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1.
Biofactors ; 37(1): 58-64, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21328629

RESUMO

Probiotics and prebiotics, which can change the colonic microenvironment, are the areas of current interest. Unutilizable fractions of the foods and fortificants, which reach the colon can affect the profile of probiotics. Effects of eight such factors viz. zinc sulphate, zinc carbonate, ferrous sulphate, ferric citrate, quercetin, gallic acid, phytic acid, and oxalic acid were, therefore, investigated on 24 H growth of Lactobacillus acidophilus (L1) and Lactobacillus plantarum (L2), two isolates of bifidobacteria (longum (L3) and bifidum (L4)) and a marketed consortium (L5) of eight probiotic cultures. MRS medium with marketed fructooligosaccharide as the only source of carbon was used for study of dose response curves. Quercetin and zinc sulphate showed significant positive effect for L1 and L5 (P < 0.01), whereas there was slight positive effect or no effect on growth of other probiotics. Phytic acid showed a significant inhibitory effect for L2 and a slight inhibitory effect on L3 and L4 whereas L5 were able to tolerate phytic acid. Oxalic acid had slight positive effect for L1 (P < 0.05) and L5 and no effect on growth of other probiotics (P > 0.05). Further, zinc sulphate, ferrous sulphate, quercetin, and oxalic acid significantly inhibited growth of E. coli (P < 0.05)


Assuntos
Escherichia coli/crescimento & desenvolvimento , Bacilos Gram-Positivos Asporogênicos/crescimento & desenvolvimento , Micronutrientes/metabolismo , Oligossacarídeos/metabolismo , Probióticos , Antioxidantes/metabolismo , Meios de Cultura , Ácido Gálico/metabolismo , Humanos , Nefelometria e Turbidimetria , Ácido Oxálico/metabolismo , Ácido Fítico/metabolismo , Quercetina/metabolismo
2.
Br J Nutr ; 105(12): 1741-9, 2011 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-21262064

RESUMO

We examined the effect of dietary nicotinic acid (NA) variations before and after oxidative stress (OS) treatment on the antioxidant defence system, function and morphology of the liver along with Zn status in rats. OS was generated by three intraperitoneal injections of tert-butyl hydroperoxide in the first week for the pre-exposure group and in the third week for the post-exposure group, respectively. These groups were further divided into subgroups and fed on a diet with marginally deficient Zn (10 mg Zn/kg diet) and NA variations as NA deficient, normal and excess with 10, 30 and 1000 mg NA/kg diet, respectively. Aspartate aminotransferase and alanine aminotransferase levels were elevated in rats with OS coupled with the Zn- and NA-deficient diet, which decreased towards normal with excess dietary NA. Excess NA supplementation in the OS pre-exposure group resulted in nearly preserved hepatic architecture with normal hepatocytes, whereas maximum tissue destruction was evident in the post-exposure group with NA deficiency. Dose-dependent improvement in the antioxidant defence system, enhanced reduced glutathione levels, lowered lipid peroxidation and higher hepatic Zn levels were observed with NA supplementation. The effect was more prominent in the pre-exposure group. In conclusion, dietary NA supplementation improves hepatic Zn uptake and results in hepatoprotection against OS-induced damage in rats.


Assuntos
Antioxidantes/farmacologia , Suplementos Nutricionais , Fígado/metabolismo , Niacina/farmacologia , Estresse Oxidativo/fisiologia , Complexo Vitamínico B/farmacologia , Zinco/farmacocinética , Alanina Transaminase/sangue , Análise de Variância , Animais , Aspartato Aminotransferases/sangue , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Fígado/citologia , Fígado/enzimologia , Niacina/deficiência , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Zinco/deficiência
3.
Nutrition ; 27(1): 40-45, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20472398

RESUMO

OBJECTIVES: The etiology of cataracts in the Asian subcontinent is not well understood. The aim of this study was to understand the differences in nutritional and lifestyle-related etiology of cataract in a high-income group (HIG) and a low-income group (LIG). RESEARCH METHODS: A cross-sectional survey was conducted on 140 cataract patients, aged 50-70 y, and 100 age- and sex-matched healthy controls. Socioeconomic information and habitual dietary intake were recorded by interview method. Cataract grading was given by ophthalmologists using a slit-lamp biomicroscope. RESULTS: In HIG patients, there was a delay of 10 y in the onset of cataracts as compared to LIG patients. Sixty-seven percent of LIG patients were alcoholic and 80% had a family history of cataracts. Further, among LIG male patients, 45%-87% were uneducated and 80% were addicted to tobacco. The intake of animal foods and fried foods was significantly higher in all the patient groups than controls (P<0.001). The intake of vegetables, fruits, salads, and tea were higher in all the controls than patients (P<0.001). For HIG male patients, between alcoholics and non-alcoholics, significant differences were noted for antioxidant status and soluble to total proteins ratio of lens. Similar differences were seen between HIG male smokers and non-smokers. Multiple regression analysis of solubility and opacity of lens indicated influence of family size, sunlight exposure, and systolic blood pressure for predisposition of cataracts. CONCLUSIONS: Along with high systolic blood pressure, waist:hip ratio, family size, sunlight exposure, and increased consumption of tobacco and alcohol were the risk factors for cataracts.


