Activity Of Antioxidant System Research Articles

Effect of Plant Growth-Promoting Bacteria on Antioxidant Status, Acetolactate Synthase Activity, and Growth of Common Wheat and Canola Exposed to Metsulfuron-Methyl.

Metsulfuron-methyl, a widely used herbicide, could cause damage to the sensitive plants in crop-rotation systems at extremely low levels in the soil. The potential of plant growth-promoting bacteria (PGPB) for enhancing the resistance of plants against herbicide stress has been discovered recently. Therefore, it is poorly understood how physiological processes occur in plants, while PGPB reduce the phytotoxicity of herbicides for agricultural crops. In greenhouse studies, the effect of strains Pseudomonas protegens DA1.2 and Pseudomonas chlororaphis 4CH on oxidative damage, acetolactate synthase (ALS), enzymatic and non-enzymatic antioxidants in canola (Brassica napus L.), and wheat (Triticum aestivum L.) were investigated under two levels (0.05 and 0.25 mg∙kg-1) of metsulfuron-methyl using spectrophotometric assays. The inoculation of herbicide-exposed wheat with bacteria significantly increased the shoots fresh weight (24-28%), amount of glutathione GSH (60-73%), and flavonoids (5-14%), as well as activity of ascorbate peroxidase (129-140%), superoxide dismutase SOD (35-49%), and ALS (50-57%). Bacterial treatment stimulated the activity of SOD (37-94%), ALS (65-73%), glutathione reductase (19-20%), and the accumulation of GSH (61-261%), flavonoids (17-22%), and shoots weight (27-33%) in herbicide-exposed canola. Simultaneous inoculation prevented lipid peroxidation induced by metsulfuron-methyl in sensitive plants. Based on the findings, it is possible that the protective role of bacterial strains against metsulfuron-metil is linked to antioxidant system activation.

Ellagic Acid Enhances Antioxidant System Activity and Maintains the Quality of Strawberry Fruit during Storage

Ellagic Acid Enhances Antioxidant System Activity and Maintains the Quality of Strawberry Fruit during Storage

Fermented Syzygium samarangense leaves mitigate oxidative stress-triggered hepatotoxicity through Nrf2 activation and epigenetic regulation

The liver, which is a vital organ for metabolism and detoxification, is susceptible to damage caused by oxidative stress. Excessive consumption of acetaminophen (APAP), a commonly used analgesic ingredient, can cause liver injury due to oxidative stress. The aim of this study is to examine the protective effects and mechanisms of fermented Syzygium samarangense (wax apple) leaves (FWAL) against damage caused by APAP in mouse AML-12 hepatocytes. Ethanolic and water extracts of FWAL (FWAL-EE and FWAL-WE) were prepared, and both contained significant phenolic compounds such as gallic acid, EGCG, ellagic acid, myricitrin, and myricetin, with potent DPPH scavenging activity. FWAL-EE demonstrated superior effectiveness in lowering the death ratio, LDH leakage, and oxidative stress in APAP-treated AML-12 cells. The protective effects of FWAL-EE included the downregulation of inflammatory markers TNF-α and cox-2 mRNA, as well as the upregulation of Nrf2, HO-1, and NQO1 proteins in APAP-treated hepatocytes. Additionally, FWAL-EE reduced the expression of epigenetic enzymes HDACs 1, 2, 3, and 4, and DNMTs 1 and 3b while causing an increase in unmethylated DNA levels in the Nrf2 promoter region. Furthermore, EGCG, a prominent active compound in FWAL, protected AML-12 hepatocytes from APAP-induced damage by activating Nrf2 and NQO1, while also inhibiting epigenetic DNMTs and HDACs. These results suggested that FWAL-EE may effectively prevent APAP-induced liver damage by enhancing the activation of the Nrf2 antioxidant system through epigenetic regulation. FWAL-EE has potential as a nutraceutical for liver protection.

Different response of females and males Neotropical catfish (Rhamdia quelen) upon short-term temperature increase.

