Effect of Dietary Supplementation with Omega-3 Fatty Acid on the Generation of Regulatory T Lymphocytes and on Antioxidant Parameters and Markers of Oxidative Stress in the Liver Tissue of IL-10 Knockout Mice

INTRODUCTION

chronic low-grade inflammation, or inflammaging, emerges as a crucial element in the aging process and is associated with cardiovascular and neurological diseases, sarcopenia, and malnutrition. Evidence suggests that omega-3 fatty acids present a potential therapeutic agent in the prevention and treatment of inflammatory diseases, mitigating oxidative stress, and improving muscle mass, attributes that are particularly relevant in the context of aging. The objective of the present study was to evaluate the effectiveness of supplementation with omega-3 fish oil in improving the immune response and oxidative stress in knockout mice for interleukin IL-10 (IL-10-/-).

MATERIAL AND METHODS

female C57BL/6 wild-type (WT) and interleukin IL-10 knockout (IL-10-/-) mice were fed during 90 days with a standard diet (control groups), or they were fed/supplemented with 10% of the omega-3 polyunsaturated fatty acid diet (omega-3 groups). Muscle, liver, intestinal, and mesenteric lymph node tissue were collected for analysis.

RESULTS

the IL-10-/-+O3 group showed greater weight gain compared to the WT+O3 (p = 0.001) group. The IL-10-/-+O3 group exhibited a higher frequency of regulatory T cells than the IL-10-/- group (p = 0.001). It was found that animals in the IL-10-/-+O3 group had lower levels of steatosis when compared to the IL-10-/- group (p = 0.017). There was even greater vitamin E activity in the WT group compared to the IL-10-/-+O3 group (p = 0.001) and WT+O3 compared to IL-10-/-+O3 (p = 0.002), and when analyzing the marker of oxidative stress, MDA, an increase in lipid peroxidation was found in the IL-10-/-+O3 group when compared to the IL-10-/- group (p = 0.03). Muscle tissue histology showed decreased muscle fibers in the IL-10-/-+O3, IL-10-/-, and WT+O3 groups.

CONCLUSION

the findings show a decrease in inflammation, an increase in oxidative stress markers, and a decrease in antioxidant markers in the IL-10-/-+O3 group, suggesting that supplementation with omega-3 fish oil might be a potential intervention for inflammaging that characterizes the aging process and age-related diseases.

Do the oxidative stress biomarkers predict COVID-19 outcome? An in-hospital cohort study

In SARSCoV-2 infections, excessive activation of the immune system dramatically elevates reactive oxygen species levels, harms cell structures, and directly increases disease severity and mortality. We aimed to evaluate whether plasma oxidative stress biomarker levels could predict mortality in adults admitted with Coronavirus Disease 2019 (COVID-19), considering potential confounders. We conducted a cohort study of 115 adults (62.1 ± 17.6 years, 65 males) admitted to a Brazilian public hospital for severely symptomatic COVID-19. Serum levels of α-tocopherol, glutathione, superoxide dismutase, 8-hydroxy-2'-deoxyguanosine, malondialdehyde, and advanced oxidation protein products were quantified at COVID-19 diagnosis using real-time polymerase chain reaction. Serum levels of α-tocopherol, glutathione, superoxide dismutase, and advanced oxidation protein products differed significantly between survivors and non-survivors. Serum glutathione levels below 327.2 μmol/mL were associated with a significant risk of death in COVID-19 patients, even after accounting for other factors (adjusted hazard ratio = 3.12 [95% CI: 1.83-5.33]).

Vitamin D deficiency predicts 30-day hospital mortality of adults with COVID-19

Background & aims

Several studies have shown conflicting results for the relationship between vitamin D deficiency and COVID-19 outcomes. Here, we aimed to evaluate whether plasma 25(OH)D levels predict mortality in adults admitted with COVID-19, considering potential confounders.

Methods

We conducted a retrospective cohort study that included 115 adults (age 62.1 ± 17.6 years, 65 males) admitted to a Brazilian public hospital for severely symptomatic COVID-19. Subjects were classified into two groups according to their plasma levels of 25(OH)D: sufficiency (≥50 nmol/L) and the deficiency (<50 nmol/L). The diagnosis of COVID-19 was performed using real-time polymerase chain reaction (qPCR). In addition, direct competitive chemiluminescence immunoassay assessed serum 25(OH)D levels.

