Querectin Alleviates Zinc Oxide Nanoreprotoxicity in Male Albino Rats

Mitigating effect of gallic acid on zinc oxide nanoparticles and arsenic trioxide-induced spermatogenesis suppression, testicular injury, hormonal imbalance, and immunohistochemical changes in rats

The current study compared the effects of incorporated exposure to arsenic trioxide (As) and zinc oxide nanoparticles (ZnONPs) on male reproductive hormones, oxidative stress, and inflammatory biomarkers in adult rats to each metal alone. A defensive trial with gallic acid (GA) has also been studied. A total of 60 adult male Sprague Dawley rats were categorized into six groups: control, GA (20 mg/kg), ZnONPs (100 mg/kg), As (8 mg/kg), ZnONPs with As, and GA concurrently with ZnONPs and As at the same previous doses. The regimens were applied for 60 days in sequence. Current findings showed significant weight loss in all study groups, with testicular weights significantly decreased in the As and combined groups. Testosterone, follicular stimulating hormone, and luteinizing hormone serum levels were also considerably reduced, while serum levels of estradiol increased. Inducible nitric oxide synthase (iNOS) immunoexpression was significantly upregulated while proliferating cell nuclear antigen (PCNA) was downregulated. Moreover, there was a significant elevation of testicular malondialdehyde, reduction of testicular superoxide dismutase, and glutathione peroxidase with disruptive testes, prostate glands, and seminal vesicle alterations in all experimental groups with marked changes in the combined group. Additionally, the present results revealed the protective effects of GA on ZnONPs and As adverse alterations in rats. GA enhanced sperm picture, oxidant status, and hormonal profile. Also, it modulates iNOS and PCNA immunoexpression and recovers the histoarchitecture of the testes, prostate glands, and seminal vesicles. Ultimately, GA may be a promising safeguarding agent against ZnONPs and As-induced disturbances to reproductive parameters.

Toxicological inhalation studies in rats to substantiate grouping of zinc oxide nanoforms

BACKGROUND

Significant variations exist in the forms of ZnO, making it impossible to test all forms in in vivo inhalation studies. Hence, grouping and read-across is a common approach under REACH to evaluate the toxicological profile of familiar substances. The objective of this paper is to investigate the potential role of dissolution, size, or coating in grouping ZnO (nano)forms for the purpose of hazard assessment. We performed a 90-day inhalation study (OECD test guideline no. (TG) 413) in rats combined with a reproduction/developmental (neuro)toxicity screening test (TG 421/424/426) with coated and uncoated ZnO nanoforms in comparison with microscale ZnO particles and soluble zinc sulfate. In addition, genotoxicity in the nasal cavity, lungs, liver, and bone marrow was examined via comet assay (TG 489) after 14-day inhalation exposure.

RESULTS

ZnO nanoparticles caused local toxicity in the respiratory tract. Systemic effects that were not related to the local irritation were not observed. There was no indication of impaired fertility, developmental toxicity, or developmental neurotoxicity. No indication for genotoxicity of any of the test substances was observed. Local effects were similar across the different ZnO test substances and were reversible after the end of the exposure.

CONCLUSION

With exception of local toxicity, this study could not confirm the occasional findings in some of the previous studies regarding the above-mentioned toxicological endpoints. The two representative ZnO nanoforms and the microscale particles showed similar local effects. The ZnO nanoforms most likely exhibit their effects by zinc ions as no particles could be detected after the end of the exposure, and exposure to rapidly soluble zinc sulfate had similar effects. Obviously, material differences between the ZnO particles do not substantially alter their toxicokinetics and toxicodynamics. The grouping of ZnO nanoforms into a set of similar nanoforms is justified by these observations.

Oxidative Stress Biomarkers in Male Infertility: Established Methodologies and Future Perspectives

Male fertility can be affected by oxidative stress (OS), which occurs when an imbalance between the production of reactive oxygen species (ROS) and the body's ability to neutralize them arises. OS can damage cells and influence sperm production. High levels of lipid peroxidation have been linked to reduced sperm motility and decreased fertilization ability. This literature review discusses the most commonly used biomarkers to measure sperm damage caused by ROS, such as the high level of OS in seminal plasma as an indicator of imbalance in antioxidant activity. The investigated biomarkers include 8-hydroxy-2-deoxyguanosine acid (8-OHdG), a marker of DNA damage caused by ROS, and F2 isoprostanoids (8-isoprostanes) produced by lipid peroxidation. Furthermore, this review focuses on recent methodologies including the NGS polymorphisms and differentially expressed gene (DEG) analysis, as well as the epigenetic mechanisms linked to ROS during spermatogenesis along with new methodologies developed to evaluate OS biomarkers. Finally, this review addresses a valuable insight into the mechanisms of male infertility provided by these advances and how they have led to new treatment possibilities. Overall, the use of biomarkers to evaluate OS in male infertility has supplied innovative diagnostic and therapeutic approaches, enhancing our understanding of male infertility mechanisms.

Ameliorative effects of Dunaliella salina microalgae on nanoparticle (ZnO NPs)-induced toxicity in fish

Dunaliella salina (D. salina) is a well-known microalga that contains considerable amounts of nutritious and medicinal bioactive components. This work studied the modulatory role of D. salina against zinc oxide nanoparticle (ZnO NPs)-induced neurotoxic effects in adult zebrafish. Fishes were subjected to 0.69 mg L-1 (1/5th 96-h LC50) for 4 weeks; then, fishes were supplemented with D. salina in the diet for 2 weeks at two levels (15 and 30%). Exposure to ZnO NPs induced a significant increase in the levels of reactive oxygen species (ROS), hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OH-dG) while accompanied with downregulation of antioxidant genes in the brain of exposed fishes. Brain neurochemistry and enzyme activities were also altered following ZnO NP exposure. ZnO NPs significantly reduced the neurotransmitters and acetylcholinesterase (AchE) activity while increasing Alzheimer's disease-related proteins and inflammatory response via upregulation of tumor necrosis factor (TNF-α). Additionally, ZnO NPs increased the indices of brain's DNA oxidative damage, increasing brain tissue's metallothionein (MT) and zinc residues. ZnO NPs upregulated the transcription patterns of apoptosis-related genes (casp3 and p53). D. salina dietary co-supplementation with ZnO NPs alleviated the ZnO NPsZnO NP-induced neuro-oxidative damages by lowering the lipid, DNA damage, and inflammatory biomarkers. Besides, D. salina alleviating responses were linked with increasing the levels of the assessed antioxidants. Conclusively, D. salina dietary supplementation induced potential alleviating effects of the ZnO NP-induced neurotoxicity in adult zebrafish.

Nanoparticles-induced potential toxicity on human health: Applications, toxicity mechanisms, and evaluation models

Nanoparticles (NPs) have become one of the most popular objects of scientific study during the past decades. However, despite wealth of study reports, still there is a gap, particularly in health toxicology studies, underlying mechanisms, and related evaluation models to deeply understanding the NPs risk effects. In this review, we first present a comprehensive landscape of the applications of NPs on health, especially addressing the role of NPs in medical diagnosis, therapy. Then, the toxicity of NPs on health systems is introduced. We describe in detail the effects of NPs on various systems, including respiratory, nervous, endocrine, immune, and reproductive systems, and the carcinogenicity of NPs. Furthermore, we unravels the underlying mechanisms of NPs including ROS accumulation, mitochondrial damage, inflammatory reaction, apoptosis, DNA damage, cell cycle, and epigenetic regulation. In addition, the classical study models such as cell lines and mice and the emerging models such as 3D organoids used for evaluating the toxicity or scientific study are both introduced. Overall, this review presents a critical summary and evaluation of the state of understanding of NPs, giving readers more better understanding of the NPs toxicology to remedy key gaps in knowledge and techniques.