Climate change has been one of the most discussed topics in the world. Global warming is characterized by an increase in global temperature, also in aquatic environments. The increased temperature can affect aquatic organisms with lethal and sublethal effects. Thus, it is necessary to understand how different species respond to temperature. This study aimed to evaluate how the Neotropical catfish species Rhamdia quelen responds to temperature increases. The fish were exposed to temperatures of 25°C (control) and 30°C after gradual temperature increase for 7days. After 96h in each temperature, the fish were anesthetized, blood was collected, and after euthanasia, brain, liver, posterior kidney, gills, muscle, and gonads were collected. The gonads were used for sexing, while other tissues were used for the hematological, biochemical, genotoxic, and histopathological biomarkers analysis. Hepatic proteomic analysis with a focus on energy production was also carried out. Blood parameter changes in both sexes, including an increase in glucose in males, leukopenia in females, and genotoxicity in both sexes. Hepatic proteins related to energy production were altered in both sexes, but mainly in males. Others biomarker alterations, such as histopathological, were not observed in other tissues; however, the antioxidant system was affected differently between sexes. These showed that R. quelen juveniles, at temperatures higher than its optimum temperature such as 30°C, has several sublethal changes, such as hematological alterations, antioxidant system activation, and energetic metabolism alteration, especially in males. Thus, short-term temperature rise can affect females and males of R. quelen differently.

Impact of Smoking on Reproductive Health: A Systematic Review

Background: Several research endeavours have endeavoured to evaluate the impact of smoking on the physiology of male and female reproduction. Encompassing sperm parameters, male reproductive architecture, and the male hormonal axes. However, the outcomes have been conflicting and ambiguous. Objectives: To investigate the published literature on the effect of smoking on female and male reproductive health. Methods: PubMed, SCOPUS, Web of Science, and Science Direct were systematically searched for relevant literature. Rayyan QRCI was employed throughout this comprehensive process. Results & interpretation: We included thirteen studies with a total of 10092 participants; 4419 (43.8%) were males, and 5673 (56.2%) were females. Smoking is a risk factor in and of itself for male reproductive health. This is more likely to explain smokers' elevated SHBG levels and differential activity of the seminal antioxidant system. These negative effects included abnormal semen motility, volume, count, and morphology. Additionally, smoking had no discernible impact on women's fertility or ovarian reserve, according to this study. More research is needed to determine whether stopping smoking can treat male infertility caused by these substances and to better understand how cigarette smoke affects both female and male fertility.

Compensative Resistance to Erastin-Induced Ferroptosis in GPX4 Knock-Out Mutants in HCT116 Cell Lines.

Ferroptosis results from the accumulation of oxidized and damaged lipids which then leads to programmed cell death. This programmed process is iron-dependent, and as a fundamental biological process, plays a crucial role in tissue homeostasis. The ferroptosis molecular pathway depends on self-regulatory genes: GPX4; TFRC; ACSL4; FSP1; SLC7A11, and PROM2. Some of them were considered here as ferro-sensitive or ferro-resistance markers. We examined the impact of GPX4 gene knock-out, using the CRISPR/Cas-9 technique, on ferroptosis induction in the HCT116 colorectal cancer cell line. The results confirmed that cells lacking the GPX4 gene (GPX4 KO) should be more susceptible to ferroptosis after erastin treatment. However, the decrease in cell viability was not as significant as we initially assumed. Based on the lipid peroxidation markers profile and RT-qPCR gene expression analysis, we revealed the activation of an alternative antioxidant system supporting GPX4 KO cells, mostly for cellular ferroptotic death avoidance. Increased expression of FSP1 and PRDX1 genes in knock-out mutants was associated with their function-recognized here as ferroptosis suppressors. For such reasons, studies on the role of GPX4 and other crucial genes from the ferroptotic pathway should be explored. Despite promising prospects, the utilization of ferroptosis mechanisms in cancer therapy remains at the stage of experimental and in vitro preclinical studies.

