Thermoneutrality or standard temperature: is there an ideal housing temperature to study the antisteatotic effects of green tea in obese mice?

Metabolic-associated fatty liver disease (MAFLD) is a condition characterized by excessive accumulation of triglycerides in hepatocytes, currently considered the number one cause of chronic liver disease. MAFLD is strongly associated with obesity, type 2 diabetes, hyperlipidaemia, and hypertension. Emphasis has been placed on the use of green tea (GT), produced from the Camellia sinensis plant, rich in antioxidants as polyphenols and catechins, on obesity and MAFLD treatment/prevention. Studies carried out in rodent models housed at a standard temperature (ST, 22°C) are being questioned as ST is a determining factor on generating changes in the physiology of immune response, and energy metabolism. On the other hand, it seems that thermoneutrality (TN, 28°C) represents a closer parallel to human physiology. In this perspective, we investigated the effects of GT (500 mg/kg of body weight, over 12 weeks, 5 days/week) by comparing mice housed at ST or TN in a model of MAFLD of diet-induced obese males C57Bl/6 mice. We show that the liver phenotype at TN exhibits a more severe MAFLD while GT ameliorates this condition. In parallel, GT restores the expression of genes involved in the lipogenic pathway, regardless of temperature, with slight modifications in lipolysis/fatty acid oxidation. We observed an increase promoted by GT in PPARα and PPARγ proteins independently of housing temperature and a dual pattern of bile acid synthesis. Thus, animals' conditioning temperature is a key factor that can interfere in the results involving obesity and MAFLD, although GT has beneficial effects against MAFLD independently of the housing temperature of mice.

Green tea actions on miRNAs expression - An update.

Compounds derived from plants have been widely studied in the context of metabolic diseases and associated clinical conditions. In this regard, although the effects of Camellia sinensis plant, from which various types of teas, such as green tea, originate, have been vastly reported in the literature, the mechanisms underlying these effects remain elusive. A deep search of the literature showed that green tea's action in different cells, tissues, and diseases is an open field in the research of microRNAs (miRNAs). miRNAs are important communicator molecules between cells in different tissues implicated in diverse cellular pathways. They have emerged as an important linkage between physiology and pathophysiology, raising the issue of polyphenols can act also by changing miRNA expression. miRNAs are short, non-coding endogenous RNA, which silence the gene functions by targeting messenger RNA (mRNA) through degradation or translation repression. Therefore, the aim of this review is to present the studies that show the main compounds of green tea modulating the expression of miRNAs in inflammation, adipose tissue, skeletal muscle, and liver. We provide an overview of a few studies that have tried to demonstrate the role of miRNAs associated with the beneficial effects of compounds from green tea. We have emphasized that there is still a considerable gap in the literature investigating the role and likely involvement of miRNAs in the extensive beneficial health effects of green tea compounds already described, indicating miRNAs as potential polyphenols' mediators with a promising field to be investigated.

Green tea beneficial effects involve changes in the profile of immune cells in the adipose tissue of obese mice.

PURPOSE: During obesity, the adipose tissue is usually infiltrated by immune cells which are related to hallmarks of obesity such as systemic inflammation and insulin resistance (IR). Green tea (GT) has been widely studied for its anti-inflammatory actions, including the modulation in the proliferation and activity of immune cells, in addition to preventing cardiovascular and metabolic diseases. METHODS: The aim of the present study was to analyze the population of immune cells present in the subcutaneous and epididymal white adipose tissue (WAT) of mice kept at thermoneutrality (TN) and fed with a high-fat diet (HFD) for 16 weeks, supplemented or not with GT extract (500 mg/kg/12 weeks). RESULTS: The HFD in association with TN has induced chronic inflammation, and IR in parallel with changes in the profile of immune cells in the subcutaneous and epidydimal WAT, increasing pro-inflammatory cytokines release, inflammatory cells infiltration, and fibrotic aspects in WAT. On the other hand, GT prevented body weight gain, in addition to avoiding IR and inflammation, and the consequent tissue fibrosis, maintaining a lower concentration of cytokines and a profile of immune cells similar to the control mice, preventing the harmful modulations induced by both HFD and TN. CONCLUSIONS: GT beneficial effects in WAT abrogated the deleterious effects triggered by HFD and TN, maintaining all immune cells and fibrotic markers at the same level as in lean mice. These results place WAT immune cells population as a potential target of GT action, also highlighting the positive effects of GT in obese mice housed at TN.

