Chemistry Related to the Catalytic Cycle of the Antioxidant Ebselen.

The antioxidant drug ebselen has been widely studied in both laboratories and in clinical trials. The catalytic mechanism by which it destroys hydrogen peroxide via reduction with glutathione or other thiols is complex and has been the subject of considerable debate. During reinvestigations of several key steps, we found that the seleninamide that comprises the first oxidation product of ebselen underwent facile reversible methanolysis to an unstable seleninate ester and two dimeric products. In its reaction with benzyl alcohol, the seleninamide produced a benzyl ester that reacted readily by selenoxide elimination, with formation of benzaldehyde. Oxidation of ebselen seleninic acid did not afford a selenonium seleninate salt as previously observed with benzene seleninic acid, but instead generated a mixture of the seleninic and selenonic acids. Thiolysis of ebselen with benzyl thiol was faster than oxidation by ca. an order of magnitude and produced a stable selenenyl sulfide. When glutathione was employed, the product rapidly disproportionated to glutathione disulfide and ebselen diselenide. Oxidation of the S-benzyl selenenyl sulfide, or thiolysis of the seleninamide with benzyl thiol, afforded a transient thiolseleninate that also readily underwent selenoxide elimination. The S-benzyl derivative disproportionated readily when catalyzed by the simultaneous presence of both the thiol and triethylamine. The phenylthio analogue disproportionated when exposed to ambient or UV (360 nm) light by a proposed radical mechanism. These observations provide additional insight into several reactions and intermediates related to ebselen.

Pro-and Antioxidant Status in Newborn with COVID-19.

There is practically no information on the state of oxidative stress reactions in newborns with coronavirus infections. At the same time, such studies are extremely important and can contribute to better understanding of the process of reactivity in patients of different ages. The content of pro- and antioxidant status indicators was assessed in 44 newborns with confirmed COVID-19. It was found that the content of compounds with unsaturated double bonds, primary, secondary, and final LPO products were elevated in newborns with COVID-19. These changes were accompanied by higher SOD activity and retinol level and reduced activity of glutathione peroxidase. Contrary to popular opinion, newborns can be a COVID-19-susceptible age group and require more close monitoring of metabolic reactions during the period of neonatal adaptation that is an aggravating background during infection.

Efficacy of Liriope platyphylla extract on improving respiratory function: A CONSORT-randomized, double-blind, placebo-controlled pilot trial.

BACKGROUND: The respiratory system is the first line of defense against outside pollutants. Recently, respiratory health has been receiving increasing attention due to the increase in fine dust, which reduces respiratory function and increases incidence of chronic obstructive pulmonary disease, and in coronavirus pandemic, which can cause severe acute respiratory syndrome. METHODS: This clinical pilot trial was designed to secure evidence for a main clinical trial and to confirm the efficacy and safety of Liriope platyphylla (LP) extract for improving respiratory function. We conducted a double-blind randomized placebo-controlled trial with 22 participants from June 30, 2021, to August 25, 2021. The primary outcome was Breathlessness, Cough, and Sputum Scale score. Secondary outcomes included forced vital capacity, forced expiratory volume at 1 second (FEV1), forced expiratory volume at 1 s/forced vital capacity ratio, cough assessment test score, chronic obstructive pulmonary disease assessment test score, peripheral blood mononuclear cell counts (white blood cells, eosinophils, T cells, and B cells), high-sensitivity C-reactive protein level, erythrocyte sedimentation rate, cytokine (interleukin-1ß, interleukin-4, tumor necrosis factor-α, interleukin-6, interleukin-8, interferon-γ, and immunoglobulin E) levels, antioxidant (glutathione peroxidase and superoxide dismutase) levels, and nitric oxide level. RESULTS: A total of 22 participants were randomly assigned to 2 groups: the LP group (n = 11), who took 1000 mg of LP extract per day, and the placebo group, who took 1000 mg of dextrin per day. Participants took 1 capsule twice a day for 4 weeks. For the Breathlessness, Cough, and Sputum Scale, the interaction between group and visit was statistically significant in a blend of analyses of variance. interleukin-8, tumor necrosis factor-α, and interferon-γ levels decreased more in the LP group than in the placebo group. The sample size required for large-scale clinical trials in the future was 50. There were no side effects. CONCLUSION: LP extract can enhance respiratory function. The detailed data we obtained support conducting the future main large-scale clinical trial.

Cucumis melo var. momordica as a Potent Antidiabetic, Antioxidant and Possible Anticovid Alternative: Investigation through Experimental and Computational Methods.