Results

The all-cause 30-day mortality was 13.8% (95% CI: 6.5%–21%) in the group of patients with sufficient plasma 25(OH)D levels and 32.1% (95% CI: 14.8%–49.4%) among those with deficient plasma 25(OH)D levels. Cox regression showed that plasma 25(OH)D levels remained a significant predictor of mortality even after adjusting for the covariates sex, age, length of the delay between symptom onset and hospitalization, and disease severity (HR = 0.98, 95% CI: 0.96–1.00; p = 0.02).

Conclusion

Vitamin D deficiency predicts higher mortality risk in adults with COVID-19.

Aqueous Pyrostegia venusta (Ker Gawl.) Miers extract attenuates allergen-induced asthma in a mouse model via an antioxidant mechanism

Objective: Pyrostegia venusta (Ker-Gawl.) Miers (Bignoniaceae) is a perennial invasive vine, distributed worldwide. In folk medicine, its parts are used for the treatment of inflammatory respiratory diseases. Extracts of P. venusta have antioxidant, antimicrobial, and antinociceptive properties. The aim of this study was to evaluate the effects of two extracts (aqueous and hydroethanolic) of P. venusta in the treatment of asthma in an animal model.Methods: Balb/c mice were sensitized twice with ovalbumin (OVA) intraperitoneally (ip), one week apart, and after one week, challenged with OVA intranasally on four alternate days. Mice were treated ip with 300 mg/kg of aqueous or hydroethanolic extracts for seven consecutive days. Control groups received saline on the same days. Bronchial hyperresponsiveness, production of Th1 and Th2 cytokines, lung and airway inflammation, and antioxidant activity in lung tissue were assessed.Results: Treatment with aqueous extract significantly decreased bronchial hyperresponsiveness, measured by total and tissue resistance and elastance. The administration of hydroethanolic extract did not reduce bronchial hyperresponsiveness. In addition, both extracts significantly reduced total cell and eosinophil counts in bronchoalveolar lavage. Both extracts did not change significantly IL-4, IL-5, IL-9, IL-13, IFN-gamma, and TGF-beta levels. Of note, only the aqueous extract significantly increased the total antioxidant activity and reduced lung inflammation.Conclusion: Aqueous extract of P. venusta reduced bronchial hyperresponsiveness, lung and airway inflammation, probably via an antioxidant mechanism. These results demonstrate that P. venusta may have potential for asthma treatment.

EFFECTS OF VITAMIN C SUPPLEMENTATION ON THE CHRONIC PHASE OF CHAGAS DISEASE

Introduction:

In order to examine the effectiveness of vitamin C (ascorbic acid) in combating the oxidative insult caused by Trypanosoma cruzi during the development of the chronic phase of Chagas disease, Swiss mice were infected intraperitoneally with 5.0 × 10⁴ trypomastigotes of T. cruzi QM1strain.

Methods:

Mice were given supplements of two different doses of vitamin C for 180 days. Levels of lipid oxidation (as indicated by thiobarbituric acid reactive substances-TBARS), total peroxide, vitamin C, and reduced glutathione were measured in the plasma, TBARS, total peroxide and vitamin C were measured in the myocardium and histopathologic analysis was undertaken in heart, colon and skeletal muscle.

Results:

Animals that received a dose equivalent to 500 mg of vitamin C daily showed increased production of ROS in plasma and myocardium and a greater degree of inflammation and necrosis in skeletal muscles than those that received a lower dose or no vitamin C whatsoever.

Conclusion:

Although some research has shown the antioxidant effect of vitamin C, the results showed that animals subject to a 500 mg dose of vitamin C showed greater tissue damage in the chronic phase of Chagas disease, probably due to the paradoxical actions of the substance, which in this pathology, will have acted as a pro-oxidant or pro-inflammatory.

Effects of vitamin C supplementation on acute phase Chagas disease in experimentally infected mice with Trypanosoma cruzi QM1 strain

The tissue changes that occur in Chagas disease are related to the degree of oxidative stress and antioxidant capacity of affected tissue. Studies with vitamin C supplementation did not develop oxidative damage caused by Chagas disease in the host, but other studies cite the use of peroxiredoxins ascorbate - dependent on T. cruzi to offer protection against immune reaction. Based on these propositions, thirty "Swiss" mice were infected with T. cruzi QM1 strain and treated with two different vitamin C doses in order to study the parasitemia evolution, histopathological changes and lipid peroxidation biomarkers during the acute phase of Chagas disease. The results showed that the parasite clearance was greater in animals fed with vitamin C overdose. There were no significant differences regarding the biomarkers of lipid peroxidation and inflammatory process or the increase of myocardium in animals treated with the recommended dosage. The largest amount of parasite growth towards the end of the acute phase suggests the benefit of high doses of vitamin C for trypomastigotes. The supplementation doesn't influence the production of free radicals or the number of amastigote nests in the acute phase of Chagas disease.