Assuntos
Catarata/etiologia , Dieta/efeitos adversos , Renda , Estilo de Vida , Estado Nutricional , Idoso , Alcoolismo/complicações , Antioxidantes , Pressão Sanguínea , Estudos de Casos e Controles , Estudos Transversais , Dieta/normas , Escolaridade , Proteínas do Olho , Família , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores de Risco , Fatores Sexuais , Fumar/efeitos adversos , Luz Solar/efeitos adversos , População Urbana
4.
Biol Trace Elem Res ; 143(2): 717-25, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21165710

RESUMO

Nonenzymatic glycation of long-lived proteins has been implicated in several complications related to age and diabetes. Dicarbonyl compounds such as methylglyoxal (MGO) have been identified as the predominant source for the formation of advanced glycation end-products (AGEs) in various tissues. We investigated the effect of 13 micronutrients on MGO-mediated in vitro glycation of bovine serum albumin (BSA), as formation of AGEs and protein carbonyls. BSA (10 mg/ml) was incubated at 37°C with 100 mM MGO for 24 hours, in presence of ascorbic acid, Trolox (water-soluble α-tocopherol analog), ß-carotene, retinol, riboflavin, thiamin, folic acid, niacin, pyridoxine, zinc, iron, manganese, and selenium. Fluorescence was measured at the wavelength pair of 370 and 440 nm as an index of the formation of AGEs and spectra were recorded for promising interactions at λex=280 nm and λex=370 nm. Within four standard antiglycating agents, aminoguanidine showed highest inhibitory response for BSA glycation followed by quercetin, gallic acid, and tannic acid. Promising antiglycation potential was seen for Trolox, riboflavin, Zn, and Mn as evidenced by decrease in the formation of AGEs and protein carbonyls.


Assuntos
Ácido Fólico/farmacologia , Micronutrientes/farmacologia , Aldeído Pirúvico/química , Soroalbumina Bovina/química , Animais , Ácido Ascórbico/farmacologia , Bovinos , Cromanos/farmacologia , Produtos Finais de Glicação Avançada/metabolismo , Glicosilação/efeitos dos fármacos , Ferro/farmacologia , Manganês/farmacologia , Piridoxina/farmacologia , Riboflavina/química , Selênio/farmacologia , Tiamina/farmacologia , Vitamina A/química , Zinco/farmacologia , beta Caroteno/farmacologia
5.
Indian J Physiol Pharmacol ; 55(2): 183-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22319901

RESUMO

An open label intervention study was undertaken on 26 mild hypertensives and 26 apparently healthy adults (30-60 y), for the effect of Sudarshan Kriya Yoga practice for two months as complementary therapy. In the hypertensives, there was a significant decrease in diastolic blood pressure (P < 0.01), serum urea (P < 0.01) and plasma MDA (malondialdehyde adducts) as oxidative stress marker (P < 0.05). Other parameters; viz.; plasma levels of cholesterol, triglycerides, glucose, did not change significantly (P > 0.1). The pattern of change in most of the study parameters was such that values above normal range were lowered but values within normal range were unaltered. The action of Yoga on diastolic blood pressure, malondialdehyde adducts and kidney function in hypertensives was of counteractive nature and felt to be distinctly different than the effect of drugs.


Assuntos
Pressão Sanguínea , Hipertensão/terapia , Yoga , Adulto , Análise de Variância , Biomarcadores/sangue , Feminino , Humanos , Hipertensão/sangue , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Índia , Rim/fisiopatologia , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Estresse Oxidativo , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Ureia/sangue
6.
Ophthalmic Res ; 44(3): 166-72, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20829640

RESUMO

BACKGROUND: The lens is the ocular structure most susceptible to oxidative damage. Antioxidants, micronutrients and phytochemicals have been extensively studied for their possible effects to prevent or delay the progression of various eye diseases. OBJECTIVES: A brief overview of the updated literature on the role of antioxidants and micronutrients in the prevention and treatment of ocular diseases is to be presented with an emphasis on cataract. DATA SOURCES: PubMed search and individual papers from journals. DATA SYNTHESIS: The review discusses linkages of various micronutrients and antioxidants as well as oxidative stress with cataract. Dietary interventions as strategy for prevention of cataract and other ocular disorders are also reviewed. CONCLUSIONS: Consumption of food-based antioxidants like ß-carotene lutein and zeaxanthin seem to be useful for the treatment of macular degeneration and cataracts. Supplements of vitamin A, vitamin C, vitamin E and zinc may prevent advanced age-related macular degeneration only in high-risk individuals.