Diabetes mellitus is a typical life threatening of disease, which generate due to the dysfunction of ß cells of pancreas. In 2014, WHO stated that 422 million people were infected with DM. The current pattern of management of diabetes included synthetic or plant based oral hypoglycemic drugs and insulin but drug resentence is become a very big issues in antidiabetic therapy. Thus, it's very earnest to discover now medication for this disease. Now the days, it is well acknowledged that diabetic patients are more prone towards covid and related complications. Thus, medical practitioners reformed the methodology of prescribing medication for covid infected antidiabetic therapy and encouraging the medication contains dual pharmacological properties. It is also well know that polyphenols specifically hold a significant role in oxidative stress and reduced the severity of many inflammatory diseases. Cucumis melo has rich history as ethano-pharmacological use in Indian subcontinent. The fruit and seed are well-known for the treatment of various diseases due to the presence of phenolics. Therefore, in this study, the combined mixture of flower and seeds were used for the extraction of polyphenolic rich extract and tested for antidiabetic activity through the antioxidant and in vivo experiments. The antioxidant potential measurement exhibited that the selected plant extract has the significant competence to down-regulate oxidative stress (DPPH scavenging IC50 at 60.7±1.05 µg/mL, ABTS IC50 at 62.15±0.50 µg/mL). Furthermore, the major polyphenolic phyto-compounds derived from the Cucumis melo were used for in silico anticovid activity, docking, and complementarity studies. The anticovid activity prognosis reflected that selected phyto-compounds amentoflavone and vanillic acid have optimal possibility to interact with 3C-like protease and through this moderate anticovid activity can be exhibit. The docking experiments established that the selected compounds have propensity to interact with protein tyrosine phosphatase 1B, 11ß-Hydroxysteroid dehydrogenase, superoxide dismutase, glutathione peroxidase, and catalase ß-glucuronidase receptor. In vivo experiments showed that 500 mg/kg, Cucumis melo extract ominously amplified body weight, plasma insulin, high-density lipoprotein levels, and biochemical markers. Furthermore, extract significantly downregulate the blood glucose, total cholesterol, triglycerides, low-density lipoprotein, and very low-density lipoprotein.

Capsanthin from Capsicum annum fruits exerts anti-glaucoma, antioxidant, anti-inflammatory activity, and corneal pro-inflammatory cytokine gene expression in a benzalkonium chloride-induced rat dry eye model.

Dry eye disease (DED) is a complex ocular surface inflammatory disease. Its occurrence varies widely over the world, ranging from 5% to 34%. The use of preservatives, specifically benzalkonium chloride, in the ocular drops worsens the DED conditions. Furthermore, the Covid-19 pandemic increased screen time and the use of face masks and shields. As a result, the number of people suffering from dry eye disease (DED) has increased significantly in recent years. The main objective of our study is to find a solution to manage the dry eye disease (DED) preferably from natural source without any adverse events. In this study, the beneficial effects of capsanthin from Capsicum annum (CCA) were evaluated on benzalkonium chloride (BAC)-induced dry eye disease (DED) in Albino Wistar rats. Oral supplementation of CCA resulted in a statistically significant decrease in intraocular pressure (IOP) (p < .0001), increase in tear break-up time (TBUT) (p < .01), decline in Schirmer test results (p < .01), and decrease in corneal surface inflammation (p < .01). Capsanthin ameliorated in reducing oxidative stress by increasing serum antioxidant levels such as glutathione peroxidase (GPX), nitric oxide (NO), and lactoferrin (LTF) and inhibiting matrix metalloproteinases 2 and 9 (MMP2 and MMP9) (p < .0001). Capsanthin treatment significantly inhibited the expression of inflammatory cytokines, tumor necrosis factor-alpha (TNF-α), interleukins (IL-2, IL-4, IL-6), and pro-inflammatory mediator, matrix metalloproteinase-9 (MMP9). Furthermore, the lacrimal gland expressed vascular cell adhesion molecule (VCAM-1), and prostaglandin-endoperoxide synthase 2 (PTGS2) was suppressed by CCA treatment. PRACTICAL APPLICATIONS: Benzalkonium chloride (BAC), a preservative widely used in the topical ocular drug delivery system (ODDS), causes undesirable effects such as dry eye disease as well as ameliorating intraocular pressure leading to optical nerve damage and irreversible vision loss. Capsanthin from Capsicum annum (CCA) can be used to treat symptoms related to dry eye disease such as inflammation, eye irritation, visual disturbance, ocular discomfort with potential damage to the ocular surface. The CCA may be beneficial in the treatment of glaucoma, an elevated intraocular pressure. Capsanthin from C. annum can be useful in managing DED by increasing tear break-up time (TBUT), declining in Schirmer test results and decreasing in corneal surface inflammation.

