The definition and measurement of antioxidants in biological systems

The Impact of ROS and NGF in the Gliomagenesis and their Emerging Implications in the Glioma Treatment

Reactive oxygen species (ROS) are highly reactive molecules derived from molecular oxygen (O2). ROS sources can be endogenous, such as cellular organelles and inflammatory cells, or exogenous, such as ionizing radiation, alcohol, food, tobacco, chemotherapeutical agents and infectious agents. Oxidative stress results in damage of several cellular structures (lipids, proteins, lipoproteins, and DNA) and is implicated in various disease states such as atherosclerosis, diabetes, cancer, neurodegeneration, and aging. A large body of studies showed that ROS plays an important role in carcinogenesis. Indeed, increased production of ROS causes accumulation in DNA damage leading to tumorigenesis. Various investigations demonstrated the involvement of ROS in gliomagenesis. The most common type of primary intracranial tumor in adults is represented by glioma. Furthermore, there is growing attention on the role of the Nerve Growth Factor (NGF) in brain tumor pathogenesis. NGF is a growth factor belonging to the family of neurotrophins. It is involved in neuronal differentiation, proliferation and survival. Studies were conducted to investigate NGF pathogenesis's role as a pro- or anti-tumoral factor in brain tumors. It has been observed that NGF can induce both differentiation and proliferation in cells. The involvement of NGF in the pathogenesis of brain tumors leads to the hypothesis of a possible implication of NGF in new therapeutic strategies. Recent studies have focused on the role of neurotrophin receptors as potential targets in glioma therapy. This review provides an updated overview of the role of ROS and NGF in gliomagenesis and their emerging role in glioma treatment.

Effect of Wild Strawberry Tree and Hawthorn Extracts Fortification on Functional, Physicochemical, Microbiological, and Sensory Properties of Yogurt

The composition analyses and health-promoting properties (antioxidant capacity, antidiabetic, and antihypertensive properties) of wild fruit extracts and the effect of the incorporation of strawberry tree (STE) and hawthorn (HTE) extracts on the physicochemical, instrumental textural, microbiological, and sensory parameters of yogurts were evaluated. The incorporation of wild fruit extracts in yogurt increased antioxidant and antidiabetic properties (inhibition of digestive α-amylase, α-glucosidase, and lipase enzymatic activities) compared to the control, without decreasing their sensory quality or acceptance by consumers. The hawthorn yogurt (YHTE) showed the highest total phenolic content (TPC) and antioxidant capacity (ABTS and ORAC methods). Yogurts containing wild fruit extracts and dietary fiber achieved high overall acceptance scores (6.16-7.04) and showed stable physicochemical, textural, and microbiological properties. Therefore, the use of wild fruit extracts and inulin-type fructans as ingredients in yogurt manufacture stands as a first step towards the development of non-added sugar dairy foods for sustainable health.

Genus Streptomyces: Recent advances for biotechnological purposes

Actinomycetes are a distinct group of filamentous bacteria. The Streptomyces genus within this group has been extensively studied over the years, with substantial contributions to society and science. This genus is known for its antimicrobial production, as well as antitumor, biopesticide, and immunomodulatory properties. Therefore, the extraordinary plasticity of the Streptomyces genus has inspired new research techniques. The newest way of exploring Streptomyces has comprised the discovery of new natural metabolites and the application of emerging tools such as CRISPR technology in drug discovery. In this narrative review, we explore relevant published literature concerning the ongoing novelties of the Streptomyces genus.

Role of Oxidative Stress on Insulin Resistance in Diet-Induced Obesity Mice

Insulin resistance is the link between obesity and type 2 diabetes mellitus. The molecular mechanism by which obese individuals develop insulin resistance has not yet been fully elucidated; however, inconclusive and contradictory studies have shown that oxidative stress may be involved in the process. Thus, this study aimed to evaluate the effect of reactive species on the mechanism of insulin resistance in diet-induced obese mice. Obese insulin-resistant mice were treated with N-acetylcysteine (NAC; 50 mg/kg per day, for 15 days) by means of oral gavage. Twenty-four hours after the last NAC administration, the animals were euthanized and their tissues were extracted for biochemical and molecular analyses. NAC supplementation induced improved insulin resistance and fasting glycemia, without modifications in food intake, body weight, and adiposity. Obese mice showed increased dichlorofluorescein (DCF) oxidation, reduced catalase (CAT) activity, and reduced glutathione levels (GSH). However, treatment with NAC increased GSH and CAT activity and reduced DCF oxidation. The gastrocnemius muscle of obese mice showed an increase in nuclear factor kappa B (NFκB) and protein tyrosine phosphatase (PTP1B) levels, as well as c-Jun N-terminal kinase (JNK) phosphorylation compared to the control group; however, NAC treatment reversed these changes. Considering the molecules involved in insulin signaling, there was a reduction in insulin receptor substrate (IRS) and protein kinase B (Akt) phosphorylation. However, NAC administration increased IRS and Akt phosphorylation and IRS/PI3k (phosphoinositide 3-kinase) association. The results demonstrated that oxidative stress-associated obesity could be a mechanism involved in insulin resistance, at least in this animal model.

Apples and Apple By-Products: Antioxidant Properties and Food Applications

In recent years, there has been a growing interest in utilizing natural antioxidants as alternatives to synthetic additives in food products. Apples and apple by-products have gained attention as a potential source of natural antioxidants due to their rich phenolic content. However, the extraction techniques applied for the recovery of phenolic compounds need to be chosen carefully. Studies show that ultrasound-assisted extraction is the most promising technique. High yields of phenolic compounds with antioxidant properties have been obtained by applying ultrasound on both apples and their by-products. Promising results have also been reported for green technologies such as supercritical fluid extraction, especially when a co-solvent is used. Once extracted, recent studies also indicate the feasibility of using these compounds in food products and packaging materials. The present review aims to provide a comprehensive overview of the antioxidant properties of apples and apple by-products, their extraction techniques, and potential applications in food products because of their antioxidant or nutritional properties. The findings reported here highlight the proper utilization of apples and their by-products in food to reduce the detrimental effect on the environment and provide a positive impact on the economy.

Solarplast®-An Enzymatically Treated Spinach Extract

In the modern world we are constantly bombarded by environmental and natural stimuli that can result in oxidative stress. Antioxidant molecules and enzymes help the human body scavenge reactive oxygen species and prevent oxidative damage. Most organisms possess intrinsic antioxidant activity, but also benefit from the consumption of antioxidants from their diet. Leafy green vegetables such as spinach are a well-researched rich source of dietary antioxidant molecules. However, plant cell walls are difficult to digest for many individuals and the bio-accessibility of nutrients and antioxidants from these sources can be limited by the degree of digestion and assimilation. Through a specific enzymatic process, Solarplast^® contains organic spinach protoplasts without the cell wall, which may facilitate higher yield and efficacy of beneficial antioxidant molecules. In this study, analytical techniques coupled to in vitro bioassays were used to determine the potential antioxidant activity of Solarplast^® and determine its antioxidant enzymatic capabilities. Solarplast^® demonstrated superior antioxidant activity when compared to frozen spinach leaves in TOC, FRAP and TEAC antioxidant assays. Several antioxidant enzymes were also increased in Solarplast^®, when compared to frozen spinach. As a functional readout, Solarplast^® attenuated hydrogen peroxide-, ethanol- and acetaminophen-induced increases in oxidative stress and cytotoxicity in both intestinal (HT-29) and liver (HepG2) cell lines. These findings suggest that Solarplast^® may represent a non-GMO, plant-based food supplement to help reduce oxidative stress in the human body.