Restorative effects of gallic acid against sub-chronic hepatic toxicity of co-exposure to zinc oxide nanoparticles and arsenic trioxide in male rats

Background and objectives

This study aimed to assess the effect of zinc oxide nanoparticles (ZNPs) and/or arsenic trioxide (ATO) exposure on the liver of adult male Sprague Dawley rats. Moreover, the probable ameliorative impact of gallic acid (GA) against ZNPs and ATO-induced hepatotoxicity and the possible underlying mechanisms were evaluated.

Methods

Sixty male Sprague Dawley rats were distributed into six groups. The 1^st and 2^nd groups were orally given distilled water (1 ml/kg) and 20 mg GA/kg b. wt, respectively. The 3^rd and 4^th groups were orally given 100 mg ZNPs/kg b. wt and 8 mg ATO/kg b. wt, respectively. The 5^th group was co-administered ZNPs and ATO at the doses mentioned above. The last one was co-administered ZNPs, ATO, and GA at the earlier described doses. All tested compounds were orally given once a day for 60 successive days. Then, serum levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total, direct, indirect bilirubin, triglycerides, total cholesterol, HDL, VLDL, and LDL were estimated. The hepatic content of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) was evaluated. Moreover, Bcl-2 and Bax's reactive proteins were immunohistochemically detected, and Zn and As residual patterns in hepatic tissues were assessed.

Results

ZNPs, ATO, and ZNPs+ATO-exposed rats showed significantly (P < 0.001) elevated serum AST (219%, 233%, and 333%), ALT (300%, 400%, and 475%), ALP (169%, 205%, and 294%), and total bilirubin (42%, 68%, and 109%) compared to the control ones. On the other hand, a significantly (P < 0.001) declined SOD (58%, 49%, and 43%) and GPx (70%, 63%, and 56%) but increased MDA (133%, 150%, and 224%) was recorded in the hepatic tissues of ZNPs, ATO, and ZNPs+ATO exposed rats, respectively, relative to the control rats. Moreover, the hepatic tissues of the ZNPs, ATO, and ZNPs+ATO exposed rats showed a significant (P < 0.001) decrease in Bcl-2 (28%, 33%, and 23%) but elevation in Bax (217%, 267%, and 236%) immunoreactivities compared to the control rats. These findings were consistent with the microscopic alterations in the hepatic architecture and accumulation of Zn and As. Furthermore, a notable hyperlipidemic condition was recorded following ZNPs and/or ATO exposure. On the contrary, GA notably reduced hepatic enzymes compared to ZNPs+ATO-exposed rats. Additionally, GA markedly improved ZNPs+ATO-afforded liver tissue damage and apoptotic events.

Conclusion

Overall, GA oral dosing significantly mitigated the negative effects of ZNPs and ATO on the liver by improving the antioxidant defense system and controlling apoptotic changes.

Pharmacological Activity of Flavonoid Quercetin and Its Therapeutic Potential in Testicular Injury

Quercetin is a natural flavonoid widely found in natural fruits and vegetables. Recent studies have shown that quercetin mediates multiple beneficial effects in a variety of organ damage and diseases, and is considered a healthcare supplement with health-promoting potential. Male infertility is a major health concern, and testicular damage from multiple causes is an important etiology. Previous studies have shown that quercetin has a protective effect on reproductive function. This may be related to the antioxidant, anti-inflammatory, and anti-apoptotic biological activities of quercetin. Therefore, this paper reviews the mechanisms by which quercetin exerts its pharmacological activity and its role in testicular damage induced by various etiologies. In addition, this paper compiles the application of quercetin in clinical trials, demonstrating its practical effects in regulating blood pressure and inhibiting cellular senescence in human patients. However, more in-depth experimental studies and clinical trials are needed to confirm the true value of quercetin for the prevention and protection against testicular injury.

Silver nanoparticles induced testicular damage targeting NQO1 and APE1 dysregulation, apoptosis via Bax/Bcl-2 pathway, fibrosis via TGF-β/α-SMA upregulation in rats

In medicine, silver nanoparticles (AgNPs) are employed often. They do, however, have negative impacts, particularly on the reproductive organs. This research aimed to assess AgNP impact on the testis and the possible intracellular mechanisms to induce testicular deteriorations in rats at various concentrations and different time intervals. Sprague Dawley rats (n = 40) were allocated into four equal groups: the control one, and three other groups injected intra-peritoneally with AgNP solution 0.25, 0.5, and 1 mg/kg b.w. respectively for 15 and 30 days. Our findings revealed that AgNPs reduced body and testicular weights, estradiol (E2) and testosterone (T) hormone levels, and sperm parameters while elevating the nitric oxide and malondialdehyde levels with inhibition of reduced glutathione contents in testicular tissue. Interestingly, AgNPs significantly upregulated the testicular inducible nitric oxide synthase, B cell lymphoma 2 (Bcl-2)-associated X, transforming growth factor, and alpha-smooth muscle actin (α-SMA) expression levels. However, apurinic/apyrimidinic endo deoxyribonuclease 1 (APE1), NAD (P) H quinone dehydrogenase 1 (NQO1), and Bcl-2 expression levels were all downregulated indicating exhaustion of body antioxidant and repairing defense mechanisms in testicles in comparison with the control rats. Various histological alterations were also detected which dramatically increased in rats sacrificed after 30 days such as loss of the lining cells of seminiferous tubules with no spermatozoa and tubular irregularities associated with thickening of their basement membranes. Immunolabeling implicated in the apoptotic pathway revealed a negative expression of Bcl-2 and marked immunoreactivity for caspase-3 after 30 days of AgNP treatment in comparison to the control rats. To our knowledge, there have been no previous publications on the role of the α-SMA, APE1, and NQO1 genes in the molecular pathogenesis of AgNP testicular cytotoxicity following AgNP acute and chronic exposure.

Application of conventional metallic nanoparticles on male reproductive system - challenges and countermeasures

The application of nanotechnology in the present era has substantial impact on different industrial and medical fields. However, the advancement in nanotechnology for potential therapeutic and consumer benefits has been an anxious cause regarding the probable hazardous consequences of these molecules in biological systems and the environment. The toxic effects can perturb the physiologic system broadly and reproductive function and fertility specifically. Despite engineered nanomaterials (ENMs) having a wide range of applications, toxicological investigations of the probable ramifications of ENMs on the reproductive systems of mammals and fertility remains in its nascence. Complication in the male reproductive system is quite a pertinent issue in today's world which comprises of benign prostatic enlargement, prostate cancer, and unhealthy sperm production. The therapeutic drugs should not only be active in minimum dose but also site-specific in action, criteria being met by nanomedicines. Nanomedicine therapy is promising but encompasses the chances of adverse effects of being cytotoxic and generating oxidative stress. These hurdles can be overcome by creating coated nanoparticles with organic substances, modification of shape and size, and synthesizing biocompatible green nanoparticles. This review attempts to look into the applications of most widely used metals like zinc, titanium, silver, and gold nanoparticles in the therapy of the male reproductive system, their prospective harmful effects, and the way out to create a safe therapeutic system by specific modifications of these metal and metal oxide nanoparticles.