Assuntos
Antioxidantes , Catarata/prevenção & controle , Micronutrientes , Fenômenos Fisiológicos da Nutrição , Animais , Dieta , Oftalmopatias/prevenção & controle , Humanos , Estresse Oxidativo
7.
Metabolism ; 59(11): 1603-11, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20359724

RESUMO

Dietary zinc (Zn) status exerts a powerful influence on the degree of oxidative damage caused by free radicals. We examined the effect of dietary Zn variations with oxidative stress (OS) treatment on antioxidant status, liver function, and status of vitamins in male Wistar rats. Oxidative stress was generated by intraperitoneal injections of tert-butyl hydroperoxide; and dietary Zn variations done were Zn deficient, normal, and excess, with 8, 30, and 60 mg Zn per kilogram diet, respectively. After 21-day dietary regimen, the animals were killed; and plasma aspartate aminotransferase, alanine aminotransferase, hepatic antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), Zn, reduced glutathione, lipid peroxidation (LPO), and hepatic riboflavin, nicotinic acid, and ascorbic acid estimations were done. The alanine aminotransferase and aspartate aminotransferase levels were elevated in rats with OS and Zn-deficient diet, which were restored to normal levels with excess dietary Zn. Hepatic antioxidant enzymes and reduced glutathione levels were significantly decreased with concomitant increase in LPO due to OS induction in animals with Zn-deficient diet. Corresponding enhanced enzyme activities, higher hepatic Zn, and lowered LPO were observed in animals with normal- and excess-Zn diet. A dose-dependent increase in hepatic nicotinic acid accumulation was observed as the dietary Zn level increased from deficient to excess; however, there was no influence on riboflavin and ascorbic acid status. The results suggest that Zn may have a therapeutic potential in treatment of oxidative liver damage along with enhanced nicotinic acid absorption.


Assuntos
Antioxidantes/análise , Fígado/metabolismo , Micronutrientes/análise , Estresse Oxidativo , Zinco/farmacologia , Animais , Dieta , Fígado/efeitos dos fármacos , Masculino , Niacina/metabolismo , Ratos , Ratos Wistar , Zinco/administração & dosagem , Zinco/uso terapêutico
8.
Biol Trace Elem Res ; 138(1-3): 346-57, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20143181

RESUMO

Using albumin as model, we conducted series of in vitro glycation experiments to examine role of zinc in glycation using glucose at 4-100 mg/ml, incubations at 37°C or 60°C, duration of 2 or 4 weeks and in presence of zinc or ascorbic acid (AA) or folic acid (FA). Modifications of bovine serum albumin (BSA) were examined by using fluorescence of advanced glycation end products (AGEs) and dityrosine, UV, and Fourier transformed infrared spectroscopy. Adding zinc (0 to 768.5 µmol/l) resulted in significant inhibition of albumin glycation by glucose with a linear fit, y = -0·0895x + 230·99(R² = 0·7676, p = 0·013). The glycation by fructose was greater than that of glucose with stronger inhibitory effect by zinc in fructose-glycation (t= -5.8, p=0.002). Addition of zinc significantly decreased fluorescence as seen in Zn + FA or Zn + AA sets as compared to sets of FA alone (p=0.00056) or AA alone (p=0.037). The fluorescence for dityrosine and AGE had a correlation of 0.897 (p<0.01). The data from fluorescence, UV, and FTIR spectra collectively suggested inhibitory effect of zinc in BSA glycation alone or in presence of FA and AA, showing new dimension for the protective action of zinc in hyperglycemic conditions.


Assuntos
Ácido Ascórbico/química , Ácido Fólico/química , Produtos Finais de Glicação Avançada/química , Tirosina/análogos & derivados , Zinco/química , Glicosilação , Espectroscopia de Infravermelho com Transformada de Fourier , Tirosina/química
9.
Eur J Nutr ; 49(1): 53-61, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19680705

RESUMO

BACKGROUND: The role of different water soluble vitamins in Zn metabolism beyond intestinal Zn absorption is poorly explored. AIM OF THE STUDY: Using Caco-2 cells, effects of different vitamins on intestinal Zn transport and their implications under oxidative stress (OS) were investigated. METHODS: Cells were apically treated with Zn (25 muM) and vitamins (Folic acid (FA), Nicotinic acid (NA), Ascorbic acid (AA), riboflavin, thiamine, pyridoxine) for 60 min. The effect of most promising vitamins on zinc transport, antioxidant enzymes (Catalase, Glutathione peroxidase, and superoxide dismutase), and intracellular OS status (ROS generation and mitochondrial transmembrane potential) were investigated. OS was generated by tert-butyl hydro peroxide and results for each vitamin were compared with respective Zn containing controls with and without OS. RESULTS: Without OS, Zn transport was slightly enhanced in presence of NA, while it was significantly reduced by thiamine, riboflavin, and pyridoxine. Under OS, NA significantly (P < 0.01) enhanced Zn transport in dose-dependent manner, while, pyridoxine and AA moderately improved it. Under both conditions, Zn transport exhibited decreasing trend with increase of FA. The antioxidant enzyme and OS markers levels varied significantly in Zn + vitamins. With Zn + FA + OS, enzyme activities decreased maximally, with twofold increase in 2',7'-dichlorofluorescin diacetate (DCF-DA) (P < 0.01) and lowering of rhodamine fluorescence (P < 0.05). In Zn + AA + OS, DCF-DA fluorescence increased (P < 0.05) but with NA, cellular enzymes, and antioxidant profile were improved. CONCLUSIONS: Results for the first time demonstrate advantageous effects of NA and deleterious consequences of FA with no effect by AA on Zn transport, especially under OS. These observed changes in the transport of Zn seem to have an impact on OS markers.