Titanate nanotubes as an efficient oral detoxifying agent against drug overdose: application in rat acetaminophen poisoning

Voluntary drug intoxication is mainly due to drug overdose or the interaction of several drugs. Coma and its associated complications such as hypoventilation, aspiration pneumopathy, and heart rhythm disorders are the main hallmarks of drug intoxication. Conventional detoxification treatments, including gastric lavage or vomiting, administration of ipecac or activated charcoal (CH), and the use of antidotes, have proven to be inefficient and are generally associated with severe adverse effects. To overcome these limitations, titanate nanotubes (TiNTs) are proposed as an efficient emerging detoxifying agent because of their tubular shape and high adsorption capacity. In the present study, the detoxifying ability of TiNTs was evaluated on paracetamol (PR)-intoxicated rats. Results indicate that the loading ability of PR into TiNTs (70%) was significantly higher than that recorded for CH (38.6%). In simulated intestinal medium, TiNTs showed a controlled drug release of less than 10% after 72 h of incubation. In PR-intoxicated rats, TiNTs treatment resulted in a 64% decrease of PR after 4 h of poisoning versus 40% for CH. Concomitantly, TiNTs efficiently reduced PR absorption by 90% after 24 h of poisoning, attenuated the elevated levels of biochemical markers (i.e., alanine aminotransferase, aspartate aminotransferase, creatinine, and TNF-α) and mitigated oxidative stress by increasing the activity of superoxide dismutase and reducing the oxidized glutathione/total glutathione ratio, suggesting a histoprotective effect of TiNTs against paracetamol-induced toxicity in rats. In addition to their safety and high stability in the entire gastro-intestinal tract, biodistribution analysis revealed that TiNTs exhibited low intestinal absorption owing to their large cluster size of compact aggregate nanomaterials across the intestinal villi hindering the absorption of paracetamol. Collectively, these data provide a new and promising solution for in vivo detoxification. TiNTs are expected to have great potential for the treatment of voluntary and accidental intoxication in emergency care.

Expected and Unexpected Effects of Pharmacological Antioxidants

In this review, we have collected the existing data on the bioactivity of antioxidants (N-acetylcysteine, polyphenols, vitamin C) which are traditionally used in experimental biology and, in some cases, in the clinic. Presented data show that, despite the capacity of these substances to scavenge peroxides and free radicals in cell-free systems, their ability to exhibit these properties in vivo, upon pharmacological supplementation, has not been confirmed so far. Their cytoprotective activity is explained mainly by the ability not to suppress, but to activate multiple redox pathways, which causes biphasic hormetic responses and highly pleiotropic effects in cells. N-acetylcysteine, polyphenols, and vitamin C affect redox homeostasis by generating low-molecular-weight redox-active compounds (H₂O₂ or H₂S), known for their ability to stimulate cellular endogenous antioxidant defense and promote cytoprotection at low concentrations but exert deleterious effects at high concentrations. Moreover, the activity of antioxidants strongly depends on the biological context and mode of their application. We show here that considering the biphasic and context-dependent response of cells on the pleiotropic action of antioxidants can help explain many of the conflicting results obtained in basic and applied research and build a more logical strategy for their use.

The oxidative nuclease activity of human cytochrome c with mutations in Ω-loop C/D

Natural and artificial nucleases have extensive applications in biotechnology and biomedicine. The exploration of protein with potential DNA cleavage activity also inspires the design of artificial nuclease and helps to understand the physiological process of DNA damage. In this study, we engineered four human cytochrome c (Cyt c) mutants (N52S, N52A, I81N, and I81D Cyt c), which showed enhanced DNA cleavage activity and degradation in comparison with WT Cyt c, especially under acidic conditions. The mechanism assays revealed that the superoxide (O₂^•-) plays an important role in the nuclease reaction. The kinetic assays showed that the peroxidase activity of the I81D Cyt c mutant enhanced up to 9-fold at pH 5. This study suggests that the mutations of Ile81 and Asn52 in Ω-loop C/D are critical for the nuclease activity of Cyt c, which may have physiological significance in DNA damage and potential applications in biomedicine.

Comparison of antioxidant activity in various spirulina containing products and factors affecting it

Spirulina is a popular food supplement known for its high antioxidant activity. Several studies have shown that antioxidant activity fluctuates depending on the combination of ingredients in the food. Fresh spirulina is a growing market trend; however, pure spirulina short shelf life is a strong limitation. This study aims to investigate antioxidant activity of various novel commercial fresh spirulina-containing products and the factors affecting it. Antioxidant activity and total phenolic content of each ingredient and binary combinations of spirulina and apple juices, Japanese quince syrup, or cranberry syrup were measured. Synergic, antagonistic, and additive interactions between samples were determined and expressed using the synergy coefficient. FRAP assay showed apparent synergism of spirulina and all the studied ingredients whereas ABTS and Folin-Ciocalteu methods revealed an antagonistic interaction between spirulina and apple juice. Despite the antagonistic interactions, all the products demonstrated at least the same antioxidant activity as pure fresh spirulina and had longer shelf life than, pointing to their commercial potential.

Potential Antioxidative Activity of Homocysteine in Erythrocytes under Oxidative Stress

Homocysteine is an amino acid containing a free sulfhydryl group, making it probably contribute to the antioxidative capacity in the body. We recently found that plasma total homocysteine (total-Hcy) concentration increased with time when whole blood samples were kept at room temperature. The present study was to elucidate how increased plasma total-Hcy is produced and explore the potential physiological role of homocysteine. Erythrocytes and leukocytes were separated and incubated in vitro; the amount of total-Hcy released by these two kinds of cells was then determined by HPLC-MS. The effects of homocysteine and methionine on reactive oxygen species (ROS) production, osmotic fragility, and methemoglobin formation in erythrocytes under oxidative stress were studied. The reducing activities of homocysteine and methionine were tested by ferryl hemoglobin (Hb) decay assay. As a result, it was discovered that erythrocytes metabolized methionine to homocysteine, which was then oxidized within the cells and released to the plasma. Homocysteine and its precursor methionine could significantly decrease Rosup-induced ROS production in erythrocytes and inhibit Rosup-induced erythrocyte's osmotic fragility increase and methemoglobin formation. Homocysteine (but not methionine) was demonstrated to enhance ferryl Hb reduction. In conclusion, erythrocytes metabolize methionine to homocysteine, which contributes to the antioxidative capability under oxidative stress and might be a supplementary protective factor for erythrocytes against ROS damage.

Neem Oil or Almond Oil Nanoemulsions for Vitamin E Delivery: From Structural Evaluation to in vivo Assessment of Antioxidant and Anti-Inflammatory Activity

Purpose

Vitamin E (VitE) may be classified in "the first line of defense" against the formation of reactive oxygen species. Its inclusion in nanoemulsions (NEs) is a promising alternative to increase its bioavailability. The aim of this study was to compare O/W NEs including VitE based on Almond or Neem oil, showing themselves antioxidant properties. The potential synergy of the antioxidant activities of oils and vitamin E, co-formulated in NEs, was explored.

Patients and Methods

NEs have been prepared by sonication and deeply characterized evaluating size, ζ-potential, morphology (TEM and SAXS analyses), oil nanodroplet feature, and stability. Antioxidant activity has been evaluated in vitro, in non-tumorigenic HaCaT keratinocytes, and in vivo through fluorescence analysis of C. elegans transgenic strain. Moreover, on healthy human volunteers, skin tolerability and anti-inflammatory activity were evaluated by measuring the reduction of the skin erythema induced by the application of a skin chemical irritant (methyl-nicotinate).

Results

Results confirm that Vitamin E can be formulated in highly stable NEs showing good antioxidant activity on keratinocyte and on C. elegans. Interestingly, only Neem oil NEs showed some anti-inflammatory activity on healthy volunteers.

Conclusion

From the obtained results, Neem over Almond oil is a more appropriate candidate for further studies on this application.

