0.01) and brain tissue (r= -0.606, P < 0.01). In conclusion, dietary supplementation of blueberry product or alpha-tocopherol inhibited lipid peroxidation in Arctic char semen. Further experiments are needed to test the effect of dietary blueberry and antioxidants on Arctic char semen quality during liquid and cryopreserved storage.

Male idiopathic oligoasthenoteratozoospermia

Idiopathic oligoasthenoteratozoospermia (iOAT) affects approximately 30% of all infertile men. This mini-review discussed recent data in this field. Age, non-inflammatory functional alterations in post-testicular organs, infective agents (Chlamydia trachomatis, herpes virus and adeno-associated viruses), alterations in gamete genome, mitochondrial alterations, environmental pollutants and "subtle" hormonal alterations are all considered possible causes of iOAT. Increase of reactive oxygen species in tubules and in seminal plasma and of apoptosis are reputed to affect sperm concentration, motility and morphology. iOAT is commonly diagnosed by exclusion, nevertheless spectral traces of the main testicular artery may be used as a diagnostic tool for iOAT. The following can be considered therapies for iOAT: 1) tamoxifen citrate (20 mg/d) + testosterone undecanoate (120 mg/d) (pregnancy rate per couple/month [prcm]: 3.8%); 2) folic acid (66 mg/d) + zinc sulfate (5 mg/d); 3) L-carnitine (2 g/d) alone or in combination with acetyl-L-carnitine (1 g/d) (prcm: 2.3%); and 4) both carnitines = one 30 mg cinnoxicam suppository every 4 days (prcm: 8.5%). Alpha-blocking drugs improved sperm concentration but not morphology, motility or pregnancy rate. Tranilast (300 mg/d) increased sperm parameters and pregnancy rates in an initial uncontrolled study. Its efficacy on sperm concentration (but not on sperm motility, morphology or prcm) was confirmed in subsequent published reports. The efficacy of tamoxifen + testosterone undecanoate, tamoxifen alone, and recombinant follicle-stimulating hormone is still a matter for discussion.

Lycopene prevents adriamycin-induced testicular toxicity in rats

OBJECTIVE

To investigate a possible protective role of lycopene on adriamycin (ADR)-induced spermiotoxicity using quantitative, biochemical and histopathological approaches.

DESIGN

Experimental study.

SETTING

Firat University Medical School, Experimental Research Centre, Elazig, Turkey.

ANIMALS

Twenty four Sprague Dawley rats (8-weeks old)

INTERVENTION(S)

Adriamycin (10 mg kg(-1)) was intraperitoneally injected and lycopene (4 mg kg(-1)) was administered by gavage in corn oil.

MAIN OUTCOME MEASURE(S)

Reproductive organ weights were evaluated along with epididymal sperm concentration, motility and morphology. Testicular histological findings, oxidative status and plasma testosterone levels were also determined.

RESULT(S)

Lycopene ameliorated ADR-induced reductions in both testes and epididymis weights. ADR decreased sperm motility, increased total abnormal sperm rates, but epididymal sperm concentration was not changed compared to control. A marked normalization was achieved in sperm motility and morphology in pretreatment with lycopene. Although testosterone level was decreased in ADR group compared to control, no changes were observed in pretreatment group. An increase in malondialdehyde and a decrease reduced glutathione concentrations were detected in alone ADR group compared to control. Pretreatment with lycopene restored significantly malondialdehyde and reduced glutathione concentrations. ADR caused severe degenerative changes in germinative cells, atrophy in the diameter size of seminiferous tubules and germinative cell thickness. However, ADR-induced histopathological alterations were effectively reverted by pretreatment with lycopene.

CONCLUSION(S)

This study clearly indicates that ADR treatment markedly impaired testicular function and that pretreatment with lycopene might prevent this toxicity.

Astaxanthin, a carotenoid with potential in human health and nutrition

Astaxanthin (1), a red-orange carotenoid pigment, is a powerful biological antioxidant that occurs naturally in a wide variety of living organisms. The potent antioxidant property of 1 has been implicated in its various biological activities demonstrated in both experimental animals and clinical studies. Compound 1 has considerable potential and promising applications in human health and nutrition. In this review, the recent scientific literature (from 2002 to 2005) is covered on the most significant activities of 1, including its antioxidative and anti-inflammatory properties, its effects on cancer, diabetes, the immune system, and ocular health, and other related aspects. We also discuss the green microalga Haematococcus pluvialis, the richest source of natural 1, and its utilization in the promotion of human health, including the antihypertensive and neuroprotective potentials of 1, emphasizing our experimental data on the effects of dietary astaxanthin on blood pressure, stroke, and vascular dementia in animal models, is described.

