Impact of Early Arsenic Exposure on the Mineral Content and Oxidative Status of the Liver and Kidney of Pubescent and Adult Rats.

This study evaluated the effect of prepubertal arsenic exposure in the liver and kidney of pubescent rats and their reversibility 30 days after arsenic withdrawal. Male pups of Wistar rats (21 days old) were divided into two groups (n = 20/group): control animals received filtered water, and exposed rats received 10 mg L-1 arsenic from postnatal day (PND) 21 to PND 51. The liver and kidney of 52 days old rats (n = 10/group) were examined to investigate the effects of arsenic on micromineral content, antioxidant enzyme activity, histology, and biochemistry parameters. The other animals were kept alive under free arsenic conditions until 82 days old and further analyzed by the same parameters. Our results revealed that 52-day-old rats increased arsenic content in their liver and arsenic and manganese in their kidney. In those animals, glycogen and zinc content and catalase activity were reduced in the liver, and the selenium content decreased in the kidney. Thirty days later, arsenic reduced the manganese and iron content and SOD and CAT activity in the liver of 82-day-old rats previously exposed to arsenic, while glycogen and selenium content decreased in their kidney. In contrast, PND 82 rats exhibited higher retention of copper in the liver, an increase in iron and copper content, and CAT and GST activity in the kidney. Significant histological alterations of liver and kidney tissues were not observed in rats of both ages. We conclude that arsenic-induced toxicity could alter differently the oxidative status and balance of trace elements in pubertal and adult rats, demonstrating that the metalloid can cause effects in adulthood.

Effect of Induced Pulmonary Arterial Hypertension on Testicular Parameters of Wistar Rats Subjected to Resistance Exercise Training.

Pulmonary arterial hypertension (PAH) is characterized by elevated arterial pressure and vascular resistance. PAH may cause alterations in the microcirculation of several organs, including the kidney, liver, brain, and testes. However, it remains unclear whether monocrotaline-induced PAH exerts detrimental effects on animal testes. Thus, we analyzed the impact of PAH on testicular morphology and function. Additionally, we investigated the effect of resistance exercise training (RT) on testicular parameters in PAH rats. Eight healthy Wistar rats and eight PAH rats were subjected to RT training for 30 days; the other PAH and healthy rats (n = 8/group) did not exercise. PAH rats had lower reproductive organ weight, serum testosterone levels, testicular glucose, and nitric oxide (NO) levels, Leydig cell parameters, tubular morphometry, germ cell counts, and daily sperm production than healthy animals did. The practice of RT attenuated the negative impact of PAH on the relative weights of the testes and epididymides, Leydig cell number, nuclear volume, testicular NO levels, and seminiferous epithelium architecture. Moreover, RT positively influenced testosterone levels in PAH animals. We conclude that PAH exerts deleterious effects on testicular histology and function. However, RT can be beneficial to the PAH-affected testicular parameters.

Oxidative stress associated with proteomic and fatty acid profiles of sperm from Nellore bulls at rest†.

Sexual rest is a transient condition, which compromises conception rates, characterized by large volumes of ejaculate with high percentages of dead sperm observed in bulls. The biochemical mechanisms leading to this ejaculate pattern are not fully understood. Six adult resting Nellore bulls were submitted to Breeding Soundness Evaluation by four consecutive semen collections through the electroejaculation method during a 30 min period. Each ejaculate had its semen phenotypic parameters; morphology and physical aspects were evaluated. To assess enzymatic activity (superoxide dismutase, catalase, and glutathione S-transferase), lipid peroxidation (concentrations of malondialdehyde and nitric oxide), fatty acid, and proteomic profile aliquots of spermatozoa from the first and fourth ejaculates were used. All sperm parameters differed between the first and fourth ejaculates. Spermatozoa from the first ejaculate showed lower enzymatic activity and a higher concentration of lipid peroxidation markers. Among the 19 identified fatty acids, 52.7% are polyunsaturated. Relative abundance analysis showed that C12:0 and C18:0 fatty acids differed between the first and fourth ejaculates, being the fourth ejaculate richer in spermatozoa. The proteomics analysis identified a total of 974 proteins in both sample groups (first and fourth ejaculates). The majority of identified proteins are related to cellular processes and signaling. Quantitative proteomics showed 36 differentially abundant proteins, 6 up-regulated proteins in the first ejaculate, and 30 up-regulated proteins in the fourth ejaculate. Spermatozoa from bulls at sexual rest have less antioxidant capacity, causing changes in their fatty acid composition and protein profile, which generates the observed sperm pattern and lower fertilization capacity.