Green tea extract increases adiponectin and PPAR α levels to improve hepatic steatosis.

We postulated that Green tea (GT) improvements in non-alcoholic fatty liver disease (NAFLD) are dependent on adiponectin action in the liver. Male wild-type and adiponectin knockout (adipoKO) mice were induced to obesity for 8 weeks with a high-fat diet and then treated with GT for the last 12 weeks of the experimental protocol. Glucose and insulin tolerance tests, indirect calorimetry, histologic analysis of liver sections, and quantification of mRNA of hepatic genes related to glucose or fatty acid metabolism were performed. In vitro, we assessed the mechanism by which GT catechins act to improve hepatic steatosis by measuring lipid accumulation, and transcript levels of lipogenic genes in HepG2 cells treated with GT in the presence of a PPAR antagonist. Additionally, we performed a PPAR transactivation assay in 293T cells to test if catechins could activate PPARs. Different from wild-type mice, adipoKO animals treated with GT and fed a HFD gain body weight and fat mass, that were associated with a decrease in energy expenditure, were insulin resistant, and had no improvements in hepatic steatosis. Increased lipid levels were associated with no modulation of PPARα levels in the liver of adipoKO mice treated with GT. In vitro, we demonstrated GT catechins act to reduce hepatic steatosis in a PPARα-dependent manner, and especially epigallocatechin and epicatechin can indirectly activate PPARα, although it seems they are not direct ligands. By providing the mechanisms by which GT catechins act in the liver to improve steatosis, our data contribute to the discovery of novel therapeutic agents in the management of NAFLD.

Effect of Resistance Training With Total and Partial Blood Flow Restriction on Biomarkers of Oxidative Stress and Apoptosis in Untrained Men.

Introduction: The characterization of immune and oxidative stress responses to acute and chronic exercise training is important because it may aid in the safety and dose-response prescription of resistance training (RT) in many populations. Purpose: The present study compared changes in acute oxidative stress and markers of apoptosis in immune cells before and after 8 weeks of low-load RT with total or partial blood flow restriction (BFR) versus high-load traditional RT. Methods: Twenty-seven untrained men were randomly divided into three groups: traditional RT [75% one-repetition maximum (1-RM)], RT with partial (20% 1-RM), and total BFR (20% 1-RM). Over an 8-week period, participants performed six sets of arm curls until failure with 90 seconds of recovery for 3 days/week. Blood samples were obtained before and after the first and last training sessions. Results: Data indicated that all training groups showed similar increases in muscular strength (p < 0.001), reduction in mitochondrial membrane potential (MMP) after exercise in neutrophils (p < 0.001), and increase in caspase-3 activity after exercise (p < 0.001). Traditional RT and total BFR showed increased plasma lipid peroxidation (p < 0.001) and protein carbonyls (p < 0.001) and lower levels of reduced glutathione (GSH) (p < 0.001) after exercise. No change was observed in oxidative stress biomarkers in response to partial BFR (p > 0.05). Conclusion: Data show that RT with partial BFR can increase muscular strength but still does not augment biomarkers of oxidative stress in untrained men. In addition, RT with total BFR promoted similar responses of oxidative stress and markers of immune cell apoptosis versus traditional RT.

On the Validity of Adipogenic Cell Lines as Model Systems for Browning Processes: In Authentic Brown, Brite/Beige, and White Preadipocytes, There is No Cell-Autonomous Thermogenic Recruitment by Green Tea Compounds.

