Biodisponibilidade de vitaminas lipossolúveis

Impact of rearing systems in the Eastern Amazon on cholesterol, β-carotene and vitamin E homologues in steer

Introduction

The quality of meat, with a focus on compounds important for human health, is directly related to the rearing systems in which the animals are produced. The search for a balanced diet, with an emphasis on low cholesterol and adequate levels of vitamins, aligns with society's emphasis on healthy eating, directly correlated with the importance of the offer made by producers for the cattle's diet.

Objective and methodology

The objective was to verify the impact of different rearing systems, in the Eastern Amazon, during the rainy season, on the concentrations of vitamins (A, E) and cholesterol in the muscle (Longissimus lumborum) of crossbred Nelore cattle, castrated, aged between 24 and 36 months, and weighing between 410 and 628 kg. Twelve animals, from each of the three pasture rearing systems: native pasture in flooded areas of Monte Alegre; native pasture in a flooded area of Santa Cruz do Arari; and pasture cultivated on dry land in São Miguel do Guamá, all located in Pará, Brazil-were sampled in commercial slaughterhouses.

Results

A notable influence was observed in the concentrations of β-carotene (p < 0.01), α-Tocopherol (p = 0.02), β-Tocopherol (p < 0.01) and the combined sum of β-Tocotrienol and γ-Tocopherol (p < 0.01), as well as δ-Tocopherol (p < 0.01) when contrasting extensive with intensive systems (confinement). However, there was a difference in the content of vitamins and cholesterol between the isolated extensive systems, or between the four rearing systems (p > 0.05). Extensive systems, mainly in Monte Alegre, demonstrated greater amounts of α-Tocopherol and δ-Tocopherol.

Conclusion

On the other hand, the intensive system exhibited higher levels of other investigated compounds, clarifying the nutritional variations generated by different livestock rearing practices in the region. Therefore, the results obtained are innovative in the Eastern Amazon, Brazil, in addition to inspiring the development of new research to meet other demands in this field, and achieve additional results, such as determining which meat, coming from cattle in production systems in the country, presents the better compositional quality of vitamins and lipids.

α-tocopherol as a selective modulator of toxicogenic damage induced by antineoplastic agents cyclophosphamide and doxorubicin

The aim of this study was to determine the oxidative/antioxidative effects, modulatory and selective potential of α-tocopherol (vitamin E) on antineoplastic drug-induced toxicogenetic damage. The toxicity, cytotoxicity and genotoxicity induced by antineoplastic agents cyclophosphamide (CPA) and doxorubicin (DOX) was examined utilizing as models Saccharomyces cerevisiae, Allium cepa, Artemia salina and human peripheral blood mononuclear cells (PBMCs) in the presence of α-tocopherol. For these tests, concentrations of α- tocopherol 100 IU/ml (67mg/ml), CPA 20 µg/ml, DOX 2 µg/ml were used. The selectivity of α-tocopherol was assessed by the MTT test using human mammary gland non-tumor (MCF10A) and tumor (MCF-7) cell lines. Data showed cytoplasmic and mitochondrial oxidative damage induced by CPA or DOX was significantly diminished by α-tocopherol in S. cerevisiae. In addition, the toxic effects on A. salina and cytotoxic and mutagenic effects on A. cepa were significantly reduced by α-tocopherol. In PBMCs, α-tocopherol alone did not markedly affect these cells, and when treated in conjunction with CPA or DOX, α-tocopherol reduced the toxicogenetic effects noted after antineoplastic drug administration as evidenced by decreased chromosomal alterations and lowered cell death rate. In human mammary gland non-tumor and tumor cell lines, α-tocopherol produced selective cytotoxicity with 2-fold higher effect in tumor cells. Evidence indicates that vitamin E (1) produced anti-cytotoxic and anti-mutagenic effects against CPA and DOX (2) increased higher selectivity toward tumor cells, and (3) presented chemoprotective activity in PBMCs.

[Analysis of the biochemical, anthropometric profile, and of antioxidant micronutrient ingestion in patients with resistant arterial hypertension]