Oleoylethanolamide protects human sperm cells from oxidation stress: studies on cases of idiopathic infertility

N-acylethanolamides are naturally occurring hydrophobic molecules usually present in a very small amount in many mammalian tissues and cells. The presence of N-acylethanolamides has also been demonstrated in human reproductive tracts and fluids, although their biological effects and molecular mechanisms of action are not yet completely elucidated. It is known that some N-acylethanolamides, such as oleoylethanolamide, have antioxidative properties. The aim of this study was to test whether oleoylethanolamide could protect sperm cells from reactive oxygen species-induced oxidative damage in cases of idiopathic infertility, because the excessive generation of these radicals was associated with this pathology. Our results show that 2.5 nM oleoylethanolamide in vitro supplementation significantly reduces DNA strand breaks both in fertile and infertile subjects. Moreover, oleoylethanolamide increases kinematic parameters, such as curvilinear velocity and amplitude of lateral head displacement and hyperactivation, both in the presence and in the absence of oxidative stress. Results of this study support the hypothesis of a possible protective action of oleoylethanolamide against reactive oxygen species, which could explain its beneficial effects on in vitro capacitated spermatozoa.

Fundamental roles of reactive oxygen species and protective mechanisms in the female reproductive system

Controlled oxidation, such as disulfide bond formation in sperm nuclei and during ovulation, plays a fundamental role in mammalian reproduction. Excess oxidation, however, causes oxidative stress, resulting in the dysfunction of the reproductive process. Antioxidation reactions that reduce the levels of reactive oxygen species are of prime importance in reproductive systems in maintaining the quality of gametes and support reproduction. While anti-oxidative enzymes, such as superoxide dismutase and peroxidase, play a central role in eliminating oxidative stress, reduction-oxidation (redox) systems, comprised of mainly glutathione and thioredoxin, function to reduce the levels of oxidized molecules. Aldo-keto reductase, using NADPH as an electron donor, detoxifies carbonyl compounds resulting from the oxidation of lipids and proteins. Thus, many antioxidative and redox enzyme genes are expressed and aggressively protect gametes and embryos in reproductive systems.

Protective role of lycopene on cisplatin-induced changes in sperm characteristics, testicular damage and oxidative stress in rats

The aim of this study was to investigate the possible protective role of lycopene on cisplatin (CP)-induced spermiotoxicity using quantitative, biochemical and histopathological approaches. Adult male Sprague-Dawley rats were randomly divided into four groups. The control group received physiological saline; animals in cisplatin group received only cisplatin; pre-treatment group received a 10-day of lycopene before administration of cisplatin while animals in post-treatment group received a 5-day of lycopene following administration of cisplatin. Cisplatin (7 mg kg(-1)) was intraperitoneally (i.p.) injected as a single dose and lycopene (4 mg kg(-1)) was administered by gavage in corn oil. Traits of reproductive organs; sperm characteristics, testicular histological findings, plasma testosterone levels and the testicular tissue oxidative status were determined. Administration of cisplatin to rats decreased sperm concentration (p < 0.05) and sperm motility (p < 0.001), increased total abnormal sperm rates (p < 0.05) as compared with the control group. While a marked normalization was achieved only in sperm concentration with lycopene in pre-treatment group, significant normalizations were achieved in the sperm concentration, sperm motility, total abnormal sperm rates in post-treatment group. No significant differences in levels of testosterone were observed among all groups. An increase in testes malondialdehyde concentrations (p < 0.05) and glutathione peroxidase activities (p < 0.001) were detected while significant decreases in glutathione levels (p < 0.001) in cisplatin alone group when compared to control group. While pre-treatment with lycopene restoring only malondialdehyde concentrations, its post-treatment caused normalization in both malondialdehyde and glutathione levels when compared with the cisplatin alone group. On the other hand, significant increases were determined in GSH-Px activities in all experimental groups when compared with the control group. Although the mechanism is not clear, the results from this experimental study suggest that the lycopene have a possible protective effect against cisplatin-induced spermiotoxicity, effect of giving lycopene after cisplatin being superior to the giving it before cisplatin.