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1.
J Food Biochem ; 46(10): e14324, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35892210

RESUMO

Avenanthramides are phenolic compounds unique to oats and may contribute to health-promoting properties associated with oat consumption. This study used Xenopus laevis oocytes expressing the glucose transporters, glucose transporter 2 (GLUT2) or sodium-glucose transport protein 1 (SGLT1) and human Caco-2 cells models to investigate the effect of oat avenanthramides on human intestinal glucose transporters. The presence of avenanthramide reduced the glucose uptake in a dose-dependent manner in Caco-2 cells. Glucose uptake in oocytes expressing either GLUT2 or SGLT1 was nullified by oat avenanthramide. There was no significant difference between the inhibition potencies of avenanthramides C and B. Thus, our results suggest that avenanthramides may contribute to the antidiabetic properties of oats. PRACTICAL APPLICATIONS: The present research focus on the antidiabetic properties of avenanthramides, which are unique phenolic compounds found in oats. Inhibiting the activities of the glucose transport proteins expressed in the small intestine is a known strategy to improve the control of postprandial glucose level. We therefore examined the inhibitory effects of avenanthramides on two glucose transporters, glucose transporter 2 and sodium-glucose transport protein 1, predominantly found in the small intestine using the human small intestinal cell model Caco-2 cell line and by heterologously expressing these two transporters in the Xenopus laevis oocytes. Based on our results, we have confirmed for the first time that the glucose uptake is indeed inhibited by the presence of avenanthramides, suggesting the possibility of incorporating avenanthramides in foods to enhance postprandial glucose response, and ultimately improve the management of diabetes. Therefore, future research could consider utilizing this evidence in the development of diabetic-friendly functional foods or nutraceuticals containing avenanthramides.


Assuntos
Avena , Glucose , Avena/metabolismo , Células CACO-2 , Grão Comestível/metabolismo , Glucose/metabolismo , Proteínas Facilitadoras de Transporte de Glucose , Humanos , Hipoglicemiantes/farmacologia , Fenóis , ortoaminobenzoatos
2.
Eur J Appl Physiol ; 116(1): 67-76, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26289619

RESUMO

PURPOSE: Rigorous exercise is known to generate reactive oxygen species (ROS) and inflict inflammatory response. The present study investigated whether dietary supplementation of avenanthramides (AVA) in oats would increase antioxidant protection and reduce inflammation in humans after an acute bout of eccentric exercise. METHODS: Young women (age 18-30 years, N = 16) were randomly divided into two groups in a double-blinded fashion, receiving two cookies made of oat flour providing 9.2 mg AVA (AVA) or 0.4 mg AVA (Control, C) each day for 8 weeks. Before and after the dietary regimen each group of subjects ran downhill (DR) on a treadmill at -9% grade for 1 h at a speed to elicit 75% of maximal heart rate. Blood samples were collected at rest, immediately and 24 h post-DR. RESULTS: Before dietary supplementation plasma creatine kinase activity and tumor necrosis factor (TNF)-α concentration were increased immediately after DR (P < 0.05), whereas neutrophil respiratory burst (NRB) was elevated 24 h post-DR (P < 0.05). CK and TNF-α response to DR was abolished during post-supplementation tests in both AVA and C groups, whereas NRB was blunted only in AVA but not in C. Plasma interleukin-6 level and mononuclear cell nuclear factor (NF) κB activity were not affected by DR either before or after dietary supplementation, but were lowered 24 h post-DR in AVA versus C (P < 0.05). Both groups increased plasma total antioxidant activity following 8-week dietary regimen (P < 0.05), whereas only AVA group increased resting plasma glutathione (GSH) concentration (P < 0.05), decreased glutathione disulfide response to DR, and lowered erythrocyte GSH peroxidase activity (P < 0.05). CONCLUSIONS: Our data of pre- and post-supplementation difference reflect an interaction between repeated measure effect of eccentric exercise and AVA in diet. Long-term AVA supplementation can attenuate blood inflammation markers, decrease ROS generation and NFkB activation, and increased antioxidant capacity during an eccentric exercise bout.


Assuntos
Antioxidantes/metabolismo , Biomarcadores/sangue , Exercício Físico/fisiologia , Inflamação/metabolismo , Músculo Esquelético/fisiologia , ortoaminobenzoatos/administração & dosagem , Adolescente , Adulto , Suplementos Nutricionais , Teste de Esforço/métodos , Feminino , Humanos , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Adulto Jovem
3.
Nutr J ; 13: 21, 2014 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-24645793