Seasonal Variability of Juniperus communis L. Berry Ethanol Extracts: 2. In Vitro Ferric Reducing Ability of Plasma (FRAP) Assay

In the present study, the seasonal variability of the in vitro ferric reducing ability of plasma (FRAP), total phenols, and terpene hydrocarbon content in 70% ethanol extracts were evaluated. The samples of crushed (CBs) and non-crushed ripe juniper berries (NCBs) collected at five localities in North-East Slovakia during the years 2012-2014 were compared. The method of preparation of the extract influenced the amount of dry matter (DM) in the extracts. In the CB extracts were statistically higher contents of DM (from 13.91 ± 0.11 g·L^-1 to 23.84 ± 0.14 g·L^-1) compared to NCB extracts (from 1.39 ± 0.01 g·L^-1 to 16.55 ± 0.09 g·L^-1). The differences in antioxidant activity between the investigated localities were statistically significant for both types of extract. For example, in 2013 in the locality of Zbojné, the FRAP in NCBs was 76.62 µmol·L^-1·g^-1 DM and in CBs was 138.27 µmol·L^-1·g^-1 DM, while in the Miľpoš locality, in NCBs there was 232.66 µmol·L^-1·g^-1 DM and in CBs there was 1178.98 µmol·L^-1·g^-1 DM. The differences in the antioxidant activity between the studied years in the case of NCB extracts were not statistically significant. In the case of CB extracts, significant differences between the evaluated years were found. Statistics by ANOVA confirmed that CB extracts prepared from berries in the year 2013 showed significantly higher activity compared to CB extracts from berries from the years 2012 and 2014. Based on the Pearson we found a negative correlation coefficient between the FRAP assay and the content of total polyphenols in NCB extracts (-0.531 in 2012; -0.349 in 2013; and -0.224 in 2014). In contrast, CB extracts showed a positive correlation coefficient (0.843 in 2012; 0.742 in 2013; 0.617 in 2014).

Nrf2 and Oxidative Stress: A General Overview of Mechanisms and Implications in Human Disease

Organisms are continually exposed to exogenous and endogenous sources of reactive oxygen species (ROS) and other oxidants that have both beneficial and deleterious effects on the cell. ROS have important roles in a wide range of physiological processes; however, high ROS levels are associated with oxidative stress and disease progression. Oxidative stress has been implicated in nearly all major human diseases, from neurogenerative diseases and neuropsychiatric disorders to cardiovascular disease, diabetes, and cancer. Antioxidant defence systems have evolved as a means of protection against oxidative stress, with the transcription factor Nrf2 as the key regulator. Nrf2 is responsible for regulating an extensive panel of antioxidant enzymes involved in the detoxification and elimination of oxidative stress and has been extensively studied in the disease contexts. This review aims to provide the reader with a general overview of oxidative stress and Nrf2, including basic mechanisms of Nrf2 activation and regulation, and implications in various major human diseases.

The effect of omega-3 fatty acids on active periodontal therapy: A systematic review and meta-analysis

AIM

"Host modulatory therapy" (HMT) with ω-3 fatty acids aims at reducing inflammation. With HMT as an adjunct, a better result of periodontal therapy is expected. The aim of this systematic review and meta-analysis (MA) was to examine the additional effect of ω-3 fatty acids to non-surgical periodontal therapy (SRP) on the probing pocket depth (PPD) and the clinical attachment level (CAL).

MATERIALS AND METHODS

MEDLINE-PubMed and Cochrane-CENTRAL libraries were searched up to January 2021 for randomized controlled trials in patients with chronic periodontitis, treated with SRP/placebo as controls and SRP/ω-3 fatty acids as the test group.

RESULTS

The search identified 173 unique abstracts, and screening resulted in 10 eligible publications. Descriptive analysis showed a significant effect on the PPD and CAL in favour of the groups with ω-3 fatty acids in the majority of comparisons. MA revealed that adjunctive use of ω-3 fatty acids to SRP resulted in 0.39 mm more PPD reduction (95% CI: -0.58; -0.21) and 0.41 mm more CAL gain (95% CI: -0.63; -0.19) than SRP alone.

CONCLUSIONS

In patients with periodontitis, dietary supplementation with ω-3 fatty acids as an adjunct to SRP is more effective in reducing the PPD and improving the CAL than SRP alone. If SRP is indicated, the use of ω-3 fatty acids can be considered for a moderate extra added effect on PPD reduction and CAL gain. The strength of this recommendation is moderate.

The Prognostic Value of Derivatives-Reactive Oxygen Metabolites (d-ROMs) for Cardiovascular Disease Events and Mortality: A Review

Oxidative stress participates in the development and exacerbation of cardiovascular diseases (CVD). The ability to promptly quantify an imbalance in an individual reductive-oxidative (RedOx) state could improve cardiovascular risk assessment and management. Derivatives-reactive oxygen metabolites (d-ROMs) are an emerging biomarker of oxidative stress quantifiable in minutes through standard biochemical analysers or by a bedside point-of-care test. The current review evaluates available data on the prognostic value of d-ROMs for CVD events and mortality in individuals with known and unknown CVD. Outcome studies involving small and large cohorts were analysed and hazard ratio, risk ratio, odds ratio, and mean differences were used as measures of effect. High d-ROM plasma levels were found to be an independent predictor of CVD events and mortality. Risk begins increasing at d-ROM levels higher than 340 UCARR and rises considerably above 400 UCARR. Conversely, low d-ROM plasma levels are a good negative predictor for CVD events in patients with coronary artery disease and heart failure. Moreover, combining d-ROMs with other relevant biomarkers routinely used in clinical practice might support a more precise cardiovascular risk assessment. We conclude that d-ROMs represent an emerging oxidative-stress-related biomarker with the potential for better risk stratification both in primary and secondary cardiovascular prevention.

Phytochemical Screening, Antioxidant and Antifungal Activities of Aconitum chasmanthum Stapf ex Holmes Wild Rhizome Extracts

Aconitum chasmanthum Stapf ex Holmes, an essential and critically endangered medicinal plant from Kashmir Himalayas, was studied for its antioxidant and antifungal properties. The shade-dried powdered rhizome was extracted sequentially with hexane, ethyl acetate, and methanol. These subsequent fractions were evaluated for total phenolic content (TPC); total flavonoid content (TFC); antioxidant assays, such as 1,1-diphenyl 1-2-picryl-hydrazyl (DPPH); ferric-reducing antioxidant power (FRAP); superoxide radical scavenging (SOR); hydroxyl radical scavenging (OH) and antifungal activity using the poisoned food technique. Highest TPC (5.26 ± 0.01 mg/g) and TFC (2.92 ± 0.04 mg/g) were reported from methanolic extracts. The highest values of radical scavenging activities were also observed in methanolic extracts with IC₅₀ values of 163.71 ± 2.69 μg/mL in DPPH, 173.69 ± 4.91 μg/mL in SOR and 159.64 ± 2.43 μg/mL in OH. The chemical profile of ethyl acetate extract was tested using HR-LCMS. Methanolic extracts also showed a promising inhibition against Aspergillus niger (66.18 ± 1.03), Aspergillus flavus (78.91 ± 1.19) and Penicillium notatum (83.14 ± 0.97) at a 15% culture filtrate concentration with minimum inhibitory concentration (MIC) values of 230 μg/mL, 200 μg/mL and 190 μg/mL, respectively. Overall, the methanolic fractions showed significant biological potential, and its pure isolates might be used to construct a potential new medicinal source.

Salidroside Exerts Beneficial Effect on Testicular Ischemia-Reperfusion Injury in Rats

Testicular torsion-detorsion results in testicular ischemia-reperfusion injury, which is associated with overgeneration of reactive oxygen species. Salidroside, a major bioactive ingredient extracted from Rhodiola rosea, has strong antioxidant activity. The purpose of this study was to examine the effect of salidroside on testicular ischemia-reperfusion injury. Sixty rats were randomly separated into 3 experimental groups: group A = sham-operated control; group B = testicular ischemia-reperfusion; and group C = testicular ischemia-reperfusion treated with salidroside. The rats in the sham-operated control group received all surgical procedures except testicular torsion-detorsion. The testicular ischemia-reperfusion group underwent 2 hours of left testicular torsion followed by detorsion. The rats in the salidroside-treated group received the same surgical procedure as in testicular ischemia-reperfusion group, but salidroside was injected intraperitoneally at reperfusion. Testicular malondialdehyde content (a reliable index of reactive oxygen species) and protein expression of superoxide dismutase and catalase which are primary antioxidant enzymes in testes were measured at 4 hours after reperfusion. Testicular spermatogenesis was evaluated at 3 months after reperfusion. The malondialdehyde content increased significantly, while superoxide dismutase and catalase protein expression and testicular spermatogenesis reduced significantly in ipsilateral testes of testicular ischemia-reperfusion group, as compared with sham-operated control group. Therapy with salidroside significantly reduced malondialdehyde content and significantly enhanced superoxide dismutase and catalase protein expression and spermatogenesis in ipsilateral testes, as compared with testicular ischemia-reperfusion group. The present findings indicate that treatment with salidroside ameliorates testicular ischemia-reperfusion injury by reducing reactive oxygen species level by upregulating superoxide dismutase and catalase protein expression.