Melatonin and multiple sclerosis: antioxidant, anti-inflammatory and immunomodulator mechanism of action.

BACKGROUND: Melatonin is an indole hormone secreted primarily by the pineal gland that showing anti-oxidant, anti-inflammatory and anti-apoptotic capacity. It can play an important role in the pathophysiological mechanisms of various diseases. In this regard, different studies have shown that there is a relationship between Melatonin and Multiple Sclerosis (MS). MS is a chronic immune-mediated disease of the Central Nervous System. AIM: The objective of this review was to evaluate the mechanisms of action of melatonin on oxidative stress, inflammation and intestinal dysbiosis caused by MS, as well as its interaction with different hormones and factors that can influence the pathophysiology of the disease. RESULTS: Melatonin causes a significant increase in the levels of catalase, superoxide dismutase, glutathione peroxidase, glutathione and can counteract and inhibit the effects of the NLRP3 inflammasome, which would also be beneficial during SARS-CoV-2 infection. In addition, melatonin increases antimicrobial peptides, especially Reg3ß, which could be useful in controlling the microbiota. CONCLUSION: Melatonin could exert a beneficial effect in people suffering from MS, running as a promising candidate for the treatment of this disease. However, more research in human is needed to help understand the possible interaction between melatonin and certain sex hormones, such as estrogens, to know the potential therapeutic efficacy in both men and women.

SOD2 rs4880 and GPX1 rs1050450 polymorphisms do not confer risk of COVID-19, but influence inflammation or coagulation parameters in Serbian cohort.

Objectives: Due to the role of oxidative stress in the pathophysiology of COVID-19, it is biologically plausible that inter-individual differences in patients' clinical manifestations might be affected by antioxidant genetic profile. The aim of our study was to assess the distribution of antioxidant genetic polymorphisms Nrf2 rs6721961, SOD2 rs4880, GPX1 rs1050450, GPX3 rs8177412, and GSTP1 (rs1695 and rs1138272) haplotype in COVID-19 patients and controls, with special emphasis on their association with laboratory biochemical parameters.Methods: The antioxidant genetic polymorphisms were assessed by appropriate PCR methods in 229 COVID-19 patients and 229 matched healthy individuals.Results: Among examined polymorphisms, only GSTP1 haplotype was associated with COVID-19 risk (p = 0.009). Polymorphisms of SOD2 and GPX1 influenced COVID-19 patients' laboratory biochemical profile: SOD2*Val allele was associated with increased levels of fibrinogen (p = 0.040) and ferritin (p = 0.033), whereas GPX1*Leu allele was associated with D-dimmer (p = 0.009).Discussion: Our findings regarding the influence of SOD2 and GPX1 polymorphisms on inflammation and coagulation parameters might be of clinical importance. If confirmed in larger cohorts, these developments could provide a more personalized approach for better recognition of patients prone to thrombosis and those for the need of targeted antiox-idant therapy.

Risk-focused differences in molecular processes implicated in SARS-CoV-2 infection: corollaries in DNA methylation and gene expression.

