Effects of Aging and Oxidative Stress on Spermatozoa of Superoxide-Dismutase 1- and Catalase-Null Mice

Gallic acid supplementation partially ameliorates reproductive aging in rooster breeders by improving semen quality, sperm kinetics, hormones, and antioxidant status

Aging leads to decreased fertility in roosters, which is likely due to increased oxidative stress. This study evaluated the antioxidant effects of gallic acid (GA) supplementation on sperm quality and fertility of aged roosters. This study evaluated whether GA supplementation can mitigate age-related fertility decline. Roosters were randomly assigned to: control, 100 mg/kg GA, or 200 mg/kg GA. Semen parameters, sperm kinetics, hormone levels, fertility rate, and hatchability were assessed. GA increased semen concentration, membrane integrity and viability while decreasing defects versus control (P < 0.01). Testosterone was higher in GA groups (P<0.01) without affecting gonadotropins. Furthermore, 200 mg/kg GA optimized motility, velocity, linearity, and beat cross frequency versus control and 100 mg/kg GA (P < 0.01). Fertility and hatchability were higher in both GA groups. In conclusion, GA supplementation in aged roosters improves sperm quality, antioxidant status, testosterone, and fertility outcomes, likely by mitigating oxidative stress. The 200 mg/kg dose elicited optimal effects on motion parameters.

Effects of Reactive Oxygen and Nitrogen Species on Male Fertility

Significance: In recent decades, male fertility has been severely reduced worldwide. The causes underlying this decline are multifactorial, and include, among others, genetic alterations, changes in the microbiome, and the impact of environmental pollutants. Such factors can dysregulate the physiological levels of reactive species of oxygen (ROS) and nitrogen (RNS) in the patient, generating oxidative and nitrosative stress that impairs fertility. Recent Advances: Recent studies have delved into other factors involved in the dysregulation of ROS and RNS levels, such as diet, obesity, persistent infections, environmental pollutants, and gut microbiota, thus leading to new strategies to solve male fertility problems, such as consuming prebiotics to regulate gut flora or treating psychological conditions. Critical Issues: The pathways where ROS or RNS may be involved as modulators are still under investigation. Moreover, the extent to which treatments can rescue male infertility as well as whether they may have side effects remains, in most cases, to be elucidated. For example, it is known that prescription of antioxidants to treat nitrosative stress can alter sperm chromatin condensation, which makes DNA more exposed to ROS and RNS, and may thus affect fertilization and early embryo development. Future Directions: The involvement of extracellular vesicles, which might play a crucial role in cell communication during spermatogenesis and epididymal maturation, and the relevance of other factors such as sperm epigenetic signatures should be envisaged in the future.

Cellular senescence in reproduction: a two-edged sword†

Cellular senescence (CS) is the state when cells are no longer capable to divide even after stimulation with grown factors. Cells that begin to undergo CS stop in the cell cycle and enter a suspended state without committing to programmed cell death. These cells assume a specific phenotype and influence their microenvironment by secreting molecules and extracellular vesicles that are part of the so-called senescent cell-associated secretory phenotype (SASP). Cellular senescence is intertwined with physiological and pathological conditions in the human organism. In terms of reproduction, senescent cells are present from reproductive tissues and germ cells to gestational tissues, and participate from fertilization to delivery, going through adverse reproductive outcomes such as pregnancy losses. Furthermore, various SASP molecules are enriched in gestational tissues throughout pregnancy. Thus, the aim of this review is to provide a basis about the features and potential roles played by CS throughout the reproductive process, encompassing its implication in each step of it and proposing a way to manage it in adverse reproductive contexts.

Differential Proteomic Analysis of Human Sperm: A Systematic Review to Identify Candidate Targets to Monitor Sperm Quality

PURPOSE

The advent of proteomics provides new opportunities to investigate the molecular mechanisms underlying male infertility. The selection of relevant targets based on a single analysis is not always feasible, due to the growing number of proteomic studies with conflicting results. Thus, this study aimed to systematically review investigations comparing the sperm proteome of normozoospermic and infertile men to define a panel of proteins with the potential to be used to evaluate sperm quality.

MATERIALS AND METHODS

A literature search was conducted on PubMed, Web of Science, and Scopus databases following the PRISMA guidelines. To identify proteins systematically reported, first the studies were divided by condition into four groups (asthenozoospermia, low motility, unexplained infertility, and infertility related to risk factors) and then, all studies were analysed simultaneously (poor sperm quality). To gain molecular insights regarding identified proteins, additional searches were performed within the Human Protein Atlas, Mouse Genome Informatics, UniProt, and PubMed databases.

RESULTS

Thirty-two studies were included and divided into 4 sub-analysis groups. A total of 2752 proteins were collected, of which 38, 1, 3 and 2 were indicated as potential markers for asthenozoospermia, low motility, unexplained infertility and infertility related to risk factors, respectively, and 58 for poor sperm quality. Among the identified proteins, ACR, ACRBP, ACRV1, ACTL9, AKAP4, ATG3, CCT2, CFAP276, CFAP52, FAM209A, GGH, HPRT1, LYZL4, PRDX6, PRSS37, REEP6, ROPN1B, SPACA3, SOD1, SPEM1, SPESP1, SPINK2, TEKT5, and ZPBP were highlighted due to their roles in male reproductive tissues, association with infertility phenotypes or participation in specific biological functions in spermatozoa.

CONCLUSIONS

Sperm proteomics allows the identification of protein markers with the potential to overcome limitations in male infertility diagnosis and to understand changes in sperm function at the molecular level. This study provides a reliable list of systematically reported proteins that could be potential targets for further basic and clinical studies.

AOP Report: Glutathione Conjugation Leading to Reproductive Dysfunction via Oxidative Stress

We propose an adverse outcome pathway (AOP) for reproductive dysfunction via oxidative stress (OS). The AOP was developed based on Organisation for Economic Co-operation and Development (OECD) Guidance Document 184 and on the specific considerations of the OECD users' handbook supplement to the guidance document for developing and assessing AOPs (no. 233). According to the qualitative and quantitative experimental data evaluation, glutathione (GSH) conjugation is the first upstream key event (KE) of this AOP to reproductive dysfunction triggering OS. This event causes depletion of GSH basal levels (KE2 ). Consequently, this drop of free GSH induces an increase of reactive oxygen species (KE3 ) generated by the natural cellular metabolic processes (cellular respiration) of the organism. Increased levels of these reactive species, in turn, induce an increase of lipid peroxidation (KE4 ). This KE consequently leads to a rise in the amount of toxic substances, such as malondialdehyde and hydroxynonenal, which are associated with decreased quality and competence of gamete cell division, consequently impairing fertility (KE5 and adverse outcome). The overall assessment of the general biological plausibility, the empirical support, and the essentiality of KE relationships was considered as high for this AOP. We conclude that GSH conjugation is able to lead to reproductive disorder in fishes and mammals, via OS, but that the amount of stressor needed to trigger the AOP differs between stressors. Environ Toxicol Chem 2023;42:2519-2528. © 2023 SETAC.

MethylRAD Sequencing Technology Reveals DNA Methylation Characteristics of Apostichopus japonicus of Different Ages

The A. japonicus industry has expanded significantly, but no research has focused on determining the age of A. japonicus during farming. Correctly estimating the age of A. japonicus can provide a decision-making basis for the breeding process and data for the protection of A. japonicus aquatic germplasm resources. DNA methylation levels in the body wall of Apostichopus japonicus at 4 months, 1 year, 2 years, and 3 years old were determined using MethylRAD-Seq, and differentially methylated genes were screened. A total of 441 and 966 differentially methylated genes were detected at the CCGG and CCWGG sites, respectively. Aspartate aminotransferase, succinate semialdehyde dehydrogenase, isocitrate dehydrogenase, the histone H2AX, heat shock protein Hsp90, aminopeptidase N, cell division cycle CDC6, Ras GTPase activating protein (RasGAP), slit guidance ligand slit1, integrin-linked kinase ILK, mechanistic target of rapamycin kinase Mtor, protein kinase A Pka, and autophagy-related 3 atg3 genes may play key roles in the growth and aging process of A. japonicus. This study provides valuable information regarding age-related genes for future research, and these candidate genes can be used to create an "epigenetic clock".