Comprehensive review on the positive and negative effects of various important regulators on male spermatogenesis and fertility

With the increasing global incidence of infertility, the influence of environmental factors, lifestyle habits, and nutrients on reproductive health has gradually attracted the attention of researchers. The quantity and quality of sperm play vital roles in male fertility, and both characteristics can be affected by external and internal factors. In this review, the potential role of genetic, environmental, and endocrine factors; nutrients and trace elements in male reproductive health, spermatozoa function, and fertility potency and the underlying mechanisms are considered to provide a theoretical basis for clinical treatment of infertility.

Impact of Nanoparticles on Male Fertility: What Do We Really Know? A Systematic Review

The real impact of nanoparticles on male fertility is evaluated after a careful analysis of the available literature. The first part reviews animal models to understand the testicular biodistribution and biopersistence of nanoparticles, while the second part evaluates their in vitro and in vivo biotoxicity. Our main findings suggest that nanoparticles are generally able to reach the testicle in small quantities where they persist for several months, regardless of the route of exposure. However, there is not enough evidence that they can cross the blood-testis barrier. Of note, the majority of nanoparticles have low direct toxicity to the testis, but there are indications that some might act as endocrine disruptors. Overall, the impact on spermatogenesis in adults is generally weak and reversible, but exceptions exist and merit increased attention. Finally, we comment on several methodological or analytical biases which have led some studies to exaggerate the reprotoxicity of nanoparticles. In the future, rigorous clinical studies in tandem with mechanistic studies are needed to elucidate the real risk posed by nanoparticles on male fertility.

Different Strategies to Attenuate the Toxic Effects of Zinc Oxide Nanoparticles on Spermatogonia Cells

Zinc oxide nanoparticles (ZnO NPs) are one of the most used nanoparticles due to their unique physicochemical and biological properties. There is, however, a growing concern about their negative impact on male reproductive health. Therefore, in the present study, two different strategies were used to evaluate the recovery ability of spermatogonia cells from the first stage of spermatogenesis (GC-1 spg cell line) after being exposed to a cytotoxic concentration of ZnO NPs (20 µg/mL) for two different short time periods, 6 and 12 h. The first strategy was to let the GC-1 cells recover after ZnO NPs exposure in a ZnO NPs-free medium for 4 days. At this phase, cell viability assays were performed to evaluate whether this period was long enough to allow for cell recovery. Exposure to ZnO NPs for 6 h and 12 h induced a decrease in viability of 25% and 41%, respectively. However, the recovery period allowed for an increase in cell viability from 16% to 25% to values as high as 91% and 84%. These results strongly suggest that GC-1 cells recover, but not completely, given that the cell viability does not reach 100%. Additionally, the impact of a synthetic chalcone (E)-3-(2,6-dichlorophenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (1) to counteract the reproductive toxicity of ZnO NPs was investigated. Different concentrations of chalcone 1 (0-12.5 µM) were used before and during exposure of GC-1 cells to ZnO NPs to mitigate the damage induced by NPs. The protective ability of this compound was evaluated through viability assays, levels of DNA damage, and cytoskeleton dynamics (evaluating the acetylated α-tubulin and β-actin protein levels). The results indicated that the tested concentrations of chalcone 1 can attenuate the genotoxicity induced by ZnO NPs for shorter exposure periods (6 h). Chalcone 1 supplementation also increased cell viability and stabilized the microtubules. However, the antioxidant potential of this compound remains to be elucidated. In conclusion, this work addressed the main cytotoxic effects of ZnO NPs on a spermatogonia cell line and analyzed two different strategies to mitigate this damage, which represent a significant contribution to the field of male fertility.

An Overview of Essential Microelements and Common Metallic Nanoparticles and Their Effects on Male Fertility

Numerous factors affect reproduction, including stress, diet, obesity, the use of stimulants, or exposure to toxins, along with heavy elements (lead, silver, cadmium, uranium, vanadium, mercury, arsenic). Metals, like other xenotoxins, can cause infertility through, e.g., impairment of endocrine function and gametogenesis or excess production of reactive oxygen species (ROS). The advancement of nanotechnology has created another hazard to human safety through exposure to metals in the form of nanomaterials (NMs). Nanoparticles (NPs) exhibit a specific ability to penetrate cell membranes and biological barriers in the human body. These ultra-fine particles (<100 nm) can enter the human body through the respiratory tract, food, skin, injection, or implantation. Once absorbed, NPs are transported to various organs through the blood or lymph. Absorbed NPs, thanks to ultrahigh reactivity compared to bulk materials in microscale size, disrupt the homeostasis of the body as a result of interaction with biological molecules such as DNA, lipids, and proteins; interfering with the functioning of cells, organs, and physiological systems; and leading to severe pathological dysfunctions. Over the past decades, much research has been performed on the reproductive effects of essential trace elements. The research hypothesis that disturbances in the metabolism of trace elements are one of the many causes of infertility has been unquestionably confirmed. This review examines the complex reproductive risks for men regarding the exposure to potentially harmless xenobiotics based on a series of 298 articles over the past 30 years. The research was conducted using PubMed, Web of Science, and Scopus databases searching for papers devoted to in vivo and in vitro studies related to the influence of essential elements (iron, selenium, manganese, cobalt, zinc, copper, and molybdenum) and widely used metallic NPs on male reproduction potential.

Cryopreservation of Pig Semen Using a Quercetin-Supplemented Freezing Extender

Reactive oxygen species (ROS) produced during freeze−thaw procedures cause oxidative damage to the sperm, reducing fertility. We aimed to improve the post-thaw quality of pig sperm by quercetin (QRN) supplementation to reduce the cryodamage associated with the freeze−thaw procedure. Four equal aliquots of pooled boar semen were diluted with a freezing extender supplemented with different concentrations of QRN (0, 25, 50, and 100 µM) and then were subjected to cryopreservation in liquid nitrogen. Semen analysis was performed following 7 days of cryopreservation. Results demonstrated that the semen samples supplemented with 50 µM QRN significantly improved the post-thaw sperm quality than those subjected to other supplementations (p < 0.05). Semen samples supplemented with 50 µM QRN showed significantly improved plasma membrane functional integrity (47.5 ± 1.4 vs. 43.1 ± 4.1, 45.3 ± 1.7, and 44.1 ± 1.4) and acrosome integrity (73.6 ± 3.4 vs. 66.3 ± 2.4, 66.7 ± 3.6, and 68.3 ± 32.9) as compared to the control, 25 µM, and 100 µM QRN groups, respectively. The mitochondrial activity of the 50 µM QRN group was greater than control and 25 µM QRN groups (43.0 ± 1.0 vs. 39.1 ± 0.9 and 41.9 ± 1.0) but showed no difference with the 100 µM QRN group. Moreover, the 50 µM QRN group showed a higher sperm number displaced to 1 cm and 3 cm points in the artificial mucus than other groups. Therefore, supplementing the freezing extender with QRN can serve as an effective tool to reduce the magnitude of oxidative damage associated with sperm freezing.