Glutathione: synthesis, mechanism of action, antioxidant and detoxifying role

Annotation. Under the conditions of entry of toxic substances into the body and activation of redox processes, compounds of natural origin with antioxidant properties are widely used to correct metabolic disorders. The purpose of the work is to conduct an analysis and systematization of basic and modern scientific sources of literature on the role of the glutathione system in the development of pathologies. For the scientific review, data from the scientometric databases PubMed, ScienceDirect, Web of Science, Google Scholar, etc. were used, and the analysis of scientific textbooks and monographs was carried out. Among water-soluble antioxidants, low- and high-molecular compounds containing SH-groups are popular in medicine, mono-, di- and tricarboxylic acids and other anions. Glutathione, a thiol-containing tripeptide, is the main endogenous non-enzymatic antioxidant that exerts cytoprotective and detoxifying properties. Various epithelial cells – enterocytes, endotheliocytes, alveolar cells of the lungs, epithelium of the proximal renal tubules, absorb and use glutathione most intensively, in particular, taken orally, so the idea of using glutathione in diseases of organs that actively participate in detoxification processes: kidneys, liver, lungs, as well as under the conditions of systemic diseases accompanied by endothelial dysfunction and oxidative stress – diabetes, atherosclerosis, nephropathy. Under physiological conditions, the body maintains a dynamic balance between the content of oxidants, which stimulate the processes of free radical oxidation of biomolecules, and the activity of antioxidant systems. But under the conditions of damage to any link of the living system, increased formation of reactive oxygen species (ROS) and inhibition of antioxidant systems contributes to the activation of free radical oxidation processes, the intensity of which depends on the concentration of oxygen in the tissues and on the enzymatic and non-enzymatic systems of antioxidant protection, which prevents the destruction of cells by active forms of oxygen.

Changes in the Activity of Antioxidant Systems of Escherichia coli under Phosphate Starvation

Changes in the Activity of Antioxidant Systems of Escherichia coli under Phosphate Starvation

Ferulic acid attenuated diethylnitrosamine-provoked hepato-renal damage and malfunction by suppressing oxidative stress, abating inflammation and upregulating nuclear factor erythroid related factor-2 signaling

Background Diethylnitrosamine (DEN) is a potent environmental toxin that can reach humans through the food chain. It induces proliferative, degenerative and cancerous lesions in the liver and kidneys. Objective The principal goal of the existing research was to assess the preventive impacts of ferulic acid (FA) versus DEN- provoked hepato-renal damage and malfunction. Materials and methods Adult male rats were divided into four groups: group 1 (normal control) animals orally received saline every day for 14 weeks; group 2 (DEN) animals intraperitoneally received DEN (150 mg/kg twice a week) for 2 weeks; group 3 (DEN + FA) animals were injected intraperitoneally twice a week with DEN for 2 weeks besides to oral administration of FA (100 mg/kg/day) for 14 weeks; group 4 (FA) animals were given a similar dose of FA for a similar period. Results The results revealed that FA treatment reversed the DEN-mediated elevation in serum values of the liver enzymes activities as well as urea and creatinine levels; it also augmented the hepato-renal antioxidant system that overcame DEN-induced oxidative stress deteriorations. Moreover, FA markedly reduced the DEN-induced elevated hepato-renal levels of immuno-inflammatory markers (IL-1β and TNF-α) as well as downregulated the inflammatory mediators (Bcl-2, NF-κB, and nuclear factor erythroid related factor-2 (Nrf-2)), reflecting its protective potential. Conclusion The existing results elucidate that ferulic acid could prevent and ameliorate DEN-induced hepato-renal toxicological changes and can restore livers and kidneys’ functions; this effect could be mechanized through activation of anti-inflammatory and antioxidant systems, as well as regulation of NF-κB, Bcl2, and nuclear factor erythroid related factor-2 expression.