RESUMO

During aging, chronic systemic inflammation increases in prevalence and antioxidant balance shifts in favor of oxidant generation. Avenanthramide (AVA) is a group of oat phenolics that have shown anti-inflammatory and antioxidant capability. The present study investigated whether dietary supplementation of avenanthramides (AVA) in oats would increase antioxidant protection and reduce inflammation after a bout of downhill walking (DW) in postmenopausal women. Women at age of 50-80 years (N = 16) were randomly divided into two groups in a double-blinded fashion, receiving two cookies made of oat flour providing 9.2 mg AVA or 0.4 mg AVA (control, C) each day for 8 weeks. Before and after the dietary regimen, each group of subjects walked downhill on a treadmill (-9% grade) for 4 bouts of 15 minutes at a speed of 4.0 km/h with 5 minutes rest between sessions. Blood samples were collected at rest, 24 h post-DW, and 48 h post-DW pre- and post-supplementation. Both DW sessions increased plasma creatine kinase activity (P < 0.05). Before supplementation, in vitro neutrophil respiratory burst (NRB) activity was increased at 24 h post-DW (P < 0.05) and C-reactive protein (CRP) was increased 48 h post-DW (P < 0.05). AVA supplementation decreased DW-induced NRB at 24 h (P < 0.05) and CRP level 48 h (P < 0.05). Plasma interleukin (IL)-1ß concentration and mononuclear cell nuclear factor (NF) κB binding were suppressed at rest and during post-DW period in AVA but not C group (P < 0.05). Plasma total antioxidant capacity (P < 0.05) and erythrocyte superoxide dismutase activity were increased in AVA vs. C (P < 0.05), whereas glutathione redox status was elevated 48 h post-DW but not affected by AVA. Thus, chronic AVA supplementation decreased systemic and DW-induced inflammation and increased blood-borne antioxidant defense in postmenopausal women.


Assuntos
Anti-Inflamatórios/uso terapêutico , ortoaminobenzoatos/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Antioxidantes/metabolismo , Avena/química , Proteína C-Reativa/metabolismo , Creatina Quinase/sangue , Suplementos Nutricionais , Método Duplo-Cego , Teste de Esforço , Feminino , Humanos , Inflamação/sangue , Inflamação/tratamento farmacológico , Interleucina-1beta/sangue , Interleucina-6/sangue , Pessoa de Meia-Idade , NF-kappa B/sangue , Pós-Menopausa , Explosão Respiratória , Superóxido Dismutase/sangue , Caminhada
4.
Food Chem ; 139(1-4): 426-31, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23561127

RESUMO

Oats are gaining increasing scientific and public interest for their purported antioxidant-associated health benefits. Most reported studies focused on specific oat extracts or particular oat components, such as ß-glucans, tocols (vitamin E), or avenanthramides. Studies on whole oats with respect to antioxidant and anti-inflammatory activities are still lacking. Here the antioxidant and anti-inflammatory activities from whole oat groats of seven common varieties were evaluated. All oat varieties had very similar oxygen radical absorption capacity compared with other whole grains. In an anti-inflammatory assay, oat variety CDC Dancer inhibited tumor necrosis factor-α induced nuclear factor-kappa B activation by 27.5% at 2 mg/ml, whereas variety Deiter showed 13.7% inhibition at a comparable dose. Avenanthramide levels did not correlate with the observed antioxidant and anti-inflammatory activities. Further investigations are needed to pinpoint the specific antioxidant and anti-inflammatory compounds, and potential synergistic and/or matrix effects that may help explain the mechanisms of oat's anti-inflammatory actions.


Assuntos
Anti-Inflamatórios/análise , Antioxidantes/análise , Avena/química , Fenóis/análise , Extratos Vegetais/análise , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Avena/classificação , Sobrevivência Celular/efeitos dos fármacos , Células HEK293 , Humanos , NF-kappa B/antagonistas & inibidores , NF-kappa B/imunologia , Fenóis/farmacologia , Extratos Vegetais/farmacologia
5.
Age (Dordr) ; 35(6): 2183-92, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23344884

RESUMO

The complex mixture of phytochemicals in fruits and vegetables provides protective health benefits, mainly through additive and/or synergistic effects. The presence of several bioactive compounds, such as polyphenols and caffeine, implicates coffee as a potential nutritional therapeutic in aging. Moderate (three to five cups a day) coffee consumption in humans is associated with a significant decrease in the risk of developing certain chronic diseases. However, the ability of coffee supplementation to improve cognitive function in aged individuals and the effect of the individual components in coffee, such as caffeine, have not been fully evaluated. We fed aged rats (19 months) one of five coffee-supplemented diets (0, 0.165, 0.275, 0.55, and 0.825% of the diet) for 8 weeks prior to motor and cognitive behavior assessment. Aged rats supplemented with a 0.55% coffee diet, equivalent to ten cups of coffee, performed better in psychomotor testing (rotarod) and in a working memory task (Morris water maze) compared to aged rats fed a control diet. A diet with 0.55% coffee appeared to be optimal. The 0.165% coffee-supplemented group (three cups) showed some improvement in reference memory performance in the Morris water maze. In a subsequent study, the effects of caffeine alone did not account for the performance improvements, showing that the neuroprotective benefits of coffee are not due to caffeine alone, but rather to other bioactive compounds in coffee. Therefore, coffee, in achievable amounts, may reduce both motor and cognitive deficits in aging.