Palliative Effect of Resveratrol against Nanosized Iron Oxide-Induced Oxidative Stress and Steroidogenesis-Related Genes Dysregulation in Testicular Tissue of Adult Male Rats

The nano-sized iron oxide (Fe₂O₃-NPs) is one of the most used engineered nanomaterials worldwide. This study investigated the efficacy of natural polyphenol resveratrol (RSV) (20 mg/kg b.wt, orally once daily) to alleviate the impaired sperm quality and testicular injury resulting from Fe₂O₃-NPs exposure (3.5 or 7 mg/kg b.wt, intraperitoneally once a week) for eight weeks. Spermiograms, sexual hormonal levels, oxidative stress indicators, and lipid peroxidation biomarker were assessed. Moreover, the steroidogenesis-related genes mRNA expressions were evaluated. The results showed that RSV substantially rescued Fe₂O₃-NPs-mediated sperm defects. Additionally, the Fe₂O₃-NPs-induced depressing effects on sperm motility and viability were markedly counteracted by RSV. Moreover, RSV significantly restored Fe₂O₃-NPs-induced depletion of testosterone, follicle-stimulated hormone, luteinizing hormone, and testicular antioxidant enzymes but reduced malondialdehyde content. Furthermore, the Fe₂O₃-NPs-induced downregulation of steroidogenesis-related genes (3 β-HSD, 17 β-HSD, and Nr5A1) was significantly counteracted in the testicular tissue of RSV-treated rats. These findings concluded that RSV could limit the Fe₂O₃-NPs-induced reduced sperm quality and testicular injury most likely via their antioxidant activity and steroidogenesis-related gene expression modulation.

Effects of Flavonoid Supplementation on Nanomaterial-Induced Toxicity: A Meta-Analysis of Preclinical Animal Studies

Background

Nanomaterials, widely applied in various fields, are reported to have toxic effects on human beings; thus, preventive or therapeutic measures are urgently needed. Given the anti-inflammatory and antioxidant activities, supplementation with flavonoids that are abundant in the human diet has been suggested as a potential strategy to protect against nanomaterial-induced toxicities. However, the beneficial effects of flavonoids remain inconclusive. In the present study, we performed a meta-analysis to comprehensively explore the roles and mechanisms of flavonoids for animals intoxicated with nanomaterials.

Methods

A systematic literature search in PubMed, EMBASE, and Cochrane Library databases was performed up to April 2022. STATA 15.0 software was used for meta-analyses.

Results

A total of 26 studies were identified. The results showed that flavonoid supplementation could significantly increase the levels of antioxidative enzymes (superoxide dismutase, catalase, glutathione, glutathione peroxidase, and glutathione-S-transferase), reduce the production of oxidative agents (malonaldehyde) and pro-inflammatory mediators (tumor necrosis factor-α, interleukin-6, IL-1β, C-reactive protein, immunoglobulin G, nitric oxide, vascular endothelial growth factor, and myeloperoxidase), and alleviate cell apoptosis (manifested by decreases in the mRNA expression levels of pro-apoptotic factors, such as caspase-3, Fas cell surface death receptor, and Bax, and increases in the mRNA expression levels of Bcl2), DNA damage (reductions in tail length and tail DNA%), and nanomaterial-induced injuries of the liver (reduced alanine aminotransferase and aspartate aminotransferase activities), kidney (reduced urea, blood urea nitrogen, creatinine, and uric acid concentration), testis (increased testosterone, sperm motility, 17β-hydroxysteroid dehydrogenase type, and reduced sperm abnormalities), and brain (enhanced acetylcholinesterase activities). Most of the results were not changed by subgroup analyses.

Conclusion

Our findings suggest that appropriate supplementation of flavonoids may be effective to prevent the occupational detriments resulting from nanomaterial exposure.

BECLIN-1-Mediated Autophagy Suppresses Silica Nanoparticle-Induced Testicular Toxicity via the Inhibition of Caspase 8-Mediated Cell Apoptosis in Leydig Cells

Accumulation of silica nanoparticles (SNPs) in the testes leads to male reproductive toxicity. However, little is known about the effect and mechanistic insights of SNP-induced autophagy on apoptosis in Leydig cells. In this study, we aimed to verify the role of SNP-induced autophagy in apoptosis and explore the possible underlying mechanism in mouse primary Leydig cells (PLCs). H&E staining showed that SNPs changed the histological structures of the testes, including a reduction in the Leydig cell populations in vivo. CCK-8 assay showed that SNPs decreased cell viability, and flow cytometry showed that SNPs increased cell apoptosis, both in a dose-dependent manner in vitro. Additionally, Western blotting further found that SNPs activated autophagy by an increase in BECLIN-1, ATG16L, and LC3-II levels and promoted the intrinsic pathway of apoptosis by an increase in the BAX/BCL-2 ratio, cleaved the caspase 8 and caspase 3 levels. Furthermore, autophagy decreased SNP-induced apoptosis via regulation of the caspase 8 level combined with rapamycin, 3-methyladenine, and chloroquine. BECLIN-1 depletion increased the caspase 8 level, leading to an increase in SNP-induced cell apoptosis. Collectively, this evidence demonstrates that SNPs activated BECLIN-1-mediated autophagy, which prevented SNP-induced testicular toxicity via the inhibition of caspase 8-mediated cell apoptosis in Leydig cells.

Lycopene Alleviates Titanium Dioxide Nanoparticle-Induced Testicular Toxicity by Inhibiting Oxidative Stress and Apoptosis in Mice

PURPOSE

The research was carried out to investigate the possible ameliorative effect of lycopene on TiO₂ NPs-induced male reproductive toxicity and explore the possible mechanism.

METHODS

Ninety-six healthy male Institute of Cancer Research (ICR) mice were equally divided into eight groups (control group, 50 mg/kg TiO₂ NPs group, 5 mg/kg LYC group, 20 mg/kg LYC group, 40 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 5 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 20 mg/kg LYC group, 50 mg/kg TiO₂ NPs + 40 mg/kg LYC group), and the mice were treated by intragastric administration every day for 30 days in this research. Sperm parameters, testicular histopathology, oxidant and antioxidant enzymes, and cell apoptosis-related protein expression in the testicular tissue were analyzed.

RESULTS

The results showed that TiO₂ NPs exposure significantly decreased sperm count and motility, and TiO₂ NPs also increased sperm malformation in the epididymis; these characteristics were improved when co-administration with LYC. Testicular histopathological lesions like disorder of germ cells arrange, detachment, atrophy, and vacuolization were observed after TiO₂ NPs exposure, and these abnormalities were effectively ameliorated by co-administration with LYC. Oxidative stress was induced by TiO₂ NPs exposure as evidenced by increased the level of MDA and decreased the activity of SOD as well as the level of anti-O₂^-, and these alterations were effectively prevented by co-administration with LYC. LYC also alleviated TiO₂ NPs-induced germ cell apoptosis by inhibiting mitochondrial apoptotic pathway, as shown by the upregulation of Bcl-2, the downregulation of Bax, Cleaved Caspase 3, and Cleaved Caspase 9.

CONCLUSION

LYC could ameliorate TiO₂ NPs-induced testicular damage via inhibiting oxidative stress and apoptosis, which could be used to alleviate the testicular toxicity associated with TiO₂ NPs intake.

Quercetin improves the apoptotic index and oxidative stress in post-thaw dog sperm

Freeze storage of ejaculated sperms is a crucial technique for the semen preservation of valuable pet animals such as dogs. The current study was conducted to investigate if quercetin (QRN) may ameliorate apoptosis and oxidative stress in post-thaw dog sperm. Herein, we evaluated the post-thaw apoptosis and oxidative stress after treatment with QRN (control, 25, 50, and 100 μM) in the freezing of dog semen. Reactive oxygen species levels were significantly affected (p < 0.05) between the various concentrations of QRN and the control (17.56 ± 1.02, 7.54 ± 0.48, 5.66 ± 0.80, and 10.41 ± 0.69), respectively. The apoptosis index was 9.1 ± 1.34, 6.66 ± 0.58, 6.77 ± 0.66, and 5.38 ± 0.86 in the control, and 25, 50, and 100 μM QRN treatment groups, respectively (p < 0.05). The effects of ameliorated cryo-induced damage by QRN on post-thaw sperm quality were also observed through improved structural and functional tests. Sperm treated with 50 μM QRN showed significantly higher motility (51.8 ± 2.1% vs. 43.1 ± 1.4%, P < 0.05), survival rates (46.9 ± 0.7% vs. 43.9 ± 0.4%, P < 0.05), and mucus penetration than control group, respectively. Results also indicated that higher concentrations of QRN (100 μM) were not effective on sperm quality and parameters when compared with the medium levels (50 μM). In conclusion, supplementation of freezing buffer with 50 μM QRN reduced oxidative damage and improved the quality of post-thaw dog sperm.