Ocean acidification impairs seagrass performance under thermal stress in shallow and deep water

Despite the effects of ocean acidification (OA) on seagrasses have been widely investigated, predictions of seagrass performance under future climates need to consider multiple environmental factors. Here, we performed a mesocosm study to assess the effects of OA on shallow and deep Posidonia oceanica plants. The experiment was run in 2021 and repeated in 2022, a year characterized by a prolonged warm water event, to test how the effects of OA on plants are modulated by thermal stress. The response of P. oceanica to experimental conditions was investigated at different levels of biological organization. Under average seawater temperature, there were no effects of OA in both shallow and deep plants, indicating that P. oceanica is not limited by current inorganic carbon concentration, regardless of light availability. In contrast, under thermal stress, exposure of plants to OA increased lipid peroxidation and decreased photosynthetic performance, with deep plants displaying higher levels of heat stress, as indicated by the over-expression of stress-related genes and the activation of antioxidant systems. In addition, warming reduced plant growth, regardless of seawater CO2 and light levels, suggesting that thermal stress may play a fundamental role in the future development of seagrass meadows. Our results suggest that OA may exacerbate the negative effects of future warming on seagrasses.

24-Epibrassinolide alleviates diazinon oxidative damage by escalating activities of antioxidant defense systems in maize plants

Excessive use of pesticides against pests has contaminated agricultural crops and raised global concerns about food safety. This research investigates the alleviation effects of 24-epibrassinolide (EBL) seed priming on diazinon (DZ) pesticide toxicity. The experiment was conducted with eight groups including control, DZ, EBL (10 µM), EBL (0.1 µM), EBL (0.01 µM), EBL (10 µM) + DZ, EBL (0.1 µM) + DZ, and EBL (0.01 µM) + DZ. Plants grown with the lowest concentration of EBL (0.01 µM) exhibited an upward increase in the activity of SOD, CAT, POD, APX, GR, and GST enzymes under DZ toxicity stress. In contrast, higher concentrations of EBL showed some inhibitory effects on the activity of antioxidant enzymes. In addition, low concentrations of EBL elevated the free radical scavenging capacity (DPPH), iron-reducing antioxidant power (FRAP), photosynthesis rate (Pn), stomatal conductance (Gs) and proline, and protein contents. EBL also reduced lipid peroxidation (MDA levels) in the DZ-exposed plants, leading to membrane integrity. The favorable effects of EBL were more evident when plants were exposed to pesticides than normal growth conditions. The results indicated that EBL seed priming intensifies the antioxidant enzymes system activity, and helps maize plants against toxic effects of DZ under proper concentration.

Effect of spraying iron, zinc and using superabsorbent on grain yield and some biochemical properties of maize under drought stress

Nutrients such as iron and zinc play a vital role in controlling the negative effects of drought stress through the synthesis of enzymes, maintenance of cell membrane, and activation of antioxidant defense system. Due to these biochemical properties, an experiment was conducted to evaluate effect of spraying iron, zinc and using superabsorbent on grain yield and some of biochemical properties of maize under drought stress in a randomized complete block design in Shooshtar city during the years 2017–2018. The experimental treatments included three levels of drought stress (Irrigation after 30%, 40% and 50% evaporation). Sub-plots consisted of superabsorbent polymer at two levels (control and 200 kg/ha) and combination of iron and zinc (control, iron, zinc, and iron-zinc). The results showed that drought stress affected chlorophyll, proline, iron grain concentration, nitrogen percent, grain protein and grain yield. Drought stress caused a significant reduction in yield. The percentage of grain protein was significantly increased in irrigation treatment at 50% of farming capacity. The highest grain yield and chlorophyll index was observed in 30% irrigation treatment. Spraying iron and zinc significantly increased the grain yield, chlorophyll index, iron, and zinc concentrations. Furthermore, drought stress and superabsorbent interacted significantly on grain yield. The interaction among drought stress and superabsorbent elements had significant effects on zinc and iron concentration. The present study suggests that using 200 kg/ha superabsorbent polymer and spraying iron and zinc under the 40% post-discharge irrigation may improve grain yield and biochemical features of maize.