Assuntos
Estresse Oxidativo/fisiologia , Vitaminas/farmacologia , Zinco/metabolismo , Antioxidantes , Ácido Ascórbico/farmacologia , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Catalase/metabolismo , Ácido Fólico/farmacologia , Glutationa Peroxidase/metabolismo , Humanos , Absorção Intestinal/efeitos dos fármacos , Niacina/farmacologia , Solubilidade , Superóxido Dismutase/metabolismo , Vitaminas/química , Água , Zinco/farmacocinética
10.
Br J Nutr ; 103(3): 370-7, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19849871

RESUMO

The present study aimed to investigate the role of Zn alone and in the presence of ascorbic acid (AA) and folic acid (FA) in albumin glycation. Glycation was performed by incubations of bovine serum albumin with glucose at 37 degrees C along with Zn, AA or FA separately and Zn + AA or Zn + FA for 150 d. Glycation-mediated modifications were monitored as fluorescence of advanced glycation endproducts, carbonyl formation, beta aggregation (thioflavin T and Congo red dyes), albumin-bound Zn, thiol groups and glycated aggregate's toxicity in HepG2 cells. Zn inhibited glycation and beta aggregation, probably due to observed higher protein-bound Zn. It also protected protein thiols and increased cell survival. AA and FA enhanced glycation, which was lowered in Zn-co-incubated samples. FA increased albumin-bound Zn and showed maximum cell survival. Although these results warrant further in vivo investigation, the present data help in the understanding of the interplay of Zn with micronutrients in albumin glycation.


Assuntos
Ácido Ascórbico/farmacologia , Ácido Fólico/farmacologia , Soroalbumina Bovina/metabolismo , Zinco/farmacologia , Benzotiazóis , Sobrevivência Celular/efeitos dos fármacos , Vermelho Congo/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Glicosilação/efeitos dos fármacos , Células Hep G2/efeitos dos fármacos , Células Hep G2/metabolismo , Humanos , Cinética , Ligação Proteica , Soroalbumina Bovina/efeitos dos fármacos , Soroalbumina Bovina/toxicidade , Compostos de Sulfidrila/análise , Tiazóis/análise , Zinco/metabolismo
11.
Nutrition ; 24(7-8): 617-24, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18472398

RESUMO

OBJECTIVES: We examined the synergism of cataract and diabetes in micronutrient and antioxidant statuses versus diabetes mellitus and cataract alone. METHODS: Indian patients with type 2 diabetes mellitus (D; n = 76), those without diabetes and with cataract (NDC; n = 100), those with diabetes and cataract (DC; n = 53), and age- and sex-matched healthy controls (n = 90) 50-70 y were investigated. Plasma oxidative stress as thiobarbituric acid-reactive substances (TBARS) and the status of 11 micronutrients were studied as lens TBARS, opacity, and ratio of soluble to total proteins in patients with cataract with or without diabetes. Lipid profile, fasting glucose, and postprandial glucose were measured for all subjects. RESULTS: A subnormal status of ascorbic acid, beta-carotene, thiamine, and ceruloplasmin was elicited for all four study groups. Plasma TBARS and fasting glucose were significantly higher in the DC group than in the NDC (P < 0.05), D, and control groups. Lens TBARS were comparable between the NDC and DC groups (5.5 and 5.08 nm/g of lens). Chi-square values for lens turbidity within the DC and NDC groups and for the ratio of soluble to total proteins and opacity within the NDC group were significant (P < 0.01). The prevalence of poor riboflavin status was 30-36% in all patients and 15-22.5% in controls. Men in the DC group showed a higher value of glycosylated hemoglobin than did men from the D group. Multivariate analysis of variance indicated significant interactions (P < 0.02) between HS and socioeconomic grades for fasting glucose and high-density lipoprotein levels, riboflavin status, plasma vitamin C, TBARS, and selenium. The DC group was found to be significantly different from the other groups with respect to beta-coefficients of a logistic regression equation for plasma levels of selenium, zinc, iron, thiamine, triacylglycerols, total cholesterol, ceruloplasmin, vitamin A, and superoxide dismutase. CONCLUSION: The combination of diabetes and cataract coupled with gender bias and influence of socioeconomic factors seem to be associated with worsening of micronutrient status, oxidative stress, and lens opacity.