Switching to nanonutrients for sustaining agroecosystems and environment: the challenges and benefits in moving up from ionic to particle feeding

The worldwide agricultural enterprise is facing immense pressure to intensify to feed the world's increasing population while the resources are dwindling. Fertilizers which are deemed as indispensable inputs for food, fodder, and fuel production now also represent the dark side of the intensive food production system. With most crop production systems focused on increasing the quantity of produce, indiscriminate use of fertilizers has created havoc for the environment and damaged the fiber of the biogeosphere. Deteriorated nutritional quality of food and contribution to impaired ecosystem services are the major limiting factors in the further growth of the fertilizer sector. Nanotechnology in agriculture has come up as a better and seemingly sustainable solution to meet production targets as well as maintaining the environmental quality by use of less quantity of raw materials and active ingredients, increased nutrient use-efficiency by plants, and decreased environmental losses of nutrients. However, the use of nanofertilizers has so far been limited largely to controlled environments of laboratories, greenhouses, and institutional research experiments; production and availability on large scale are still lagging yet catching up fast. Despite perceivable advantages, the use of nanofertilizers is many times debated for adoption at a large scale. The scenario is gradually changing, worldwide, towards the use of nanofertilizers, especially macronutrients like nitrogen (e.g. market release of nano-urea to replace conventional urea in South Asia), to arrest environmental degradation and uphold vital ecosystem services which are in critical condition. This review offers a discussion on the purpose with which the nanofertilizers took shape, the benefits which can be achieved, and the challenges which nanofertilizers face for further development and real-world use, substantiated with the significant pieces of scientific evidence available so far.

Attributes of oxidative stress in the reproductive toxicity of nickel oxide nanoparticles in male rats

The nanoparticles of nickel are now being widely used in industrial, commercial, and biomedical applications. In recent years, health safety issues posed by them have aroused concerns among health scientists. The aim of the present study was to investigate the role of oxidative stress in male reproductive toxicity induced by nickel oxide nanoparticles in rats. Male Wistar rats (140-170 g) were administered with nickel oxide nanoparticles (NiONPs) (particles size <30 nm) (5 mg/kg body weight) by gavage for 30 days. Its effects on different parameters, viz., sperm count, motility, and morphology, were investigated. DNA damage in sperms was monitored through comet assay. All these observations indicated a spermicidal effect of NiONPs. Results on lipid peroxidation (MDA, H₂O₂, and NO) and oxidative stress (GSH, GPx, and catalase) thus studied in testes exhibited adverse effects of NiONPs. Histopathological results on male reproductive organs, viz., testis, epididymis, vas deferens, seminal vesicles, and prostate also demonstrated moderate to severe toxicity. A comparison of these results with those obtained on nickel oxide microparticle (NiOMP)-treated rats showed that NiONPs are more toxic than NiOMPs. Furthermore, NiONPs could create an imbalance between oxidants and antioxidants in the testes. It is concluded that redox imbalance in testes constitutes a major mechanism of NiONP-induced reproductive toxicity.

Advances in endocrine toxicity of nanomaterials and mechanism in hormone secretion disorders

The size of nanoparticles is about 1-100 nm. People are exposed to nanoparticles in environmental pollutants from ancient times to the present. With the maturity of nanotechnology in the past two decades, the production of manufactured nanomaterials is rapidly increasing and they are used in a wide range of aerospace, medicine, food, and industrial applications. However, both natural and manufactured nanomaterials have been proved to pose a threat to diverse organs and systems. The endocrine system is critical to maintaining homeostasis. Endocrine disorders are associated with many diseases, including cancer, reduced fertility, and metabolic diseases. Therefore, we review the literatures dealing with the endocrine toxicity of nanomaterial. This review provides an exhaustive description of toxic effects of several common nanomaterials in the endocrine system; more involved are reproductive endocrinology. Then physicochemical factors that determine the endocrine toxicity of nanomaterials are discussed. Furthermore, oxidative stress, changes in steroid production and metabolic enzymes, organelle disruption, and alterations in signal pathways are introduced as potential mechanisms that may cause changes in hormone levels. Finally, we suggest that a risk assessment of endocrine toxicity based on standard procedures and consideration of endocrine disrupting effects of nanomaterials in the field and its environmental and population effects could be future research directions for endocrine toxicity of nanomaterials.

Potential toxicity of nanoparticles on the reproductive system animal models: A review

Over the past two decades, nanotechnology has been involved in an array of applications in various fields, including diagnostic kits, disease treatment, drug manufacturing, drug delivery, and gene therapy. But concerns about the toxicity of nanoparticles have greatly hindered their use; also, due to their increasing use in various industries, all members of society are exposed to the toxicity of these nanoparticles. Nanoparticles have a negative impact on various organs, including the reproductive system. They also can induce abortion in women, reduce fetal growth and development, and can damage the reproductive system and sperm morphology in men. In some cases, it has been observed that despite the modification of nanoparticles in composition, concentration, and method of administration, there is still damage to the reproductive organs. Therefore, understanding how nanoparticles affect the reproductive system is of very importance. In several studies, the nanoparticle toxicity effect on the genital organs has been investigated at the clinical and molecular levels using the in vivo and in vitro models. This study reviews these investigations and provides important data on the toxicity, hazards, and safety of nanoparticles in the reproductive system to facilitate the optimal use of nanoparticles in the industry.

Metal Oxide Nanoparticles: Evidence of Adverse Effects on the Male Reproductive System

Metal oxide nanoparticles (MONPs) are inorganic materials that have become a valuable tool for many industrial sectors, especially in healthcare, due to their versatility, unique intrinsic properties, and relatively inexpensive production cost. As a consequence of their wide applications, human exposure to MONPs has increased dramatically. More recently, their use has become somehow controversial. On one hand, MONPs can interact with cellular macromolecules, which makes them useful platforms for diagnostic and therapeutic interventions. On the other hand, research suggests that these MONPs can cross the blood–testis barrier and accumulate in the testis. Although it has been demonstrated that some MONPs have protective effects on male germ cells, contradictory reports suggest that these nanoparticles compromise male fertility by interfering with spermatogenesis. In fact, in vitro and in vivo studies indicate that exposure to MONPs could induce the overproduction of reactive oxygen species, resulting in oxidative stress, which is the main suggested molecular mechanism that leads to germ cells’ toxicity. The latter results in subsequent damage to proteins, cell membranes, and DNA, which ultimately may lead to the impairment of the male reproductive system. The present manuscript overviews the therapeutic potential of MONPs and their biomedical applications, followed by a critical view of their potential risks in mammalian male fertility, as suggested by recent scientific literature.