Gamma-Aminobutyric Acid Accumulation Contributes to Citrus sinensis Response against ‘Candidatus Liberibacter Asiaticus’ via Modulation of Multiple Metabolic Pathways and Redox Status

Huanglongbing (HLB; also known as citrus greening) is the most destructive bacterial disease of citrus worldwide with no known sustainable cure yet. Herein, we used non-targeted metabolomics and transcriptomics to prove that γ-aminobutyric acid (GABA) accumulation might influence the homeostasis of several metabolic pathways, as well as antioxidant defense machinery, and their metabolism-related genes. Overall, 41 metabolites were detected in ‘Valencia’ sweet orange (Citrus sinensis) leaf extract including 19 proteinogenic amino acids (PAA), 10 organic acids, 5 fatty acids, and 9 other amines (four phenolic amines and three non-PAA). Exogenous GABA application increased most PAA in healthy (except L-threonine, L-glutamine, L-glutamic acid, and L-methionine) and ‘Candidatus L. asiaticus’-infected citrus plants (with no exception). Moreover, GABA accumulation significantly induced L-tryptophan, L-phenylalanine, and α-linolenic acid, the main precursors of auxins, salicylic acid (SA), and jasmonic acid (JA), respectively. Furthermore, GABA supplementation upregulated most, if not all, of amino acids, phenolic amines, phytohormone metabolism-related, and GABA shunt-associated genes in both healthy and ‘Ca. L. asiaticus’-infected leaves. Moreover, although ‘Ca. L. asiaticus’ induced the accumulation of H2O2 and O2•− and generated strong oxidative stress in infected leaves, GABA possibly stimulates the activation of a multilayered antioxidative system to neutralize the deleterious effect of reactive oxygen species (ROS) and maintain redox status within infected leaves. This complex system comprises two major components: (i) the enzymatic antioxidant defense machinery (six POXs, four SODs, and CAT) that serves as the front line in antioxidant defenses, and (ii) the non-enzymatic antioxidant defense machinery (phenolic acids and phenolic amines) that works as a second defense line against ‘Ca. L. asiaticus’-induced ROS in citrus infected leaves. Collectively, our findings suggest that GABA might be a promising alternative eco-friendly strategy that helps citrus trees battle HLB particularly, and other diseases in general.

Changes in Activity of Antioxidant Systems of <i>Escherichia coli</i> under Phosphate Starvation

Changes in the activity of antioxidant systems in Escherichia coli during phosphate starvation were studied. It was shown that starvation was accompanied by a decrease in the intensity of respiration, an increase in the rate of superoxide production, and a decrease in the level of ATP. Simultaneously, there was a decrease in H2O2 in the medium and a significant increase in the expression of the katG and katE genes encoding the HPI and HPII catalases, respectively. At the same time, there was no drop in the membrane potential, which may indicate the retention of normal membrane activity in starving cells. It has been shown for the first time that the transition of E. coli to phosphate starvation is accompanied by significant changes in the status of glutathione. The most important of them are associated with a decrease in the level of glutathione reductive form (GSH) in the medium (GSHout) and with a simultaneous increase in its content in the cytoplasm (GSHin), as well as a shift in the GSHin to oxidized glutathione form (GSSGin) ratio towards reductive values, and GSHout/GSSGout towards oxidative values. Among the mutants used in the work, the double mutant gor trxB, deficient in the synthesis of glutathione reductase and thioredoxin reductase, showed the most pronounced distinctive features. Compared to the parental strain, this mutant showed a multiple higher expression of katG::lacZ, the highest level of oxidized intra- and extracellular glutathione, and, accordingly, the lowest GSH/GSSG ratio in both compartments. In general, the data obtained indicate that during phosphate starvation the interaction of the glutathione redox-system and regulons that control protection against reactive oxygen species creates conditions that allow maintaining the concentration of ROS below the toxic level. As a result, phosphate-starved E. coli cells can maintain a high viability for a long time that allows them quickly to resume growth after the addition of phosphate.

