Alpha-lipoic acid rebalances redox and immune-testicular milieu in septic rats

The effect of alpha-lipoic acid on sperm functions in rodent models for male infertility: A systematic review

In this systematic review, we assessed different studies to evaluate the protective effect of alpha-lipoic acid (ALA), as a multifaceted antioxidant, on sperm functions in rodent models. Four databases were searched to find papers reporting the effect of ALA treatment on animal models of male infertility. Up to December 2022, 11,787 articles were identified to explain the ALA protective effects. The included studies were evaluated for eligibility and risk of bias (CRD42022341370). Finally, we identified 23 studies that explain the effect of ALA on sperm functions in rodents. Among them, 15 studies indicated that ALA could restore sperm parameters. Six studies showed a significant reduction in sperm DNA damage by ALA treatment. Seventeen papers displayed the ALA antioxidant ability, and four studies indicated the ALA anti-inflammatory effect. Besides, thirteen studies displayed that ALA could modulate androgenesis. Also, eighteen studies revealed that ALA restored the testicular architecture to normal, and was also effective in restoring reproductive performance in two included studies. This systematic review provided cogent evidence for the protective effect of ALA in rodent models for male infertility by re-establishing spermatogenesis and steroidogenesis and maintaining redox and immune systems homeostasis.

Effect of alpha-lipoic acid on oxidative stress, viability and motility in the common carp (Cyprinus carpio) spermatozoa after short-term storage and cryopreservation

As known for different metabolic functions, α-lipoic acid (ALA) has been tested for spermatozoa preservation of animals as well as of human, but not for fish spermatozoa. The present study determined the effects of ALA on short and long-term (cryopreservation) preservation of common carp (Cyprinus carpio) spermatozoa, for the first time. For that, spermatozoa were diluted in extenders containing 0 (control), 0.025, 0.05, 0.1, 0.5, 1, 2, 5, and 10 mM of ALA concentrations in both short-term preservation and cryopreservation. Spermatozoa motility parameters by computer-assisted semen analysis, viability, lipid peroxidation and catalase activity in spermatozoa were conducted in both 2nd and 120th hours of short-term storage and post-thaw samples. Higher percentages of total spermatozoa motility (80 ± 3) and viability (87 ± 3) were observed in 0.5 mM ALA group after 120 h of incubation. In post-thaw samples, higher percentages of these parameters were in 1 mM ALA group (74 ± 3 and 83 ± 2, respectively). Moreover, the results have shown that the addition of ALA until concentrations of 2 mM improved especially spermatozoa curvilinear velocity, maintained viability, and suppressed excessive lipid peroxidation during the preservations. In conclusion, the additions of 0.5 mM ALA for short-term preservation and 1 mM ALA for cryopreservation were the optimal concentrations, and shown the protective effects on common carp spermatozoa, when considering all measured parameters together.

Alpha-Lipoic Acid improves the testicular dysfunction in rats induced by varicocele

Alpha-lipoic acid (ALA) is a disulphide compound with multifunctional antioxidant properties and is soluble in both water and lipid. Several recent studies evaluated efficacy of ALA in various diseases related to oxidative damage such as diabetes, multiple sclerosis and Alzheimer and concluded that ALA can reduce oxidative stress by quenching reactive oxygen and nitrogen species, restoring antioxidants such as glutathione, vitamins C and E, and/or improving activity of antioxidant enzymes. Varicocele, an enlargement of the veins in scrotum, is considered as the most common repairable cause of male infertility and is associated with high levels of oxidative stress. In this study, surgical varicocele was induced in 30 adult male Wistar rats with other 20 rats serving as sham-operated and nonoperated control. Varicocele caused significant worsening of sperm parameters, DNA damage and lipid peroxidation 2 and 4 months after surgery. A 2-month ALA administration after surgery was able to revert these effects. These results clearly showed that ALA can reduce the negative side effects of elevated testicular temperature and increased oxidative stress in varicocelised rats. This study warrants future clinical research to assess whether ALA is of help in the treatment of infertile men with varicocele.

α-lipoic acid inhibits oxidative stress in testis and attenuates testicular toxicity in rats exposed to carbimazole during embryonic period

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The intrauterine exposure of carbiamzole (CBZ) on male fertility is not well defined.

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CBZ exposure in utero results in spermatotoxic effects and impaired steroidogenesis in offspring rats at their adulthood.

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Gestational exposure to CBZ augmented testicular oxidative damage in offspring rats.