Zinc oxide nanoparticles improve testicular steroidogenesis machinery dysfunction in benzo[α]pyrene-challenged rats

Zinc oxide nanoparticles (ZnO NPs) demonstrate potential positive effects on reproduction. However, their protective role against the reproductive toxicity pollutants has not yet been adequately studied at the molecular level. This study was designed to assess this objective using Benzo[α]pyrene B[a]P as reproductive toxic agent . Forty-eight mature male rats were randomly distributed into six groups: Group1 (negative control); Groups 2 and 3 (positive control I and II, wherein the animals were treated with 10 and 30 mg ZnO NPs/kg BW, respectively); Group 4 (B[a]P group; treated with 150 mg B[a]P/kg BW); and Groups 5 and 6 (subjected to B[a]P treatment co-administered with different concentrations of ZnO NPs). We investigated oxidative stress biomarkers; cholesterol side-chain cleavage enzyme (CYP11A1), steroidogenic acute regulatory protein (StAR), and 3β-hydroxysteroid dehydrogenase (3β-HSD) gene expression; testosterone levels; and histopathology of the liver, kidney, and testicles. The B[a]P-treated group showed significant deterioration in all reproductive parameters and displayed induced oxidative stress. ZnO NPs remarkably reduced oxidative stress, effectively upregulated the mRNA levels of CY11A1, StAR, and 3β-HSD, and improved the histological pictures in the examined organs. At their investigated doses and given their NPs properties, ZnO NPs demonstrated a marked ameliorative effect against the reproductive toxic effects of B[a]P. Further studies are needed to thoroughly investigate the molecular mechanisms of ZnO NPs.

Toxicity mechanisms of nanoparticles in the male reproductive system

The field of nanotechnology has allowed for increasing nanoparticle (NP) exposure to the male reproductive system. Certain NPs have been reported to have adverse consequences on male germ and somatic cells. Germ cells are the bridge between generations and are responsible for the transmission of genetic and epigenetic information to future generations. A number of NPs have negative impacts on male germ and somatic cells which could ultimately affect fertility or the ability to produce healthy offspring. These impacts are related to NP composition, modification, concentration, agglomeration, and route of administration. NPs can induce severe toxic effects on the male reproduction system after passing through the blood-testis barrier and ultimately damaging the spermatozoa. Therefore, understanding the impacts of NPs on reproduction is necessary. This review will provide a comprehensive overview on the current state of knowledge derived from the previous in vivo and in vitro research on effects of NPs on the male reproductive system at the genetic, cellular, and molecular levels.

Nanoparticle delivery system, highly active antiretroviral therapy, and testicular morphology: The role of stereology

The conjugation of nanoparticles (NPs) with antiretroviral drugs is a drug delivery approach with great potential for managing HIV infections. Despite their promise, recent studies have highlighted the toxic effects of nanoparticles on testicular tissue and their impact on sperm morphology. This review explores the role of stereological techniques in assessing the testicular morphology in highly active antiretroviral therapy (HAART) when a nanoparticle drug delivery system is used. Also, NPs penetration and pharmacokinetics concerning the testicular tissue and blood-testis barrier form the vital part of this review. More so, various classes of NPs employed in biomedical and clinical research to deliver antiretroviral drugs were thoroughly discussed. In addition, considerations for minimizing nanoparticle-drugs toxicity, ensuring enhanced permeability of nanoparticles, maximizing drug efficacy, ensuring adequate bioavailability, and formulation of HAART-NPs fabrication are well discussed.

Perspectives of Nanoparticles in Male Infertility: Evidence for Induced Abnormalities in Sperm Production

Advancement in the field of nanotechnology has prompted the need to elucidate the deleterious effects of nanoparticles (NPs) on reproductive health. Many studies have reported on the health safety issues related to NPs by investigating their exposure routes, deposition and toxic effects on different primary and secondary organs but few studies have focused on NPs’ deposition in reproductive organs. Noteworthy, even fewer studies have dealt with the toxic effects of NPs on reproductive indices and sperm parameters (such as sperm number, motility and morphology) by evaluating, for instance, the histopathology of seminiferous tubules and testosterone levels. To date, the research suggests that NPs can easily cross the blood testes barrier and, after accumulation in the testis, induce adverse effects on spermatogenesis. This review aims to summarize the available literature on the risks induced by NPs on the male reproductive system.

Quercetin ameliorates cytotoxic effects of zinc oxide nanoparticles on sertoli cells by enhancing autophagy and suppressing oxidative stress

Previous studies have demonstrated the toxic impacts of zinc oxide nanoparticles (ZO-NPs) on male reproductive cells. The effect of quercetin (QCT) on ZO-NPs-induced mouse Sertoli cell (TM4 cell line) toxicity and its underlying mechanisms were investigated in this study. The TM4 cells were exposed to ZO-NPs or QCT in different groups for 24 hr. The TM4 cells pre-treated with 3MA (3-Methyladenine, an autophagy inhibitor) to evaluate the autophagy role of QCT and ZO-NPs in the TM4 cells. ZO-NPs significantly reduced the viability percentage of the TM4 cells. The apoptosis percentage and Bax/Bcl-2 ratio of the ZO-NPs group were significantly increased, while the expression of autophagy-related genes was considerably downregulated. ZO-NPs also induced oxidative stress in the TM4 cells through increasing malondialdehyde contents and reactive oxygen species levels (ROS) and reducing antioxidant factors including superoxide dismutase, catalase, glutathione and glutathione peroxidase. In QCT + ZO-NPs group, these events were considerably reversed. 3MA could significantly decrease the cell viability of TM4 cells exposed to the QCT and ZO-NPs in comparison with the untreated 3MA groups. According to these results, the protective effects of QCT on ZO-NPs-exposed TM4 cells are related to inducing autophagy, prevention apoptosis and suppressing oxidative stress.

Protective Impact of Edaravone Against ZnO NPs-induced Oxidative Stress in the Human Neuroblastoma SH-SY5Y Cell Line

Extensive applications of ZnO NPs (zinc oxide nanoparticles) in daily life have created concern about their biotoxicity. Zinc oxide nanoparticles induce oxidative stress, inflammation, and apoptosis in neurons. Edaravone applies antioxidant agent and anti-inflammatory impacts in the different cells, as evaluated in both in vitro and in vivo experimental models. This study is designed to explore, how edaravone would avert mitochondrial impairment in human neuronal cells against ZnO NPs-induced toxicity. Accordingly, we analyzed here whether a pretreatment (for 24 h) with edaravone (10-100 μM) would enhance mitochondrial protection in the human neuroblastoma cells SH-SY5Y against ZnO NPs-induced toxicity. We found that edaravone at 25 μM averted the ZnO NPs-induced decrease in the amounts of adenosine triphosphate (ATP), just as on the activity of the complexes I and V. Also, edaravone induced an antioxidant activity by diminishing the levels of lipid peroxidation, protein carbonylation, and protein nitration in the mitochondrial membranes. Edaravone blocked the ZnO NPs-induced transcription factor nuclear factor-κB (NF-κB) upregulation. The inhibition of the heme oxygenase-1 (HO-1) enzyme by zinc protoporphyrin IX (ZnPP IX, 10 μM) smothered the preventive impacts brought about by edaravone with respect to mitochondrial function and inflammation. After this examination, it can be concluded that edaravone caused cytoprotective impacts in an HO-1-dependent manner in SH-SY5Y cells against ZnO NPs-induced toxicity.