Transcription Factor NRF2 in Endothelial Functions

The transcription factor NRF2 is the major regulator of cellular antioxidant defense. NRF2 is activated by various stimuli, such as oxidants and electrophiles, which induce the transcription of a number of genes whose products are involved in xenobiotic metabolism and contribute to the reduction of oxidative stress. NRF2 is one of the key transcription factors for endothelial cell function. Endothelium is a cell layer lining the inner cavity of blood vessels, which performs various homeostatic functions: it controls migration of leukocytes, regulates thrombosis and vascular tone, and drives angiogenesis. Endothelial dysfunction is often accompanied by inflammation and oxidative stress, which may lead to cellular aging as well as cell death by apoptosis, necrosis, and ferroptosis. Endothelial dysfunction contributes to the development of such common cardiovascular diseases as hypertension, diabetes, and atherosclerosis. Many pathophysiological processes in the endothelium, including senile changes, are associated with decreased NRF2 activity, leading to inflammatory activation and decreased activity of cellular antioxidant defense systems. Activation of the NRF2 signaling pathway generally contributes to the resolution of inflammation and oxidative stress. This review focuses on the importance of NRF2 in the basic functions of endothelium in normal and pathological conditions. In addition, the advantages and disadvantages of NRF2 activation as a way to prevent and treat cardiovascular diseases are discussed.

Metal-free multifunctional nanozymes mimicking endogenous antioxidant system for acute kidney injury alleviation

Cellular redox homeostasis is highly dependent on endogenous antioxidant systems, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). The nanozymes mimicking the catalytic activities of natural antioxidant systems serve as potential candidates for the therapy of reactive oxygen species (ROS)-related diseases. However, previously reported metal-containing nanozymes possessed unsatisfactory catalytic activity and inevitable peroxidase activity, limiting their translational applications. Therefore, inspired by the superior ROS scavenging activities of natural polyphenols and metal-free carbon dots (CDs) with ultra-small size, phenol-functionalized CDs that mimic endogenous antioxidant system have been fabricated. The SOD activity was determined at an extremely high level (18187 U/mg), which was substantially comparable to natural SOD. Notably, this study reveals for the first time that CDs, as selenium-free nanomaterials, show robust GPx activity in vitro. The theory calculation suggests that the bond dissociation of phenols on CDs is considerably lower than selenocysteine of natural GPx, which facilitates the formation of peroxide intermediate to initiate GPx-like reactions. Furthermore, the kidney-targeting and intracellular antioxidant mimicking properties contribute to the effective alleviating cisplatin-induced acute kidney injury via suppressing oxidative stress-mediated ferroptosis in vivo. These results provide an effective polyphenol-functionalized strategy for synthesizing metal-free multifunctional antioxidant nanozyme to treat ROS-related diseases.

Comparison of effect of CdS QD and ZnS QD and their corresponding salts on growth, chlorophyll content and antioxidative capacity of tomato

When applied in the same concentration to tomato plants, cadmium sulfate (CdSO4) and zinc sulfate (ZnSO4) were transported from soil to roots and from roots to shoots more readily than their nano counterparts: cadmium sulfide quantum dots (CdS QD) and zinc sulfide quantum dots (ZnS QD). Compared to the CdS QD, he higher rate of transport of CdSO4 resulted in a greater negative effect on growth, chlorophyll content, antioxidant properties, lipid peroxidation and activation of antioxidant defence systems. Although ZnSO4 was transported more rapidly than ZnS QD, the overall effect of Zn addition was positive (increase in total plant mass, stem length, antioxidant content and decrease in lipid peroxidation). However, these effects were more pronounced in the case of ZnS QD, suggesting that the mechanisms underpinning the activity of ZnS QD and ZnSO4 were different. Thus, the risk of phytotoxicity and food chain transfer of the two elements depended on their form (salt or nanoform), and consequently their effects on plants’ growth and physiology were different.

Unraveling rotational remedies: Deciphering the autotoxicity of Panax notoginseng saponins

Continuous cropping obstacles (CCO) refer to abnormal crop growth resulting from consecutive cultivation of related crops in the same soil. Panax notoginseng is severely affected by CCO. Crop rotation is the most effective approach to alleviate CCO. This study examined the impact of eight crop rotations on soil fertility, crop photosynthetic physiology, yield, and autotoxic substance levels in subsequent P. notoginseng crops. The findings indicate that maize is the most suitable rotational crop for P. notoginseng, significantly reducing saponin content by 18.5% and increasing biomass and chlorophyll content by 32.8% and 46.3%, respectively. Correlation analysis revealed that ginsenoside R1 enhances antioxidant enzyme activity, while saponin-like autotoxic substances are negatively correlated with chlorophyll. In conclusion, allelopathic autotoxicity primarily impairs plant growth by inhibiting photosynthesis and inducing changes in antioxidant system activity, leading to cell structure damage. Introducing maize in crop rotation reduces autotoxic substance levels and increases P. notoginseng biomass.