Assuntos
Antioxidantes/metabolismo , Catarata/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Micronutrientes/sangue , Estado Nutricional , Estresse Oxidativo , Idoso , Biomarcadores/sangue , Glicemia/metabolismo , Estudos de Casos e Controles , Catarata/sangue , Catarata/patologia , Comorbidade , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/patologia , Feminino , Humanos , Índia/epidemiologia , Insulina/sangue , Cristalino/metabolismo , Cristalino/patologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Classe Social , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
12.
Clin Nutr ; 27(3): 464-72, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18342406

RESUMO

BACKGROUND & AIMS: Habitual food and nutrient intakes of 140 Indian cataract patients and 100 age- and sex-matched controls (50-75 years), from high income group and low income groups, were assessed. METHODS: Food intake was recorded by food frequency questionnaire and data were examined for linkages with blood/lens parameters of oxidative stress through a case-control study. RESULTS: Intake of animal foods and fried snacks was significantly higher while vegetables, green leafy vegetables, fruit, tea and micronutrient intakes were lower in patients than in controls (p<0.001). Lens oxidative stress and opacity showed a significant negative association with fruit intake (p<0.05). Multiple regression analysis indicated association of intakes of iron, beta-carotene, ascorbic acid, tannic acid and inositol pentaphosphate with plasma oxidative stress (p<0.01) and association of intakes of iron, ascorbic acid and inositol triphosphate with lens oxidative stress (p<0.01). Weighted least square regression for lens opacity revealed that intakes of ascorbic acid, folic acid and inositol pentaphosphate explained 59.7% of the total variation (p<0.01). CONCLUSIONS: Dietary deficiency of antioxidant micronutrients was greater for patients than controls. Deficiency of beta-carotene, ascorbic acid, folic acid, iron, phytate and polyphenols increased oxidative stress in blood and lens.


Assuntos
Catarata/patologia , Comportamento Alimentar , Micronutrientes/administração & dosagem , Micronutrientes/deficiência , Estresse Oxidativo , Idoso , Antioxidantes/administração & dosagem , Biomarcadores/sangue , Estudos de Casos e Controles , Catarata/epidemiologia , Catarata/etiologia , Catarata/metabolismo , Feminino , Humanos , Índia/epidemiologia , Cristalino/química , Cristalino/metabolismo , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores Socioeconômicos
13.
Int J Food Sci Nutr ; 58(5): 341-9, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17558726

RESUMO

Considering the scanty information on Indian fruits, 36 commonly consumed fruits were assessed for inhibition of thiobarbituric acid reactive substances, superoxide scavenging activity and ferrous ion-chelating ability along with levels of micronutrients (namely ascorbic acid, beta-carotene, riboflavin, thiamine, zinc, copper, iron, manganese, selenium and total polyphenols). Fruits exhibited 24-173% variability for the 13 study parameters. Fresh fruits exhibited 3.5-4 times higher antioxidant capacity than dry fruits. Ascorbic acid was highest in gooseberry (445 mg/100 g), and beta-carotene was highest in ripe mango 1,200 mg/100 g. Selenium levels could supply 0-33% of the recommended dietary allowance. There was a strong association between different indices of antioxidant capacity (P<0.001), thiobarbituric acid reactive substances with selenium levels (P<0.01), and superoxide scavenging activity and ferrous ion-chelating ability with zinc content (P<0.05). Results emphasize need for the antioxidant quality of fruit in addition to the quantity of fruit consumption.


Assuntos
Antioxidantes/análise , Frutas/metabolismo , Micronutrientes/análise , Flavonoides/análise , Índia , Quelantes de Ferro/metabolismo , Peroxidação de Lipídeos , Fenóis/análise , Polifenóis , Superóxidos/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Oligoelementos/análise , Vitaminas/análise
14.
Asia Pac J Clin Nutr ; 16(2): 227-39, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17468077

RESUMO

Individual cooked foods (104) and composite meals (92) were examined for agreement between nutritive value estimated by indirect analysis (E) (Indian National database of nutrient composition of raw foods, adjusted for observed moisture contents of cooked recipes), and by chemical analysis in our laboratory (M). The extent of error incurred in using food table values with moisture correction for estimating macro as well as micronutrients at food level and daily intake level was quantified. Food samples were analyzed for contents of iron, zinc, copper, beta-carotene, riboflavin, thiamine, ascorbic acid, folic acid and also for macronutrients, phytate and dietary fiber. Mean percent difference in energy content between E and M was 3.07+/-0.6%, that for protein was 5.3+/-2.0%, for fat was 2.6+/-1.8% and for carbohydrates was 5.1+/-0.9%. Mean percent difference in vitamin contents between E and M ranged from 32 (vitamin C) to 45.5% (beta-carotene content); and that for minerals between 5.6 (copper) to 19.8% (zinc). Percent E/M were computed for daily nutrient intakes of 264 apparently healthy adults. These were observed to be 108, 112, 127 and 97 for energy, protein, fat and carbohydrates respectively. Percent E/M for their intakes of copper (102) and beta-carotene (114) were closer to 100 but these were very high in the case of zinc (186), iron (202), and vitamins C (170), thiamine (190), riboflavin (181) and folic acid (165). Estimates based on food composition table values with moisture correction show macronutrients for cooked foods to be within +/- 5% whereas at daily intake levels the error increased up to 27%. The lack of good agreement in the case of several micronutrients indicated that the use of Indian food tables for micronutrient intakes would be inappropriate.