Effect of Lactobacillus brevis (MG000874) on antioxidant-related gene expression of the liver and kidney in D-galactose-induced oxidative stress mice model

Oxidative stress (OS) is a phenomenon induced by excessive production and accumulation of reactive oxygen species (ROS) in living cells. These increased ROS productions connected, coupled with many neurological and physiological diseases. Several antioxidants were utilized recently to combat OS, and lactic acid bacteria have a potent radical-scavenging activity to minimize OS. The present work was designed to find out the protective effects of Lactobacillus brevis MG000874 (L. brevis MG000874) against oxidative injuries induced by D-galactose (D-gal) in vivo and to explore the gene expression of OS-related gene mice. Sixty male mice were randomly split into six groups. The first four groups were different control groups as no treatment (N), positive (G), probiotic (B), and ascorbic acid (A); the remaining two groups were treatment groups such as probiotic treatment (BG) and ascorbic acid treatment (AG). L. brevis MG000874 (0.2 ml of 1010 CFU/ml) and ascorbic acid (0.2 ml of 25 mg/ml) were administered orally daily for 5 weeks. It was revealed that these significantly affect the weight of treated mice: 40.22 ± 1.5 and 33.0 ± 0.57 g on days 0 and 36, respectively. D-gal induction in mice declined the levels of SOD and CAT determined by spectrophotometer. Administration of L. brevis MG000874 improved the antioxidant status of the stress mice and recovered the antioxidant activities of SOD and CAT enzymes. In addition, L. brevis MG000874-altered gene expression of OS marker at the messenger RNA (mRNA) levels was determined by RT-PCR in the mouse model. L. brevis MG000874 significantly improved the GST, GPX, SOD, CAT, and ß-actin levels in the kidney and the liver of the D-gal-induced mice (p < 0.05). Moreover, the histological investigation indicated that L. brevis MG000874 mitigated damage to the kidney and liver effectively in mice induced by D-gal. Therefore, it could be concluded from the current results that L. brevis MG000874 may act as a powerful antioxidant agent, and this study can provide the baseline data for drug development against OS-linked diseases.

Erxian decoction alleviates cisplatin-induced premature ovarian failure in rats by reducing oxidation levels in ovarian granulosa cells

ETHNOPHARMACOLOGICAL RELEVANT

Erxian Decoction (EXD) has been used empirically for more than 70 years to treat premature ovarian failure (POF), but more research is needed to understand how it works.

AIM OF THE RESEARCH

The study aims to ascertain both in vivo and in vitro rewards of EXD.

MATERIALS AND METHODS

EXD is composed of Curculiginis Rhizoma, Epimedii Folium, Morindae Officinalis, Angelicae Sinensis, Anemarrhenae Rhizoma, and Phellodendri Chinensis Cortex. UPLC/MS analysis was used to investigate the components of EXD. Using a POF model created by administering cisplatin to rats intraperitoneally, the pharmacodynamic effects of EXD were investigated. Three dose groups of EXD were garaged into rats: high (15.6 g/kg), medium (7.8 g/kg), and low (3.9 g/kg). By using a vaginal smear, the impact of EXD on the rat estrous cycle was evaluated. An ELISA test was used to measure the anti-Mullerian hormone (AMH), estradiol (E2), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels in the serum of rats. By using HE stains, pathological alterations in the ovaries may be seen. MDA and SOD levels in ovarian samples were used to measure the degree of ovarian oxidation. TUNEL labeling of ovarian sections was used to find apoptosis levels. By using ATP, energy production was evaluated. The relative expression of proteins connected to aging and the RAGE pathway was assessed using Western blot. Then, using H₂O₂, a model of senescent human ovarian granulosa cells (KGN) was created in vitro. The impact of EXD and H₂O₂ on cellular senescence was discovered using-galactosidase staining. Cell apoptosis levels were found using PI/Hoechest33342. By using DCFH-DA, intracellular ROS was examined. MDA and SOD concentrations were used to measure the degree of cellular oxidation. RAGE-related mRNA and protein expression were evaluated using RT-qPCR and western blotting.

RESULTS

Using UPLC/MS analysis, 39 chemicals in EXD were found. Rats' estrous cycles were enhanced by EXD, which increased ovarian index and follicle count and reduced the proportion of atretic follicles in the rats. EXD reduced LH and FSH output while restoring AMH and E2 secretion. In ovarian tissues, EXD reduced the amount of apoptosis and MDA while raising SOD activity and ATP levels. The protein levels of p16, p21, p53, and Lamin A/C were among the senescence-related proteins that EXD lowered, along with the levels of RAGE, PI3K, BAX, and CASPASE 3. Anti-apoptotic protein BCL-2 was also raised in the RAGE pathway. Senescence, apoptosis, ROS, and MDA levels in the KGN cells were lowered in vitro by EXD. Additionally, EXD increased the anti-apoptotic potential by changing the expression of CAT, SOD2, and SIRT1. RAGE, BAX, BCL-2, CASPASE 3, and p38 expression levels were altered by EXD, enhancing its anti-apoptotic capability.

CONCLUSION

EXD boosted the ovary's antioxidant and anti-apoptotic capabilities while enhancing the estrous cycle and hormone output. These findings strongly suggested that EXD may contribute to the alleviation of POF and ovarian granulosa cells senescence.

Intake of Fluted Pumpkin Seeds Rebalances Oxidative Stress Parameters in the Aged Rat’s Testes

The effect of fluted pumpkin seeds (FPS) consumption on the antioxidant status of the testes of aged Wistar rats was evaluated in this study. Sixty (50 aged, 6 months old, and 10 young, 2 months old) rats were divided into six groups of 10 per each group. Testosterone (15 mg kg-1 body weight, once weekly for 40 days) was injected intraperitoneally and used as positive control. FPS intake (50, 100, and 200 mg kg-1 body weight) or vehicle control (corn oil) were administered orally, twice weekly for 40 days and compared with the untreated aged and young control rats. Changes in antioxidant status in the testis of the aged rats was reflected as increased superoxide dismutase and catalase activities and glutathione and decreased lipid peroxidation levels which were attenuated more efficiently by the lowest dose FPS (50 mg kg-1 body weight). Additionally, nitrite concentration that was found to be diminished in the aged rats was raised to the young control values after intake of the FPS (50 mg kg-1 body weight). As expected, testosterone injection increased endogenous testosterone concentration and also remained higher in the untreated aged animals than in young control and treated aged rats. In conclusion, compromised antioxidant defense system of the testes that is associated with ageing could be reversed to the status of the young control by the intake of FPS.

Testicular aging, male fertility and beyond

Normal spermatogenesis and sperm function are crucial for male fertility. The effects of healthy testicular aging and testicular premature aging on spermatogenesis, sperm function, and the spermatogenesis microenvironment cannot be ignored. Compared with younger men, the testis of older men tends to have disturbed spermatogenic processes, sperm abnormalities, sperm dysfunction, and impaired Sertoli and Leydig cells, which ultimately results in male infertility. Various exogenous and endogenous factors also contribute to pathological testicular premature aging, such as adverse environmental stressors and gene mutations. Mechanistically, Y-chromosomal microdeletions, increase in telomere length and oxidative stress, accumulation of DNA damage with decreased repair ability, alterations in epigenetic modifications, miRNA and lncRNA expression abnormalities, have been associated with impaired male fertility due to aging. In recent years, the key molecules and signaling pathways that regulate testicular aging and premature aging have been identified, thereby providing new strategies for diagnosis and treatment. This review provides a comprehensive overview of the underlying mechanisms of aging on spermatogenesis. Furthermore, potential rescue measures for reproductive aging have been discussed. Finally, the inadequacy of testicular aging research and future directions for research have been envisaged to aid in the diagnosis and treatment of testicular aging and premature aging.