The effects of eugenol on histological, enzymatic, and oxidative parameters in the major salivary glands and pancreas of healthy male Wistar rats.

OBJECTIVE: We evaluated the effects of eugenol on histological, enzymatic, and oxidative parameters in the pancreas, parotid, submandibular, and sublingual glands of healthy male rats. DESIGN: Twenty-four adult Wistar rats were assigned into four groups (n = 6/group). Control rats received 2% Tween-20 (eugenol vehicle), whereas the other animals received 10, 20, and 40 mg kg-1 eugenol through gavage daily for 60 d. Major salivary and pancreatic glands were weighed and preserved fixed for microscopic analysis and frozen for in vitro assays. RESULTS: Eugenol did not alter glands' weight and serum amylase activity regardless of the concentration. The highest dose of eugenol caused an increase in pancreatic amylase activity and a reduction of lipase activity from serum and pancreas. Eugenol at 40 mg kg-1 diminished the activity of SOD and FRAP in the submandibular gland and CAT and FRAP in the sublingual gland. However, it did not exert any effect on GST regardless of the gland. Additionally, 40 mg kg-1 eugenol increased MDA levels in pancreatic, parotid, and submandibular glands and NO levels in the sublingual. The concentrations of eugenol induced distinct responses in the glands regarding the activity of Na+/K+, Mg2+, and total ATPase activity. They also affected histomorphometrical and histochemistrical parameters in the submandibular gland only. CONCLUSIONS: Results indicated that 40 mg kg-1 eugenol altered most of the biochemical and oxidatived parameters of digestive glands. Only submandibular glands presented histological changes after eugenol exposure suggesting potential implications for its function.

Does environmental pollution affect male reproductive system in naturally exposed vertebrates? A systematic review.

Due to environmental contamination, the environment constantly receives pollutants from various anthropic actions. These pollutants put ecological health at risk due to contamination and accumulation in living organisms, including wild animals and humans. Exposure can cause physiological, morphological, and behavioral changes in living beings. In this context, laboratory studies have frequently investigated how environmental contaminants affect the male reproductive system and gametes. However, few studies have examined how these contaminants affect male reproduction in naturally exposed animals. To better understand this topic, we conducted a systematic review of the effects of exposing male vertebrate animals to polluted environments on their reproductive functions. After an extensive search using the PubMed/MEDLINE, Scopus, and Web of Science databases, 39 studies met our inclusion criteria and were eligible for this review. This study showed that reproductive damages were frequent in fishes, amphibians, reptiles, birds, and mammals exposed to contaminated environments. Wild animals are exposed mainly to endocrine-disrupting compounds (EDCs), toxic metals, and radiation. Exposure to pollutants causes a reduction in androgen levels, impaired spermatogenesis, morphological damage to reproductive organs, and decreased sperm quality, leading to reduced fertility and population decline. Although several species have been studied, the number of studies is limited for some groups of vertebrates. Wildlife has proven valuable to our understanding of the potential effects of environmental contaminants on human and ecosystem health. Thus, some recommendations for future investigations are provided. This review also creates a baseline for the understanding state of the art in reproductive toxicology studies.

Contributions of seminal plasma proteins to fertilizing ability of bull sperm: A meta-analytical review.

Seminal plasma is a dynamic, intricate combination of fluids from the testicles, epididymides, seminal vesicles, bulbourethral glands, and prostate, containing molecules that modulate sperm functions, post-fertilization events, and the female reproductive tract physiology. Significant variations in sperm parameters and fertility status of bulls relate to differences in the seminal plasma proteome. In this framework, a meta-analytical study was conducted examining 29 studies (published between 1990 and 2021) to ascertain the effects of seminal fluid proteins on parameters associated with bull fertility and the influence of distinct methodologies on such effects. Our results revealed that seminal proteins ameliorate sperm parameters, such as motility, integrity, capacitation, and fertilizing ability, and favours sperm protection. Seminal binder of sperm proteins and beta-defensin 126 highly favoured sperm protection when cells were collected from the epididymis by retrograde flux and analysed under room temperature conditions. Furthermore, seminal proteins improved the motility and quality of Bos taurus sperm collected by artificial vagina, mainly in the presence of heparin-binding proteins. The key limitations faced by this meta-analysis were the paucity of studies evaluating the effects of whole seminal fluid proteins and the limited number of studies conducted in vivo. In conclusion, the present meta-analytical study confirms that seminal proteins improve fertility-related parameters in the bovine species. However, methodological strategies used by authors are diverse, with distinct endpoints and methods. Thus, the translational aspects of seminal plasma research should be taken into consideration to precisely define how seminal proteins can be harnessed to advance reproductive biotechnology.