Toxicity evaluation and oxidative stress response of fumaronitrile, a persistent organic pollutant (POP) of industrial waste water on tilapia fish (Oreochromis mossambicus)

The study was designed to determine the impact of acute toxicity of fumaronitrile exposure through tissue damaging, oxidative stress enzymes and histopathological studies in gills, liver and muscle cells of freshwater tilapia fish (Oreochromis mossambicus). In gill, liver, and muscle cells, biochemical indicators such as tissue damage enzymes (Acid Phosphatase (ACP), Alkaline Phosphatase (ALP), and Lactate Dehydrogenase (LDH)) and antioxidative enzymes (Superoxide Dismutase (SOD); Catalase (CAT); Glutathione-S-transferase (GST); Reduced Glutathione (GSH); Glutamate oxaloacetate transaminase (GOT) and Glutamate pyruvate transaminase (GPT) were quantified in the time interval of 30, 60 and 90 days exposure to the fumaronitrile. After 90 days, under 6 ppb exposure conditions, the acid phosphatase (ACP) levels of fish increased significantly in the gills (3.439 μmol/mg protein/min), liver (1.743 μmol/mg protein/min), and muscles (2.158 μmol/mg protein/min). After 90 days of exposure to the same concentration and days, ALP activity increased significantly in gills (4.354 μmol/mg protein/min) and liver (1.754 μmol/mg protein/min), but muscle cells had a little decrease in ALP activity (2.158 μmol/mg protein/min). The LDH concentration in gills following treatment with fumaronitrile over a period of 0-90 days was 3.573 > 3.521 > 2.245 μmol/mg protein/min over 30 > 60 > 90 days. However, at the same dose and treatment duration, a greater LDH level of 0.499 μmol/mg protein/min was found in liver and muscle cells. Histopathological abnormalities in the gills, liver, and muscle cells of treated fish were also examined, indicating that fumaronitrile treatment generated the most severe histological changes. The current study reveals that fumaronitrile exposure has an effect on Oreochromis mossambicus survival, explaining and emphasising the risk associated with this POP exposure to ecosystems and human populations.

The Role of Flavonoids as a Cardioprotective Strategy against Doxorubicin-Induced Cardiotoxicity: A Review

Doxorubicin is a widely used and promising anticancer drug; however, a severe dose-dependent cardiotoxicity hampers its therapeutic value. Doxorubicin may cause acute and chronic issues, depending on the duration of toxicity. In clinical practice, the accumulative toxic dose is up to 400 mg/m² and increasing the dose will increase the probability of cardiac toxicity. Several molecular mechanisms underlying the pathogenesis of doxorubicin cardiotoxicity have been proposed, including oxidative stress, topoisomerase beta II inhibition, mitochondrial dysfunction, Ca²⁺ homeostasis dysregulation, intracellular iron accumulation, ensuing cell death (apoptosis and necrosis), autophagy, and myofibrillar disarray and loss. Natural products including flavonoids have been widely studied both in cell, animal, and human models which proves that flavonoids alleviate cardiac toxicity caused by doxorubicin. This review comprehensively summarizes cardioprotective activity flavonoids including quercetin, luteolin, rutin, apigenin, naringenin, and hesperidin against doxorubicin, both in in vitro and in vivo models.

Pterostilbeno Reduz o Estresse Oxidativo no Pulmão e no Ventrículo Direito Induzido por Infarto do Miocárdio Experimental

Fundamento

O pterostilbeno (PS), um composto polifenólico natural e antioxidante, surge como uma intervenção promissora para minimizar danos do infarto agudo do miocárdio (IAM).

Objetivo

Este estudo teve como objetivo avaliar o desempenho do PS na promoção da homeostase redox nos pulmões e no ventrículo direito (VD) de animais infartados.

Métodos

Ratos Wistar machos (60 dias de idade) foram randomizados em três grupos: SHAM, IAM (infarto) e IAM+PS (IAM + pterostilbeno). Sete dias após o procedimento de IAM, os ratos foram tratados com PS (100 mg/kg/dia) por gavagem por oito dias. Os animais foram depois sacrificados e os pulmões e VD foram coletados para análise do balanço redox (diferenças foram consideradas significativas quando p<0,05).

Resultados

Nossos resultados mostram que o IAM desencadeia a interrupção redox no VD e nos pulmões, o que pode contribuir para danos induzido pelo IAM nesses órgãos. Consistentemente, o PS mitigou o estresse oxidativo e restaurou as defesas antioxidantes (Glutationa – GSH nos pulmões: SHAM = 0,79 ± 0,07; IAM = 0,67 ± 0,05; IAM + PS = 0,86 ± 0,14; p<0,05), indicando seu papel protetor neste cenário.

Conclusão

Nosso trabalho evidencia o potencial do uso de PS como abordagem terapêutica adjuvante após IAM para proteção dos tecidos pulmonares e cardíacos direitos.

Association of Maternal Diabetes and Autism Spectrum Disorders in Offspring: a Study in a Rodent Model of Autism

The present study investigated that maternal type 1 diabetes may contribute to autism pathogenesis in offspring, and that insulin therapy during pregnancy may prevent the onset of autism. As evidenced, selected brain biomarkers representing the accepted etiological mechanism of autism in newborn rats from diabetic mothers and diabetic mothers receiving insulin therapy compared to the propionic acid (PPA) rodent model of autism were screened. Female Wistar rats with a controlled fertility cycle were randomly divided into three groups: a control group, a group treated with a single dose of 65 mg/kg streptozotocin (STZ) to induce type 1 diabetes (T1D), and a group treated with a single dose of STZ to induce T1D along with insulin therapy. Neonatal rats from these groups were divided into four experimental groups of six animals each: the control group, oral buffered PPA-treated group administered a neurotoxic dose of 250 mg/kg PPA for 3 days to induce autism, neonatal rats from mothers with T1D, and neonatal rats from mothers with T1D receiving insulin therapy. Biochemical parameters of oxidative stress, neuroinflammation, and glutamate excitotoxicity were examined in brain homogenates from all neonatal rats. The development of pathogenic bacteria was monitored in stool samples from all rat groups. Descriptive analyses of changes in fecal microbiota and overgrowth of Clostridium species were performed in diabetic mothers, diabetic mothers treated with insulin therapy, and their offspring. Clostridium species may induce autism-relevant behaviors in offspring from mothers with T1D. Maternal T1D without insulin therapy increased lipid peroxidation levels, reduced GST activity, and lower offspring' vitamin C and GSH levels. Increased IL-6 levels and reduced GABA levels were detected in brain homogenates from neonatal rats whose mothers had T1D. Interestingly, insulin therapy reduced MDA and IL-6 levels and increased GST, GSH, and vitamin C levels in brain homogenates of neonatal rats from mothers with T1D receiving insulin therapy compared to the PPA-treated group. Based on our results, the PPA-treated group and neonatal rats from mothers with T1D exhibited similar results. These findings suggest that neonatal rats from mothers with T1D may develop autism-relevant biochemical autistic features and that insulin therapy may ameliorate oxidative stress, poor detoxification, inflammation, and excitotoxicity as ascertained mechanisms involved in the etiology of autism.