Reactive Oxygen Species and Their Consequences on the Structure and Function of Mammalian Spermatozoa

Significance: Among the 200 or so cell types that comprise mammals, spermatozoa have an ambiguous relationship with the reactive oxygen species (ROS) inherent in the consumption of oxygen that supports aerobic metabolism. Recent Advances: In this review, we shall see that spermatozoa need the action of ROS to reach their structural and functional maturity, but that due to intrinsic unique characteristics, they are, perhaps more than any other cell type, susceptible to oxidative damage. Recent studies have improved our knowledge of how oxidative damage affects sperm structures and functions. The focus of this review will be on how genetic and epigenetic oxidative alterations to spermatozoa can have dramatic unintended consequences in terms of both the support and the suppression of sperm function. Critical Issues: Oxidative stress can have dramatic consequences not only for the spermatozoon itself, but also, and above all, on its primary objective, which is to carry out fertilization and to ensure, in part, that the embryonic development program should lead to a healthy progeny. Future Directions: Sperm oxidative DNA damage largely affects the integrity of the paternal genetic material to such an extent that the oocyte may have difficulties in correcting it. Diagnostic and therapeutic actions should be considered more systematically, especially in men with difficulties to conceive. Research is underway to determine whether the epigenetic information carried by spermatozoa is also subject to changes mediated by pro-oxidative situations. Antioxid. Redox Signal. 37, 481-500.

Advanced Paternal Age and Future Generations

Paternal age at conception has been increasing. In this review, we first present the results from the major mammalian animal models used to establish that increasing paternal age does affect progeny outcome. These models provide several major advantages including the possibility to assess multi- transgenerational effects of paternal age on progeny in a relatively short time window. We then present the clinical observations relating advanced paternal age to fertility and effects on offspring with respect to perinatal health, cancer risk, genetic diseases, and neurodevelopmental effects. An overview of the potential mechanism operating in altering germ cells in advanced age is presented. This is followed by an analysis of the current state of management of reproductive risks associated with advanced paternal age. The numerous challenges associated with developing effective, practical strategies to mitigate the impact of advanced paternal age are outlined along with an approach on how to move forward with this important clinical quandary.

The Role of NLRP3 Inflammasome Activation and Oxidative Stress in Varicocele-Mediated Male Hypofertility

Varicocele (VC) is the most common abnormality identified in men evaluated for hypofertility. Increased levels of reactive oxygen species (ROS) and reduced antioxidants concentrations are key contributors in varicocele-mediated hypofertility. Moreover, inflammation and alterations in testicular immunity negatively impact male fertility. In particular, NLRP3 inflammasome activation was hypothesized to lead to seminal inflammation, in which the levels of specific cytokines, such as IL-1β and IL-18, are overexpressed. In this review, we described the role played by oxidative stress (OS), inflammation, and NLRP3 inflammasome activation in VC disease. The consequences of ROS overproduction in testis, including inflammation, lipid peroxidation, mitochondrial dysfunction, chromatin damage, and sperm DNA fragmentation, leading to abnormal testicular function and failed spermatogenesis, were highlighted. Finally, we described some therapeutic antioxidant strategies, with recognized beneficial effects in counteracting OS and inflammation in testes, as possible therapeutic drugs against varicocele-mediated hypofertility.

Epimedium protects against dyszoospermia in mice with Pex3 knockout by exerting antioxidant effects and regulating the expression level of P16

Oxidative stress (OS) is one of the primary factors leading to male infertility. Oral administration of antioxidants has thus far been found to significantly improve the quality of human sperm. Therefore, antioxidant treatment has become the consensus among international experts on male infertility. In this study, peroxisomal biogenesis factor 3 (Pex3)-knockout (KO, -/-) mice were used as a model to compare the efficacy of three types of traditional Chinese medicine (TCM) granules (Epimedium [YYH], Cuscuta [TSZ], and Rhodiola [HJT]) for male reproductive function rescue. YYH was revealed to be the best and exerted a rescue effect on Pex3-/- mice with spermatogenesis defects. In addition, YYH prominently reduced ROS levels in the testes, inhibited DNA oxidative damage in spermatogenic cells, promoted the proliferation of spermatogenic cells, and inhibited apoptosis in Pex3-/- male mice. Furthermore, the mechanism by which YYH ameliorated dyszoospermia was confirmed via the establishment of cyclin-dependent kinase inhibitor 2 A (P16Ink4a)-KO mice. Specifically, Pex3-/- mice produced elevated amounts of ROS, which damaged germ cell DNA and further activated the signaling pathway of the cell senescence regulatory protein P16-CDK6, resulting in cell cycle arrest and eventually contributing to spermatogenesis dysfunction. YYH supplementation partially corrected the associated phenotype in gene KO mice by affecting P16 expression levels, thus improving the reproductive outcome to a certain extent.

Delayed parenthood and its influence on offspring health: What have we learned from the mouse model

Delayed parenthood is constantly increasing worldwide due to various socio-economic factors. In the last decade, a growing number of epidemiological studies have suggested a link between advanced parental age and an increased risk of diseases in the offspring. Also, poor reproductive outcome has been described in pregnancies conceived by aged parents. Similarly, animal studies showed that aging negatively affects gametes, early embryonic development, pregnancy progression and the postnatal phenotype of resulting offspring. However, how and to what extent parental age is a risk factor for the health of future generations is still subject to debate. Notwithstanding the limitation of an animal model, the mouse model represents a useful tool to understand not only the influence of parental age on offspring phenotype but also the biological mechanisms underlying the poor reproductive outcome and the occurrence of diseases in the descendants. The present review aims at i) providing an overview of the current knowledge from mouse model about the risks associated with conception at advanced age (e.g. neurodevelopmental and metabolic disorders), ii) highlighting the candidate biological mechanisms underlying this phenomenon, and iii) discussing on how murine-derived data can be relevant to humans.

Oxidative Stress: A Comprehensive Review of Biochemical, Molecular, and Genetic Aspects in the Pathogenesis and Management of Varicocele

Oxidative stress is a condition due to an imbalance between the concentrations of oxidants and antioxidants, and it is a well-recognized contributor in several male infertility conditions. Varicocele, a common vascular condition, may cause male infertility due to hyperthermia, hypoxia and/or exposure to toxic adrenal and renal metabolites. In this review, the mechanisms by which oxidative stress can affect cellular integrity and functions are described, along with molecular markers of cellular oxidative damage, and the most commonly performed techniques for their detection in seminal fluid. Moreover, we focus on the role of oxidative stress in the pathophysiology of varicocele based on recently published evidence from omics based studies, such as proteomics and genomics. Finally, we discuss strategies for the management of oxidative stress and the clinical guidelines for testing oxidative stress-related sperm DNA fragmentation in this group of patients.

