Pro-oxidant Activity Research Articles

Multilevel assessment of chlorothalonil sediment toxicity to Latin American estuarine biota: Effects on biomarkers, reproduction and survival in different benthic organisms

Chlorothalonil is an organochlorine compound that has long been used in agriculture. In recent years, this compound has been used as an antifouling booster biocide and its presence has been reported in marine coastal environments, especially in navigational areas. Although sediment can be a sink for chlorothalonil due to high affinity to fine particulate matter, toxicity studies with non-target marine and/or estuarine organisms is focused on waterborne exposure only. This study aimed to determine sediment-borne ecotoxicological effects of chlorothalonil on different benthic organisms of the Latin American biota using a integrative multilevel approach. Marine/estuarine organisms were exposed to sediments spiked with chlorothalonil (from 0 to 10.0 μg g−1) and effects at sub-individual (biochemical biomarkers in Anomalocardia flexuosa), individual (lethal effects to Tiburonella viscana and Artemia salina) and subpopulation levels (Nitokra sp. reproduction) were assessed. Increasing chlorothalonil concentrations in sediment caused increasing ecotoxicological effects in different levels of biological organisation, from biochemical to subpopulation levels. The highest exposure concentrations showed increased biomarkers of effects (lipid peroxidation and DNA damage in gills and/or digestive gland of A. flexuosa), lower fecundity and lower survival of the test organisms. GPx activity associated with LPO levels in the digestive gland suggested a response to the oxidant challenge provided by the biocide. At the lowest concentration (0.001 μg g−1), chlorothalonil detoxification mechanisms and defense against its oxidising action, involving GSH and glutathione-dependent enzymes (GST and GPx) were induced. At intermediate concentrations, there was a tendency of decreasing GSH levels, probably due to conjugation with chlorothalonil, which also affected the activities of the glutathione-dependent enzymes. At the highest tested concentration (10.0 μg g−1), chlorothalonil may have restimulated GSH synthesis in the gills of A. flexuosa, although the prooxidant activity has induced effects. This study contributes to assessing the environmental risk of chlorothalonil in sediment for non-target marine and estuarine organisms.

Cytogenotoxic, insecticidal, and phytotoxic activity from biomass extracts of the freshwater algae Nitella furcata

ABSTRACT Agroecology, the application of ecological concepts to agricultural production, has been developing over the last years with consequent promotion for discovery of bioactive compounds to control pests and abolish crop diseases. In this context, algae from Nitella genus are characterized by high potential for bioeconomic applications due to (1) available biomass for harvesting or cultivation and (2) production of allelochemicals, which present a potential to protect field crops from insect infestation. Therefore, this study aimed to determine primary and secondary metabolites derived from aqueous and hydroethanolic extracts of Nitella furcata and to evaluate phytotoxic, cytogenotoxic, insecticidal, and pro-oxidative activities of these extracts. Determination of metabolites showed the presence predominantly of carbohydrates, proteins, phenols, and flavonoids in hydroethanolic extract. Both extracts of N. furcata interfered in the germination of seeds and development of seedlings of Lactuca sativa, with hydroethanolic extract exhibiting greater inhibition. Both extracts also interfered with meristematic cells of Allium cepa as evidenced by chromosomal alterations and higher pro-oxidative activity. Aqueous extract at 5 and 0 mg/ml produced 100% insect mortality. Further, hydroethanolic extract at 0 mg/ml was lethal immediately upon exposure. Therefore, results demonstrate that N. furcata is potential algae species to be considered for development of environmental and ecotoxicological studies as a source of compounds with potential use in agroecological strategies.

Phaeolschidin F, a new symmetrical bis(styrylpyrone) derivative with redox-catalyzing activity from the mushroom Gymnopilus aeruginosus (order Agaricales).

Phaeolschidin F (1) was isolated from fruiting bodies of the bitter and toxic mushroom Gymnopilus aeruginosus. Structure analysis by NMR and MS revealed that 1 is a new symmetrical bis(styrylpyrone). A series of anti-oxidant and pro-oxidant tests characterized that 1 is a redox catalyst having more anti-oxidant and less pro-oxidant activities than quercetin.