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α-lipoic acid supplementation with its antioxidant properties ameliorated diminished male reproductive health in rats exposed to CBZ prenatally.

The aim of this study was to evaluate the probable protective effect of α-lipoic acid against testicular toxicity in rats exposed to carbimazole during the embryonic period. Time-mated pregnant rats were exposed to carbimazole from the embryonic days 9–21. After completion of the gestation period, all the rats were allowed to deliver pups and weaned. At postnatal day 100, F1 male pups were assessed for the selected reproductive endpoints. Gestational exposure to carbimazole decreased the reproductive organ indices, testicular daily sperm count, epididymal sperm variables viz., sperm count, viable sperm, motile sperm and HOS-tail coiled sperms. Significant decrease in the activity levels of 3β- and 17β-hydroxysteroid dehydrogenases and expression of StAR mRNA levels with a significant increase in the total cholesterol levels were observed in the testis of experimental rats over the controls. These events were also accompanied by a significant reduction in the serum testosterone levels in CBZ exposed rats, indicating reduced steroidogenesis. In addition, the deterioration of the testicular architecture and reduced fertility ability were noticed in the carbimazole exposed rats. Significant reduction in the activity levels of superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione content with a significant increase in the levels of lipid peroxidation were observed in the testis of carbimazole exposed rats over the controls. Conversely, supplementation of α-lipoic acid (70 mg/Kg bodyweight) ameliorated the male reproductive health in rats exposed to carbimazole during the embryonic period as evidenced by enhanced reproductive organ weights, selected sperm variables, testicular steroidogenesis, and testicular enzymatic and non-enzymatic antioxidants. To conclude, diminished testicular antioxidant balance associated with reduced spermatogenesis and steroidogenesis might be responsible for the suppressed reproduction in rats exposed to the carbimazole transplacentally. On the other hand, α-lipoic acid through its antioxidant and steroidogenic properties mitigated testicular toxicity which eventually restored the male reproductive health of carbimazole-exposed rats.

Effect of alpha-lipoic acid on boar spermatozoa quality during freezing–thawing

Alpha-lipoic acid (ALA) is known to be a natural antioxidant. The aim of the present study was to evaluate the cryoprotective effect of ALA on the motility of boar spermatozoa and its antioxidant effect on boar spermatozoa during freezing–thawing. Different concentrations (2.0, 4.0, 6.0, 8.0 or 10.0 mg/ml) of ALA were added to the extender used to freeze boar semen, and the effects on the quality and endogenous antioxidant enzyme activities of frozen–thawed spermatozoa were assessed. The results indicated that the addition of ALA to the extender resulted in a higher percentage of motile spermatozoa post-thaw (P < 0.05). The activities of superoxide dismutase, lactate dehydrogenase, glutamic-oxaloacetic transaminase and catalase improved after adding ALA to the extender (P < 0.05). Artificial insemination results showed that pregnancy rate and litter size were significantly higher at 6.0 mg/ml in the ALA group than in the control group (P < 0.05). In conclusion, ALA conferred a cryoprotective capacity to the extender used for boar semen during the process of freezing–thawing, and the optimal concentration of ALA for the frozen extender was 6.0 mg/ml.

Randomized, triple-blind, placebo-controlled clinical trial examining the effects of alpha-lipoic acid supplement on the spermatogram and seminal oxidative stress in infertile men

OBJECTIVE

To evaluate effects of supplementation with alpha-lipoic acid (ALA) on the spermatogram and seminal oxidative stress biomarkers.

DESIGN

Randomized, triple-blind, placebo-controlled clinical trial.

SETTING

Infertility clinic.

PATIENT(S)

Infertile men.

INTERVENTION(S)

ALA (600 mg) or placebo for 12 weeks.

MAIN OUTCOME MEASURE(S)

Semen analysis, anthropometric, dietary, and physical activity assessments, total antioxidant capacity, and malondialdehyde.

RESULT(S)

At the end of study, the total sperm count, sperm concentration, and motility in the intervention group were significantly higher than in the control group. In the ALA group, the total sperm count, sperm concentration, and motility levels were also significantly increased at the end of study compared with baseline values. However, there were no significant differences in ejaculate volume, normal morphology percentage, and live sperm between groups. ALA supplementation also resulted in a significant improvement in seminal levels of total antioxidant capacity (TAC) and malondialdehyde compared with the placebo.