Could metal exposure affect sperm parameters of domestic ruminants? A meta-analysis.

During the last decade, environmental toxicants have been considered a potential cause for declining sperm quality. Toxic metals are not easily degraded and may accumulate along the food chain, which may negatively impact the semen quality of animals. In this framework, we conducted a meta-analysis to determine whether exposure to Al, As, Cd, Cr, Co, Cu, Fe, Mg, Mn, Hg, Ni, and Pb affects sperm and andrological parameters of domestic ruminants. We extracted 217 independent comparisons from 39 published articles selected from PubMed, Web of Science, and Scopus. Our findings showed that metal exposure reduced sperm viability (d++ = - 1.04, df 51, CI - 1.47 to - 0.61) and motility (d++ = - 0.83, df 104, CI -1.19 to - 0.51) by increasing oxidative metabolites production (d++ = 2.98, df 20, CI 1.95-0.11). Sperm viability and motility were affected by Cd, As, Hg, and Fe contamination. Metal poisoning impaired andrological parameters (d++ = - 0.83, df 17, CI - 1.10 to - 0.02) after arsenic intake using 3 and 5 mg L-1 orally. Detrimental effects on spermatozoa were mostly observed after in vitro incubation with metals using concentrations < 2.99 mg L-1 up to 24 h. The review limitations were the heterogeneity of methodologies used in the studies and absence of investigations focused on the effect of Al, Co, Cr, Mg, and Ni exposure on sperm parameters in ruminants. Nevertheless, our findings contribute to understanding the impact of metal exposure on reproductive parameters in ruminants, with potential damage to their fertility.

Eugenol reduces serum testosterone levels and sperm viability in adult Wistar rats.

Eugenol is the main constituent of clove extract. It is a remarkably versatile molecule incorporated as a functional ingredient in several food products and widely applied in the pharmaceutical industry. Men consume natural products enriched with eugenol for treating sexual disorders and using as aphrodisiacs. Nevertheless, there is no information about the impact of eugenol intake on the reproductive parameters of healthy males. Therefore, we provided 10, 20, and 40 mg kg-1 pure eugenol to adult Wistar rats for 60 days. Testis, epididymis, and spermatozoa were analyzed under microscopic, biochemical, and functional approaches. This phenolic compound did not alter testicular and epididymal biometry and microscopy. However, 20 and 40 mg kg-1 eugenol reduced serum testosterone levels. The highest dose altered lactate and glucose concentrations in the epididymis. All the eugenol concentrations diminished CAT activity and MDA levels in the testis and increased FRAP and CAT activity in the epididymis. Epididymal sperm from rats receiving 10, 20, and 40 mg kg-1 eugenol presented high Ca2+ ATPase activity and low motility. In conclusion, eugenol at low and high doses negatively impacted the competence of epididymal sperm and modified oxidative parameters in male organs, with no influence on their microscopy.

High doses of eugenol cause structural and functional damage to the rat liver.

Eugenol is a phenolic compound found in clove extract and extensively used in traditional medicine. It is unclear whether its intake can cause positive or negative effects on liver morphology and physiology in healthy individuals. Thus, we aimed to evaluate liver parameters of rats treated with 10, 20, and 40 mg kg-1 eugenol. After 60 days of treatment, liver samples were collected and analyzed by biometric, histological, biochemical, and oxidative analyses. Our results showed that 10, 20, and 40 mg kg-1 eugenol did not alter body and liver weights, serum and hepatic ALT levels and catalase, glutathione-s-transferase, total, Ca2+, and Mg2+ ATPases activities in treated animals. However, 20 and 40 mg kg-1 eugenol reduced Na+/K+ ATPase pump activity and blood glucose levels. They also increased hepatic glycogen content, superoxide dismutase activity, ferric reducing antioxidant power, and nitric oxide and malondialdehyde levels. Still, 20 and 40 mg kg-1 eugenol caused structural and functional damage to the liver tissue of eugenol-treated rats. We concluded that 10 mg kg-1 eugenol is a safe dose for consumption in long-term treatment for rats. Doses higher than 20 mg kg-1 lead to hepatic damage that can impair vital processes of liver functionality.

Effects of terpenes in the treatment of visceral leishmaniasis: A systematic review of preclinical evidence.