Silica nanoparticles enhance germ cell apoptosis by inducing reactive oxygen species (ROS) formation in Caenorhabditis elegans

Silica nanoparticles (SiO₂ NPs) are widely used in daily life and can enter organisms through several pathways, often causing unpredictable toxicity. Although SiO₂ NPs are known to cause damage to the respiratory system, little is known about their oral toxicity, and their potential harm to the reproductive system is unclear. In this study, we used a Caenorhabditis elegans model to clarify SiO₂ NPs oral toxicity in vivo and explore their effect on the reproductive system. We exposed C. elegans to 0.25, 0.5 and 1 mg /mL SiO₂ NPs for 24 hr. Our results showed that SiO₂ NPs exposure for 24 hr did not affect nematode survival rates, but did affect, to varying degrees, the reproduction, development, and movement of nematodes, with nematode fecundity being the most sensitive to SiO₂ NPs toxicity. The NPs exposed group showed enhanced germ cell apoptosis and increased oxidative stress as seen through an increase in ROS and malondialdehyde (MDA), and decrease in reduced glutathione (GSH). N-acetyl-L-cysteine (NAC), an antioxidant, negated SiO₂ NPs effect on germ cells and restored nematodes reproductive ability. We also found that SiO₂ NPs could affect the expression of genes related to metal detoxification, oxidative stress, and apoptosis. The expression of metallothionein coding genes mtl-1 and mtl-2 changed most significantly among the tested genes. We demonstrated that SiO₂ NPs could enhance germ cell apoptosis by inducing oxidative stress, providing a new area for studies of the mechanism of SiO₂ NP toxicity.

Short time exposure to low concentration of zinc oxide nanoparticles up-regulates self-renewal and spermatogenesis-related gene expression

Extensive application of zinc oxide (ZnO) nanoparticles (NPs) in everyday life results in increased exposure to these NPs. Spermatogonial stem cells (SSCs) guarantee sperm production throughout the male reproductive life by providing a balance between self-renewal and differentiation. We used an in vitro platform to investigate the ZnO NPs effects on SSCs. We successfully synthesized ZnO NPs. In order to investigate these NPs, we isolated SSCs from mouse testes and cultured them in vitro. Our results confirmed the uptake of ZnO NPs by the cultured SSCs. We observed a dose- and time-dependent decrease in SSC viability. Both spherical and nanosheet ZnO NPs had the same cytotoxic effects on the SSCs, irrespective of their shapes. Moreover, we have shown that short time (one day) exposure of SSCs to a low concentration of ZnO NPs (10 μg/mL) promoted expressions of specific genes (Plzf, Gfr α1 and Bcl6b) for SSC self-renewal and differentiation genes (Vasa, Dazl, C-kit and Sycp3) expressed by spermatogonia during spermatogenesis. Our study provides the first insight into ZnO NPs function in SSCs and suggests a new function for ZnO NPs in the male reproductive system. We demonstrated that ZnO NPs might promote spermatogenesis via upregulation of gene expression related to SSC self-renewal and differentiation at low concentrations. Additional research should clarify the possible effect of ZnO NPs on the SSC genome and its effects on human SSCs.

Nitric oxide synthase-mediated sub-chronic injury and recovery in the small intestine of mice after oral administration with halloysite nanotubes

Natural halloysite nanotubes (HNTs) with a hollow lumen have been widely applied in many fields, such as water purification, drug carriers, cosmetics, antibacterial, and scaffolds for tissue engineering. However, their in vivo toxicity is still largely unclear. The aim of this study is to evaluate sub-chronic oral toxicity of HNTs in the small intestine of mice. The results demonstrated that oral HNTs at low dose (5 mg/kg) for 30 days promoted mouse growth with no obvious adverse effect on the small intestine. The promotive effect on mouse growth disappeared after cessation of oral administration of HNTs. Oral HNTs at high dose (50 mg/kg) for 30 days induced aluminum (Al) and silicon (Si) accumulation and oxidative stress in the small intestine, which caused significant increases in the levels of cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) and inflammatory response and iNOS-mediated damages in the organ. Oral HNTs-induced changes in the small intestine at high dose were not observed after a 30-day recovery period. These findings provided the first evidence that oral HNTs-induced sub-chronic toxicity in the small intestine was reversible. The results suggest that HNTs at low concentration in environments have no adverse effect on mice, while there are health risks to mice under severe contamination by HNTs.

In Vitro Cytotoxicity Effects of Zinc Oxide Nanoparticles on Spermatogonia Cells

Zinc Oxide Nanoparticles (ZnO NPs) are a type of metal oxide nanoparticle with an extensive use in biomedicine. Several studies have focused on the biosafety of ZnO NPs, since their size and surface area favor entrance and accumulation in the body, which can induce toxic effects. In previous studies, ZnO NPs have been identified as a dose- and time-dependent cytotoxic inducer in testis and male germ cells. However, the consequences for the first cell stage of spermatogenesis, spermatogonia, have never been evaluated. Therefore, the aim of the present work is to evaluate in vitro the cytotoxic effects of ZnO NPs in spermatogonia cells, focusing on changes in cytoskeleton and nucleoskeleton. For that purpose, GC-1 cell line derived from mouse testes was selected as a model of spermatogenesis. These cells were treated with different doses of ZnO NPs for 6 h and 12 h. The impact of GC-1 cells exposure to ZnO NPs on cell viability, cell damage, and cytoskeleton and nucleoskeleton dynamics was assessed. Our results clearly indicate that higher concentrations of ZnO NPs have a cytotoxic effect in GC-1 cells, leading to an increase of intracellular Reactive Oxygen Species (ROS) levels, DNA damage, cytoskeleton and nucleoskeleton dynamics alterations, and consequently cell death. In conclusion, it is here reported for the first time that ZnO NPs induce cytotoxic effects, including changes in cytoskeleton and nucleoskeleton in mouse spermatogonia cells, which may compromise the progression of spermatogenesis in a time- and dose-dependent manner.

The Impact of Zinc Oxide Nanoparticles on Male (In)Fertility

Zinc oxide nanoparticles (ZnO NPs) are among nanoscale materials, attracting increasing attention owing to their exceptional set of characteristics, which makes these engineered nanoparticles a great option for improving the quality and effectiveness of diagnosis and treatment. The capacity of ZnO NPs to induce reactive oxygen species (ROS) production, DNA damage, and apoptosis represents a promise for their use in both cancer therapy and microbial treatment. However, their intrinsic toxicity together with their easy entrance and accumulation in organism have raised some concerns regarding the biomedical use of these NPs. Several studies have reported that ZnO NPs might induce cytotoxic effects on the male reproductive system, compromising male fertility. Despite some advances in this area, the knowledge of the effects of ZnO NPs on male fertility is still scarce. Overall, a brief outline of the major ZnO NPs biomedical applications and promises in terms of diagnostic and therapeutic use will also be explored. Further, this review intends to discuss the effect of ZnO NPs exposure on the male reproductive system and speculate their effects on male (in)fertility.

Comparison between the Effects of Adding Vitamins, Trace Elements, and Nanoparticles to SHOTOR Extender on the Cryopreservation of Dromedary Camel Epididymal Spermatozoa

Simple Summary

This is a comprehensive study to compare between the effects of different supplements (vitamins C and E, trace elements Na₂SeO₃ and ZnSO₄, and nanoparticles of zinc oxide and selenium) to the semen extender of camel epididymal spermatozoa during cooling and freezing/thawing cryopreservation. Supplementation of the semen SHOTOR extender with zinc oxide and selenium nanoparticles lead to improved progressive motility, vitality, and anti-oxidative defense, and reduced the ultrastructural abnormalities in camel epididymal spermatozoa.