The potential ability of nutritional compounds to induce or enhance the browning of adipocytes has attracted large interest as a workable means of combatting the obesity epidemic. Green tea compounds are discussed as such inducers of an enhanced thermogenic capacity and activity. However, the cell-autonomous effects of green tea compounds on adipocytes have until now only been demonstrated in adipogenic cell lines (3T3-L1 and 3T3-F442A), i.e., cells of undefined tissue lineage. In this study, we examine the ability of green tea compounds to cell-autonomously induce thermogenic recruitment in authentic brown and brite/beige adipocytes in vitro. In primary brown adipocytes, the green tea compounds suppressed basal UCP1 gene expression, and there was no positive interaction between the compounds and adrenergic stimulation. In white adipocytes, green tea compounds decreased both basal and norepinephrine-induced UCP1 mRNA levels, and this was associated with the suppression of cell differentiation, indicated by reduced lipogenic gene expression and lipid accumulation. A lack of interaction between rosiglitazone and green tea compounds suggests that the green tea compounds do not directly interact with the PPARγ pathway. We conclude that there is a negative effect of the green tea compounds on basal UCP1 gene expression, in both brown and white primary adipocytes, in contrast to the positive effects earlier reported from studies in adipogenic cell lines. We posit that the epigenetic status of the adipogenic cell lines is fundamentally different from that of genuine brown and white adipocytes, reflected, e.g., in several-thousand-fold differences in UCP1 gene expression levels. Thus, results obtained with adipogenic cell lines cannot unreservedly be extrapolated as being relevant for authentic effects in brown and white adipocytes. We suggest that this conclusion can be of general concern for studies attempting to establish physiologically relevant cell-autonomous effects.

Green tea improves the metabolism of peripheral tissues in ß3-adrenergic receptor-knockout mice.

Our goal was to establish the requirement of ß3 adrenoceptor (ß3Adr) for green tea (GT) effects on the energy metabolism of obese mice. This study was carried out in wild-type (WT) and ß3Adr knockout (KO) male mice fed with a standard diet or a high-fat diet (HFD/16 weeks) treated or not with GT (0.5 g/kg of body weight (BW)/12 weeks). GT-treatment attenuated final BW, BW gain, and adiposity index increased by HFD, improving insulin resistance (IR) and FGF21 level, without changing the food intake of WT mice. GT-treatment of ß3AdrKO mice attenuated only IR, denoting GT-effects independent of ß3Adr. We observed increased lipolysis accompanied by decreased adipocyte size in white adipose tissue (WAT) as well as browning of the subcutaneous WAT induced by GT in a way dependent on ß3Adr. In brown adipose tissue (BAT) mRNA levels of lipolytic/oxidative genes, including ß3Adr/Ucp1 and energy expenditure (EE) was increased by GT dependent on ß3Adr. GT-treatment increased adiponectin independent of ß3Adr. Also, independent of ß3Adr pathway GT promoted an increase in ß2Adr/Ucp1 mRNA levels and EE in BAT whereas; in the liver, GT has a dual role in increasing lipid synthesis and oxidation. These data lead us to suggest that GT uses ß3Adr pathway activation to achieve some of its beneficial health effects.

Adipogenic commitment induced by green tea polyphenols remodel adipocytes to a thermogenic phenotype.

The potential contribution of green tea (GT) to the development of thermogenic/beige cells have been scarcely investigated. Here we investigated if the beneficial effects of GT in the induction of thermogenic/beige adipocytes results from an initial cell commitment during adipogenesis. Male C57Bl/6 mice (3 months) were divided into 3 groups: Control (chow diet), Obese (cafeteria diet), and Obese + GT. Mice received GT gavage (500 mg/kg of BW) over 12 weeks (5 days/week), after 4 weeks of diet, totalizing 16 weeks of experimentation. GT treatment increased energy expenditure (EE) in mice fed with cafeteria-diet leading to reduced BW gain, decreased adiposity, reduced inflammation, and improving insulin sensitivity. Those phenotypes were associated with enhanced expression of oxidative, thermogenic and beige genes. GT induced a futile cycle through de novo lipogenesis activating the thermogenic pathway. Induction of beige phenotype occurs autonomously in adipocytes and involves the PPARγ/FGF21/AMPK/UCP1 pathway. Our study identified that metabolic changes caused by GT may involve the temporal expression of PPARγ promoting the induction of thermogenic cells by reprogramming initial steps of adipocyte commitment.

Polyphenol-rich green tea extract induces thermogenesis in mice by a mechanism dependent on adiponectin signaling.