The dynamic changes of Nrf2 mediated oxidative stress, DNA damage and base excision repair in testis of rats during aging

Accumulation of oxidative stress, DNA damage and impaired DNA repair appear to play critical roles in the decline of testicular function with aging. However, when those factors begin to lose control in testis during aging has not yet been well understood. This study was designed to assess the changes of oxidative stress and DNA damage status, and DNA repair capacity in testis during aging. Thus, male Sprague-Dawley rats at 3, 9, 15 and 24 months of age were used to delineate the dynamic changes in testicular weight and index, testosterone concentration, testicular histology, Nrf2-mediated oxidative stress, DNA damage, DNA repair and apoptosis. Results showed that testicular weight and index, testosterone concentration and spermatid number progressively declined from 9 to 24 months of age. Similarly, seminiferous tubule diameters and seminiferous epithelium heights gradually diminished with aging. Nrf2-mediated antioxidant defense ability was significantly impaired in testis with increasing age including decreased the activity of SOD and the expression levels of Nrf2, HO-1 and NQO-1, and increased the contents of MDA. In addition, DNA damage including DNA single-strand breaks (SSBs) and DNA double-strand breaks (DSBs) also progressively increased accompanied by increased levels of 8-hydroxydeoxyguanosine (8-OHdG) and γ-H2AX, and activated ATM/Chk2 and ATR/Chk1 pathway. Consistent with the results of Nrf2 pathway, the expression levels of APE1, OGG1 and XRCC1 involved in base excision DNA repair (BER) pathway increased from 3 to 9 months of age, and then gradually decreased after 9 months of age. Finally, TUNEL and Western blot results further confirmed germ cell apoptosis progressively increased from 3 to 24 months of age as evidenced by decreased ratio of Bcl-2/Bax and levels of Bcl-2 expression, and increased Bax expression levels. Taken together, our results suggest that downregulation of antioxidant ability mediated by Nrf2 pathway and impairment of BER capacity might correlate with increased DNA damage, and then induce declining testicular function during aging after adult.

Male and female gonadal ageing: its impact on health span and life span

Ageing is linked to changes in the hypothalamic-pituitary-gonadal axis and a progressive decline in gonadal function. While women become infertile when they enter menopause, fertility decline in ageing men does not necessarily involve a complete cessation of spermatogenesis. Gonadal dysfunction in elderly people is characterized by morphological, endocrine and metabolic alterations affecting the reproductive function and quality of life. With advancing age, sexuality turns into a critical emotional and physical factor actually defining the number of years that ageing people live a healthy life. Gonadal ageing correlates with comorbidities and an increased risk of age-related diseases including diabetes, kidney problems, cardiovascular failures and cancer. This article briefly summarizes the current state of knowledge on ovarian and testicular senescence, explores the experimental models used in the study of gonadal ageing, and describes the local pro-inflammatory, oxidative and apoptotic events and the associated signalling pathways that take place in the gonads while people get older. Overall, literature reports that ageing exacerbates a mutual crosstalk among oxidative stress, apoptosis and the inflammatory response in the gonads leading to detrimental effects on fertility. Data also highlight the clinical implications of novel therapeutic interventions using antioxidant, anti-apoptotic and anti-inflammatory drugs on health span and life span.

Aging and oxidative stress alter DNA repair mechanisms in male germ cells of superoxide dismutase-1 null mice

The efficiency of antioxidant defense system decreases with aging, thus resulting in high levels of reactive oxygen species (ROS) and DNA damage in spermatozoa. This damage can lead to genetic disorders in the offspring. There are limited studies investigating the effects of the total loss of antioxidants, such as superoxide dismutase-1 (SOD1), in male germ cells as they progress through spermatogenesis. In this study, we evaluated the effects of aging and removing SOD1 (in male germ cells of SOD1-null (Sod1-/-) mice) in order to determine the potential mechanism(s) of DNA damage in these cells. Immunohistochemical analysis showed an increase in lipid peroxidation and DNA damage in the germ cells of aged wild-type (WT) and Sod1-/- mice of all age. Immunostaining of OGG1, a marker of base excision repair (BER), increased in aged WT and young Sod1-/- mice. In contrast, immunostaining intensity of LIGIV and RAD51, markers of non-homologous end-joining (NHEJ) and homologous recombination (HR), respectively, decreased in aged and Sod1-/- mice. Gene expression analysis showed similar results with altered mRNA expression of these key DNA repair transcripts in pachytene spermatocytes and round spermatids of aged and Sod1-/- mice. Our study indicates that DNA repair pathway markers of BER, NHEJ, and HR are differentially regulated as a function of aging and oxidative stress in spermatocytes and spermatids, and aging enhances the repair response to increased oxidative DNA damage, whereas impairments in other DNA repair mechanisms may contribute to the increase in DNA damage caused by aging and the loss of SOD1.

Should we be measuring DNA damage in human spermatozoa? New light on an old question

Assessments of sperm DNA damage are controversial because of perceived uncertainties over the relationship with pregnancy and the limited range of therapies available should positive results be returned. In this article, we highlight recent data supporting a chain of associations between oxidative stress in the male germ line, DNA damage in spermatozoa, defective DNA repair in the oocyte, the mutational load carried by the resulting embryo and the long-term health trajectory of the offspring. Any condition capable of generating oxidative damage in spermatozoa (age, obesity, smoking, prolonged abstinence, varicocele, chemical exposures, radiation etc.) is capable of influencing offspring health in this manner, creating a range of pathologies in the progeny including neuropsychiatric disorders and cancer. If sperm DNA damage is detected, there are several therapeutic interventions that can be introduced to improve DNA quality prior to the use of these cells in ART. We therefore argue that infertility specialists should be engaged in the diagnosis and remediation of sperm DNA damage as a matter of best practice, in order to minimize the risk of adverse health outcomes in children conceived using ART.

The role of endogenous antioxidants in male animal fertility

Mammalian semen is a physiological fluid composed of a cellular fraction (spermatozoa), and a liquid fraction (seminal plasma). Once delivered to the female genital tract, spermatozoa should be able to capacitate; a process which involves a plethora of biochemical and physiological changes required to fertilize the oocyte. Sperm production (spermatogenesis) occurs in the testes, whereby pluripotent spermatogonia differentiate to form the most morphologically specialized cells in the body. Further maturation of spermatozoa occurs in the epididymis, where they are stored prior to ejaculation. During this whole process, spermatozoa are exposed to different environments and cellular processes which may expose them to substantial levels of oxidative stress. To avoid damage associated with the unchecked production of reactive oxygen species (ROS), both spermatozoa, and the parts of the male genital tract in which they reside, are furnished with a suite of antioxidant molecules which are able to provide protection to these cells, thereby increasing their chance of being able to fertilize the oocyte and deliver an intact paternal genome to the future offspring. However, there are a host of reasons why these antioxidant systems may fail, including nutritional deficiencies, genetics, and disease states, and in these situations, a reduction or abolition of fertilizing capacity may result. This review paper focuses on the endogenous antioxidant defences available to spermatozoa during spermatogenesis and sperm maturation, the site of their production and their physiological role. Furthermore, we revised the causes and effects of antioxidant deficiencies (congenital or acquired during the animal's adulthood) on reproductive function in different animal species.

Protective effects of ginseng stem-leaf saponins on D-galactose-induced reproductive injury in male mice

Panax ginseng is a perennial plant in the Araliaceae family. In this study, we investigated the protective effects of ginseng stem-leaf saponins (GSLS) isolated from P. ginseng against D-galactose-induced reproductive function decline, oxidative stress, and inflammatory response. Reproductive injuries were induced in mice via the subcutaneous injection of D-galactose (300 mg/kg) for six weeks. The mice were then treated with GSLS by intragastric administration. GSLS inhibited markers of oxidative stress and inflammatory cytokines induced by D-galactose in serum, liver and kidney, whereas GSLS increased the activities of antioxidant enzymes. Compared to the mice treated only with D-galactose, GSLS treatment significantly increased the average path velocity, straight line velocity, curvilinear velocity, and amplitude of the lateral head displacement of mouse sperm. Meanwhile, GSLS significantly increased the testosterone level and reduced the cortisol, FSH, and LH levels. Histopathological examination revealed alterations in the number and the arrangement of spermatogenic cells in the seminiferous tubules of the mice in the GSLS group. GSLS treatment suppressed MAPKs pathway activation in testes. These results suggest that GSLS can attenuate D-galactose-induced oxidative stress and inflammatory response in serum, liver and kidney, and ameliorate reproductive damage by inhibiting MAPKs signaling pathway.