Physiological Effects of Bioactive Compounds Derived from Whole Grains on Cardiovascular and Metabolic Diseases

Cardiovascular diseases are a global health burden with an increasing prevalence. In addition, various metabolic diseases, such as obesity, diabetes, and hypertension are associated with a higher risk of cardiovascular diseases. Dietary strategies based on healthy foods have been suggested for the prevention or improvement of cardiovascular and metabolic diseases. Grains are the most widely consumed food worldwide, and the preventive effects of whole grains (e.g., oats, barley, and buckwheat) on metabolic diseases have been reported. The germ and bran of grains are rich in compounds, including phytochemicals, vitamins, minerals, and dietary fiber, and these compounds are effective in preventing and improving cardiovascular and metabolic diseases. Thus, this review describes the characteristics and functions of bioactive ingredients in whole grains, focusing on mechanisms by which polyphenols, antioxidants, and dietary fiber contribute to cardiovascular and metabolic diseases, based on preclinical and clinical studies. There is clear evidence for the broad preventive and therapeutic effects of whole grains, supporting the value of early dietary intervention.

Effects of Restricted Feeding on Growth Performance, Intestinal Immunity, and Skeletal Muscle Development in New Zealand Rabbits

Simple Summary

The high prevalence of gastrointestinal diseases in young rabbits is the major cause of impediment in the development of the rabbit industry. Presently, few companies have adopted methods of restricting feeding to improve the survival rate independent of the effect on their growth and development. To explore the effects of different feeding-restriction levels on the growth performance, intestinal immunity, and skeletal muscle development of meat rabbits, 198 New Zealand meat rabbits of 35 days old were selected and randomly divided into three groups: (1) a control group, (2) a 15% feeding restriction group, and (3) a 30% feeding restriction group, with 66 in each group with an equal number of males and females. The growth performance measurement and health-risk assessment indicators, measurement of digestive enzyme activity, immune and antioxidant indexes, and regulation mechanism were evaluated and explored. Finally, we found that a 30% feeding limit affected the growth and development of skeletal muscle in growing rabbits by regulating the PI3K/Akt signaling pathway.

Abstract

This study aimed to explore the effects of different feeding restriction levels on the growth performance, intestinal immunity, and skeletal muscle development of meat rabbits. Additionally, we studied whether complete compensatory growth could be obtained post 2 weeks of restricted feeding, in order to seek a scientific mode of feeding restriction. Each of three groups was exposed to 3 weeks of feeding restriction and 2 weeks of compensatory growth. The 15% feeding restriction showed a negligible effect on the final body-weight of the rabbits (p > 0.05), but significantly reduced the feed-to-weight ratio (p < 0.05); reduced diarrhea and mortality; and increased digestive enzyme activity and antioxidant capacity. However, a 30% feeding-restriction level substantially reduced the growth rate of the rabbits (p < 0.05), impaired skeletal muscle development, and showed no compensatory growth after 2 weeks of nutritional recovery. Additionally, immunoglobulin and antioxidant enzyme synthesis were impaired due to reduced nutritional levels, and levels of pro-inflammatory factors were increased during the compensation period. The IGF1 mRNA expression decreased significantly (p < 0.05), whereas MSTN and FOXO1 expression increased noticeably (p < 0.05). Moreover, protein levels of p-Akt and p-p70 decreased significantly in the 15% feeding restriction group. Overall, the 15% feeding limit unaffected the weight and skeletal muscle development of rabbits, whereas the 30% feeding limit affected the growth and development of skeletal muscle in growing rabbits. The PI3K/Akt signaling pathway is plausibly a mediator of this process.

New Mutant Amaranth Varieties as a Potential Source of Biologically Active Substances

Amaranth species represent a diverse group of plants. Many of them are a rich source of secondary metabolites with many positive biological effects. Total phenolic, total flavonoid and rutin content, antioxidant activity against superoxide and hydroxyl radicals, FRAP (Ferric-reducing ability of plasma) assay and DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging assay were determined in ethanol extracts of dried leaves of the new Slovak amaranth varieties ‘Pribina’ and ‘Zobor’. The amount of total phenolic substances (‘Pribina’ GAE 38.3 mg.g⁻¹ DM and ‘Zobor’ GAE 26.1 mg.g⁻¹ DM), content of total flavonoids (‘Pribina’ QE 26.5 mg.g⁻¹ DM and ‘Zobor’ QE 20.3 mg.g⁻¹ DM) and rutin (‘Pribina’ 50.8 mg.g⁻¹ DM and ‘Zobor’ 15.2 mg.g⁻¹ DM) were higher in the variety ‘Pribina’, compared to the variety ‘Zobor’. A statistically higher antioxidant activity against superoxide radical (1.63%·mg⁻¹g⁻¹ DM), hydroxyl radical (3.20%.mg⁻¹g⁻¹ DM), FRAP assay (292.80 µmol.L⁻¹·mg⁻¹.g⁻¹ DM) and DPPH (54.2 ± 1.78 µg.mL⁻¹ DM) were detected in the ‘Pribina’ variety. Antiradical and antioxidant activities of both extracts showed high positive correlations in relation to the content of total phenolic substances, total flavonoids and rutin. Amaranth is an undemanding crop on specific environmental conditions and is resistant to abiotic and biotic stress.

Can Wolf Spider Mothers Detect Insecticides in the Environment? Does the Silk of the Egg-Sac Protect Juveniles from Insecticides?

The use of pesticides for plague control in agroecosystems generates a threat to wildlife and a major problem for human health. Pesticide compounds are also an important source of water and atmosphere contamination. Although insecticides are effective on their target organisms, they often affect organisms that are not their target. The aim of the present study was to research the effects of 3 types of neurotoxic insecticides-a pyrethroid (cypermethrin), a neonicotinoid (imidacloprid), and an organophosphate (chlorpyrifos)-on behavioral and physiological parameters of Pardosa saltans spider (Lycosidae). Our study analyzed for the first time the exploratory behavior of the spider mothers in the presence of these 3 insecticides on their egg-sacs and also on the ground. We also evaluated the oxidative stress effects on the juveniles hatched in the egg-sac protected by silk in relation to variations in detoxification enzymes (catalase, glutathione reductase, superoxide dismutase, glutathione-S-transferase, and glutathione peroxidase) and lipid peroxidation (reactive oxygen species [ROS]). The results show that these insecticides are repellents for mothers (cypermethrin is the most repellent), and maternal behavior is modified after detection of an insecticide on their egg-sac but mothers do not abandon their egg-sacs. These neurotoxic insecticides affect the juveniles inside their egg-sac. Cypermethrin and chlorpyrifos caused more oxidative stress in juveniles than did imidacloprid. The ROS generated by these insecticides seemed to be adequately eliminated by the juveniles' antioxidant systems. Environ Toxicol Chem 2021;40:2861-2873. © 2021 SETAC.

Free Radicals and Actinobacteria as a Misexplored Goldmine of Antioxidant Compounds

Free radicals are highly reactive unstable molecules, which can be synthesized in different ways, considered harmful and threatening to humans; these chemical species have free traffic throughout the human body, interacting with biological molecules and human body organ tissues. The interaction between free radicals and biological molecules is the main factor for disease development or pre-existing disease symptoms aggravation. Antioxidants are chemical compounds able to donate electric charge to stabilize molecules such as free radicals. Recent studies have proved the benefits of antioxidants intake in health improvement. In this way, the search for natural sources of antioxidants has become an ascending trend. In this field, the microbial sources are considered poorly explored compared to the numerous amount of other compounds obtained from them, especially from Actinobacteria. The searched literature about Actinobacteria highlights an important capacity of producing natural antioxidants; however, there is a lack of in vivo studies of these isolated compounds. In this review, we gathered information that supports our point of view that Actinobacteria is a truly renewable and superficially explored source of natural antioxidants. Furthermore, our purpose is also to point this limitation and stimulate more researches in this area.