Adiponectin is downregulated in obesity negatively impacting the thermogenesis and impairing white fat browning. Despite the notable effects of green tea (GT) extract in the enhancement of thermogenesis, if its effects are being mediated by adiponectin has been scarcely explored. For this purpose, we investigated the role of adiponectin in the thermogenic actions of GT extract by using an adiponectin-knockout mice model. Male wild-type (WT) and knockout (AdipoKO) C57Bl/6 mice (3 months) were divided into 6 groups: mice fed a standard diet+gavage with water (SD WT, and SD AdipoKO), high-fat diet (HFD)+gavage with water (HFD WT, and HFD AdipoKO), and HFD + gavage with 500 mg/kg of body weight (BW) of GT extract (HFD + GT WT, and HFD + GT AdipoKO). After 20 weeks of experimentation, mice were euthanized and adipose tissue was properly removed. Our findings indicate that treatment with GT extract reversed complications of obesity in WT mice by decreasing final BW gain, adiposity index, adipocyte size and insulin resistance (IR). However, the action of the GT extract was not effective in reversing those markers in the AdipoKO mice, although GT acts independently in the reversal of IR. GT-treatment induced enhancement in energy expenditure (EE), BAT thermogenesis, and promoted browning phenotype in the subcutaneous WAT (scWAT) of WT mice. On the other hand, the thermogenic program was markedly impaired in BAT and scWAT of AdipoKO mice. Our outcomes unveiled adiponectin as a key direct signal for GT extract inducing adaptive thermogenesis and browning in scWAT.

Memory impairments and increased GFAP expression in hippocampal astrocytes following hypercaloric diet in rats.

OBJECTIVE: Hypothalamic inflammation and glial fibrillary acidic protein (GFAP) overexpression in astrocytes are well described in obese animals, as are some cognitive and memory deficits. As the hippocampus plays important roles in the consolidation of information, this investigation aimed to observe the memory function and the astrocyte expression of GFAP in the hippocampus of rats that received either a hypercaloric or a normocaloric diet. METHODS: Adult male Wistar rats received a high-fat (cafeteria) or a standard diet for 60 days. On the 61st day, the rats were submitted to the novel object recognition (NOR) test at three and 24 hours after the first contact with objects, to assess short-term and long-term memory, respectively. Thereafter, the rats were euthanized and their brains were collected for GFAP immunohistochemical investigation in the hippocampus (CA1, CA2, CA3 areas) and hypothalamus (periventricular and arcuate nuclei). Astrocytic reactivity was assessed by morphometry. Different white adipose tissue depots and brown adipose tissue were weighed to calculate the adiposity index. RESULTS: The hypercaloric diet increased body weight gain, adiposity index, white adipose tissue weight (epididymal, subcutaneous and retroperitoneal) and brown adipose tissue weight. Rats fed with the hypercaloric diet showed short-term and long-term memory impairments in the NOR test, as well as increased GFAP expression in astrocytes from all analyzed hypothalamic and hippocampal areas. CONCLUSION: This astrogliosis suggests that the neuroinflammatory response also occurs in the hippocampus and may be involved in the memory losses observed in obese/overweight animals.

Memory impairments and increased GFAP expression in hippocampal astrocytes following hypercaloric diet in rats / Prejuízos de memória e expressão aumentada de GFAP em astrócitos hipocampais após dieta hipercalórica em ratos

ABSTRACT Objective: Hypothalamic inflammation and glial fibrillary acidic protein (GFAP) overexpression in astrocytes are well described in obese animals, as are some cognitive and memory deficits. As the hippocampus plays important roles in the consolidation of information, this investigation aimed to observe the memory function and the astrocyte expression of GFAP in the hippocampus of rats that received either a hypercaloric or a normocaloric diet. Methods: Adult male Wistar rats received a high-fat (cafeteria) or a standard diet for 60 days. On the 61st day, the rats were submitted to the novel object recognition (NOR) test at three and 24 hours after the first contact with objects, to assess short-term and long-term memory, respectively. Thereafter, the rats were euthanized and their brains were collected for GFAP immunohistochemical investigation in the hippocampus (CA1, CA2, CA3 areas) and hypothalamus (periventricular and arcuate nuclei). Astrocytic reactivity was assessed by morphometry. Different white adipose tissue depots and brown adipose tissue were weighed to calculate the adiposity index. Results: The hypercaloric diet increased body weight gain, adiposity index, white adipose tissue weight (epididymal, subcutaneous and retroperitoneal) and brown adipose tissue weight. Rats fed with the hypercaloric diet showed short-term and long-term memory impairments in the NOR test, as well as increased GFAP expression in astrocytes from all analyzed hypothalamic and hippocampal areas. Conclusion: This astrogliosis suggests that the neuroinflammatory response also occurs in the hippocampus and may be involved in the memory losses observed in obese/overweight animals.