The Impact of Antarctic Ice Microalgae Polysaccharides on D-Galactose-Induced Oxidative Damage in Mice

Antarctic ice microalgae (Chlamydomonas sp.) are a polysaccharide-rich natural marine resource. In this study, we evaluated the impact of Antarctic ice microalgae polysaccharides (AIMP) on D-galactose-induced oxidation in mice. We conducted biological and biochemical tests on tissue and serum samples from mice treated with AIMP. We found that AIMP administration was associated with improved thymus, brain, heart, liver, spleen, and kidney index values. We also found that AIMP treatment inhibited the reduced aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, superoxide dismutase, glutathione peroxidase, and glutathione levels as well as the increased serum, splenic, and hepatic nitric oxide and malondialdehyde levels arising from oxidation in these animals. Pathological examination revealed that AIMP also inhibited D-galactose-induced oxidative damage to the spleen, liver, and skin of these animals. AIMP was additionally found to promote the upregulation of neuronal nitric oxide synthase, endothelial nitric oxide synthase, cuprozinc-superoxide dismutase, manganese superoxide dismutase, catalase, heme oxygenase-1, nuclear factor erythroid 2-related factor 2, γ-glutamylcysteine synthetase, and NAD(P)H dehydrogenase [quinone] 1 as well as the downregulation of inducible nitric oxide synthase in these animals. High-performance liquid chromatography analysis revealed AIMP to be composed of five monosaccharides (mannitol, ribose, anhydrous glucose, xylose, and fucose). Together, these results suggest that AIMP can effectively inhibit oxidative damage more readily than vitamin C in mice with D-galactose-induced oxidative damage, which underscores the value of developing AIMP derivatives for food purposes.

Adiponectin/AdipoRs signaling as a key player in testicular aging and associated metabolic disorders

Aging undergoes serious worsening of peripheral organs and vital physiological processes including reproductive performances. Altered white adipose tissue and adipocyte functioning during aging results in ectopic lipid storage/obesity or metabolic derangements, leading to insulin resistance state. Eventually, accelerating cellular senescence thereby enhancing the high risk of age-associated metabolic alterations. Such alterations may cause derangement of numerous physiologically active obesity hormones, known as "adipokines." Specifically, adiponectin exhibits insulin sensitizing action causing anti-aging and anti-obesity effects via activation of adiponectin receptors (AdipoRs). The male reproductive physiology from reproductive mature stage to advanced senescent stage undergoes insidious detrimental changes. The mechanisms by which testicular functions decline with aging remain largely speculative. Adiponectin has also recently been shown to regulate metabolism and longevity signaling thus prolonging lifespan. Therefore, the strategy for activating adiponectin/AdipoRs signaling pathways are expected to provide a solid basis for the prevention and treatment of aging and obesity-associated reproductive dysfunctions, as well as for ensuring healthy reproductive longevity in humans.

Mitochondrial Reactive Oxygen Species (ROS) Production Alters Sperm Quality

Besides ATP production, mitochondria are key organelles in several cellular functions, such as steroid hormone biosynthesis, calcium homoeostasis, intrinsic apoptotic pathway, and the generation of reactive oxygen species (ROS). Despite the loss of the majority of the cytoplasm occurring during spermiogenesis, mammalian sperm preserves a number of mitochondria that rearrange in a tubular structure at the level of the sperm flagellum midpiece. Although sperm mitochondria are destroyed inside the zygote, the integrity and the functionality of these organelles seem to be critical for fertilization and embryo development. The aim of this review was to discuss the impact of mitochondria-produced ROS at multiple levels in sperm: the genome, proteome, lipidome, epigenome. How diet, aging and environmental pollution may affect sperm quality and offspring health—by exacerbating oxidative stress—will be also described.

Paternal Subclinical Hypothyroidism Affects the Clinical Outcomes of In Vitro Fertilization/Intracytoplasmic Sperm Injection

Background: Maternal subclinical hypothyroidism (SCH) is a risk factor for adverse pregnancy outcomes. However, it is still unclear whether SCH affects male fertility. The aim of this study was to determine the association between paternal SCH and clinical outcomes after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). Methods: This retrospective study included 2511 couples with paternal euthyroidism (n = 2282) or SCH (n = 229) who visited our clinic for infertility treatment between April 1, 2017, and September 30, 2019. The primary outcomes were the fertilization rate and clinical pregnancy rate; the secondary outcomes were the good-quality embryo rate, blastocyst formation rate, implantation rate, and early miscarriage rate. These outcomes were compared between the euthyroid and the SCH groups after adjusting for various potential confounders. Results: The mean paternal ages in the euthyroid and SCH groups were 34.5 and 36.0 years, respectively (p = 0.002). Semen parameters and sperm DNA fragmentation index were similar between the two groups (all p > 0.05). The adjusted fertilization (0.69 vs. 0.71, p = 0.30), good-quality embryo (0.49 vs. 0.52, p = 0.31), blastocyst formation (0.51 vs. 0.53, p = 0.57), and early miscarriage (0.11 vs. 0.10, p = 0.81) rates were also similar between the two groups. There was a significantly decreased adjusted clinical pregnancy rate [confidence interval, CI] and implantation rate [CI] in the paternal SCH group compared with the euthyroid group (0.32 [0.26-0.40] vs. 0.42 [0.40-0.45], p = 0.009 for the clinical pregnancy rate; 0.24 [0.19-0.29] vs. 0.29 [0.27-0.31], p = 0.037 for the implantation rate). Stratified analysis indicated that these differences were only significant in men aged ≥35 years (p = 0.009 and 0.022, respectively) and not in men <35 years (p = 0.39 and 0.45, respectively). Conclusions: Paternal SCH was associated with worse clinical outcomes after IVF/ICSI, whereas this detrimental impact was only present in males ≥35 years old. Prospective studies and basic research are warranted to confirm these results and to clarify the mechanisms underlying these associations, respectively.

Dietary alpha-lipoic acid supplementation improves spermatogenesis and semen quality via antioxidant and anti-apoptotic effects in aged breeder roosters

The purpose of the present study was to investigate the effects of dietary alpha-lipoic acid (ALA) supplementation on the reproductive performance of aged breeder roosters. Sixteen 50-wk-old ROSS 308 breeder roosters were randomly allocated to two groups: roosters received a basal diet (CON), or a basal diet supplemented with 300 mg/kg of ALA (ALA). The results indicated that dietary ALA supplementation significantly increased sperm concentration, motility, viability, and membrane functional integrity. ALA also dramatically increased seminiferous tubule epithelial height (SEH) and testis scores. The ALA group had a higher serum concentration of testosterone than the CON group. ALA supplementation remarkably increased total antioxidant capacity (T-AOC), the enzyme activities of glutathione peroxidase (GPx), and catalase (CAT) in the testes; following a decrease in malondialdehyde (MDA) levels. In addition, we noted significant upregulation of Nrf2 mRNA and protein expression of and mRNA expression of its Downstream Genes (GPx1, NQO1, and GCLC), as well as significant downregulation of Keap1 mRNA expression in testicular tissue of aged roosters with ALA supplementation. The protein expression of Caspase 3 was downregulated and the protein expression of proliferating cell nuclear antigen (PCNA) was upregulated by ALA supplementation. The mRNA expression of spermatogenesis-related genes (ER1, AKT1, and Cav1) were markedly augmented in the ALA group compared with the CON group. In conclusion, dietary ALA supplementation enhanced the testicular antioxidant capacity through the Nrf2-signaling pathway, exerted anti-apoptotic effects, and improved the reproductive performance of aged roosters.