Modelos experimentais de desnutrição e sua influência no trofismo cutâneo

FUNDAMENTOS: A pele, para exercer suas funções, necessita de níveis adequados de nutrientes. OBJETIVO: Analisar o trofismo cutâneo de ratos nutridos e desnutridos por meio de dois modelos de desnutrição. MÉTODOS: No Modelo Marasmo, utilizaram-se 60 ratos Wistar em controle dietético, dos quais 30 foram selecionados aleatoriamente para receber metade da dieta diária durante 60 dias. No Modelo Gelatina, empregaram-se 60 ratos, dos quais 30 receberam dieta associada a proteína de baixa qualidade (gelatina) durante 30 dias. Avaliou-se o estado nutricional dos animais por meio da massa corporal, dos sinais clínicos e da dosagem de albumina sérica. Após o período de desnutrição, fez-se a histologia da pele dos animais para análise da espessura da derme e epiderme com o software Leica Application Suite; nas lâminas coradas com tricrômio de Gomori, analisou-se a colagênese com o software ImageJ. RESULTADOS: A massa corporal dos animais desnutridos pelo marasmo e gelatina foi significativamente menor (p<0,0001 e p<0,0001) do que a dos grupos nutridos. Quanto à albumina sérica, não houve diferença entre os grupos nos dois modelos. Em relação à análise histológica da espessura da pele, os desnutridos apresentaram a derme significativamente menos espessa em comparação aos nutridos (p<0,0001 e p<0,0001). No que respeita à colagênese, os grupos desnutridos apresentaram menores percentuais de colágeno em relação aos nutridos (p<0,0005 e p<0,003). CONCLUSÕES: Os animais desnutridos pelos dois modelos apresentaram diminuição na espessura dérmica, confirmada histologicamente pelo menor percentual de colágeno, mostrando a influência negativa da desnutrição no trofismo cutâneo

Folic acid supplementation during early hepatocarcinogenesis: cellular and molecular effects

Folic acid (FA) supplementation during carcinogenesis is controversial. Considering the impact of liver cancer as a public health problem and mandatory FA fortification in several countries, the role of FA supplementation in hepatocarcinogenesis should be elucidated. We evaluated FA supplementation during early hepatocarcinogenesis. Rats received daily 0.08 mg (FA8 group) or 0.16 mg (FA16 group) of FA/100 g body weight or water (CO group, controls). After a 2-week treatment, animals were subjected to the "resistant hepatocyte" model of hepatocarcinogenesis (initiation with diethylnitrosamine, selection/promotion with 2-acetylaminofluorene and partial hepatectomy) and euthanized after 8 weeks of treatment. Compared to the CO group, the FA16 group presented: reduced (p < 0.05) number of persistent and increased (p < 0.05) number of remodeling glutathione S-transferase (GST-P) positive preneoplastic lesions (PNL); reduced (p < 0.05) cell proliferation in persistent GST-P positive PNL; decreased (p < 0.05) hepatic DNA damage; and a tendency (p < 0.10) for decreased c-myc expression in microdissected PNL. Regarding all these parameters, no differences (p > 0.05) were observed between CO and FA8 groups. FA-treated groups presented increased hepatic levels of S-adenosylmethionine but only FA16 group presented increased S-adenosylmethionine/S-adenosylhomocysteine ratio. No differences (p > 0.05) were observed between experimental groups regarding apoptosis in persistent and remodeling GST-P positive PNL, and global DNA methylation pattern in microdissected PNL. Altogether, the FA16 group, but not the FA8 group, presented chemopreventive activity. Reversion of PNL phenotype and inhibition of DNA damage and of c-myc expression represent relevant FA cellular and molecular effects.