Assuntos
Envelhecimento/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Cafeína/farmacologia , Café , Transtornos Cognitivos/prevenção & controle , Cognição/fisiologia , Desempenho Psicomotor/efeitos dos fármacos , Animais , Bebidas , Estimulantes do Sistema Nervoso Central/farmacologia , Cognição/efeitos dos fármacos , Transtornos Cognitivos/fisiopatologia , Modelos Animais de Doenças , Masculino , Ratos , Ratos Endogâmicos F344
6.
J Agric Food Chem ; 57(20): 9801-8, 2009 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-19772322

RESUMO

Oxidative stress is involved in many neurodegenerative processes leading to age-related cognitive decline. Coffee, a widely consumed beverage, is rich in many bioactive components, including polyphenols with antioxidant potential. In this study, regular and decaffeinated samples of both roasted and green coffee all showed high hydrophilic antioxidant activity in vitro, whereas lipophilic antioxidant activities were on average 30-fold higher in roasted than in green coffee samples. In primary neuronal cell culture, pretreatment with green and roasted coffees (regular and decaffeinated) protected against subsequent H(2)O(2)-induced oxidative stress and improved neuronal cell survival (green coffees increased neuron survival by 78%, compared to 203% by roasted coffees). All coffee extracts inhibited ERK1/2 activation, indicating a potential attenuating effect in stress-induced neuronal cell death. Interestingly, only roasted coffee extracts inhibited JNK activation, evidencing a distinctive neuroprotective benefit. Analysis of coffee phenolic compounds revealed that roasted coffees contained high levels of chlorogenic acid lactones (CGLs); a significant correlation between CGLs and neuroprotective efficacy was observed (R(2) = 0.98). In conclusion, this study showed that roasted coffees are high in lipophilic antioxidants and CGLs, can protect neuronal cells against oxidative stress, and may do so by modulation of the ERK1/2 and JNK signaling pathways.


Assuntos
Antioxidantes/farmacologia , Ácido Clorogênico/farmacologia , Café/química , Lactonas/farmacologia , Fármacos Neuroprotetores/farmacologia , Animais , Antioxidantes/química , Sobrevivência Celular , Células Cultivadas , Ácido Clorogênico/análise , Coffea/química , Manipulação de Alimentos , Lactonas/análise , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/análise , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
7.
Life Sci ; 77(15): 1892-901, 2005 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-15982671

RESUMO

Cardiovascular disease (CVD) is the leading cause of death in most industrialized countries. Cranberries were evaluated for their potential roles in dietary prevention of CVD. Cranberry extracts were found to have potent antioxidant capacity preventing in vitro LDL oxidation with increasing delay and suppression of LDL oxidation in a dose-dependent manner. The antioxidant activity of 100 g cranberries against LDL oxidation was equivalent to 1000 mg vitamin C or 3700 mg vitamin E. Cranberry extracts also significantly induced expression of hepatic LDL receptors and increased intracellular uptake of cholesterol in HepG2 cells in vitro in a dose-dependent manner. This suggests that cranberries could enhance clearance of excessive plasma cholesterol in circulation. We propose that additive or synergistic effects of phytochemicals in cranberries are responsible for the inhibition of LDL oxidation, the induced expression of LDL receptors, and the increased uptake of cholesterol in hepatocytes.


Assuntos
Hepatócitos/efeitos dos fármacos , Lipoproteínas LDL/metabolismo , Extratos Vegetais/farmacologia , Receptores de LDL/metabolismo , Vaccinium macrocarpon/química , Aldeídos/metabolismo , Amidinas/metabolismo , Linhagem Celular Tumoral , Colesterol/metabolismo , Relação Dose-Resposta a Droga , Hepatócitos/metabolismo , Humanos , Oxirredução/efeitos dos fármacos , Peróxidos/metabolismo
8.
J Agric Food Chem ; 52(22): 6818-23, 2004 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-15506821

RESUMO

A novel model of peroxyl radical initiated low-density lipoprotein (LDL) oxidation (LDL oxidation model for antioxidant capacity, or LOMAC) was developed to assess the free radical scavenging capacity of antioxidants and the extracts of natural products. A water-soluble free radical initiator, 2,2'-azobis(amidinopropane) dihydrochloride, was used at physiological temperature (37 degrees C) to generate peroxyl radicals to catalyze lipid oxidation of LDL isolated from human plasma samples. Headspace hexanal, a major decomposition product of LDL oxidation, was measured by a headspace gas chromatograph as an indicator of antioxidant capacity of different concentrations of pure antioxidants (vitamins C and E) and the extracts of natural products (fresh apple phytochemical extracts). All vitamin C and E and apple extract concentrations tested resulted in increasing partial suppression and delay of LDL oxidation. On the basis of the median effective dose (EC(50)) calculated for each compound or extract tested, the LOMAC value of 100 g of apple against LDL oxidation was equivalent to 1470 mg of vitamin E or to 402 mg of vitamin C. This study shows that the LOMAC assay can be routinely used to analyze or screen antioxidants or phytochemical extracts against LDL oxidation to prevent cardiovascular disease. The food-specific LOMAC values will be very useful as a new alternative biomarker for future epidemiological studies of cardiovascular disease.