Introduction

Introduction: resistant arterial hypertension (HAR) is associated with a high risk for cardiovascular events due to oxidative stress. Research has shown the beneficial effects of dietary antioxidants on cardiovascular health. Objective: to analyze and correlate the biochemical, anthropometric profile and intake of antioxidant micronutrients of patients with HAR. Material and methods: the patients underwent a biochemical assessment, and an anthropometric assessment to calculate body mass index (IMC), waist circumference (PCI), hip circumference (PCA), waist-to-hip ratio (ICC), and micronutrient intake assessment: vitamin A, vitamin C, vitamin E, selenium and zinc, estimated by a semi-quantitative food frequency questionnaire and 24-hour recall. The statistical analysis was performed using the SPSS Statistics 20 software. A p-value < 0.05 was considered significant. Results: sixty individuals with HAR were studied, with a mean age of 62.83 ± 10.73 years. Mean IMC was 31.01 ± 5.60 kg/m², PCI, 98.12 ± 15.04 cm, PCA, 110.55 ± 13.16 cm, and ICC, 0.879 ± 0.084. Regarding the biochemical profile, mean total colesterol was 187.65 ± 48.29 mg/dL, triglycerides, 136.38 ± 99.91 mg/dL; HDL-col, 49.00 ± 10.99 mg/dL; LDL-col, 112.01 ± 41.89 mg/dL; glucose, 105.37 ± 14.81 mg/dL, and glycated hemoglobin, 6.29 ± 1.76 %. The average daily intake of antioxidants was: vitamin A, 241.47 ± 191.87 µg/d; vitamin C, 147.02 ± 192.94 mg/d; vitamin E, 1.99 ± 1.82 mg/d; selenium, 36.80 ± 34.56 µg/d, and zinc, 99.91 ± 6.64 mg/d, where 91.38 %, 46.55 %, 93.10 %, 67.24 %, and 46.55 % of the sample were below the recommended intakes, respectively. Conclusion: inadequate antioxidant intake was observed in these patients with HAR, with a high prevalence of obesity, especially visceral adiposity and alterations in lipid profile, conditions that require a greater usage of these micronutrients. We suggest there is a need for dietary planning for these patients to improve their quality of life and their response to antihypertensive treatment.

Vitamin D deficiency in pregnancy after bariatric surgery

The objective of this study was to describe the main factors related to the installation and/or aggravation of vitamin D deficiency (VDD) and its clinical consequences in pregnant women after bariatric surgery. An electronic search on VDD in pregnancy and after bariatric surgery was conducted in publications from 1998 until 2012 that presented studies performed in humans. We provided an overview of VDD after bariatric surgery, in pregnancy, and in pregnancy in women who underwent bariatric surgery. In view of the high percentage of VDD postoperatively and the role of this vitamin in pregnancy, we recommend the investigation of vitamin D nutritional status in prenatal care.

Vitaminas antioxidantes e prevenção da arteriosclerose na infância

OBJETIVO: Revisar os potenciais efeitos antioxidantes das vitaminas A, C e E na prevenção do desenvolvimento da arteriosclerose na infância, com ênfase na prevenção da dislipidemia. FONTES DE DADOS: Pesquisa bibliográfica em revistas científicas, livros técnicos e publicações de órgãos oficiais dos últimos 20 anos. Utilizaram-se as bases de dados Lilacs, SciELo e Medline em português, inglês e espanhol, com as palavras-chave: "antioxidantes", "arteriosclerose", "dislipidemias", "peroxidação de lipídeos", "infância", "vitamina A", "vitamina C" e "vitamina E". SÍNTESE DE DADOS: A prevalência de dislipidemia na infância e na adolescência mostra frequência crescente, provavelmente relacionada às mudanças dos hábitos alimentares e à redução na prática de atividades físicas. O elevado nível plasmático da lipoproteína de baixa densidade (LDL-c) é fator de risco para o desenvolvimento da arteriosclerose. O consumo de frutas, verduras e legumes, ricos em antioxidantes, é um dos fatores de maior importância na prevenção da peroxidação lipídica. A baixa ingestão dessas fontes naturais de antioxidantes sugere a necessidade de intervenção nutricional para atingir as metas diárias de consumo de vitaminas A, C e E, não sendo preconizada a sua suplementação medicamentosa. CONCLUSÕES: O pediatra e o nutricionista devem orientar as famílias sobre o consumo de alimentos saudáveis, principalmente frutas, verduras e legumes, por seu potencial efeito antioxidante, especialmente nos primeiros anos de vida.

Efeito da fibra de coprodutos agroindustriais e sua avaliação nutricional para coelhos

Estudou-se a influência da fibra oriunda de diferentes fontes - feno de alfafa, polpa de cítrus e casca de soja - sobre o desempenho, coeficientes de digestibilidade, parâmetros sanguíneos e características da carne de coelhos submetidos às dietas experimentais. Os animais foram distribuídos em três tratamentos, que consistiram de: FA - ração-controle, com feno de alfafa; PC - substituição total do feno de alfafa por polpa de cítrus; e CS - substituição total do feno de alfafa por casca de soja. As diferentes frações da fibra advindas da polpa de cítrus e da casca de soja não influenciaram o desempenho dos animais aos 89 dias e mostram que esses ingredientes podem ser utilizados como substitutos do feno de alfafa na dieta de coelhos. A qualidade de fibra da polpa de cítrus reduziu os níveis séricos de triacilglicerol, colesterol e hemoglobina dos animais. A baixa quantidade de lignina em relação à celulose e à hemicelulose da casca de soja propiciou melhor coeficiente de digestibilidade dos nutrientes e maior maciez da carne, porém menor deposição proteica quando comparada com a dieta com polpa de cítrus.