Therapeutic effect of oral quercetin in hamsters infected with Leishmania Viannia braziliensis.

Leishmaniasis is a parasitic disease caused by several species of intracellular protozoa of the genus Leishmania that present manifestations ranging from cutaneous ulcers to the fatal visceral form. Leishmania Viannia braziliensis is an important species associated with American tegumentary leishmaniasis and the main agent in Brazil, with variable sensitivity to available drugs. The search for new therapeutic alternatives to treat leishmaniasis is an urgent need, especially for endemic countries. Not only is quercetin well known for its antioxidant activity in radical scavenging but also several other biological effects are described, including anti-inflammatory, antimicrobial, and pro-oxidant activities. This study aimed to investigate the flavonoid quercetin's therapeutic potential in L. (V.) braziliensis infection. Quercetin showed antiamastigote (IC50 of 21 ± 2.5 µM) and antipromastigote (25 ± 0.7 µM) activities and a selectivity index of 22. The treatment of uninfected or L. (V.) braziliensis-infected macrophages with quercetin increased reactive oxygen species (ROS)/H202 generation without altering Nitric Oxide (NO) production. Oral treatment with quercetin of infected hamsters, starting at 1 week of infection for 8 weeks, reduced the lesion thickness (p > 0.01) and parasite load (p > 0.001). The results of this study suggest that the antiamastigote activity of the flavonoid quercetin in vitro is associated, at least in part, with the modulation of ROS production by macrophages. The efficacy of oral quercetin treatment in hamsters infected with L. (V.) braziliensis was presented for the first time and shows its promising therapeutic potential.

Correlation between antioxidant and anticancer activity and phenolic profile of new Apulian table grape genotypes (V. Vinifera L.).

Grapes represent a significant source of phenolic compounds known for their health-promoting properties, such as antioxidant capacity on normal cells and prooxidant activity on tumor cells. The genotype highly affects the polyphenolic composition in grapes and, consequently, the nutritional quality of berries. This work aimed to characterize the phenolic composition, the antioxidant, and anticancer activity of grape skin extracts (GSEs) of nine new table grape genotypes selected from a breeding program to obtain new cultivars of seedless table grapes, well adapted to the climatic change and with higher nutraceutical properties. The grape polyphenolic profile was characterized by Ultra-High-Performance Liquid Chromatography/Quadrupole-Time of Flight mass spectrometry analysis. GSE antioxidant activity was determined by the ABTS, DPPH, and ORAC assays; GSE cell growth inhibition test was carried out in the Caco2 human cancer cell line. The nine GSEs showed different flavonoid and non-flavonoid profiles, and all possessed antioxidant activity, with the 'Aika N.', 'Turese N.', and 'Egnatia N.' the most active. As anticancer activity against the tested cancer cell line, 'Daunia N.' and 'Apenestae N.' showed the EC50 after 24 h of 35.60 µg/mL and 150.91 µg/mL, respectively. The relationship between polyphenolic profile and the antioxidant and anticancer activity of GSE was also investigated. Interestingly, among the different classes of polyphenolics, flavan-3-ols e proanthocyanidins showed the highest positive correlation with the anticancer activity of extracts. These findings can be helpful for the preparation of new extracts for the pharmaceutical and nutraceutical industry and geneticists working in vine breeding programs.

Physicochemical stability of Pickering emulsion stabilized with spherical and fibrous iron ions loaded whey protein isolate/gum Arabic complexes