Assuntos
Bases de Dados Factuais/normas , Dieta , Análise de Alimentos/métodos , Valor Nutritivo , Água/análise , Adulto , Culinária/métodos , Carboidratos da Dieta/análise , Gorduras na Dieta/análise , Fibras na Dieta/análise , Proteínas Alimentares/análise , Ingestão de Energia , Feminino , Análise de Alimentos/normas , Humanos , Masculino , Micronutrientes/análise , Pessoa de Meia-Idade , Ácido Fítico/análise
15.
Int J Food Sci Nutr ; 57(7-8): 434-50, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17162323

RESUMO

Availability of non-heme iron has been extensively discussed when meals comprise heme as well as non-heme iron, but seldom so for exclusively vegetarian meals. The present study aimed to develop a statistical model for predicting non-heme iron availability from a composite vegetarian meal. Radioisotopic measurements of in vitro iron dialyzability of 208 out of 274 meals representing vegetarian diets from Asia, Africa, Europe and Latin America and the meal contents of iron, zinc, copper, ascorbic acid, beta-carotene, riboflavin, thiamin, folic acid, tannic acid, fiber and degraded phytate forms (IP6-IP1) were used for development of the model. A multiple regression model weighted for calorie contents was developed for the percentage iron dialyzability with the possible predictors as meal contents along with plausible interaction terms. The model was validated with in vitro iron dialyzability of 66 meals and in vivo iron absorption in five ileostomized adults. Application of the model was demonstrated using data on the daily dietary intake of 215 young adults whose hemoglobin levels were estimated twice in 3 weeks. Weighted multiple regression model was: ln(% Fe dialyzability)=1.340-0.259xln(IP2 [mg])+0.188xln(IP3 [mg])-0.278xln(IP5 [mg])+0.0912xln(ascorbic acid [mg])+0.06693xln(tannins [mg])+0.09552xln(beta-carotene [microg])+0.137xln(hemicellulose [g]) (P<0.01, R2=0.51). Good agreement was seen between observed and predicted dialyzability (r=0.90) and human absorption (r=0.89). The model would be useful to estimate bioavailable iron intakes of vegetarian populations and to identify at-risk individuals.


Assuntos
Dieta Vegetariana , Ferro/metabolismo , Modelos Estatísticos , Ferroproteínas não Heme/metabolismo , Adulto , Ácido Ascórbico/análise , Disponibilidade Biológica , Feminino , Ácido Fólico/análise , Hemoglobinas/análise , Humanos , Absorção Intestinal , Masculino , Micronutrientes/análise , Ácido Fítico/análise , Polissacarídeos/análise , Taninos/análise , Oligoelementos/análise , Zinco/análise , beta Caroteno/análise
16.
J Am Coll Nutr ; 25(1): 26-33, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16522929

RESUMO

OBJECTIVE: To develop a statistical model for predicting zinc bioavailability from cereal-based vegetarian meals using relative proportion of nutrients, non-nutrients and their interactive effects. METHODS: A database on in vitro zinc dialysability (by isotopic tracer, 65Zn) of vegetarian meals (266 out of 326) from Asia, Africa, Europe /US and Latin America was used to develop a model for estimating zinc bioavailability. A multiple regression analysis adjusted for energy content was carried out for net bioavailable zinc from a meal with the predictor variables as meal contents of iron, zinc, copper, ascorbic acid, beta-carotene, riboflavin, thiamine, folic acid, tannic acid, fiber, phytate degradation products (IP6 to IP1), along with their interaction terms. Reproducibility of the model was tested with remaining 60 meals. Validation of the model was done with zinc absorption data of i) 12 young adults on 24 meals and ii) 5 adults with ileostomy on 7 meals. RESULTS: Folic acid, IP3 and IP5 were significant influencing factors for bioavailable zinc. Weighted multiple regression equation was: ln (bioavailable zinc in mg) = -1.701 + 1.285 x ln [(IP5 in mg] x (Zn in mg)] -1.222 x ln(IP5 in mg) -0.0078 x folic acid in microg -0.137 x ln [(IP3 in mg) x (Zn in mg)] with adjusted R--[2] = 0.64, p = 0.0001. The correlation between predicted and observed dialysability of meals was found to be 0.96 (p < 0.01). A significant correlation between observed and predicted amount of absorbed zinc (r = 0.85, p < 0.01) was obtained for the human data of zinc absorption in 12 healthy and 5 subjects with ileostomy. CONCLUSIONS: Bioavailable amount of zinc from vegetarian meals was influenced by IP3, IP5 and folic acid content and their interactive effect with zinc content.