Oxidative Stress and Reproductive Function in the Aging Male

With the delay of parenthood becoming more common, the age at which men father children is on the rise. While the effects of advanced maternal age have been well documented, only recently have studies started to focus on the impact of advanced paternal age (APA) in the context of male reproduction. As men age, the antioxidant defense system gradually becomes less efficient and elevated levels of reactive oxygen species (ROS) accumulate in spermatozoa; this can impair their functional and structural integrity. In this review, we present an overview of how oxidative stress is implicated in male reproductive aging by providing a summary of the sources and roles of ROS, the theories of aging, and the current animal and human studies that demonstrate the impacts of APA on the male germ line, the health of progeny and fertility, and how treatment with antioxidants may reverse these effects.

Preventive effect of insect tea primary leaf (Malus sieboldii (Regal) Rehd.) extract on D-galactose-induced oxidative damage in mice

Insect tea is consumed as a health beverage in China. The insect tea primary leaf (ITPL) is rich in bioactive substances, which are also used as traditional Chinese medicine. This study investigated the role of ITPL in reducing the oxidative response induced by D-galactose in mice. Mice were intraperitoneally injected with D-galactose to induce oxidative damage. The effect of ITPL was tested by pathological observation, serum detection with kits, quantitative polymerase chain reaction, and Western blot. The experimental results show that ITPL increased the thymus, brain, heart, liver, spleen, and kidney indices of oxidized mice. ITPL increased superoxide dismutase, glutathione peroxidase, and glutathione levels and reduced nitric oxide and malondialdehyde levels in the serum, liver, and spleen in oxidative damaged mice. The pathological observations show that ITPL reduced the oxidative damage of the liver and spleen in mice induced with D-galactose. Simultaneously, ITPL upregulated mRNA expression of neuronal nitric oxide synthase, endothelial nitric oxide synthase, cuprozinc-superoxide dismutase, manganese superoxide dismutase, catalase, heme oxygenase-1, nuclear factor-erythroid 2 related factor 2, γ-glutamylcysteine synthetase, and NAD(P)H dehydrogenase [quinone] 1, and downregulated the expression of inducible nitric oxide synthase in the liver and spleen of oxidized mice. ITPL had beneficial preventive effects on the oxidative damage caused by D-galactose in mice and was more effective as an antioxidant than vitamin C. The component analysis test by high-performance liquid chromatography indicated that ITPL contained the following seven compounds: neochlorogenic acid, cryptochlorogenic acid, rutin, kaempferin, isochlorogenic acid B, isochlorogenic acid A, and hesperidin. ITPL is a plant with excellent antioxidant activities derived from its bioactive substances.

Dysregulation of Steroid Hormone Receptors in Motor Neurons and Glia Associates with Disease Progression in ALS Mice

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease targeting motor neurons which shows sexual dimorphism in its incidence, age of onset, and progression rate. All steroid hormones, including androgens, estrogens, and progestogens, have been implicated in modulating ALS. Increasing evidence suggests that steroid hormones provide neuroprotective and neurotrophic support to motor neurons, either directly or via surrounding glial cell interactions, by activating their respective nuclear hormone receptors and initiating transcriptional regulatory responses. The SOD1G93A transgenic mouse also shows sex-specific differences in age of onset and progression, and remains the most widely used model in ALS research. To provide a more comprehensive understanding of the influences of steroid hormone signaling in ALS, we systemically characterized sex hormone receptor expression at transcript and protein levels, cellular localization, and the impact of disease course in lumbar spinal cords of male and female SOD1G93A mice. We found that spinal motor neurons highly express nuclear androgen receptor (AR), estrogen receptor (ER)α, ERβ, and progesterone receptor with variations in glial cell expression. AR showed the most robust sex-specific difference in expression and was downregulated in male SOD1G93A mouse spinal cord, in association with depletion in 5α-reductase type 2 isoform, which primarily metabolizes testosterone to 5α-dihydrotestosterone. ERα was highly enriched in reactive astrocytes of SOD1G93A mice and ERβ was strongly upregulated. The 5α-reductase type 1 isoform was upregulated with disease progression and may influence local spinal cord hormone levels. In conclusion, steroid hormone receptor expression is dynamic and cell-type specific in SOD1G93A mice which may provide targets to modulate progression in ALS.

Reactive Oxygen Species and Male Fertility

Human infertility affects ~15% of couples worldwide, and it is now recognized that in half of these cases, the causes of infertility can be traced to men[...].

Antioxidant Enzymes and Male Fertility: Lessons from Knockout Models

Significance: Spermatozoa are very sensitive to high levels of reactive oxygen species (ROS) due to the limited antioxidant systems present in these terminal cells. However, tight regulation of ROS levels must be ensured to accomplish the unique goal of the spermatozoon, that is, the transfer of the paternal genome into the mature oocyte during the fertilization process. Thus, it is essential that the restricted antioxidant enzymatic systems are active for sperm function. Recent Advances: Oxidative stress is associated with low sperm quality. High levels of ROS in spermatozoa produce oxidation of lipids, proteins, and DNA that lead to lipid peroxidation, oxidation of essential structural proteins and enzymes, and mutations due to oxidation of DNA. Critical Issues: In this study, we described the available knockout mouse models that helped to better understand the role of different antioxidant enzymes in male fertility. We focused mainly on those studies that directly explore the effects of the lack of these enzymes in male fertility and included information when existing knockout mouse models produced for other purposes were used. Special attention was given in this review to the consequences of the absence of antioxidant enzymes on sperm quality and fertility of aging males from the knockout models. Future Directions: Further studies using novel mouse models lacking different antioxidants and their combinations are essential to understand the consequences of high levels of ROS in aging testes, epididymes, spermatozoa, and embryo development to produce a healthy baby.

The Exacerbation of Aging and Oxidative Stress in the Epididymis of Sod1 Null Mice

There is growing evidence that the quality of spermatozoa decreases with age and that children of older fathers have a higher incidence of birth defects and genetic mutations. The free radical theory of aging proposes that changes with aging are due to the accumulation of damage induced by exposure to excess reactive oxygen species. We showed previously that absence of the superoxide dismutase 1 (Sod1) antioxidant gene results in impaired mechanisms of repairing DNA damage in the testis in young Sod1^−/− mice. In this study, we examined the effects of aging and the Sod^−/− mutation on mice epididymal histology and the expression of markers of oxidative damage. We found that both oxidative nucleic acid damage (via 8-hydroxyguanosine) and lipid peroxidation (via 4-hydroxynonenal) increased with age and in Sod1^−/− mice. These findings indicate that lack of SOD1 results in an exacerbation of the oxidative damage accumulation-related aging phenotype.

Tetrahydroxystilbene Glucoside Ameliorates Infrasound-Induced Central Nervous System (CNS) Injury by Improving Antioxidant and Anti-Inflammatory Capacity

Background

Infrasound is a major threat to global health by causing injuries of the central nervous system (CNS). However, there remains no effective therapeutic agent for preventing infrasound-caused CNS injury. 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glycoside (THSG) exerts protective function against CNS injuries and may have beneficial effects on infrasound-induced CNS impairment.

Methods

A mouse model with CNS (oxidative stress-induced inflammation and neuronal apoptosis) injuries was established when the mouse was exposed to the infrasound of 16 Hz at 130 dB for 2 h each day and the duration of treatment was 8 d. The mice were divided into the control (CG, healthy mice), the model (MG, model mice), and the THSG (EG, experimental group, model mice treated with THSG) groups. The learning and memory impairments caused by infrasound were examined using a Morris water maze test. Lipid profiles, antioxidant biomarkers, and inflammatory cytokines in hippocampus tissue were measured by using corresponding ELISA kits. Meanwhile, BCL-2/BAX/caspase-3 signaling pathway was measured in the hippocampi and prefrontal cortex of the mouse brain using real-time qPCR and Western blot. Nissl's stain was used to measure neuronal necrosis in the hippocampi and prefrontal cortex of the mouse brain.