Iron deficiency is widespread worldwide and shows significant impact on human health. The direct iron supplementation produced little effect because of the physicochemical properties and gastrointestinal stimulation of iron ions, and thus the biomolecules loaded iron delivery systems developed rapidly. Pickering emulsions (PEs) could be stabilized by colloidal particles and provide potentials for delivery of various bioactives effectively and simultaneously. Here, the feasibility of PEs stabilized with Fe3+ loaded colloid granules for iron delivery was explored. The binary WPI-GAFe3+ (whey protein isolate/containing Fe3+ gum arabic) complexes with spherical (WGS) or fibrous (WGF) morphology were constructed by adjusting the reaction conditions of protein aggregation. Compared to GAFe3+, WGS and WGF exhibited better interfacial activity in terms of the lower interfacial tension and the competitive interfacial adsorption with the pre-adsorbed T-80 and sodium caseinate, and favorable physical stability on PEs, as well as the significant retardation of the pro-oxidant activity of lipids by Fe3+. WGS-PE exhibited more uniform droplets, lower droplets mobility, less variation of turbiscan stability index and lower content of lipids oxidation products than that of WGF-PE. This may be related to the spherical assembled structure and inside entrapped GAFe3+ of WGS that could adsorb onto the droplets interface tightly and neatly, accordingly increase the physical stability of PEs, but also prevent the leakage of iron ions, thus reducing the lipid oxidation. It is suggested that PEs would be a feasible and effective iron ions delivery platform, which would provide a reference for designing iron fortification in food.

Functionalized Magnetite Nanoparticles: Characterization, Bioeffects, and Role of Reactive Oxygen Species in Unicellular and Enzymatic Systems.

The current study evaluates the role of reactive oxygen species (ROS) in bioeffects of magnetite nanoparticles (MNPs), such as bare (Fe3O4), humic acids (Fe3O4-HA), and 3-aminopropyltriethoxysilane (Fe3O4-APTES) modified MNPs. Mössbauer spectroscopy was used to identify the local surrounding for Fe atom/ions and the depth of modification for MNPs. It was found that the Fe3O4-HA MNPs contain the smallest, whereas the Fe3O4-APTES MNPs contain the largest amount of Fe2+ ions. Bioluminescent cellular and enzymatic assays were applied to monitor the toxicity and anti-(pro-)oxidant activity of MNPs. The contents of ROS were determined by a chemiluminescence luminol assay evaluating the correlations with toxicity/anti-(pro-)oxidant coefficients. Toxic effects of modified MNPs were found at higher concentrations (>10-2 g/L); they were related to ROS storage in bacterial suspensions. MNPs stimulated ROS production by the bacteria in a wide concentration range (10-15-1 g/L). Under the conditions of model oxidative stress and higher concentrations of MNPs (>10-4 g/L), the bacterial bioassay revealed prooxidant activity of all three MNP types, with corresponding decay of ROS content. Bioluminescence enzymatic assay did not show any sensitivity to MNPs, with negligible change in ROS content. The results clearly indicate that cell-membrane processes are responsible for the bioeffects and bacterial ROS generation, confirming the ferroptosis phenomenon based on iron-initiated cell-membrane lipid peroxidation.

Колебательный характер окислительных процессов в крови крыс при хроническом многочастотном электромагнитном облучении от систем сотовой связи стандартов GSM, UMTS и LTE

The paper presents results of research on effects of long term continuous animals exposure to multi-frequency electromagnetic fields of the mobile communication standards (GSM, UMTS and LTE). Prooxidant and antioxidant activity was investigated in the blood of exposed Wistar rats. The animals were continuously exposed to electromagnetic fields at frequencies of 1800, 2100 and 2600 MHz with the total power density of 250 muW/cm2 (GSM-20%; UMTS-20%; LTE-60%). Peripheral blood samples were taken from the affected and control rats after the decapitation at the end of each month of exposure. Fluctuations in indices of lipid peroxidation (diene conjugates) and antioxidant activity (enzyme, catalases) were observed at all stages of the exposure. The modulation effect of prooxidant and antioxidant activity in animals blood serum is suggested to depend on the amount of formed reactive oxygen species, and it may be caused by the direct effect of electromagnetic fields. The modulation effect of long-term continuous exposure to multi-frequency electromagnetic fields of mobile communication base stations on the blood lipid peroxidation may cause unfavorable consequences, which requires further study. The obtained results indicate necessity to take into account the detected modulating effect that can affect the level of reactive oxygen species.

