Implications of Exposure to Air Pollution on Male Reproduction: The Role of Oxidative Stress.

Air pollution, either from indoor (household) or outdoor (ambient) sources, occurs when there is presence of respirable particles in the form of chemical, physical, or biological agents that modify the natural features of the atmosphere or environment. Today, almost 2.4 billion people are exposed to hazardous levels of indoor pollution, while 99% of the global population breathes air pollutants that exceed the World Health Organization guideline limits. It is not surprising that air pollution is the world's leading environmental cause of diseases and contributes greatly to the global burden of diseases. Upon entry, air pollutants can cause an increase in reactive oxygen species (ROS) production by undergoing oxidation to generate quinones, which further act as oxidizing agents to yield more ROS. Excessive production of ROS can cause oxidative stress, induce lipid peroxidation, enhance the binding of polycyclic aromatic hydrocarbons (PAHs) to their receptors, or bind to PAH to cause DNA strand breaks. The continuous and prolonged exposure to air pollutants is associated with the development or exacerbation of pathologies such as acute or chronic respiratory and cardiovascular diseases, neurodegenerative and skin diseases, and even reduced fertility potential. Males and females contribute to infertility equally, and exposure to air pollutants can negatively affect reproduction. In this review, emphasis will be placed on the implications of exposure to air pollutants on male fertility potential, bringing to light its effects on semen parameters (basic and advanced) and male sexual health. This study will also touch on the clinical implications of air pollution on male reproduction while highlighting the role of oxidative stress.

The effect of Aspalathin linearis, Cyclopia intermedia and Sutherlandia frutescene on sperm functional parameters of healthy male wistar rats.

Introduction: Rooibos (Aspalathin linearis), honeybush (Cyclopia intermedia), and sutherlandia (Sutherlandia frutescene) are three Southern Africa indigenous plants, of which the extracts have become house-hold items and are consumed on a large scale. Although, they are known for their antioxidant properties, studies have highlighted danger in the excessive intake. Therefore, the current study investigated whether treatment with rooibos, honeybush, and sutherlandia will impact sperm functional parameters positively or otherwise, in healthy rats. Methods: Fourteen-week-old pathogen-free adult male Wistar rats (250-300 g) were randomly divided into four groups of ten, including a control, rooibos (RF), honeybush (HB) and a sutherlandia (SL) group. After 7 weeks of treatment, animals were sacrificed. Spermatozoa were retrieved from the cauda epididymis for motility, morphology and concentration analysis and the testis was used for all biochemical assays. Results: The infusion treated animals (RF, HB, and SL) presented with a non-significant decrease of -14.3%, -18.2%, -17.2% and -24.8%, -20.7%, -27.3% in total motility and progressive motility when compared to the control group, respectively. There was a significant increase in number of spermatozoa with slow speed (p = 0.03), especially in SL treated group compared to the control (p = 0.03). Additionally, there was an increase of 28.8%, 31.7%, 23% in superoxide dismutase (SOD) activity of RF, HB and SL compared to control, respectively. This was accompanied with a percentage decrease of -21.1%, -23.7%, 45.9% in malondialdehyde (MDA) levels compared to the control group. Conclusion: In summary, animals treated with the respective infusions presented with a percentage increase in SOD activity but have reduced sperm motility and decreased normal morphology. Paradoxically, they presented with increased sperm concentration. Hence, it is presumed that rooibos, honeybush and sutherlandia may enhance sperm quantity (concentration) but may impair sperm quality (motility morphology) when consumed by healthy animals.

Oxidative Stress and Male Infertility: Evidence From a Research Perspective.

Male fertility potential can be influenced by a variety of conditions that frequently coincide. Spermatozoa are particularly susceptible to oxidative damage due to their limited antioxidant capacity and cell membrane rich in polyunsaturated fatty acids (PUFAs). The role of oxidative stress (OS) in the etiology of male infertility has been the primary focus of our Stellenbosch University Reproductive Research Group (SURRG) over the last 10 years. This review aims to provide a novel insight into the impact of OS on spermatozoa and male reproductive function by reviewing the OS-related findings from a wide variety of studies conducted in our laboratory, along with those emerging from other investigators. We will provide a concise overview of the production of reactive oxygen species (ROS) and the development of OS in the male reproductive tract along with the physiological and pathological effects thereof on male reproductive functions. Recent advances in methods and techniques used for the assessment of OS will also be highlighted. We will furthermore consider the current evidence regarding the association between OS and ejaculatory abstinence period, as well as the potential mechanisms involved in the pathophysiology of various systemic diseases such as obesity, insulin resistance, hypertension, and certain mental health disorders which have been shown to cause OS induced male infertility. Finally, special emphasis will be placed on the potential for transferring and incorporating research findings emanating from different experimental studies into clinical practice.

The mutagenic effect of tobacco smoke on male fertility.

Despite the association between tobacco use and the harmful effects on general health as well as male fertility parameters, smoking remains globally prevalent. The main content of tobacco smoke is nicotine and its metabolite cotinine. These compounds can pass the blood-testis barrier, which subsequently causes harm of diverse degree to the germ cells. Although controversial, smoking has been shown to cause not only a decrease in sperm motility, sperm concentration, and an increase in abnormal sperm morphology, but also genetic and epigenetic aberrations in spermatozoa. Both animal and human studies have highlighted the occurrence of sperm DNA-strand breaks (fragmentation), genome instability, genetic mutations, and the presence of aneuploids in the germline of animals and men exposed to tobacco smoke. The question to be asked at this point is, if smoking has the potential to cause all these genetic aberrations, what is the extent of damage? Hence, this review aimed to provide evidence that smoking has a mutagenic effect on sperm and how this subsequently affects male fertility. Additionally, the role of tobacco smoke as an aneugen will be explored. We furthermore aim to incorporate the epidemiological aspects of the aforementioned and provide a holistic approach to the topic.