Homozygous C677T Methylenetetrahydrofolate Reductase (MTHFR) Polymorphism as a Risk Factor for Endometriosis: A Retrospective Case-Control Study.

This study was conducted to evaluate the role of methylenetetrahydrofolate reductase (MTHFR) C677T homozygous polymorphism as a risk factor for endometriosis. A retrospective case-control study was conducted from January 2020 to December 2022 on all patients attending the gynecological outpatient clinic of our institution who had performed an MTHFR polymorphisms test. Patients with endometriosis were considered cases, while those without endometriosis were considered controls. The presence of an MTHFR C677T homozygous polymorphism was defined as exposure. Risk factors for endometriosis were considered confounders in a binomial logistic regression, with endometriosis diagnosis as the dependent variable. Among the 409 included patients, 106 (25.9%) cases and 303 (74.1%) controls were identified. A higher rate of MTHFR C677T homozygous polymorphism was found in patients with endometriosis (24.5% vs. 15.8%, p = 0.0453), with an adOR of 1.889 (95% CI 1.076-3.318, p = 0.0269) at the binomial logistic regression. A history of no previous pregnancy was associated with an endometriosis diagnosis (adOR 2.191, 95% CI 1.295-3.708, p = 0.0035). An MTHFR C677T homozygous polymorphism could be considered a risk factor for endometriosis. Epigenetic modifications may be the most important mechanism explaining the observed association through the processes of altered DNA methylation and reduced activity of antioxidant systems.

Effects of cigarette smoking on semen quality, reproductive hormone levels, metabolic profile, zinc and sperm DNA fragmentation in men: results from a population-based study.

Cigarette smoking seems to have a negative impact on men's reproductive health, but our knowledge of its effects on the reproductive function of Russian men is still very limited. The purpose of this study was to evaluate the effect of cigarette smoking on semen quality, including sperm DNA fragmentation, hormonal, zinc and metabolic status in young men from the general multi-ethnic Russian population (n=1,222, median age 23 years) and to find out the ethno-specific effects of smoking by comparing male groups of different ethnicity. Each participant filled out a standardized questionnaire, provided one blood and semen sample. Semen parameters, serum reproductive hormones, lipids, glucose, uric acid and seminal zinc were analyzed. Participants were classified as smokers (n=450) and non-smokers (n=772), and smokers were stratified into moderate (≤10 cigarettes/day) and heavy (>10 cigarettes/day) smokers. In the entire study population, heavy smokers were characterized by a decrease in semen volume, total sperm count, sperm concentration and motility, and an increase in sperm DNA fragmentation and teratozoospermia compared with non-smokers (p<0.05). There was also a reduction in the serum and seminal zinc level as well as an impairment in metabolic health in smokers compared with non-smokers (p<0.05). No significant differences between smokers and non-smokers were found for serum levels of LH, FSH, inhibin B, testosterone and estradiol. In the second part of our study, the most numerous ethnic groups of Slavs (n=654), Buryats (n=191), and Yakuts (n=125) were selected from the entire study population. Among three ethnic groups, the smoking intensity was higher in Slavs than in Buryats or Yakuts suggesting a greater tobacco addiction in Slavs than in Asians. A decrease in semen parameters and seminal zinc levels, and an increase in sperm DNA fragmentation and teratozoospermia was observed only in smoking Slavs (p<0.05); moderate decrease in testosterone and increase in triglyceride levels were revealed in smoking Yakuts (p<0.05), but no significant changes were detected in smoking Buryats. We concluded that cigarette smoking has an ethno-specific effect on male reproductive function, probably due to the different activity of the seminal antioxidant system, which is yet to be elucidated.