RESUMO Objetivo: A inflamação hipotalâmica e a superexpressão da proteína glial fibrilar ácida (GFAP) em astrócitos são bem descritas em animais obesos, assim como déficits cognitivos e de memória. Como o hipocampo desempenha importante papel na consolidação de informações, esta investigação teve como objetivo observar a função da memória e a expressão astrocitária da GFAP no hipocampo de ratos que receberam dieta hipercalórica ou normocalórica. Métodos: Ratos Wistar machos adultos receberam dieta rica em gordura (cafeteria) ou dieta padrão por 60 dias. No 61º dia, os ratos foram submetidos ao teste de reconhecimento de objetos (NOR) 3 e 24 horas após o primeiro contato com os objetos, para avaliação da memória de curto e de longo prazo, respectivamente. Após, os ratos foram eutanasiados e os encéfalos coletados para pesquisa imuno-histoquímica da expressão astrocitária de GFAP no hipocampo (áreas CA1, CA2 e CA3) e no hipotálamo (núcleos periventricular e arqueado). A reatividade astrocitária foi avaliada por morfometria. Diferentes depósitos de tecido adiposo branco e marrom foram pesados para calcular o índice de adiposidade. Resultados: A dieta hipercalórica aumentou o ganho de peso corporal, o índice de adiposidade, o peso do tecido adiposo branco (epididimal, subcutâneo e retroperitoneal) e marrom. Ratos alimentados com dieta hipercalórica apresentaram prejuízos na memória de curto e longo prazo no teste NOR e aumento da expressão de GFAP em astrócitos de todas as áreas hipotalâmicas e hipocampais analisadas. Conclusão: Esta astrogliose sugere que a resposta neuroinflamatória também ocorre no hipocampo, podendo estar envolvida nas perdas de memória observadas em animais obesos/com sobrepeso.

Comparison of perceptual responses between different upper-body sprint interval exercise protocols.

This study examined the perceptual responses to various upper-body sprint interval exercise (SIE) protocols matched for total work and work/rest ratio. Fourteen active men (24 ±â€¯4 years, BMI = 26.2 ±â€¯2.7 kg/m2, body fat = 11.5 ±â€¯4.4%) participated in 3 all-out SIE protocols consisting of battling rope exercise: P10:30 (12 × 10-s bouts with 30-s recovery); P15:45 (8 × 15-s bouts with 45 s recovery); and P30:90 (4 × 30-s bouts with 90-s recovery). During exercise, affective valence (FS +5 to -5), arousal (FAS 1-6), rating of perceived exertion (RPE 6-20), and heart rate (HR) were assessed. Post-exercise, enjoyment, self-efficacy, and intentions were measured. Results revealed a significant decline in FS (p = .02; partial eta squared [η2p] = 0.27) and a progressive increase in FAS (p = .001; η2p = 0.86), RPE (p = .001; η2p = 0.88), and HR (p = .001; η2p = 0.94), but no protocol X time interaction. Affective valence reached a nadir at values equal to -0.36 ±â€¯3.41 (Cohen's d = -0.49), -0.43 ±â€¯3.75 (Cohen's d = -0.44), and - 0.93 ±â€¯3.49 (Cohen's d = -0.56) in response to P10:30, P15:45, and P30:90, respectively. There were no differences between protocols for enjoyment, intention, or self-efficacy. A negative relationship exhibited between FS and RPE was moderated by participants' tolerance of exercise intensity (ß = 1.84, p < .05). Further, the association between FS and future intention was mediated by self-efficacy. Overall, upper-body SIE protocols exhibit similar perceptual responses when volume and work to rest ratio (1:3) are matched. Tolerance of exercise intensity may be used to predict changes in FS during SIE.

Redox status on different regions of the central nervous system of obese and lean rats treated with green tea extract.