Assuntos
Peroxidação de Lipídeos , Lipoproteínas LDL/química , Aldeídos/análise , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Cromatografia Gasosa , Frutas/química , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Lipoproteínas LDL/sangue , Malus/química , Oxirredução , Peróxidos/química , Extratos Vegetais/farmacologia , Vitamina E/farmacologia
9.
J Agric Food Chem ; 50(25): 7449-54, 2002 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-12452674

RESUMO

Consumption of fruits and vegetables has been associated with reduced risk of chronic diseases such as cardiovascular disease and cancer. Phytochemicals, especially phenolics, in fruits and vegetables are suggested to be the major bioactive compounds for the health benefits. However, the phenolic contents and their antioxidant activities in fruits and vegetables were underestimated in the literature, because bound phenolics were not included. This study was designed to investigate the profiles of total phenolics, including both soluble free and bound forms in common fruits, by applying solvent extraction, base digestion, and solid-phase extraction methods. Cranberry had the highest total phenolic content, followed by apple, red grape, strawberry, pineapple, banana, peach, lemon, orange, pear, and grapefruit. Total antioxidant activity was measured using the TOSC assay. Cranberry had the highest total antioxidant activity (177.0 +/- 4.3 micromol of vitamin C equiv/g of fruit), followed by apple, red grape, strawberry, peach, lemon, pear, banana, orange, grapefruit, and pineapple. Antiproliferation activities were also studied in vitro using HepG(2) human liver-cancer cells, and cranberry showed the highest inhibitory effect with an EC(50) of 14.5 +/- 0.5 mg/mL, followed by lemon, apple, strawberry, red grape, banana, grapefruit, and peach. A bioactivity index (BI) for dietary cancer prevention is proposed to provide a new alternative biomarker for future epidemiological studies in dietary cancer prevention and health promotion.


Assuntos
Antioxidantes/análise , Frutas/química , Ananas/química , Divisão Celular/efeitos dos fármacos , Citrus/química , Fragaria/química , Ácido Gálico/análise , Malus/química , Musa/química , Fenóis/análise , Extratos Vegetais/química , Prunus/química , Pyrus/química , Vaccinium macrocarpon/química , Verduras/química , Vitis/química
10.
J Agric Food Chem ; 50(23): 6910-6, 2002 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-12405796

RESUMO

Epidemiological studies have shown that consumption of fruits and vegetables is associated with reduced risk of chronic diseases. Increased consumption of fruits and vegetables containing high levels of phytochemicals has been recommended to prevent chronic diseases related to oxidative stress in the human body. In this study, 10 common vegetables were selected on the basis of consumption per capita data in the United States. A more complete profile of phenolic distributions, including both free and bound phenolics in these vegetables, is reported here using new and modified methods. Broccoli possessed the highest total phenolic content, followed by spinach, yellow onion, red pepper, carrot, cabbage, potato, lettuce, celery, and cucumber. Red pepper had the highest total antioxidant activity, followed by broccoli, carrot, spinach, cabbage, yellow onion, celery, potato, lettuce, and cucumber. The phenolics antioxidant index (PAI) was proposed to evaluate the quality/quantity of phenolic contents in these vegetables and was calculated from the corrected total antioxidant activities by eliminating vitamin C contributions. Antiproliferative activities were also studied in vitro using HepG(2) human liver cancer cells. Spinach showed the highest inhibitory effect, followed by cabbage, red pepper, onion, and broccoli. On the basis of these results, the bioactivity index (BI) for dietary cancer prevention is proposed to provide a simple reference for consumers to choose vegetables in accordance with their beneficial activities. The BI could be a new alternative biomarker for future epidemiological studies in dietary cancer prevention and health promotion.


Assuntos
Antioxidantes/análise , Divisão Celular/efeitos dos fármacos , Fenóis/análise , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Verduras/química , Antineoplásicos/análise , Antineoplásicos/farmacologia , Brassica/química , Capsicum/química , Carcinoma Hepatocelular/patologia , Humanos , Neoplasias Hepáticas/patologia , Cebolas/química , Spinacia oleracea/química , Células Tumorais Cultivadas
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