Effects of triterpenoids in fatty products on liver condition of laboratory animals with acute toxic hepatitis

One of the principles of prevention and non-medicamentous treatment of liver diseases, including hepatitis of different etiology, is the normalization of the diet through the consumption of food with physiologically active ingredients, in particular betulin, which helps to eliminate the causes of metabolic and oxidative disorders within liver cells. The aim of the research was to assess in vivo the influence of triterpene alcohol betulin extracted from Betula pendula Roth. birch bark in fat-containing products (for example mayonnaise) on the blood biochemical parameters and liver morphological structure of rats with initiated acute toxic hepatitis. Material and methods. Hepatoprotective and antioxidant activities of betulin as part of mayonnaise samples has been investigated in vivo on the model of toxic hepatitis initiated by carbon tetrachloride in male Wistar rats weighing 210-265 g. The animals were divided into 4 groups of 10 animals each: CG-1 - intact, CG-2 and MG - with carbon tetrachloride initiated toxic hepatitis. rats of the main groups were orally administered mayonnaise once a day at a dosage of 1 ml for 21 days after the formation of the model pathology: OG-1 with the added betulin (1 mg per 1 kg of body weight), OG-2 without betulin. Disorders of metabolic and oxidative processes in liver cells of animals were evaluated by biochemical indicators of blood plasma: the level of glucose, albumin, total cholesterol, triglycerides and urea and the activity of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and γ-glutamyltransferase. Oxidative stress in rats was estimated by the activity of catalase and superoxide dismutase in blood hemolysate (at a dilution of 1:200 and 1:10, respectively); the total prooxidant (in blood plasma) and total antioxidant (in blood hemolysate at a dilution of 1:10) activity were determined spectrophotometrically (colored complexes of TWIN-80 oxidation products with thiobarbituric acid). The morphological structure of rats' liver was estimated by microscopy of prepared cuts of hepatic tissue. Results. Based on biochemical parameters of rat blood plasma, it has been established that the administration of mayonnaise with betulin prevents the development of cytolic syndrome and suppresses the process of peroxidation by directly neutralizing free radicals. Aspartate aminotransferase and alkaline phosphatase activity in blood plasma of the experimental animals of the main group MG-1 reduced by 20.7 and 35.2% compared with indicators of the rats of the main group MG-2. Glucose concentration normalized to the level of the control group CG-1. The concentration of bilirubin and triglycerides decreased by 22.9 and by 48.1%, which indicates a significant reduction in the indicators of cholestatic syndrome in the group of animals OG-1 compared to OG-2. The total prooxidant activity and the concentration of thiobarbiturate-reactive products decreased compared to the CG-2 and MG-2 groups, which indicates the suppression of oxidative stress and, as a result, an improvement in liver conditions of animals with toxic hepatitis even when taking a fat-containing product. In liver histopeparates of animals receiving mayonnaise with betulin, necrobotic changes were less pronounced in comparison with the group MG-2. They were estimated at 1 point: small-drip dystrophy spots were found, haemorrhages in the interregional septum with inflammatory infiltration in the course of hemorrhages against the presence of necrosis hepatocytes with pronounced adipose dystrophy in the centres of the lobules, step necrosis with signs of replacing the damaged hepatocytes of the connective tissue, accompanied by centrolobular hemorrhages in MG-2 rats. Conclusion. Introduced into the composition of mayonnaise betulin, reduces the development of cytolic syndrome in toxic hepatitis and suppresses the process of peroxidation, on the basis of which fat-containing foods with betulin can be recommended for clinical examination as specialized products in acute and chronic liver diseases, including complicated cholestasis.