Visceral leishmaniasis (VL) is a severe and potentially fatal neglected tropical disease, being considered a public health concern in many countries worldwide. There are still no vaccines against human VL, and the existing chemotherapy is often toxic. Thereby, alternative treatments have been investigated, and byproducts from plant metabolism have been a source of promising pharmacological compounds. Terpenes are secondary metabolites that exhibit a large spectrum of therapeutic activities. Herein, we conducted a systematic review to evaluate the effects of terpenes in the treatment of VL in rodents. After an extensive search using the PubMed/MEDLINE, Scopus, and Web of Science databases, we included 34 articles in this review. Our results revealed that triterpenes were the most used terpenes by the eligible studies. Overall, terpene treatment showed no or negligible toxicity, causing an increase in the Th1-type immune response profile and nitric oxide production. It also reduced the Th2 cytokines levels and parasite load (> 90% to > 99%). Moreover, terpenes induced apoptosis by damaging the plasma membrane and inhibiting DNA topoisomerases in the parasite. The use of terpene carriers increased the terpene bioavailability in the body, preventing their rapid excretion and promoting the drug delivery at the site of Leishmania infection. Terpene derivatives showed better pharmacokinetics than the original terpenes. Altogether, the benefits of VL treatment with terpenes in preclinical studies may open new directions for other preclinical and human trials.

Green Tea Infusion Ameliorates Histological Damages in Testis and Epididymis of Diabetic Rats.

Green tea is a popular drink used for therapeutic purposes to mitigate the consequences of diabetes. In this study, we aimed at evaluating the potential of green tea infusion to ameliorate structural and enzymatic damages caused by hyperglycemia in the testis and epididymis of Wistar rats. For that, nondiabetic and streptozotocin-induced diabetic rats (negative control and diabetes control, respectively) received 0.6 mL of water by gavage. Another set of diabetic animals received 100 mg/kg of green tea infusion diluted in 0.6 mL of water/gavage (diabetes + green tea) daily. After 42 days of treatment, the testes and epididymides were removed and processed for histopathological analysis, micromineral determination, and enzymatic assays. The results showed that treatment with green tea infusion preserved the testicular and epididymal histoarchitecture, improving the seminiferous epithelium and the sperm production previously affected by diabetes. Treatment with green tea reduced tissue damages caused by this metabolic condition. Given the severity of hyperglycemia, there was no efficacy of the green tea infusion in maintaining the testosterone levels, antioxidant enzyme activity, and microminerals content. Thus, our findings indicate a protective effect of this infusion on histological parameters, with possible use as a complementary therapy for diabetes.

Functional attributes of seminal proteins in bull fertility: a systematic review.

Proteomic approaches have been widely used in reproductive studies to uncover protein biomarkers of bull fertility. Seminal plasma is one of the most relevant sources of these proteins that may influence sperm physiology. Nonetheless, there are still gaps in existing knowledge in the functional attributes of seminal proteins. Thus, we reviewed the relationships between seminal plasma proteins and bull fertility by conducting a systematic review with data obtained from 71 studies. This review showed that the associations related to fertility improvement with the use of total seminal plasma proteins are still controversial. None of the studies explored the sperm fertilizing ability following these interactions. By contrast, the exposure to a single protein, such as osteopontin, binder of sperm proteins, and heparin binding proteins, can increment sperm motility, capacitation, and fertilizing ability by modulating intracellular calcium concentrations, removing lipids from sperm membranes, and regulating the acrosome reaction. Variations in protein analyses and the protein contents and their abundances between animals contributed to the difficulty of establishing protein biomarkers of fertilizing potential of the bull sperm. Indeed, the heterogenicity of methodologies was a limitation of this review. Standardized methods of seminal protein analyses, as well as sperm endpoints, may minimize such discrepancies. In conclusion, potential biomarkers of sperm parameters are still to be established. Future studies should evaluate protein isoforms and how they interact with sperm to ascertain their biological functions.

Effect of eugenol treatment in hyperglycemic murine models: A meta-analysis.

Diabetes is a highly prevalent health condition affecting many people worldwide. In vitro studies have described the positive effects of cloves and its major compound, eugenol, in the treatment of diabetes. However, it is unclear whether the effects of this compound are negative, neutral, or positive, on hyperglycemic animals. Therefore, a meta-analytical review was conducted to determine the magnitude of effects of eugenol on variables directly and indirectly related to diabetes. This study revealed that eugenol treatment decreased the glucose levels and the activity of carbohydrate-metabolizing enzymes, ameliorated the lipid profile, and reduced the oxidative, renal, and hepatic damages in hyperglycemic rodents. Moreover, eugenol alleviated the weight loss and restored the activity of the antioxidant defense system. Insulin levels was not affected by eugenol treatment. Also, mixed model analyses revealed that the use of purified or non-purified eugenol and the concentrations administered significantly affected the treatment outcome. In conclusion, our findings indicate that eugenol may have potential therapeutic effects in the treatment of diabetes. Furthermore, this study can direct future preclinical and clinical trials, with important implications for human health.