Results

THSG significantly ameliorated the learning and memory impairments caused by infrasound. On the other hand, THSG improved lipid profiles, increased antioxidant properties by affecting the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and malondialdehyde (MDA), and displayed anti-inflammatory action via the downregulation of IL- (interleukin-) 6, IL-8, IL-10, TNF- (tumor necrosis factor-) α, and hs-CRP (high-sensitivity C-reactive protein) in the hippocampal tissues of the mouse model (P < 0.05). Additionally, Nissl's stain showed that THSG inhibited infrasound-induced neuronal necrosis in the hippocampi and prefrontal cortex. Besides, THSG exerted antiapoptosis function by upregulating the level of Bcl-2 and downregulating the levels of BAX and caspase-3 in the hippocampi.

Conclusion

THSG may be an effective anti-infrasound drug against CNS injury by improving antioxidant, anti-inflammatory, antiapoptosis, and antinecrosis capacities. Further research is still needed to confirm the exact molecular mechanism.

Oxidative stress and male infertility: current knowledge of pathophysiology and role of antioxidant therapy in disease management

Infertility is a global health problem involving about 15% of couples. Approximately half of the infertility cases are related to male factors. The oxidative stress, which refers to an imbalance in levels of reactive oxygen species (ROS) and antioxidants, is one of the main causes of infertility in men. A small amount of ROS is necessary for the physiological function of sperm including the capacitation, hyperactivation and acrosomal reaction. However, high levels of ROS can cause infertility through not only by lipid peroxidation or DNA damage but inactivation of enzymes and oxidation of proteins in spermatozoa. Oxidative stress (OS) is mainly caused by factors associated with lifestyle. Besides, immature spermatozoa, inflammatory factors, genetic mutations and altering levels of sex hormones are other main source of ROS. Since OS occurs due to the lack of antioxidants and its side effects in semen, lifestyle changes and antioxidant regimens can be helpful therapeutic approaches to overcome this problem. The present study aimed to describe physiological ROS production, roles of genetic and epigenetic factors on the OS and male infertility with various mechanisms such as lipid peroxidation, DNA damage, and disorder of male hormone profile, inflammation, and varicocele. Finally, the roles of oral antioxidants and herbs were explained in coping with OS in male infertility.

Oxidative stress and male infertility: current knowledge of pathophysiology and role of antioxidant therapy in disease management

Infertility is a global health problem involving about 15% of couples. Approximately half of the infertility cases are related to male factors. The oxidative stress, which refers to an imbalance in levels of reactive oxygen species (ROS) and antioxidants, is one of the main causes of infertility in men. A small amount of ROS is necessary for the physiological function of sperm including the capacitation, hyperactivation and acrosomal reaction. However, high levels of ROS can cause infertility through not only by lipid peroxidation or DNA damage but inactivation of enzymes and oxidation of proteins in spermatozoa. Oxidative stress (OS) is mainly caused by factors associated with lifestyle. Besides, immature spermatozoa, inflammatory factors, genetic mutations and altering levels of sex hormones are other main source of ROS. Since OS occurs due to the lack of antioxidants and its side effects in semen, lifestyle changes and antioxidant regimens can be helpful therapeutic approaches to overcome this problem. The present study aimed to describe physiological ROS production, roles of genetic and epigenetic factors on the OS and male infertility with various mechanisms such as lipid peroxidation, DNA damage, and disorder of male hormone profile, inflammation, and varicocele. Finally, the roles of oral antioxidants and herbs were explained in coping with OS in male infertility.

Lactobacillus plantarum KSFY06 on d-galactose-induced oxidation and aging in Kunming mice

Yogurt from Xinjiang, China, is a traditional Chinese fermented food rich in beneficial microorganisms, such as Lactobacillus plantarum KSFY06. In this study, the effect of KSFY06 on oxidative aging was investigated using live animal experiments. Molecular biological methods were used to analyze the serum and tissues of mice with oxidative aging induced by d-galactose, which showed that KSFY06 can inhibit the decline of heart, liver, spleen, and kidney caused by aging. The KSFY06 strain increased the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and glutathione (GSH) in serum and liver of aging mice, while the content of malondialdehyde (MDA) is reduced. Pathological observation showed that KSFY06 alleviated damage to the liver, spleen, and skin of oxidative aging mice. qPCR showed that, at high dose (2 × 109 cfu/kg per day), KSFY06 upregulates copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), catalase (CAT) mRNA expression, and its downstream inducible nitric oxide synthase (iNOS) mRNA expression in liver and spleen tissues induced by d-gal. To a certain extent, these findings indicate that L. plantarum KSFY06 is able to protect against oxidative stress in the d-gal-induced aging model. In conclusion, L. plantarum KSFY06 may provide a potential research value in the prevention or alleviation of related diseases caused by oxidative stress.

Effect of insect tea on D-galactose-induced oxidation in mice and its mechanisms

Insect tea is a traditional Chinese drink that contains abundant bioactive substances. In this study, the preventive effect of Insect tea on D-galactose-induced oxidation in mice was studied. The serum, liver, and spleen of mice were measured by biochemical and molecular biological methods, which showed that Insect tea could increase the biochemical indexes of the thymus, brain, heart, liver, spleen, and kidney in mice with induced oxidative damage. Insect tea can increase the levels of SOD (superoxide dismutase), GSH-Px (glutathione peroxidase), and GSH (glutathione) and decrease the levels of MDA (malondialdehyde) in the serum, liver, and spleen of mice with oxidative damage. Pathological observation also confirmed that Insect tea could inhibit oxidative damage of the liver and spleen tissue caused by D-galactose in mice. Further molecular biological experiments also showed that Insect tea could upregulate the mRNA and protein expression of Cu/Zn-SOD (cuprozinc-superoxide dismutase), Mn-SOD (manganese superoxide dismutase), CAT (catalase), HO-1 (heme oxygenase-1), Nrf2 (nuclear factor-erythroid 2 related factor 2), γ-GCS (γ-glutamylcysteine synthetase), and NQO1 (NAD(P)H dehydrogenase [quinone] 1) in the liver and spleen of oxidized mice. Insect tea has a good preventive effect on D-galactose-induced oxidation in mice, and the effect is better than vitamin C, an antioxidant. Insect tea is rich in isochlorogenic acid A, quercetin, rutin, hesperidin, neochlorogenic acid, and cryptochlorogenic acid. The combination of these bioactive substances has good antioxidant effects. Thus, Insect tea is a functional food with a good antioxidant effect that has value for future development and utilization.

The preventive effect of Apocynum venetum polyphenols on D-galactose-induced oxidative stress in mice

Apocynum venetum is a traditional medicine that is rich in polyphenols. Apocynum venetum polyphenol extract (AVP) contains the active substances neochlorogenic acid, chlorogenic acid, rutin, isoquercitrin, astragaloside and rosmarinic acid. In the present study, the preventive effect of AVP against D-galactose-induced oxidative stress was studied in a mouse model. The sera, skin, livers and spleens of mice were examined using hematoxylin and eosin staining, reverse transcription-quantitative PCR and western blot analysis. The biochemical results showed that AVP improved the thymus, brain, heart, liver, spleen and kidney indices in a mouse model of oxidative stress. AVP was also able to reverse the reduction in levels of superoxide dismutase (SOD), glutathione peroxidase and glutathione, and increased the levels of nitric oxide and malondialdehyde identified in the serum, liver, spleen and brain of mice exposed to oxidative stress. Pathological observations confirmed that AVP could inhibit oxidative damage to the skin, liver and spleen of mice caused by D-galactose. Further molecular biological experiments also demonstrated that AVP increased the expression of neuronal nitric oxide synthase, endothelial nitric oxide synthase, Cu/Zn-SOD, Mn-SOD, catalase, heme oxygenase-1, nuclear factor-erythroid 2-related factor 2, γ-glutamylcysteine synthetase and NAD(P)H quinone dehydrogenase 1 and reduced the expression of inducible nitric oxide synthase in the liver and spleen of treated mice compared to controls. Notably, the preventive effect of AVP against D-galactose-induced oxidative damage in mice was better than that of the confirmed antioxidant vitamin C. In conclusion, AVP exhibited an antioxidant effect and the AVP-rich Apocynum venetum may be considered a plant resource with potential antioxidative benefits.