THE ROLE OF PHYSICAL ACTIVITY IN THE TREATMENT OF PATIENTS WITH ARTERIAL HYPERTENSION AND OBESITY

The study aimed to assess the impact of physical activity on the dynamics of neurohumoral and cardio hemodynamic indicators in patients with arterial hypertension and concomitant obesity under different pharmacotherapy regimens. Materials and Methods: Two hundred patients with stage II arterial hypertension grade 2 and obesity grade I–II were examined using clinical-anamnestic, anthropometric, biochemical, automated immunological analysis, spectrophotometric and instrumental methods. Per the research objective, patients underwent a re-evaluation after six months of prescribed treatment. Non-pharmacological treatment included dietary therapy aimed at weight correction, with recommendations to increase physical activity primarily through brisk or moderately brisk walking for at least 45 minutes daily. Pharmacological treatment followed the European recommendations in 2018, involving dual antihypertensive therapy. The combination included perindopril and amlodipine. Patients who achieved target BP levels within 3 months of treatment continued to receive the prescribed therapy. For the rest of the patients, a third antihypertensive drug, indapamide, was additionally prescribed. In addition to assessing the achievement of target blood pressure levels after 6 months and at interim stages of the study, patients' adherence to recommendations regarding expanding physical activity was evaluated. Patients were divided into groups with sufficient and reduced physical activity accordingly. Statistical analysis of the obtained data was conducted using the SPSS 17 software package (IBM), Microsoft Office Excel-2003. The data are presented as mean values ± standard deviation. Significance was established at the level of p < 0.05 in all cases. Results of the study: Patients who achieved target blood pressure levels on dual antihypertensive therapy and had sufficient physical activity after six months of treatment differed significantly from patients with low physical activity levels. They exhibited lower values of the pulse wave velocity in the carotid artery and abdominal aorta, a considerably higher degree of endothelium-dependent vasodilation, lower values of end-systolic and end-diastolic diameters, left ventricular mass, a lower E/e´ ratio, and showed better dynamics in metabolic and pro-inflammatory indicators. Additionally, they had a higher level of antioxidant protection. Patients who reached the target blood pressure levels on three-component antihypertensive therapy and engaged in sufficient physical activity after six months displayed significant differences compared to patients with low physical activity. These differences included a more substantial reduction in the pulse wave velocity in the carotid artery, an increase in endothelium-dependent vasodilation, lower indicators of carbohydrate metabolism, reduced levels of pro-inflammatory and pro-oxidant activity, lower levels of leptin, and a more pronounced increase in adiponectin. Conclusions: Physical activity is a crucial factor influencing the treatment outcomes for patients with arterial hypertension and obesity across different antihypertensive therapy regimens. Irrespective of the chosen antihypertensive therapy option, physical activity positively impacted cardiovascular remodelling, the dynamics of metabolic and pro-inflammatory indicators, and the equilibrium within the oxidative stress-antioxidant protection system and activity of the renin-angiotensin-aldosterone system.

Dopaminergic potential of domestic 3-hydroxypyridine and succinic acid derivatives and prospects for their therapeutic «retargeting»

The review is devoted to the assessment of the pharmacological effects of 3-hydroxypyridine and succinic acid derivatives (emoxipin, reamberin and mexidol) from the standpoint of their dopaminergic activity. A systematic analysis of the data has been performed, allowing us to consider emoxipin, reamberin and mexidol as «normalizers of dopaminergic neurotransmission», the dopaminergic action of which in its phenotype corresponds to the effects of partial dopamine receptor agonists. The position that the dopaminergic effect, antioxidant and antidepressant potential of drugs containing 2-ethyl-6-methyl-3-oxypyridine (emoxipine and mexidol) are associated with their inhibitory effect on monoamine oxidase-A (MAO-A) has been substantiated. A direct relationship between the stimulating effect of succinate-containing drugs (reamberin and mexidol) on MAO-B, their prooxidant activity, insulin-potentiating and antidepressant effects was analyzed. A hypothesis has been put forward on the general pathological significance of dopaminergic regulation disorders, the correction of which with the 3-hydroxypyridine and succinic acid derivatives can be considered as a promising strategy for improving the complex therapy of socially significant and common human diseases.