BACKGROUND: Understanding the molecular basis of susceptibility factors to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global health imperative. It is well-established that males are more likely to acquire SARS-CoV-2 infection and exhibit more severe outcomes. Similarly, exposure to air pollutants and pre-existing respiratory chronic conditions, such as asthma and chronic obstructive respiratory disease (COPD) confer an increased risk to coronavirus disease 2019 (COVID-19). METHODS: We investigated molecular patterns associated with risk factors in 398 candidate genes relevant to COVID-19 biology. To accomplish this, we downloaded DNA methylation and gene expression data sets from publicly available repositories (GEO and GTEx Portal) and utilized data from an empirical controlled human exposure study conducted by our team. RESULTS: First, we observed sex-biased DNA methylation patterns in autosomal immune genes, such as NLRP2, TLE1, GPX1, and ARRB2 (FDR < 0.05, magnitude of DNA methylation difference Δß > 0.05). Second, our analysis on the X-linked genes identified sex associated DNA methylation profiles in genes, such as ACE2, CA5B, and HS6ST2 (FDR < 0.05, Δß > 0.05). These associations were observed across multiple respiratory tissues (lung, nasal epithelia, airway epithelia, and bronchoalveolar lavage) and in whole blood. Some of these genes, such as NLRP2 and CA5B, also exhibited sex-biased gene expression patterns. In addition, we found differential DNA methylation patterns by COVID-19 status for genes, such as NLRP2 and ACE2 in an exploratory analysis of an empirical data set reporting on human COVID-9 infections. Third, we identified modest DNA methylation changes in CpGs associated with PRIM2 and TATDN1 (FDR < 0.1, Δß > 0.05) in response to particle-depleted diesel exhaust in bronchoalveolar lavage. Finally, we captured a DNA methylation signature associated with COPD diagnosis in a gene involved in nicotine dependence (COMT) (FDR < 0.1, Δß > 0.05). CONCLUSION: Our findings on sex differences might be of clinical relevance given that they revealed molecular associations of sex-biased differences in COVID-19. Specifically, our results hinted at a potentially exaggerated immune response in males linked to autosomal genes, such as NLRP2. In contrast, our findings at X-linked loci such as ACE2 suggested a potentially distinct DNA methylation pattern in females that may interact with its mRNA expression and inactivation status. We also found tissue-specific DNA methylation differences in response to particulate exposure potentially capturing a nitrogen dioxide (NO2) effect-a contributor to COVID-19 susceptibility. While we identified a molecular signature associated with COPD, all COPD-affected individuals were smokers, which may either reflect an association with the disease, smoking, or may highlight a compounded effect of these two risk factors in COVID-19. Overall, our findings point towards a molecular basis of variation in susceptibility factors that may partly explain disparities in the risk for SARS-CoV-2 infection.

Investigation of the effects of three different generations of fluoroquinolone derivatives on antioxidant and immunotoxic enzyme levels in different rat tissues.

Fluoroquinolones (FQs) are synthetic and broad-spectrum antimicrobial drugs derived from nalidixic acid. FQs are used against SARS-CoV-2 in our country, and for the treatment of some urinary tract diseases, gastrointestinal diseases, respiratory tract diseases, sexually transmitted diseases, and dermatological diseases. The present study investigated the effect of 1-,7-,14-day treatments of three different FQ derivatives; ciprofloxacin (CIP) 80 mg/kg/day, levofloxacin (LVX) 40 mg/kg/day, and moxifloxacin (MXF) 40 mg/kg/day, on biochemical parameters, lipid peroxidation, antioxidant enzymes, and immunotoxicity. 72 Wistar albino male rats were distributed to four groups including 18 rats in each group and were sacrificed on three different time points. The 14-day treatment of MXF significantly reduced the levels of aspartate aminotransferase (AST), glucose, reduced glutathione (GSH), malondialdehyde (MDA), catalase (CAT), myeloperoxidase (MPO), adenosine deaminase (ADA), and glutathione peroxidase (GPx). Furthermore, 14-day treatment of LVX increased liver [GSH, MPO, ADA, superoxide dismutase (SOD)], and GSH (erythrocyte) levels; whereas it significantly reduced the levels of AST, TG (triglycerides) and associated parameters levels in all the tissues (MDA), erythrocytes, and liver (MPO, CAT, SOD, GPx). After 14-day treatment of CIP; the erythrocyte levels of GSH, MPO, GPx, and CAT significantly decreased; whereas the levels of glucose, creatinine, MPO (liver), and GST (kidney and erythrocyte) significantly increased. It has been concluded that FQ derivatives used in this experiment did not display any correlation in terms of the efficacies in the different time points and tissues. Thus, it is recommended to use such FQ derivatives considering the duration of use and target tissue.

Ebselen and Analogues: Pharmacological Properties and Synthetic Strategies for Their Preparation.

Ebselen is the leader of selenorganic compounds, and starting from its identification as mimetic of the key antioxidant enzyme glutathione peroxidase, several papers have appeared in literature claiming its biological activities. It was the subject of several clinical trials and it is currently in clinical evaluation for the treatment of COVID-19 patients. Given our interest in the synthesis and pharmacological evaluation of selenorganic derivatives with this review, we aimed to collect all the papers focused on the biological evaluation of ebselen and its close analogues, covering the timeline between 2016 and most of 2021. Our analysis evidences that, even if it lacks specificity when tested in vitro, being able to bind to every reactive cysteine, it proved to be always well tolerated in vivo, exerting no sign of toxicity whatever the administered doses. Besides, looking at the literature, we realized that no review article dealing with the synthetic approaches for the construction of the benzo[d][1,2]-selenazol-3(2H)-one scaffold is available; thus, a section of the present review article is completely devoted to this specific topic.