Assuntos
Dieta Vegetariana , Ácido Fólico/farmacologia , Ácido Fítico/farmacologia , Zinco/farmacocinética , Adulto , Disponibilidade Biológica , Relação Dose-Resposta a Droga , Feminino , Humanos , Ileostomia , Absorção Intestinal , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Oligoelementos/metabolismo , Oligoelementos/farmacocinética , Complexo Vitamínico B/farmacologia , Zinco/metabolismo , Radioisótopos de Zinco
17.
Eur J Nutr ; 45(1): 29-36, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15834756

RESUMO

BACKGROUND: Green leafy vegetables (GLV) are rich sources of beta-carotene, iron and other micronutrients. Our in vitro studies have demonstrated good antioxidant potential in GLV. Moreover linkages of GLV intakes with plasma retinol and ascorbic acid were seen in apparently healthy Indians. AIM OF THE STUDY: To investigate the effect of GLV as a natural fortificant of multiple micronutrients through a prospective human trial. METHODS: Short-term (0-4 h) response (AUC) of single dose of 7.9 mg beta-carotene and 130 mg ascorbic acid through a spinach-carrot meal against the standard meal without GLV plus10 mg beta-carotene and 150 mg ascorbic acid tablets was studied in two groups of 4 young volunteers each. In the second trial of 3 weeks' supplementation, 5 groups of young adults (n = 40) were given either 100 g GLV/day alone or with tablets of vitamin E (100 mg/day), or C (100 mg/day) or more oil (5 g/day) or non-GLV meal with tablet of beta-carotene (10 mg/day). Hemoglobin (Hb), plasma beta-carotene, zinc, vitamin C, glucose, and triglycerides were measured. RESULTS: In a postprandial response, AUC were comparable in both GLV and standard meals for beta-carotene and ascorbic acid. In case of triglycerides and glucose AUC the GLV meal showed a better recovery to the baseline value after 4 hours than the standard meal. Three weeks' supplementation of GLV with more oil resulted in significant increase of plasma beta-carotene (51%) and Hb (9%). GLV with vitamin E showed a significant increase in plasma beta-carotene (40%), Hb (8%) and plasma vitamin C (6%). Supplementing beta-carotene without GLV significantly increased Hb (11%), plasma zinc (14%) in addition to beta-carotene. Multiple regression analyses weighted for energy intake indicated a significant association of percent increase in Hb with intakes of iron, riboflavin, folic acid, beta-carotene, copper, phytate and fiber (p < 0.01), percent change in plasma zinc with intakes of zinc, beta-carotene, vitamin C, riboflavin, copper, iron, and thiamin (p < 0.01), percent change in vitamin C with intakes of vitamin C, vitamin E, niacin, riboflavin, thiamin, beta-carotene, zinc, phytate and fiber (p < 0.05) and percent change in plasma beta-carotene with intakes of beta-carotene, thiamin, folic acid, zinc, phytate and tannins (p < 0.05). CONCLUSION: Using 100 g GLV/day with 10 g oil could be a single moderate strategy for supplementation of iron, beta-carotene, ascorbic acid and zinc.


Assuntos
Antioxidantes/farmacocinética , Ácido Ascórbico/farmacocinética , Suplementos Nutricionais , Ferro da Dieta/farmacocinética , Verduras/química , Vitamina E/farmacologia , beta Caroteno/farmacocinética , Adolescente , Adulto , Antioxidantes/metabolismo , Ácido Ascórbico/sangue , Disponibilidade Biológica , Glicemia/análise , Glicemia/metabolismo , Gorduras Insaturadas na Dieta/administração & dosagem , Feminino , Hemoglobinas/análise , Hemoglobinas/metabolismo , Humanos , Masculino , Estudos Prospectivos , Triglicerídeos/sangue , Vitamina E/sangue , Zinco/sangue , Zinco/farmacocinética , beta Caroteno/sangue
18.
J Am Coll Nutr ; 24(5): 334-41, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16192257

RESUMO

OBJECTIVES: To identify dietary, environmental and socio-economic factors associated with mild zinc deficiency, three zinc status indices; erythrocyte membrane zinc (RBCMZn), plasma zinc and super oxide dismutase (SOD) were assessed in free living and apparently healthy Indian population. METHODS: Dietary patterns of 232 men and 223 women (20-65 yr) from rural, industrial and urban regions of Western India were evaluated by food frequency questionnaire. RBCMZn was estimated using atomic absorption spectrometry, hemoglobin and serum ceruloplasmin by spectrophotometer. On a sub sample (48 men and 51 women) plasma zinc and SOD were also assessed. RESULTS: Mean RBCMZn was 0.5 +/- 0.1 micromols/g protein with 46% individuals showing zinc deficiency. Mean plasma zinc was 0.98 +/- 0.12 microg/mL with 25% men and 2.5% women having values below normal range. Mean SOD was 0.97 +/- 0.1 (u/mL cells). A significant positive correlation was observed between intakes of green leafy vegetables, other vegetables and milk products with RBCMZn status (p < 0.05). But these were not correlated with plasma zinc (p > 0.2). Cereal and legume intakes were negatively correlated with RBCMZn (p < 0.05) but positively correlated with plasma zinc (p < 0.05) and not correlated with SOD (p > 0.2). Fruit and other vegetable intake were positively correlated with SOD (p < 0.05) alone. Logistic regression analyses revealed that RBCMZn was positively associated with intakes of beta-carotene, zinc and environmental conditions and negatively associated with family size (p < 0.05). Plasma zinc indicated positive association with zinc, thiamin and riboflavin intakes (p < 0.05) and SOD showed negative association with iron and family size. CONCLUSION: RBCMZn was a more sensitive indicator of long-term zinc status than plasma zinc and SOD. Prominent determinants of zinc status were intakes of beta-carotene and zinc along with environmental conditions and family size.