Physical Properties and Identification of Flavonoids by Ultraviolet-Visible Spectroscopy

Flavonoids are major functional components of many vegetable or animal preparations with medical uses. Flavonoids are also used in the treatment of numerous diseases, inhibiting specific enzymes, stimulating hormones and neurotransmitters and reducing the activity of free radicals. Due to the fact that flavonoids contain a variable number of phenolic groups in their chemical structure and due to their excellent properties to form chelates with iron and other transition metals, they have a high antioxidant capacity. For the human body, the antioxidant activity is highlighted due to the fact that they protect the cells of the body from free radicals that are formed as a result of numerous processes that use oxygen as an energy source and thus play an essential role in the protection of oxidative degradation phenomena. Their antiradical properties are due to hydroxyl and superoxide radicals, reactive groups that are involved in the initiation of lipid peroxidation processes, their ability to modify the synthesis of eicosanoids, to prevent platelet aggregation (antimicrobial effect) and to protect basic lipoproteins from oxidation. Although some studies indicate that some flavonoids possess a pro-oxidative action, this occurs only at high doses, and most investigations show the existence of anti-inflammatory, antiviral and anti-allergic effects, as well as the protective role in various pathologies.

Homeostaza redoks sistema, oksidativni stres i antioksidativni sistem u zdravlju i bolesti - mogućnost modulacije antioksidansima

Redox imbalance occurs when the factors of oxidative stress, known as prooxidants, outweigh the mechanisms of antioxidant protection. In a healthy state, homeostatic mechanisms ensure the balanced production of free radicals and a complete series of antioxidants responsible for their safe removal. The generation of free radicals is a part of physiological processes in a healthy organism, some of which act as specific signaling molecules, and their presence and activity are necessary in these processes. In various diseases such as cancer, cardiovascular disease, diabetes, autoimmune diseases, rheumatic diseases, systemic lupus, and skin diseases, the generation of free radicals overwhelms the protective mechanisms, leading to the development of "oxidative stress" that damages cells and tissues. To prevent the harmful effects of free radicals within cells, there exists a system of enzymatic antioxidant protection composed of superoxide dismutase (SOD), glutathione peroxidase (GSHPx), glutathione reductase (GR), glutaredoxin, reduced/oxidized glutathione (GSH/GSSG), and thioredoxin (TRX). The examples of non-enzymatic antioxidants are: antioxidant vitamins such as A, C and E, dihydrolypoic acid, metallothioneins, ceruloplasmin, coenzyme Q 10, urea, creatinine, etc. Redox balance is influenced by the circadian rhythm and external factors that constitute the "exposome", including dietary habits and lifestyle. Antioxidant supplementation has become increasingly popular for maintaining optimal body function. However, it is important to note that some antioxidants can exhibit prooxidant activity, emphasizing the need for controlled use. The relationship between the redox status of the body and the action of antioxidants enables the development of multidisciplinary research that connects biochemistry, molecular biology, nutritional science, natural product chemistry, and clinical practice.

Dual Role of Plant Phenolic Compounds as Antioxidants and Prooxidants

Natural phenolic compounds are secondary metabolites found in a wide range of plants including food crops. As many of them are known to be antioxidants and can prevent several chronic and degenerative diseases in humans, they are a part of a healthy diet. However, these antioxidants can act as prooxidants under high phenolic concentration, high pH, or in the presence of transition metal ions such as Cu2+ or Fe3+, producing reactive oxygen species (ROS) including hydroxyl radicals resulting in oxidative stress and cell toxicity. While this can lead to pathogenesis including the development of various types of cancers, elevated levels of ROS are beneficial to kill malignant cells and foodborne pathogens to improve food safety. Thus, the dual nature of phenolic compounds allows them to act as antioxidants and prooxidants. Similarly, depending on the level of prooxidant activity, ROS can induce either pathogenesis or serve as a potential agent to kill malignant cells and foodborne pathogens.

Anti- and Pro-Oxidant Activity of Polyphenols Extracts of Syrah and Chardonnay Grapevine Pomaces on Melanoma Cancer Cells.