The burgeoning role of global health diplomacy to alleviate suffering of cancer patients in low- and middle-income countries.

The science of global health diplomacy (GHD) consists of cross-disciplinary, multistakeholder credentials comprised of national security, public health, international affairs, management, law, economics and trade policy. GHD is well placed to bring about better and improved multilateral stakeholder leverage and outcomes in the prevention and control of cancer. It is important to create an evidence base that provides clear and specific guidance for health practitioners in low- and middle-income countries (LMICs) through involvement of all stakeholders. GHD can assist LMICs to negotiate across multilateral stakeholders to integrate prevention, treatment and palliative care of cancer into their commercial and trade policies.

Improved sperm motility after 4 h of ejaculatory abstinence: role of accessory sex gland secretions.

Various studies have sought to determine the typical v. optimal abstinence period after which semen samples should be collected, with many contradictory results reported. Several factors influence the semen microenvironment, and thus sperm parameters. In this study we focused on the secretions of the prostate, seminal vesicles and the epididymis. Semen samples were obtained from healthy normozoospermic males (n=16) after 4-day and 4-h periods of ejaculatory abstinence, and standard semen analysis was performed using computer-aided sperm analysis, whereas seminal plasma citric acid, neutral α-glucosidase and fructose concentrations were measured using assay kits. There were significant decreases in total sperm count (P<0.001), sperm concentration (P<0.05) and semen volume (P<0.05) after 4h compared with 4 days ejaculatory abstinence. Furthermore, increases were observed in total sperm motility (P<0.05) and sperm progressive motility (P<0.01) after a 4-h abstinence period, accompanied by significant reductions in citric acid (P<0.05), α-glucosidase (P<0.01) and fructose (P<0.01) concentrations. In addition, due to the decreased number of spermatozoa, these concentrations translated to a significant decrease in fructose (P<0.05) per spermatozoon, indicating an intrinsic mechanism capitalising on alternative sources of energy for increased metabolic function and subsequent sperm motility.

Highly Active Antiretroviral Therapy Alters Sperm Parameters and Testicular Antioxidant Status in Diet-Induced Obese Rats.

The efficacy of highly active antiretroviral therapy (HAART) has led to an increase demand for therapeutic use, thereby necessitating investigation into drug toxicity. This study was designed to investigate the in vivo effects of HAART on sperm parameters and testicular oxidative stress in lean and obese rats. Wistar rats (males, n = 40, weighing 180~200 g) were assigned randomly into 4 groups and treated accordingly for 16 weeks as follows: Control (C): lean group fed with standard rat chow; Diet induced obesity (DIO): obese animals fed a high caloric diet; C + ART: lean animals treated with HAART; DIO + ART: obese animals treated with HAART. An antiretroviral drug combination of Tenofovir, Emtricitabine and Efavirenz at a dose of 17, 26 and 50 mg/kg/day was administered for the latter 6 weeks via jelly cube feeding. At the end of the experimental period, sperm analysis was performed on sperm collected from the caudal epididymis, while the testis was homogenized for antioxidant enzyme and lipid peroxidation assays. Results showed that HAART significantly decreased sperm motility (p < 0.05) in both lean and obese animals, and viability (p < 0.05) in the DIO group. Testicular glutathione, catalase and superoxide dismutase were significantly decreased (p < 0.05), while Thiobarbituric acid reactive substances (TBARS) levels were significantly increased (p < 0.05) when the DIO+ART group was compared to Control group. Thus, the decreased sperm qualities associated with HAART might be as a result of increased testicular oxidative stress prominent in obese animals.

Diabetes mellitus- induction: Effect of different streptozotocin doses on male reproductive parameters.

Diabetes mellitus (DM) is reported to be involved in male reproductive impairment, and its impact is evident in the increased prevalence of infertility. Various studies have reported that a single parenteral injection of <40 mg/kg Streptozotocin (STZ) is ineffective in ablating pancreatic ß-cells and creating a rat model to investigate the effect of DM on the male reproductive system. This study therefore aims to validate these claims. Adult male Wistar rats received either a single intraperitoneal injection of STZ (30 mg/kg or 60 mg/kg) or saline (0.9%, Control). Diabetes was confirmed after 72 h if plasma glucose levels were ≥14 mmol/L. Body weight, glucose level, fluid and food intake were measured weekly. Animals were sacrificed after 8 weeks of treatment by an overdose of sodium pentobarbital (160 mg/kg body weight). The testis and epididymis were harvested and weighed prior to preparation for histological evaluation. Epididymal sperm morphology was analysed using computer aided sperm analysis (CASA). STZ60 animals presented with significantly lower body weights compared to both control and STZ30 groups. Animals in both STZ30 and STZ60 groups showed decreased normal sperm morphology compared to control. Histological evaluation of the testes showed a decrease in the number of spermatozoa in the seminiferous tubules of animals in the STZ30 and STZ60 groups compared to control. A complete absence of spermiogenesis was observed in the seminiferous tubules of STZ60 animals. These findings prove that an STZ concentration of 30 mg/kg, which is much lower than the reported 40 mg/kg, has adverse effects on the male reproductive system via its diabetogenic effect and can therefore be used to study the impact of DM on male fertility.