Effect of Zinc, Selenium, and Vitamin E Administration on Semen Quality and Fertility of Male Dromedary Camels with Impotentia Generandi

Trace and essential elements as vital components to improve the performance of the male reproductive system: Implications in cell signaling pathways

Successful male fertilization requires the main processes such as normal spermatogenesis, sperm capacitation, hyperactivation, and acrosome reaction. The progress of these processes depends on some endogenous and exogenous factors. So, the optimal level of ions and essential and rare elements such as selenium, zinc, copper, iron, manganese, calcium, and so on in various types of cells of the reproductive system could affect conception and male fertility rates. The function of trace elements in the male reproductive system could be exerted through some cellular and molecular processes, such as the management of active oxygen species, involvement in the action of membrane channels, regulation of enzyme activity, regulation of gene expression and hormone levels, and modulation of signaling cascades. In this review, we aim to summarize the available evidence on the role of trace elements in improving male reproductive performance. Also, special attention is paid to the cellular aspects and the involved molecular signaling cascades.

A Dietary Supplement Jinghuosu Ameliorates Reproductive Damage Induced by Tripterygium Glycosides

OBJECTIVE

To determine the possible protective effects of Jinghuosu, a dietary supplement (DS), on tripterygium glycosides (TG)-induced reproductive system injury in rats and its underlying mechanisms.

METHODS

A reproductive damage model was established in rats by feeding of TGs. Twenty-eight male Sprague Dawley rats were randomly divided into 4 groups using a random number table (n=7 in each): control (C) group, model (M) group, DS group and L-carnitine (LC) group. Rats in M, DS and LC groups received 40 mg/kg TGs orally. Starting from the 5th week, after administration of TGs for 4 h every day, rats in DS and LC groups were administered with 2.7 g/kg DS and 0.21 g/kg LC, respectively, for protective treatment over the next 4 weeks. Rats in Group C continued to receive the control treatment. Hematoxylin-eosin staining was used for histopathological analysis of rat testicular tissues. Enzyme-linked immunosorbent assay was performed to measure alkaline phosphatase (ALP), lactate dehydrogenase, alcohol dehydrogenase, total antioxidant capacity (T-AOC), superoxide dismutase, glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) concentrations. Chemiluminescence assay was used to determine the serum testosterone content. Quantitative real-time PCR and Western blotting were conducted to analyze the expression of genes and proteins related to the testosterone synthesis pathway and the nuclear factor erythroid 2-related factor 2/heme oxygenase 1 antioxidant pathway.

RESULTS

Oral administration of TGs induced significant increases in the testicular levels of zinc transporter 1 and MDA (P<0.05). On the other hand, sperm concentration, sperm motility, and serum testosterone, serum zinc, testicular zinc, Zrt-, Irt-like protein 1, ALP, luteinizing hormone (LH) receptor, steroidogenic acute regulatory protein, Cytochrome P450 family 11 subfamily A member 1, 3 β -hydroxysteroid dehydrogenase 1 T-AOC, GSH-Px, nuclear factor erythroid 2-related factor 2, heme oxygenase-1 and NAD (P)H: quinone oxidoreductase 1 levels decreased following TGs exposure (P<0.05). All of these phenotypes were evidently reversed by DS (P<0.05).

CONCLUSION

DS Jinghuosu protects against TG-induced reproductive system injury in rats, probably by improving zinc homeostasis, enhancing the testosterone synthesis and attenuating oxidative stress.

Melatonin and selenium supplementation in extenders improves the post-thaw quality parameters of rat sperm

Objective

The aim of this study was to determine the effects of melatonin and selenium in freezing extenders on frozen-thawed rat sperm.

Methods

Semen samples were collected from 20 adult male Wistar albino rats. Following dilution, the samples were divided into six groups: four cryopreserved groups with 1 mM and 0.5 mM melatonin and selenium supplements, and two fresh and cryopreserved control groups. The rapid freezing technique was used to freeze the samples. Flow cytometry was used to assess plasma membrane integrity, mitochondrial membrane potential, and DNA damage, while computer-assisted sperm analysis was used to assess motility.

Results

Total motility was higher in the 1 mM melatonin supplementation group than in the cryopreserved control group (mean±standard error of the mean, 69.89±3.05 vs. 59.21±1.31; p≤0.05). The group with 1 mM selenium had the highest plasma membrane integrity (42.35%±1.01%). The cryopreserved group with 0.5 mM selenium had the highest mitochondrial membrane potential, whereas the cryopreserved control group had the lowest (45.92%±4.53% and 39.45%±3.52%, respectively).

Conclusion

Cryopreservation of rat semen supplemented with 1 mM melatonin increased sperm motility after freeze-thawing, while supplementation with 0.5 mM selenium increased mitochondrial activity.

Effects of vitamin C, vitamin E, selenium, zinc, or their nanoparticles on camel epididymal spermatozoa stored at 4 °C

This study determined the effects of antioxidant supplementation and storage time at cool temperatures on the characteristics of epididymal camel spermatozoa. Camel testes were collected at the abattoir after animal slaughtering and kept at 4 °C during transportation and until processing (max 6 h). Spermatozoa were retrieved and diluted with SHOTOR extender, split in aliquots, supplemented with the following antioxidants: 200 μm/mL vitamin E, 1.0 g/L vitamin C, 1 μg/mL selenium nanoparticles, 50 μg/mL zinc nanoparticles, 2 μg/mL sodium selenite, and 100 μg/mL zinc sulfate, and stored at 4 °C for 2, 48, 96, and 144 h. The storage time significantly affected (P < 0.05) the sperms' motility and livability, the sperms' membrane integrity, and the percentages of cytoplasmic droplets as well as the percentage of morphologically normal spermatozoa. Epididymal sperm characteristics (progressive motility, livability, membrane integrity, and abnormalities) were significantly improved (P < 0.05) when the spermatozoa were diluted with antioxidants as compared with the control group, and the best additives were identified as nano-selenium, sodium selenite, nano-zinc, and zinc sulfate. In conclusion, adding nano-sized minerals or inorganic trace elements and vitamins maintained the progressive motility, livability, and membrane integrity, and decreased abnormalities and cytoplasmic droplet percentages of epididymal camel spermatozoa stored at 4 °C up to 144 h.