CONCLUSION(S)

According to the results, medical therapy of asthenoteratospermia with ALA supplement could improve quality of semen parameters. However, further investigation is suggested in this regard.

CLINICAL TRIAL REGISTRATION NUMBER

IRCT2013111010181N3.

Amelioration of nandrolone decanoate-induced testicular and sperm toxicity in rats by taurine: effects on steroidogenesis, redox and inflammatory cascades, and intrinsic apoptotic pathway

The wide abuse of the anabolic steroid nandrolone decanoate by athletes and adolescents for enhancement of sporting performance and physical appearance may be associated with testicular toxicity and infertility. On the other hand, taurine; a free β-amino acid with remarkable antioxidant activity, is used in taurine-enriched beverages to boost the muscular power of athletes. Therefore, the purpose of this study was to investigate the mechanisms of the possible protective effects of taurine on nandrolone decanoate-induced testicular and sperm toxicity in rats. To achieve this aim, male Wistar rats were randomly distributed into four groups and administered either vehicle, nandrolone decanoate (10mg/kg/week, I.M.), taurine (100mg/kg/day, p.o.) or combination of taurine and nandrolone decanoate, for 8 successive weeks. Results of the present study showed that taurine reversed nandrolone decanoate-induced perturbations in sperm characteristics, normalized serum testosterone level, and restored the activities of the key steroidogenic enzymes; 3β-HSD, and 17β-HSD. Moreover, taurine prevented nandrolone decanoate-induced testicular toxicity and DNA damage by virtue of its antioxidant, anti-inflammatory, and anti-apoptotic effects. This was evidenced by taurine-induced modulation of testicular LDH-x activity, redox markers (MDA, NO, GSH contents, and SOD activity), inflammatory indices (TNF-α, ICAM-1 levels, and MMP-9 gene expression), intrinsic apoptotic pathway (cytochrome c gene expression and caspase-3 content), and oxidative DNA damage markers (8-OHdG level and comet assay). In conclusion, at the biochemical and histological levels, taurine attenuated nandrolone decanoate-induced poor sperm quality and testicular toxicity in rats.

Alfa-lipoic acid protects testosterone secretion pathway and sperm quality against 4-tert-octylphenol induced reproductive toxicity

The protective effect of α-lipoic acid (LA) (50 mg/kg bw) against 4-tert-octylphenol (OP) (50 mg/kg bw) induced reproductive toxicity in male rats was studied. LA was injected 1h prior to OP administration three times a week. OP caused significant increase in oxidative stress in hypothalamus and epididymal sperm, disturbed hormonal levels in serum, decreased sperm quality, increased DNA fragmentation and loss of 35 and 95 kDa proteins in sperm, as well as elevated proliferating index in testis. LA protected against oxidative stress through promoting the levels of glutathione and glutathione-S-transferase in hypothalamus and sperm. In addition, LA prevented the decrease in testosterone, dehydroepiandrosterone sulfate, 3β-hydroxysteroid dehydrogenase, and inhibited the elevations in sex-hormone-binding globulin levels and showed normal sperm quality. LA modulated proliferation of germ cell, protected against DNA fragmentation and maintained membrane protein organization in the sperm. In conclusion, LA normalized oxidative stress and protected testosterone synthesis pathway across hypothalamus-testicular axis and sperm quality indicating its defensive influence against OP-induced oxidative reproductive dysfunction in male rats.

Alfa-lipoic acid controls tumor growth and modulates hepatic redox state in Ehrlich-ascites-carcinoma-bearing mice

The effect of oral supplementation of α-lipoic (LA) on growth of Ehrlich ascites carcinoma cells (EACs) and hepatic antioxidant state in mice was investigated. The results revealed that α-lipoic (LA) acid at 50 mg/kg body wt reduced the viability and volume of EAC cells and increased the survival of the treated animals. In addition, LA normalized oxidative stress in liver of mice-bearing EAC cells evidenced by increasing the levels of total thiols, glutathione, glutathione-S-transferase, superoxide dismutase, and catalyse. On the other hand, significant decreases in the levels of malondialdehyde and protein carbonyl were demonstrated in liver indicating controlled oxidative stress in these animals. As a consequence, LA regulated liver enzymes, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase. The data also indicated the efficiency of LA as cancer inhibitor and therapeutic influence. In conclusion, the present data suggest LA as a potential therapeutic complement in the treatment or prevention of different pathologies that may be related to an imbalance of the cellular oxidoreductive status associated with malignancy.