Evaluation of pancreatic regeneration activity of Tephrosia purpurea leaves in rats with streptozotocin-induced diabetes

Background and aim

Flavonoid rich plant Tephrosia purpurea (T. purpurea), commonly known as Sarpunkha has been used in traditional systems of medicine to treat diabetes mellitus. However, its effectiveness in promoting regeneration of pancreas in diabetes has not been investigated. Therefore, the present study was undertaken to evaluate pancreatic β-cells regeneration, antioxidant and antihyperlipidemic potentials of T. purpurea leaves extract, its fractions and main constituent Rutin in diabetic rats.

Experimental procedure

The leaves extract and its fractions were first screened for acute and sub-chronic antidiabetic activity in a dose range of 250–500 mg/kg orally. Further, fractions with potent antidiabetic activity were screened for pancreatic β-cells regeneration activity using histopathological studies and morphometric analysis, which was followed by estimation of biochemical parameters.

Results and conclusion

The most significant antidiabetic, pancreatic regeneration and antihyperlipidemic activity was exhibited by n-butanol soluble fraction of ethanol extract at the dose level of 500 mg/kg. Histopathology revealed that treatment with this fraction improved the β-cell granulation of islets and prevented the β-cells damage which was further confirmed by morphometric analysis. Thus, the present study validated the traditional use of T. purpurea plant in the treatment of diabetes, which might be attributed to pancreatic β-cells regeneration potential of its active constituent Rutin.

Taxonomy (classification by EVISE)

Traditional Medicine; Metabolic Disorder; Experimental Design; Cell Regeneration and Histopathology.

•

Polyphenol rich extract possesses potent in vitro antioxidant activity.

•

Extract and its fractions are having pancreatic regeneration potential in STZ induced diabetic model.

•

Histopathological study of the pancreas extract and fraction treated diabetic rats showed islets expansion and decreased fatty infiltrate of the islets.

•

Study validates the use of plant in treatment of diabetes.

Decreased Cerebrospinal Fluid Antioxidative Capacity Is Related to Disease Severity and Progression in Early Multiple Sclerosis

Background: Oxidative stress-induced neuronal damage in multiple sclerosis (MS) results from an imbalance between toxic free radicals and counteracting antioxidants, i.e., antioxidative capacity (AOC). The relation of AOC to outcome measures in MS still remains inconclusive. We aimed to compare AOC in cerebrospinal fluid (CSF) and serum between early MS and controls and assess its correlation with clinical/radiological measures. Methods: We determined AOC (ability of CSF and serum of patients to inhibit 2,2′-azobis(2-amidinopropane) dihydrochloride-induced oxidation of dihydrorhodamine) in clinically isolated syndrome (CIS)/early relapsing-remitting MS (RRMS) (n = 55/11) and non-inflammatory neurological controls (n = 67). MS patients underwent clinical follow-up (median, 4.5; IQR, 5.2 years) and brain MRI at 3 T (baseline/follow-up n = 47/34; median time interval, 3.5; IQR, 2.1 years) to determine subclinical disease activity. Results: CSF AOC was differently regulated among CIS, RRMS and controls (p = 0.031) and lower in RRMS vs. CIS (p = 0.020). Lower CSF AOC correlated with physical disability (r = −0.365, p = 0.004) and risk for future relapses (exp(β) = 0.929, p = 0.033). No correlations with MRI metrics were found. Conclusion: Decreased CSF AOC was associated with increased disability and clinical disease activity in MS. While our finding cannot prove causation, they should prompt further investigations into the role of AOC in the evolution of MS.

Is There a Balance in Oxidative-Antioxidant Status in Blood Serum of Patients with Advanced Endometriosis?

Can redox homeostasis indicators be potential non-invasive markers, crucial in the diagnosis and treatment of endometriosis? We checked if the differences in levels of serum oxidative-antioxidant balance parameters (TAS, FRAP, albumin, total bilirubin, uric acid, iron, SIRT3, SIRT5, SIRT6, telomerase, AOPP) are significant between patients with advanced endometriosis (E), healthy women (control group, C) and non-endometriosis women, but with other gynecological disorders (NE). The FRAP concentrations were significantly higher in E and NE group than in the control group (p = 0.015 and p = 0.017, respectively). The telomerase concentrations were significantly higher in the endometriosis group than in the control group (p = 0.004). Significantly higher concentrations of AOPP were observed in E (p < 0.001) and NE groups (p = 0.028) in comparison to the control subjects. Between stages III and IV of endometriosis, a significant difference existed only in concentration of iron (p = 0.013). There were no significant differences between the studied groups in the values of the remaining parameters. Based on the results of ROC curve analysis, we can conclude that the levels of serum FRAP, telomerase and AOPP may be taken into account as promising diagnostics markers that reflect the degree of oxidative stress accompanying advanced endometriosis.

Alpha2-Adrenoblockers Regulate Development of Oxidative Stress and Cognitive Behaviour of Rats under Chronic Acoustic Stress Conditions

Noise is a wide-spread stress factor in modern life produced by urbanization, traffic, and an industrialized environment. Noise stress causes dysfunction and neurotransmission impairment in the central nervous system, as well as changes in hormone levels. In this study, we have examined the level of α-Tocopherol (α-T) and malondialdehyde (MDA) in plasma and the erythrocytes’ membrane (EM), as well as the behavioral characteristics of a noise-induced stress model in rats. In addition, the modulating effect of α²-adrenoblockers, beditin, and mesedin on the aforementioned parameters has been investigated. For these purposes, albino male rats were divided into four groups: (1) untreated; (2) noise-exposed, (3) noise-exposed and beditin-treated (2 mg/kg, i.p.), and (4) noise-exposed and mesedin-treated (10 mg/kg, i.p.) animals. Noise-exposed groups were treated with 91dBA noise on 60 days with a daily duration of 8 h. Increased MDA and decreased α-T levels in plasma and EM were observed upon chronic high-level noise exposure. Locomotor and behavioral activity assessed with a Y-maze revealed disorientation and increased anxiety under chronic noise exposure. Prominently, α²-adrenoblockers alleviated both behavioral deficits and oxidative stress, providing evidence for the involvement of α²-adrenoceptor in the pathophysiology of noise-induced stress.

Pharmacological intervention in oxidative stress as a therapeutic target in neurological disorders

OBJECTIVES

Oxidative stress is a major cellular burden that triggers reactive oxygen species (ROS) and antioxidants that modulate signalling mechanisms. Byproducts generated from this process govern the brain pathology and functions in various neurological diseases. As oxidative stress remains the key therapeutic target in neurological disease, it is necessary to explore the multiple routes that can significantly repair the damage caused due to ROS and consequently, neurodegenerative disorders (NDDs). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is the critical player of oxidative stress that can also be used as a therapeutic target to combat NDDs.

KEY FINDINGS

Several antioxidants signalling pathways are found to be associated with oxidative stress and show a protective effect against stressors by increasing the release of various cytoprotective enzymes and also exert anti-inflammatory response against this oxidative damage. These pathways along with antioxidants and reactive species can be the defined targets to eliminate or reduce the harmful effects of neurological diseases.

SUMMARY

Herein, we discussed the underlying mechanism and crucial role of antioxidants in therapeutics together with natural compounds as a pharmacological tool to combat the cellular deformities cascades caused due to oxidative stress.

Oxidative status of blue tit nestlings varies with habitat and nestling size

Oxidative status has been proposed as an important ecological and evolutionary force given that pro-oxidant metabolites damage molecules, cells and tissues, with fitness consequences for organisms. Consequently, organisms usually face a trade-off between regulating their oxidative status and other physiological traits. However, environmental stressors and the availability of dietary-derived antioxidants vary according to local conditions and, thus, organisms inhabiting different habitats face different oxidative pressures. Still, there is little information on how different environmental conditions influence the oxidative status of animals inhabiting terrestrial environments. In this work, we examined the variation in oxidative status in the blue tit (Cyanistes caeruleus), a bird species with hatching asynchrony. Specifically, we examined the oxidative status of the largest and the smallest nestlings in the brood, inhabiting four forests differing in food availability and ectoparasite prevalence. We measured lipid peroxidation (malondialdehyde; MDA) as a marker of oxidative damage, total antioxidant capacity (Trolox-equivalent antioxidant capacity; TEAC) and antioxidant enzymatic activity (catalase, glutathione S-transferase, glutathione peroxidase) in blood samples. The glutathione peroxidase (GPX) activity differed among the forests, being the highest in the pine forest and the lowest in a mixed oak (Quercus) forest in the most humid area. Lipid peroxidation was higher in larger nestlings, suggesting higher oxidative damage with an increasing growth rate. Neither brood size, laying date, nor ectoparasites were related to the oxidative status of nestlings. These results suggest that nest rearing conditions might shape the oxidative status of birds, having consequences for habitat-dependent variation in regulation of oxidative status.