OBJECTIVES: The purpose of this study was to evaluate some indicators of redox status, and inflammation on different regions of the central nervous system (CNS) of obese rats treated with green tea (GT). We hypothesized that obesity could affect the redox balance in different brain regions due to the diverse nature of the cells as well as the selective neuronal vulnerability to oxidative stress, and GT could triggers benefits effects restoring the redox status. METHODS: Male Wistar rats were treated with GT by gavage (12 weeks/5 days/week; 500 mg/kg of body weight) and obesity was induced by cafeteria diet (8 weeks). After this period, the animals were killed and brain tissue (cerebral cortex, cerebellum, and brainstem) was removed to evaluate oxidative stress and inflammation (cytokine release). RESULTS: We showed that the cafeteria diet had little effect on redox balance in the cerebral cortex and cerebellum; however, the brainstem was the region of the CNS most sensitive to cafeteria diet-induced redox unbalance. GFAP expression was increased in the cerebral cortex of obese rats and reduced by GT. It was also evident that GT treatment had numerous beneficial effects against oxidative damage to biomolecules in all brain regions analyzed. DISCUSSION: Our study established that different CNS regions show selective neuronal vulnerability when exposed to a diet enriched with fats and sugars, and the beneficial effect of GT was similar among these regions. We conclude that GT could be a good strategy for improving and maintaining brain function under healthy and pathological conditions.

Polyphenol-rich green tea extract improves adipose tissue metabolism by down-regulating miR-335 expression and mitigating insulin resistance and inflammation.

Obesity leads to changes in miRNA expression in adipose tissue, and this modulation is linked to the pathophysiology of the disease. Green tea (GT) is a natural source of polyphenols that have been shown to confer health benefits, particularly preventing metabolic diseases. Here, we investigated if the beneficial effects of GT in obesity results from changes in the miRNA profile in white adipose tissue. GT treatment [500 mg/body weight (BW)/12 weeks] increased energy expenditure of high-fat diet-fed mice (16 weeks), leading to reduced weight gain, decreased adiposity, reduced inflammation and improved insulin sensitivity. These phenotypes were associated with a decrease in the expression of miR-335 in the adipose tissue. miR-335 was up-regulated by TNF-α in adipocytes and, in turn, down-regulated genes involved in insulin signaling and lipid metabolism. On the other hand, GT inhibited TNF-α effect. In conclusion, miR-335 serves as a link between inflammation and impaired metabolism in adipose tissue, providing an important mechanistic insight into the molecular basis underlying GT action during obesity.

Green tea extract activates AMPK and ameliorates white adipose tissue metabolic dysfunction induced by obesity.

PURPOSE: Beneficial effects of green tea (GT) polyphenols against obesity have been reported. However, until this moment the molecular mechanisms of how green tea can modulate obesity and regulates fat metabolism, particularly in adipose tissue, remain poorly understood. The aim of this study was to evaluate the role of GT extract in the adipose tissue of obese animals and its effect on weight gain, metabolism and function (de novo lipogenesis and lipolysis), and the involvement of AMP-activated protein kinase (AMPK). METHODS AND RESULTS: Male Wistar rats were treated with GT by gavage (12 weeks/5 days/week; 500 mg/kg of body weight), and obesity was induced by cafeteria diet (8 weeks). Here, we show that obese rats treated with GT showed a significant reduction in indicators of obesity such as hyperlipidemia, fat synthesis, body weight, and fat depots as compared to those treated with standard control diet. AMPK was induced in adipose tissue in rats that were treated with GT and likely restored insulin sensitivity, increased mRNA expression of GLUT4, reducing the concentrations of plasma and liver lipid content, also stimulating fatty acid oxidation in the same tissue. Importantly, repression of de novo lipogenesis in the adipose tissue, reduced lipid droplets in the liver, and the development of insulin resistance in diet-induced obese rats were accompanied by AMPK activation. CONCLUSION: Our study identified that metabolic changes caused by GT intake induced AMPK activation and modulate the expression of genes involved in metabolism, particularly in adipose tissue, thus offering a therapeutic strategy to combat insulin resistance, dyslipidemia, and obesity in rats.

Comparative effect of fucoxanthin and vitamin C on oxidative and functional parameters of human lymphocytes.