Influência da resposta inflamatória de fase aguda nos níveis séricos de retinol e da proteína de ligação do retinol em pacientes com AIDS

INTRODUÇÃO: a hiporretinolemia constitui fator prognóstico independente em pacientes com AIDS, e a atividade inflamatória causa redução dos níveis séricos deste nutriente na população em geral. Entretanto, faltam estudos que avaliem o impacto da atividade inflamatória sobre o nível sérico do retinol em pacientes com AIDS. MÉTODOS: foram avaliados transversalmente 41 pacientes internados por complicações da AIDS, que tiveram quantificados alguns marcadores de inflamação (proteína C reativa e fator de necrose tumoral alfa) e concentrações séricas de retinol e da proteína de ligação do retinol. RESULTADOS: apesar da baixa (14,6%) prevalência de hiporretinolemia evidenciou-se correlação negativa dos marcadores de inflamação com os níveis séricos de retinol e de sua proteína de ligação nos pacientes com AIDS. CONCLUSÕES: a atividade inflamatória de fase aguda está associada a baixos níveis séricos de retinol em indivíduos com AIDS.

Oxidative stress and acute-phase response in patients with pressure sores

OBJECTIVE

We investigated the relation between oxidative stress and the occurrence of the acute-phase response with serum ascorbic acid and alpha-tocopherol levels in patients with pressure sores.

METHODS

The following groups of patients were studied: 1) those who had patients with pressure sores, 2) those who had pneumonia, and 3) those who did not develop pressure sores or any type of infection (control). Concentrations of total proteins, albumin, creatinine, iron, ferritin, transferrin, C-reactive protein, alpha1-acid glycoprotein, total iron-binding capacity, ascorbic acid, alpha-tocopherol, and malondialdehyde were measured during the first days of hospitalization.

RESULTS

Albumin concentrations were significantly lower (P < 0.05) and C-reactive protein concentrations were significantly higher (P < 0.05) in patients with pressure sores compared with controls. Concentrations of ascorbic acid and alpha-tocopherol were significantly decreased (P < 0.05) in patients who had pressure sores or infection, whereas malondialdehyde concentrations were significantly increased (P < 0.05) compared with control patients. Five of 11 patients (55.56%) with pressure sores and 10 of 12 patients (83.33%) with pneumonia presented serum ascorbic acid concentrations below the reference value (34 to 91 micromol/L). Concentrations of ascorbic acid and alpha-tocopherol versus malondialdehyde were significantly correlated in the three patient groups (r = -0.44, P < 0.05; r = -0.55, P < 0.01, respectively).

CONCLUSION

Patients with pressure sores and acute infection present a systemic inflammatory response accompanied by an increase in lipid peroxidation that is associated with decreased serum ascorbic acid and alpha-tocopherol levels, suggesting that these patients may be at risk for important nutritional deficiencies.

Lipid peroxidation and urinary excretion of vitamin E in rats submitted to an immunological inflammatory process

Inflammation is a protective physiologic response, generally controlled by the organism at the injury site. Vitamin E is the most important antioxidant in the lipid phase present in nature and acts by interrupting the chain reaction produced by free radicals. The objective of this study was to evaluate the effect of inflammation on vitamin E levels and lipid peroxidation in rats. Forty Wistar rats (four groups of 10 rats each) were studied over a period of 15 days. Two substances inducing the inflammatory process were parenterally administered, anti-rat basement membrane serum (ABMG) and Freund's complete adjuvant (FAG). Lipid peroxidation levels in hepatic and renal tissue and in plasma and urine were analyzed and compared with the control (CG). Vitamin E was determined by HPLC and lipid peroxidation by quantification of thiobarbituric acid reactive substances (TBARS). ABMG produced more (p < 0.05) TBARS in renal and hepatic tissues (0.7 +/- 0.11 and 1.28 +/- 0.27 nmol/g protein, respectively) compared to CG (0.65 +/- 0.81 and 0.69 +/- 0.13 nmol/g protein). Analysis of TBARS in urine did not show statistically significant differences between the experimental groups and the control. Vitamin E levels in the hepatic tissue of ABMG and FAG (40.7 +/- 10.04 and 44.26 +/- 20.24 micrograms/g tissue) were higher than in CG (22.37 +/- 8.20 micrograms/g tissue) while in kidney tissue and plasma these values were lower (P < 0.05). Renal excretion was increased (P < 0.05) in the group that received anti-rat basement membrane serum (22.39 +/- 0.11 mmol/mL) compared to CG (0.56 +/- 0.056 mmol/mL). We conclude that the acute inflammatory process causes important alterations in the metabolism of vitamin E and lipid peroxidation leading to a significantly increased excretion of this vitamin in the urine.