Oxygen Consumption Evaluation: An Important Indicator of Metabolic State, Cellular Function, and Cell Fate Along Neural Deregulation

Depletion of oxygen (O₂) levels and reduction in the ATP synthesis (or even its complete blockage) are important characteristics of mitochondrial dysfunction; features that are often correlated with neurodegeneration. The measurement of oxygen consumption rate (OCR) is thus essential to evaluate cellular metabolism, survival, and neuroprotective strategies. In the present chapter, we describe the oxygen consumption assay using a Clark-type oxygen electrode in different types of samples named cells suspension (from primary and established cell culture), brain slices (ex vivo), and fresh brain tissues. In addition, we demonstrate herein how the program Oxygraph can be used in order to analyze the data and different approaches to normalize it.

Antioxidant, Cytotoxicity and Cytoprotective Potential of Extracts of Grewia Flava and Grewia Bicolor Berries

Objectives

Accumulation of cellular reactive oxygen species (ROS) leads to oxidative stress. Increased production of ROS, such as superoxide anion, or a deficiency in their clearance by antioxidant defences, mediates cellular pathology. Grewia Spp fruits are a source of bioactive compounds and have notable antioxidant activity. Although the antioxidant capacity of Grewia Spp has been studied, there is very limited evidence that links the antioxidant activities of Grewia bicolor and Grewia flava to the inhibition of free radical formation associated with damage in biological systems.

Methods

This study evaluated the protective effects of Grewia bicolor and Grewia flava extracts against free radical-induced oxidative stress and the resulting cytotoxicity effect using HeLa cells. Antioxidant properties determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total phenolic content (TPC) assays showed significantly higher (p < 0.05) antioxidant activity in Grewia flava (ethanol extract) than Grewia flava (water extract) and Grewia bicolor (ethanol and water extracts).

Results

Using 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide or MTT assay, cytotoxicity results showed that extracts of Grewia bicolor and Grewia flava were less toxic to HeLa cells at tested concentrations compared to the untreated control. This confirmed the low toxicity of these edible fruits at the tested concentrations in HeLa cells. Furthermore, hydrogen peroxide (H₂O₂)-induced cell loss was effectively reduced by pre-incubating HeLa cells with Grewia bicolor and Grewia flava extracts, with Grewia flava (ethanol extract) revealing better protection.

Conclusion

The effect was speculated to be associated with the higher antioxidant activity of Grewia flava (ethanol extract). Additional studies will warrant confirmation of the mechanism of action of such effects.

Fasting ameliorates oxidative stress: A review of physiological strategies across life history events in wild vertebrates

Fasting is a component of many species' life history due to environmental factors or behavioral patterns that limit access to food. Despite metabolic and physiological challenges associated with these life history stages, fasting-adapted wild vertebrates exhibit few if any signs of oxidative stress, suggesting that fasting promotes redox homeostasis. Here we review mammalian, avian, reptilian, amphibian, and piscine examples of animals undergoing fasting during prolonged metabolic suppression (e.g. hibernation and estivation) or energetically demanding processes (e.g. migration and breeding) to better understand the mechanisms underlying fasting tolerance in wild vertebrates. These studies largely show beneficial effects of fasting on redox balance via limited oxidative damage. Though some species exhibit signs of oxidative stress due to energetically or metabolically extreme processes, fasting wild vertebrates largely buffer themselves from the negative consequences of oxidative damage through specific strategies such as elevating antioxidants, selectively maintaining redox balance in critical tissues, or modifying behavioral patterns. We conclude with suggestions for future research to better elucidate the protective effects of fasting on oxidative stress as well as disentangle the impacts from other life history stages. Further research in these areas will facilitate our understanding of the mechanisms wild vertebrates use to mitigate the negative impacts associated with metabolically-extreme life history stages as well as potential translation into therapeutic interventions in non-fasting-adapted species including humans.

The Impact of Oxidative Stress in Human Pathology: Focus on Gastrointestinal Disorders

Accumulating evidence shows that oxidative stress plays an essential role in the pathogenesis and progression of many diseases. The imbalance between the production of reactive oxygen species (ROS) and the antioxidant systems has been extensively studied in pulmonary, neurodegenerative cardiovascular disorders; however, its contribution is still debated in gastrointestinal disorders. Evidence suggests that oxidative stress affects gastrointestinal motility in obesity, and post-infectious disorders by favoring the smooth muscle phenotypic switch toward a synthetic phenotype. The aim of this review is to gain insight into the role played by oxidative stress in gastrointestinal pathologies (GIT), and the involvement of ROS in the signaling underlying the muscular alterations of the gastrointestinal tract (GIT). In addition, potential therapeutic strategies based on the use of antioxidants for the treatment of inflammatory gastrointestinal diseases are reviewed and discussed. Although substantial progress has been made in identifying new techniques capable of assessing the presence of oxidative stress in humans, the biochemical-molecular mechanisms underlying GIT mucosal disorders are not yet well defined. Therefore, further studies are needed to clarify the mechanisms through which oxidative stress-related signaling can contribute to the alteration of the GIT mucosa in order to devise effective preventive and curative therapeutic strategies.

Redox activation of ATM enhances GSNOR translation to sustain mitophagy and tolerance to oxidative stress

The denitrosylase S-nitrosoglutathione reductase (GSNOR) has been suggested to sustain mitochondrial removal by autophagy (mitophagy), functionally linking S-nitrosylation to cell senescence and aging. In this study, we provide evidence that GSNOR is induced at the translational level in response to hydrogen peroxide and mitochondrial ROS. The use of selective pharmacological inhibitors and siRNA demonstrates that GSNOR induction is an event downstream of the redox-mediated activation of ATM, which in turn phosphorylates and activates CHK2 and p53 as intermediate players of this signaling cascade. The modulation of ATM/GSNOR axis, or the expression of a redox-insensitive ATM mutant influences cell sensitivity to nitrosative and oxidative stress, impairs mitophagy and affects cell survival. Remarkably, this interplay modulates T-cell activation, supporting the conclusion that GSNOR is a key molecular effector of the antioxidant function of ATM and providing new clues to comprehend the pleiotropic effects of ATM in the context of immune function.

Iron Homeostasis and Metabolism: Two Sides of a Coin

Iron is an ancient, essential and versatile transition metal found in almost all living organisms on Earth. This fundamental trace element is used in the synthesis of heme and iron-sulfur (Fe-S) containing proteins and other vital cofactors that are involved in respiration, redox reactions, catalysis, DNA synthesis and transcription. At the same time, the ability of iron to cycle between its oxidized, ferric (Fe³⁺) and its reduced, ferrous (Fe²⁺) state contributes to the production of free radicals that can damage biomolecules, including proteins, lipids and DNA. In particular, the regulated non-apoptotic cell death ferroptosis is driven by Fe²⁺-dependent lipid peroxidation that can be prevented by iron chelation or genetic inhibition of cellular iron uptake. Therefore, iron homeostasis must be tightly regulated to avoid iron toxicity. This review provides an overview of the origin and chemistry of iron that makes it suitable for a variety of biological functions and addresses how organisms evolved various strategies, including their scavenging and antioxidant machinery, to manage redox-associated drawbacks. Finally, key mechanisms of iron metabolism are highlighted in human diseases and model organisms, underlining the perils of dysfunctional iron handlings.