Preventive Effect of Small-Leaved Kuding Tea (Ligustrum robustum (Roxb.) Bl.) Polyphenols on D-Galactose-Induced Oxidative Stress and Aging in Mice

Small-leaved Kuding tea is a traditional Chinese tea that is rich in polyphenols. In the current study, we investigated the preventive effect of small-leaved Kuding tea (SLKDT) on D-galactose-induced oxidative aging in mice. Changes in serum, skin, liver, and spleen of experimental animals were determined using biochemical and molecular biology techniques. Biochemical analysis demonstrated that polyphenol extract of SLKDT (PSLKDT) improved the indices of the thymus, brain, heart, liver, spleen, and kidney function in model mice. PSLKDT prevented a decrease in the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione (GSH) as well as an increase in nitric oxide (NO) and malondialdehyde (MDA) levels in serum, liver, and spleen. Pathological assessment also showed that PSLKDT reduced oxidative damage induced by D-galactose in skin, liver, and spleen. We further found that PSLKDT upregulated neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), Cu/Zn-SOD, Mn-SOD, catalase (CAT), heme oxygenase-1 (HO-1), nuclear factor (nuclear factor-erythroid 2 related factor 2 (Nrf2), γ-glutamylcysteine synthetase (γ-GCS), and NAD(P)H dehydrogenase [quinone] 1 (NQO1) mRNA expression and downregulated inducible nitric oxide synthase (iNOS) mRNA expression. Protein levels of SOD1 (Cu/Zn-SOD), SOD2 (Mn-SOD), CAT, GSH1 (γ-glutamate-cysteine ligase), and GSH2 (glutathione synthetase) in the liver and spleen were also increased by PSLKDT treatment. Collectively, these results indicate that PSLKDT is effective in preventing D-galactose-induced oxidative aging in mice, and its efficacy is significantly higher than antioxidant vitamin C. Because PSLKDT is a potent antioxidant and antiaging polyphenol, Kuding tea rich in PSLKDT should be considered an ideal drink with antioxidative and antiaging effects.

An SOD1 deficiency aggravates proteasome inhibitor bortezomib-induced testicular damage in mice

Proteasomes play a key role in maintaining cellular homeostasis by the proteolytic removal of proteins, including ubiquitinated proteins and/or oxidatively-damaged proteins. The proteasome inhibitor bortezomib (BTZ) has been reported to exert testicular toxicity in mice. In the current study, we treated SOD1-knockout (KO) mice with BTZ and investigated the issue of whether oxidative stress is involved in the development of testicular toxicity. The BTZ treatment significantly increased superoxide production and cell death in the testes of SOD1-KO mice compared to wild-type (WT) mice. We also found that high levels of both ubiquitinated proteins and p62 accumulated and underwent aggregation in the seminiferous tubules of BTZ-injected SOD1-KO mice. Furthermore, the proteolytic activities of proteasomes were significantly decreased in the testes of BTZ-injected SOD1-KO mice compared to their WT counterparts. These results suggest that a combination of oxidative stress caused by an SOD1 deficiency and proteasome inhibition by BTZ accelerates the impairment of proteasomes, which results in severe testicular damage in SOD1-KO mice.

The negative effect of magnetic nanoparticles with ascorbic acid on peritoneal macrophages

Superparamagnetic iron oxide nanoparticles (SPIOn) are widely used as a contrast agent for cell labeling. Macrophages are the first line of defense of organisms in contact with nanoparticles after their administration. In this study we investigated the effect of silica-coated nanoparticles (γ-Fe₂O₃-SiO₂) with or without modification by an ascorbic acid (γ-Fe₂O₃-SiO₂-ASA), which is meant to act as an antioxidative agent on rat peritoneal macrophages. Both types of nanoparticles were phagocytosed by macrophages in large amounts as confirmed by transmission electron microscopy and Prusian blue staining, however they did not substantially affect the viability of exposed cells in monitored intervals. We further explored cytotoxic effects related to oxidative stress, which is frequently documented in cells exposed to nanoparticles. Our analysis of double strand breaks (DSBs) marker γH2AX showed an increased number of DSBs in cells treated with nanoparticles. Nanoparticle exposure further revealed only slight changes in the expression of genes involved in oxidative stress response. Lipid peroxidation, another marker of oxidative stress, was not significantly affirmed after nanoparticle exposure. Our data indicate that the effect of both types of nanoparticles on cell viability, or biomolecules such as DNA or lipids, was similar; however the presence of ascorbic acid, either bound to the nanoparticles or added to the cultivation medium, worsened the negative effect of nanoparticles in various tests performed. The attachment of ascorbic acid on the surface of nanoparticles did not have a protective effect against induced cytotoxicity, as expected.

Liver Injury Induced by Carbon Tetrachloride in Mice Is Prevented by the Antioxidant Capacity of Anji White Tea Polyphenols

Anji white tea is a unique variety of green tea that is rich in polyphenols. In this study, the effect of Anji white tea polyphenols (AJWTP) on the prevention of carbon tetrachloride (CCl₄)-induced liver injury through its antioxidant properties was studied. Biochemical and molecular biology methods were used to analyze the serum and liver tissue of mice. The antioxidant capacity and liver injury preventive effect of AJWTP were determined, and the mechanism was elaborated. The results showed that AJWTP decreased the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (TC) in mice with liver injury, it increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the serum and liver tissue of mice with liver injury, and it also decreased the amount of malondialdehyde (MDA). Further quantitative polymerase chain reaction (qPCR) results showed that AJWTP upregulated the mRNA expression of Cu/Zn-SOD, Mn-SOD, catalase (CAT), and nuclear factor of kappa light polypeptide gene enhancer in B-cell inhibitor alpha (IκB-α) and downregulated the expression of nuclear factor κ-light-chain-enhancer of activated B-cells (NF-κB), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-1 beta (IL-1β), and tumor necrosis factor alpha (TNF-α) in the liver tissue of mice with liver injury. Therefore, AJWTP produces sufficient antioxidant action to prevent liver injury, and the effect increases with the increase in AJWTP concentration. The effect of 200 mg/kg AJWTP was similar to that of the same concentration of the drug (silymarin) used for the treatment of liver injury. This indicates excellent potential for the development and utilization of AJWTP because it is an active substance with excellent antioxidant effects and can prevent liver injury.

Lifestyle and fertility: the influence of stress and quality of life on male fertility

BACKGROUND

Male infertility is a widespread condition among couples. In about 50% of cases, couple infertility is attributable to the male partner, mainly due to a failure in spermatogenesis. In recent times, the crucial role that modifiable lifestyle factors play in the development of infertility have generated a growing interest in this field of study, i.e. aging, psychological stress, nutrition, physical activity, caffeine, high scrotal temperature, hot water, mobile telephone use. Several studies have investigated associations between semen quality and the presence of lifestyle stressors i.e. occupational, life events (war, earthquake, etc.) or couple infertility; overall, these studies provide evidence that semen quality is impaired by psychological stress. In this review, we will discuss the impact of quality of life (modifiable lifestyle factors) and psychological stress on male fertility. In addition, the role that increased scrotal temperature along with inappropriate nutritional and physical exercise attitudes exert on male fertility will be presented.

CONCLUSION

The decline of male fertility, particularly associated with advancing age, incorrect lifestyles and environmental factors plays an important role on natality, and its consequences on the future on human population makes this an important public health issue in this century. Thus, modification of lifestyle through a structured program of educational, environmental, nutritional/physical exercise and psychological support, combined with the use of nutraceutical antioxidants can prevent infertility and therefore, may help couples to obtain better quality of life and improved possibility to conceive spontaneously or optimize their chances of conception.