The aim of this study was to evaluate the effects of FUCO alone or combined with vitamin C on different features of lymphocyte function related to ROS/RNS (reactive oxygen/nitrogen species) production. For this purpose we have evaluated the cytotoxicity of increasing concentrations of FUCO and vitamin C, the proliferative capacity of stimulated T- and B-lymphocytes, superoxide anion radicals (O(2)), hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) production, antioxidant enzyme activities and the indexes of oxidative damage in proteins (carbonyl and thiol content). We have also evaluated the release of inflammatory cytokines and glucose-6-phosphate dehydrogenase (G6PDH) activity. Healthy human lymphocytes were acutely treated in vitro with FUCO (2 µM) with or without vitamin C (100 µM). Results revealed that human lymphocytes treated with FUCO at 2µM did not present any significant alteration in the proliferation of T- and B-lymphocytes at both resting and stimulated conditions. Moreover, FUCO used at low concentrations showed more pro-oxidant than antioxidant effects, which were recognized by the increased H(2)O(2) and increased NO production. Anti-inflammatory activity of FUCO was confirmed by significantly increased IL-10 and decreased TNF-α production. Vitamin C increased T-lymphocyte proliferation, whereas vitamin C plus FUCO promoted a reduction in the proliferation rate of these cells. All groups decreased pro-inflammatory cytokine TNF-α and increased anti-inflammatory IL-10 production although only vitamin C decreased IFN-γ either alone or when combined with FUCO. Overall, the combination of the antioxidants had more antioxidant and anti-inflammatory effects than when they were applied alone.

Effect of astaxanthin and fish oil on enzymatic antioxidant system and ?-amylase activity of salivary glands from rats

Salivary glands contribute to oral health. It is therefore of interest to study therapies that may favor their function and protection. AIM: To evaluate the effect of astaxanthin, fish oil and association of them on enzymatic antioxidant system and functional parameters of salivary glands. METHODS: Healthy rats (n=32) were divided into 4 groups: untreated-control, astaxanthin-treated (1 mg/kg body weight- BW), fish oil-treated (10 mg EPA/kg BW and 7 mg DHA/kg BW), and fish oil plus astaxanthin-treated. A prophylactic dose was administered in each group daily by gavage, for 45 days. Superoxide dismutase (SOD), catalase, glutathione peroxidase, reductase, and α-amylase activities were determined in salivary glands and compared by ANOVA and Tukey post-test (p<0.05). RESULTS: Parotid gland presented increased catalase and glutathione system and unaffected SOD activity after astaxanthin and astaxanthin plus fish oil treatment (p<0.05). Fish oil stimulated only glutathione peroxidase activity of parotid gland (p<0.05). Submandibular gland presented stimulated SOD and catalase, and reduced glutathione reductase activities after fish oil and fish oil plus astaxanthin treatment (p<0.05). SOD and glutathione reductase activities were reduced by astaxanthin treatment in submandibular gland (p<0.05). Parotid gland presented increased α-amylase activity in all groups supplemented and submandibular glands presented no changes (p<0.05). CONCLUSIONS: Astaxanthin, fish oil and combination of them stimulated the antioxidant system and functional parameter of salivary glands, which could be beneficial to oral health.

Oxidative stress and antioxidant status response of handball athletes: implications for sport training monitoring.

The chronic exposure to regular exercise training seems to improve antioxidant defense systems. However, the intense physical training imposed on elite athletes may lead to overtraining associated with oxidative stress. The purpose of the present study was to investigate the effect of different training loads and competition on oxidative stress, biochemical parameters and antioxidant enzymatic defense in handball athletes during 6-months of monitoring. Ten male elite handball athletes were recruited to the study. Blood samples were collected four times every six weeks throughout the season. During most intense periods of training and competitions there were significant changes in plasma indices of oxidative stress (increased TBARS and decreased thiols). Conversely, chronic adaptations to exercise training demonstrated a significant protective effect against oxidative stress in erythrocyte (decrease in TBARs and carbonyl group levels). Erythrocyte antioxidant enzyme activities were significantly increased, suggesting a training-induced antioxidant adaptation. Biomarkers of skeletal muscle damage were significantly increased during high-intensity training period (creatine kinase, lactate dehydrogenase and aspartate aminotransferase). No significant changes were observed in plasma IL-6, TNF-α and uric acid, whereas a significant reduction was found in the IL-1ß concentration and gamma-glutamyl transferase activity. Oxidative stress and antioxidant biomarkers can change throughout the season in competitive athletes, reflecting the physical stress and muscle damage that occurs as the result of competitive handball training. In addition, these biochemical measurements can be applied in the physiological follow-up of athletes.