Assuntos
Dieta , Superóxido Dismutase/metabolismo , Zinco/sangue , Zinco/deficiência , beta Caroteno/administração & dosagem , Adulto , Laticínios , Meio Ambiente , Membrana Eritrocítica/química , Características da Família , Feminino , Humanos , Índia/epidemiologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Fatores Socioeconômicos , Inquéritos e Questionários , Verduras , Zinco/administração & dosagem
19.
Nutrition ; 21(6): 678-85, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15925291

RESUMO

OBJECTIVES: Apparent absorption of eight micronutrients and degradation of phytic acid were studied in human subjects who underwent ileostomy. The prominent factors affecting micronutrient absorption from vegetarian Indian meals (n = 11) were identified. METHODS: Levels of beta-carotene, ascorbic acid, riboflavin, and thiamine in food and ileostomy contents were estimated by spectrophotometry and spectrofluorometry. Contents of zinc, iron, copper, and manganese were estimated by atomic absorption spectrometry and that of phytic acid by gradient elution ion exchange chromatography. Statistical analyses were done with SPSS 10.0. RESULTS: Absorption of beta-carotene, ascorbic acid, riboflavin, and thiamine was 63% to 75.6%. There was a negative non-significant trend in values of beta-carotene absorption with increased intake of beta-carotene (r = - 0.51, P > 0.1) and iron (r = -0.67, P = 0.1) but a positive significant trend with riboflavin intakes (r = 0.84, P = 0.018). Percentage of absorption of ascorbic acid showed weak positive associations with intakes of riboflavin (r = 0.71) and ascorbic acid (r = 0.5). Percentage of absorption of ascorbic acid was positively correlated with percentage of absorption of beta-carotene (r = 0.80, P < 0.05), iron, and riboflavin (r = 0.64, P = 0.086), indicating some common influencing factors. Percentages of absorption for zinc (20.2), iron (9.9), and copper (17.6) was comparable with those reported for soy protein-based, high phytate diets. Pattern of phytic acid in the meals and output indicated partial degradation and absorption (34%). CONCLUSIONS: For vegetarian Indian meals, apparent absorptions of beta-carotene and ascorbic acid were 76% and 73.5% and of riboflavin and thiamine was 63%. Zinc, copper, and iron showed a lower absorption (10% to 20%).


Assuntos
Dieta Vegetariana , Ileostomia , Absorção Intestinal , Micronutrientes/farmacocinética , Ácido Fítico/farmacocinética , Adulto , Cromatografia por Troca Iônica/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Nutritivo , Espectrometria de Fluorescência/métodos , Espectrofotometria/métodos
20.
Biol Trace Elem Res ; 99(1-3): 99-112, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15235145

RESUMO

In vitro zinc uptake by human erythrocytes was studied under a range of zinc concentrations representing three different plasma zinc levels i.e., zinc deficient [0.35-0.61 ppm], zinc normal [0.74-1.59 ppm], and zinc excess [1.65-2.3 ppm]. Further, interactions of physiological levels of riboflavin, flavin adenine dinucleotide (FAD), nicotinic acid, nicotinamide adenine dinucleotide (NAD), thiamine, thiamine pyrophosphate (TPP), folic acid, and ascorbic acid with zinc uptakes were studied in independent experiments. In control experiments, as compared to the normal zinc state, the rate of change of zinc uptake over change in zinc levels was 1.6 times in the excess state and 0.12 times in the deficient state, indicating three distinct patterns. Under the zinc-deficient state, thiamine significantly enhanced the zinc uptakes (p< 0.05), whereas ascorbic acid and riboflavin inhibited zinc uptakes (p< 0.05). The percent hemolysis of the cells was also significantly lower in the presence of thiamine (p< 0.05). Under normal and excess zinc states, the vitamin-zinc interactions were not significant. The results suggest that with erythrocytes as the vehicles, thiamine might be playing an enhancer role in uptake of zinc, whereas the action of ascorbic acid might be inhibitory for zinc uptakes under deficient zinc states.


Assuntos
Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Vitaminas/farmacologia , Zinco/metabolismo , Zinco/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Hemólise/efeitos dos fármacos , Humanos , Zinco/sangue
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