In Vitro and In Vivo Antioxidative Activity against Radiation-Induced Damage and the Systematic Chemical Components of Different Extracts of Lagotis brevituba Maxim

Lagotis brevituba Maxim is a perennial species distributed in the highlands of China, which has been used for more than 2000 years as a traditional Tibetan medicinal plant. However, no attention has been paid to the antioxidant activities of Lagotis brevituba Maxim in vitro or in vivo. Thus, this study aimed to evaluate the in vitro and in vivo antioxidant activity of Lagotis brevituba Maxim against radiation-induced damage as well as the systematic chemical components. To explore the relationship between the antioxidant activity and extraction solvent, Lagotis brevituba Maxim was extracted with three different solvents: methanol, water, and acetone. In antioxidant assays in vitro, the water extract had the strongest reducing power, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with the methanol and acetone extracts. However, the methanol extract was more potent in the β-carotene/linoleic acid cooxidation assay. In antioxidant assays in vivo, mice that were exposed to 6.0 Gy⁶⁰Co γ-ray whole-body radiation on day 15 after administration of Lagotis brevituba Maxim decreased their level of malondialdehyde (MDA) in a dose-dependent manner compared with the control group, indicating that Lagotis brevituba Maxim had favorable antioxidant activities in vivo. In addition, a total of 44 compounds were tentatively identified by liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS), including 19 flavonoids, 14 phenols, 8 phenylethanoid glycosides, 2 iridoid glycosides, and 1 carbohydrate. We obtained 25 compounds from plants in the genus Lagotis for the first time. These results suggested that Lagotis brevituba Maxim had potent antioxidant activity and could be explored as a novel natural antioxidant.

The Crosstalk of Adipose-Derived Stem Cells (ADSC), Oxidative Stress, and Inflammation in Protective and Adaptive Responses

The potential use of stem cell-based therapies for the repair and regeneration of various tissues and organs is a major goal in repair medicine. Stem cells are classified by their potential to differentiate into functional cells. Compared with other sources, adipose-derived stem cells (ADSCs) have the advantage of being abundant and easy to obtain. ADSCs are considered to be tools for replacing, repairing, and regenerating dead or damaged cells. The capacity of ADSCs to maintain their properties depends on the balance of complex signals in their microenvironment. Their properties and the associated outcomes are in part regulated by reactive oxygen species, which mediate the oxidation-reduction state of cells as a secondary messenger. ADSC therapy has demonstrated beneficial effects, suggesting that secreted factors may provide protection. There is evidence that ADSCs secrete a number of cytokines, growth factors, and antioxidant factors into their microenvironment, thus regulating intracellular signaling pathways in neighboring cells. In this review, we introduce the roles of ADSCs in the protection of cells by modulating inflammation and immunity, and we develop their potential therapeutic properties.

Understanding the complicated relationship between antioxidants and carcinogenesis

Reactive oxygen species (ROS) are generated as by-product of cellular respiration and also due to the exposure of various xenobiotics, whereas mitochondrial electron transport chain is considered as the main source of ROS generation. The sequential addition to molecular oxygen gives rise to various forms of ROS like superoxide anion, peroxide, hydroxyl radical, hydroxyl ion, and so forth. However, the uncontrolled level of ROS generation and accumulation alters the body homeostasis. Excessive generation of ROS leads to oxidative stress and various kinds of diseases including cancer. To counteract ROS, enzymatic and nonenzymatic antioxidants' armory is available in our body. Apart from endogenous antioxidants, we are also consuming various exogenous antioxidants. Antioxidants protect us from ROS-mediated damages and inhibit ROS-induced carcinogenesis. Recent studies have revealed that antioxidants could also act as tumor-promoting agents. Various anticancer drugs are used to kill the cancer cells through the generation of oxidative stress in them, but the cancer cells can counteract the effect with the help of various endogenous as well as exogenous antioxidants. Our review will summarize the multifaceted relationship between antioxidants and carcinogenesis, and it will help to create new directions in antioxidant-based chemotherapy.

Alcohol as an early life stressor: Epigenetics, metabolic, neuroendocrine and neurobehavioral implications

Ethanol exposure during gestation is an early life stressor that profoundly dysregulates structure and functions of the embryonal nervous system, altering the cognitive and behavioral development. Such dysregulation is also achieved by epigenetic mechanisms, which, altering the chromatin structure, redraw the entire pattern of gene expression. In parallel, an oxidative stress response at the cellular level and a global upregulation of neuroendocrine stress response, regulated by the HPA axis, exist and persist in adulthood. This neurobehavioral framework matches those observed in other psychiatric diseases such as mood diseases, depression, autism; those early life stressing events, although probably triggered by specific and different epigenetic mechanisms, give rise to largely overlapping neurobehavioral phenotypes. An early diagnosis of prenatal alcohol exposure, using reliable markers of ethanol intake, together with a deeper understanding of the pathogenic mechanisms, some of them reversible by their nature, can offer a temporal "window" of intervention. Supplementing a mother's diet with protective and antioxidant substances in addition to supportive psychological therapies can protect newborns from being affected.

Importance of the Use of Oxidative Stress Biomarkers and Inflammatory Profile in Aqueous and Vitreous Humor in Diabetic Retinopathy

Diabetic retinopathy is one of the leading causes of visual impairment and morbidity worldwide, being the number one cause of blindness in people between 27 and 75 years old. It is estimated that ~191 million people will be diagnosed with this microvascular complication by 2030. Its pathogenesis is due to alterations in the retinal microvasculature as a result of a high concentration of glucose in the blood for a long time which generates numerous molecular changes like oxidative stress. Therefore, this narrative review aims to approach various biomarkers associated with the development of diabetic retinopathy. Focusing on the molecules showing promise as detection tools, among them we consider markers of oxidative stress (TAC, LPO, MDA, 4-HNE, SOD, GPx, and catalase), inflammation (IL-6, IL-1ß, IL-8, IL-10, IL-17A, TNF-α, and MMPs), apoptosis (NF-kB, cyt-c, and caspases), and recently those that have to do with epigenetic modifications, their measurement in different biological matrices obtained from the eye, including importance, obtaining process, handling, and storage of these matrices in order to have the ability to detect the disease in its early stages.

Role of Antioxidant Molecules and Polymers in Prevention of Bacterial Growth and Biofilm Formation

Background:

Antioxidants are multifaceted molecules playing a crucial role in several cellular functions. There is by now a well-established knowledge about their involvement in numerous processes associated with aging, including vascular damage, neurodegenerative diseases and cancer. An emerging area of application has been lately identified for these compounds in relation to the recent findings indicating their ability to affect biofilm formation by some microbial pathogens, including Staphylococcus aureus, Streptococcus mutans, and Pseudomonas aeruginosa.

Methods:

A structured search of bibliographic databases for peer-reviewed research literature was performed using a focused review question. The quality of retrieved papers was appraised using standard tools.

Results:

One hundred sixty-five papers extracted from pubmed database and published in the last fifteen years were included in this review focused on the assessment of the antimicrobial and antibiofilm activity of antioxidant compounds, including vitamins, flavonoids, non-flavonoid polyphenols, and antioxidant polymers. Mechanisms of action of some important antioxidant compounds, especially for vitamin C and phenolic acids, were identified.

Conclusion:

The findings of this review confirm the potential benefits of the use of natural antioxidants as antimicrobial/antibiofilm compounds. Generally, gram-positive bacteria were found to be more sensitive to antioxidants than gram-negatives. Antioxidant polymeric systems have also been developed mainly derived from functionalization of polysaccharides with antioxidant molecules. The application of such systems in clinics may permit to overcome some issues related to the systemic delivery of antioxidants, such as poor absorption, loss of bioactivity, and limited half-life. However, investigations focused on the study of antibiofilm activity of antioxidant polymers are still very limited in number and therefore they are strongly encouraged in order to lay the foundations for application of antioxidant polymers in treatment of biofilm-based infections.