Abstract

There are several obstacles in camel semen cryopreservation; such as increasing semen viscosity and the reduction in motile spermatozoa after ejaculation. Epididymal spermatozoa offer an efficient alternative to overcome these problems and are well-suited for artificial insemination in camels. In the current study, we compared the effects of supplementation with vitamin C, E, inorganic trace elements of selenium (Na₂SeO₃) and zinc (ZnSO₄), and zinc and selenium nanoparticles (ZnONPs and SeNPs, respectively) on the cryopreservation of dromedary camel epididymal spermatozoa. When the SHOTOR extender was supplemented with ZnONPs and SeNPs; the sperm showed increased progressive motility; vitality; and membrane integrity after cooling at 5 °C for 2 h; when compared to the control and vitamin-supplemented groups. Moreover, the ZnONPs and SeNPs supplementation improved the progressive motility, vitality, sperm membrane integrity, ultrastructural morphology, and decreased apoptosis when frozen and thawed. SeNPs significantly increased reduced glutathione (GSH), superoxide dismutase (SOD), and decreased lipid peroxide malondialdehyde (MDA) levels. The advantageous effects of the trace elements were potentiated by reduction into a nano-sized particle, which could increase bioavailability and reduce the undesired liberation of toxic concentrations. We recommend the inclusion of SeNPs or ZnONPs to SHOTOR extenders to improve the cryotolerance of camel epididymal spermatozoa.

Amelioration of titanium dioxide nanoparticle reprotoxicity by the antioxidants morin and rutin

The present study aimed to examine the ameliorative effects of morin and rutin on the reproductive toxicity induced by titanium dioxide nanoparticles (TiO₂NPs) in male rats. A total of seventy adult male Sprague-Dawley rats were randomly divided into seven groups, each comprising ten rats. Nanoreprotoxicity was induced by treating rats with TiO₂NPs at a dosage of 300 mg/kg body weight for 30 days. Morin (30 mg/kg body weight) and rutin (100 mg/kg body weight) were co-administered with or without TiO₂NPs to rats either individually or combined. Only distilled water was administered to the control group. The results showed that TiO₂NPs enhanced oxidative stress, indicated by reduced levels of antioxidants such as superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in testicular tissues, and increased levels of the lipid peroxidation marker malondialdehyde (MDA). TiO₂NPs significantly reduced the levels of sex hormones (testosterone, FSH, and LH), reduced sperm motility, viability, and sperm cell count, and increased sperm abnormalities, in addition to damaging the testicular histological architecture. TiO₂NPs resulted in the downregulation of 17β-HSD and the upregulation of proapoptotic gene (Bax) transcripts in the testicular tissues. Conversely, morin and/or rutin had a protective effect on testicular tissue. They effectively counteracted TiO₂NP-induced oxidative damage and morphological injury in the testis by conserving the endogenous antioxidant mechanisms and scavenging free radicals. Thus, we suggest that morin and rutin could be used to alleviate the toxicity and oxidative damage associated with TiO₂NP intake.

Morin ameliorates the testicular apoptosis, oxidative stress, and impact on blood-testis barrier induced by photo-extracellularly synthesized silver nanoparticles

Silver nanoparticles (AgNPs) have been widely produced for different industrial purposes. Recently, biogenic synthesis of AgNPs has emerged although the extent of effects from exposure, oral exposure in particular, to nanomaterials synthesized in such a manner remains elusive. The main objective of this study was to evaluate the effects of oral administration of a dose of 50 mg/Kg body weight AgNPs biosynthesized in baker's yeast (Saccharomyces cerevisiae) over a period of eight weeks on the reproductive performance and the possibility of a protective effect through co-administration of morin. Forty-eight male Sprague-Dawley rats were used in four experimental groups (control, morin-treated group, AgNP-treated, and AgNP + morin co-treatment). AgNPs produced no significant alteration in daily food intake or body weight. Both the absolute and relative testicular weights were significantly reduced but not the epididymal weight. Also, serum levels of urea, creatinine, uric acid, and liver enzymes were significantly elevated. Furthermore, AgNPs significantly downregulated the hypothalamic-pituitary-gonadal axis. This corresponds to lower motility and viability percent, reduced sperm concentration, and a higher abnormality ratio as well as a prominent alteration in the blood-testis barrier (BTB) and testicular histology and induction of testicular apoptosis and oxidative stress. The supplementation of morin evidently restored most of the reproductive characters to its physiological range. We can conclude that exposure to the biologically synthesized AgNPs for an extended period of time has proven to be a health risk that can be ameliorated via oral administration of some bioactive agents including morin.

Potential adverse effects of nanoparticles on the reproductive system

With the vigorous development of nanometer-sized materials, nanoproducts are becoming widely used in all aspects of life. In medicine, nanoparticles (NPs) can be used as nanoscopic drug carriers and for nanoimaging technologies. Thus, substantial attention has been paid to the potential risks of NPs. Previous studies have shown that numerous types of NPs are able to pass certain biological barriers and exert toxic effects on crucial organs, such as the brain, liver, and kidney. Only recently, attention has been directed toward the reproductive toxicity of nanomaterials. NPs can pass through the blood–testis barrier, placental barrier, and epithelial barrier, which protect reproductive tissues, and then accumulate in reproductive organs. NP accumulation damages organs (testis, epididymis, ovary, and uterus) by destroying Sertoli cells, Leydig cells, and germ cells, causing reproductive organ dysfunction that adversely affects sperm quality, quantity, morphology, and motility or reduces the number of mature oocytes and disrupts primary and secondary follicular development. In addition, NPs can disrupt the levels of secreted hormones, causing changes in sexual behavior. However, the current review primarily examines toxicological phenomena. The molecular mechanisms involved in NP toxicity to the reproductive system are not fully understood, but possible mechanisms include oxidative stress, apoptosis, inflammation, and genotoxicity. Previous studies have shown that NPs can increase inflammation, oxidative stress, and apoptosis and induce ROS, causing damage at the molecular and genetic levels which results in cytotoxicity. This review provides an understanding of the applications and toxicological effects of NPs on the reproductive system.

Zinc Oxide Nanoparticles Induced Oxidative DNA Damage, Inflammation and Apoptosis in Rat's Brain after Oral Exposure

Growing evidences demonstrated that zinc oxide nanoparticles (ZnONPs) could reach the brain after oral ingestion; however, the "neurotoxicity of" ZnONPs after oral exposure has not been fully investigated. This study aimed to explore the "neurotoxicity of" ZnONPs (.

In vitro exposure of bull sperm cells to DMSA-coated maghemite nanoparticles does not affect cell functionality or structure

Magnetic nanoparticles can be used in different areas of biology. It is therefore important to know the effects of such nanomaterials on germline cells as they may traverse the blood-testis barrier. This work aimed to evaluate the response of bull sperm after exposure to a magnetic fluid containing DMSA-coated maghemite nanoparticles (MNP-DMSA) in order to determine nanotoxicity. Bull sperm was incubated with MNP-DMSA at final concentrations of 0.06, 0.03 or 0.015 mg Fe/mL. Sperm kinetics, plasma membrane integrity and acrosome reaction were evaluated over a 4 h incubation period. The sperm cells were also evaluated by transmission electron microscopy. Exposure of bull sperm to MNP-DMSA did not affect sperm kinetics or integrity. Neither ultrastructural damage of sperm cells nor uptake of nanoparticles by the spermatozoa was observed. In conclusion, MNP-DMSA does not affect sperm function or structure under the conditions tested.