The phenolic composition of Syrah and Chardonnay grape pomaces was studied to assess their antioxidant and prooxidant properties. Polyphenols were extracted by a "green" hydroalcoholic solvent (ethanol/water 1:1 v/v), and a detailed chemical and electrochemical characterization of the phenolic compounds was performed. The antioxidant and prooxidant capacity of the pomace was first studied by cyclic voltammetry (CV) and other reference analytical assays, then with biological tests on B16F10 metastatic melanoma cancer cells. Electrochemical data showed that, when a +0.5 V potential was applied, a low to moderate antioxidant capacity was observed. MTT test showed an increasing viability of melanoma cells, after treatments at low concentration (up to 100 μg/mL) and for a short time (6 h), but when cells were treated with higher doses of extract (≥250 μg/mL for 12/24 h), their viability decreased from 25 to 50% vs. control, depending on treatment time, dose, and extract origin. A stronger prooxidant activity resulted when 250 μg/mL of extract was combined with non-toxic doses of H2O2; this activity was correlated with the presence of copper in the extracts. This study shows the potential of winemaking by-products and suggests the opportunity to exploit them for the production of cosmeceuticals, or for combined therapies with approved anticancer drugs.

The Role of Helicobacter pylori Neutrophil-Activating Protein in the Pathogenesis of H. pylori and Beyond: From a Virulence Factor to Therapeutic Targets and Therapeutic Agents.

Helicobacter pylori neutrophil-activating protein (HP-NAP), a major virulence factor of H. pylori, plays a role in bacterial protection and host inflammation. HP-NAP activates a variety of innate immune cells, including neutrophils, monocytes, and mast cells, to induce their pro-oxidant and pro-inflammatory activities. This protein also induces T-helper type 1 (Th1) immune response and cytotoxic T lymphocyte (CTL) activity, supporting that HP-NAP is able to promote gastric inflammation by activation of adaptive immune responses. Thus, HP-NAP is a potential therapeutic target for the treatment of H. pylori-induced gastric inflammation. The inflammatory responses triggered by HP-NAP are mediated by a PTX-sensitive G protein-coupled receptor and Toll-like receptor 2. Drugs designed to block the interactions between HP-NAP and its receptors could alleviate the inflammation in gastric mucosa caused by H. pylori infection. In addition, HP-NAP acts as a promising therapeutic agent for vaccine development, allergy treatment, and cancer immunotherapy. The high antigenicity of HP-NAP makes this protein a component of vaccines against H. pylori infection. Due to its immunomodulatory activity to stimulate the Th1-inducing ability of dendritic cells, enhance Th1 immune response and CTL activity, and suppress Th2-mediated allergic responses, HP-NAP could also act as an adjuvant in vaccines, a drug candidate against allergic diseases, and an immunotherapeutic agent for cancer. This review highlights the role of HP-NAP in the pathogenesis of H. pylori and the potential for this protein to be a therapeutic target in the treatment of H. pylori infection and therapeutic agents against H. pylori-associated diseases, allergies, and cancer.

Green tea and kombucha characterization: Phenolic composition, antioxidant capacity and enzymatic inhibition potential

The present study aimed to carry out the physical–chemical, antioxidant, and enzymatic characterization of green tea and kombucha. It was observed that kombucha had lower pH, higher acidity, and solids content compared to green tea. As for the concentration of total phenolic compounds by the Folin Ciocalteu method, there was no significant difference between the beverages. In the antioxidant analysis by the DPPH assay, it was observed that both green tea and kombucha presented significant antioxidant capacity. In the TBARS analysis with the pH of the beverages neutralized, both showed a significant reduction in lipid peroxidation; however, kombucha exhibited pro-oxidant activity when evaluated in its natural form by this method. The beverages also showed significant inhibitory activity of the α-glucosidase enzyme, however, green tea presented superior inhibitory potential.

Cashew (Anacardium occidentale) Nut-Shell Liquid as Antioxidant in Bulk Soybean Oil.