Efeito do gênero (masculino e feminino) sobre a cárie dentária e parâmetros salivares de crianças / Effect of gender on dental caries and salivary parameters of children

Objetivo: avaliar o índice de cárie dentária e parâmetros salivares comparando meninos e meninas.Métodos: a saliva total estimulada mecanicamente com parafilm foi coletada de 46 crianças saudáveis, com quatro a seis anos de idade, sendo 24 meninos e 22 meninas. As crianças foram divididas em subgrupos de acordo com o gênero (meninos e meninas) e presença de cárie dentária (cavidades de cárie, CC; livres de cárie, CF). A cárie dentária foi avaliada usando os critérios da OMS e Kappa=0,87. O grupo CC foi definido pela presença de no mínimo três superfícies com necessidade de restauração e o grupo CF pela ausência de dentes com lesões de cárie clinicamente detectáveis (ceo-s=o). Os parâmetros salivares avaliados foram o fluxo salivar, a concentração de proteína total e a atividade enzimática da peroxidase. Os resultados foram comparados por teste t de Student e Análise de Variância e teste de Tukey para contraste de média (p≤0,05). Resultados: crianças com cárie dentária apresentaram redução de 33% do fluxo salivar comparadas com crianças sem cárie dentária (p≤0,05). Entre as crianças com cárie dentária, as meninas apresentaram maior índice de cárie dentária comparadas com os meninos (98%, p≤0.05). As meninas apresentaram diferenças salivares mais pronunciadas comparados aos meninos, com maior concentração de proteína total e menor fluxo salivar e atividade da peroxidase (p≤0,05). Conclusão: o estudo sugere que o gênero pode influenciar o desenvolvimento de cárie dentária e parâmetros salivares de crianças...

Objective: To evaluate the dental caries index and salivary parametersin boys and girls. Method: Whole stimulated saliva by chewing Parafilm® was collected from 46 healthy children (24 boys and 22 girls) aged 4 to 6 years. The children were assigned to subgroups according to gender (boys andgirls) and dental caries (CC û caries cavities; CF û caries free). Dentalcaries was evaluated using the WHO criteria and kappa=0.87. The CC group was defined by the presence of at least three surfaces requiring restoration while the CF group was characterized by the absence of clinically detectable caries (ceo-s=0). The following salivary parameters were evaluated: salivary flow, total protein concentration andperoxidase enzymatic activity. The results were compared by theStudentÆs t-test, ANOVA and TukeyÆs multiple-comparison test (p≤0.05).Results: Children with dental caries presented a 33% reduction of salivary flow compared to the caries-free children (p≤0.05). Among the children with dental caries, the girls had a greater caries index than the boys (98%, p≤0.05). The girls presented more accentuated salivary parameters than boys, with greater total protein concentration, lower salivary flow and lower peroxidase activity (p≤0.05).Conclusion: This study suggests that gender might influence the development of dental caries and the salivary parameters in children...

Glycolaldehyde impairs neutrophil biochemical parameters by an oxidative and calcium-dependent mechanism--protective role of antioxidants astaxanthin and vitamin C.

AIM: The present study examined the effects of glycolaldehyde (GC) on biochemical parameters of human neutrophils and whether the antioxidant astaxanthin associated with vitamin C can modulate these parameters. METHODS: Neutrophils from healthy subjects were treated with GC (1mM) followed or not by the antioxidants astaxanthin (2 µM) and vitamin C (100 µM). We examined the phagocytic capacity, hypochlorous acid, myeloperoxidase (MPO) and glucose-6-phosphate dehydrogenase (G6PDH) activities, cytokines and [Ca(2+)](i). Also, superoxide anion, hydrogen peroxide, nitric oxide production, antioxidant enzyme activities and glutathione-recycling system were evaluated. RESULTS: GC promoted a marked reduction on the phagocytic capacity, maximal G6PDH and MPO activities, hypochlorous acid production and release of IL-1ß, IL-6 and TNF-α cytokines. Some impairment in the neutrophils biochemical parameters appears to be mediated by oxidative stress through ROS/RNS production and calcium reduction. Oxidative stress was evidenced by reduction in the activities of the main antioxidant enzymes, GSH/GSSG ratio and in the increment of O(2)(-) and H(2)O(2) and NO. CONCLUSIONS: Treatment of cells with the combination of the antioxidants astaxanthin and vitamin C was able to restore some neutrophils function mainly by decreasing ROS/RNS production and improving the redox state. Overall, our findings demonstrate that GC modulates several neutrophils biochemical parameters in vitro.