Recently, natural antioxidants for the food industry have become an important focus. Cashew nut-shell liquid (CNSL) is composed of compounds that can act as natural antioxidants in food systems. The aim of this work was to evaluate the potential of CNSL and its components to act as natural antioxidants in a bulk oil system. CNSL was treated with calcium hydroxide to obtain two fractions [cardol/cardanols acid fraction (CCF) and anacardic acid fraction (AF)]. CNSL, FF and AF were analyzed by thin-layer chromatography and Fourier-transform infrared spectroscopy. The protective effects of CNSL, CCF and AF were tested in terms of the peroxide value of bulk soybean oil in accelerated assays and were compared against controls with and without synthetic antioxidants (CSA and CWA). CNLS, CCF, AF and CSA were tested at 200 mg/kg soybean oil by incubation at 30, 40, 50 and 60 °C for five days. The activation energy (Ea) for the production of peroxides was calculated by using the linearized Arrhenius equation. Thin-layer chromatography and Fourier-transform infrared spectroscopy revealed that (i) CNSL contained cardanols, anacardic acids, and cardols; (ii) CCF contained cardanols and cardols; and (iii) AF contained anacardic acids. CSA (Ea 35,355 J/mol) was the most effective antioxidant, followed by CCF (Ea 31,498 J/mol) and by CNSL (Ea 26,351 J/mol). AF exhibited pro-oxidant activity (Ea 8339 J/mol) compared with that of CWA (Ea 15,684 J/mol). Therefore, cardols and cardanols from CNSL can be used as a natural antioxidant in soybean oil.

Switchable Nanozyme Activity of Porphyrins Intercalated in Layered Gadolinium Hydroxide

In this study, organo-inorganic nanohybrids LHGd-MTSPP with enzyme-like activity were prepared by in situ intercalation of anionic 5,10,15,20-tetrakis-(4-sulfonatophenyl)porphyrin and its complexes with Zn(II) and Pd(II) (MTSPP, M = 2H, Zn(II) and Pd(II)) into gadolinium layered hydroxide (LHGd). The combination of powder XRD, CHNS analysis, FT-IR, EDX, and TG confirmed the layered structure of the reaction products. The basal interplanar distances in LHGd-MTSPP samples were 22.3-22.6 Å, corresponding to the size of an intercalated tetrapyrrole molecule. According to SEM data, LHGd-MTSPP hybrids consisted of individual lamellar nanoparticles 20-50 nm in thickness. The enzyme-like activity of individual constituents, LHGd-Cl and sulfoporphyrins TSPP, ZnTSPP and PdTSPP, and hybrid LHGd-MTSPP materials, was studied by chemiluminescence analysis using the ABAP/luminol system in phosphate buffer solution. All the individual porphyrins exhibited dose-dependent antioxidant properties with respect to alkylperoxyl radicals at pH 7.4. The intercalation of free base TSPP porphyrin into the LHGd preserved the radical scavenging properties of the product. Conversely, in LHGd-MTSPP samples containing Zn(II) and Pd(II) complexes, the antioxidant properties of the porphyrins changed to dose-dependent prooxidant activity. Thus, an efficient approach to the design and synthesis of advanced LHGd-MTSPP materials with switchable enzyme-like activity was developed.

Boosting ROS-Mediated Lysosomal Membrane Permeabilization for Cancer Ferroptosis Therapy.

Due to the deficient catalase, abundant reduced iron and low acidic environment in lysosomes, inducing lysosomal membrane permeabilization (LMP) through Fenton reaction-based reactive oxygen species (ROS) generation recently attracts increasing attention in cancer therapy. However, the lysosomal membranes are protected by highly glycosylated membrane proteins and several endolysosomal damage-response mechanisms can rapidly repair the injured lysosomes. To produce sufficient ROS and cause complete lysosomal membranes rupture, a lysosome-targeted ROS inducer, N-(3-Aminopropyl) morpholine grafted cross-linked lipoic acid vesicles with vitamin C-loading (VC@N3AM cLAVs), is developed. VC@N3AM cLAVs efficiently accumulate in lysosomes and convert into two redox couples LA/DHLA (dihydrolipoic acid, reduced form of LA) and VC/DHA (dehydroascorbic acid, oxidized form of VC) by the lysosomal glutathione, which can not only produce a large amount of H2 O2 by pro-oxidant action but also accelerate iron transformation through the cyclic redox reactions between each other and cause the efficient conversion of the generated H2 O2 into highly toxic •OH. Both in vitro and in vivo experiments demonstrate that VC@N3AM cLAVs can effectively enhance ROS production and boost LMP, finally initiation irreversible death of tumor cells via ferroptosis pathway, thus representing a potential anticancer drug for cancer therapy.