氨基酸维生素制剂对力竭疲劳大鼠下丘脑超微结构及神经递质的影响

目的 探讨氨基酸维生素制剂对力竭运动大鼠下丘脑超微结构及中枢神经递质变化的影响.方法 雄性SD大鼠36只,适应性游泳后随机分为胶囊组、对照组和冲剂组,每组12只.3组分别给予复方氨基酸胶囊、正常饮用水和氨基酸果糖粉固体饮料(2.5ml/100g,每日灌胃2次,连续14d).采用无负重游泳方式建立大鼠力竭游泳模型,实验持续14d.末次游泳力竭结束后,取大鼠下丘脑组织,采用电镜观察下丘脑超微结构;采用高效液相色谱仪(HPLC-ECD)检测下丘脑组织5-羟色胺(5-HT)、5-羟吲哚乙酸(5-HIAA)、对羟基苯乙酸(HOPAC)和y-氨基丁酸(GABA)的浓度.结果 胶囊组和冲剂组脑细胞胞质内线粒体结构基本完整;对照组细胞肿胀变性,线粒体可见不同程度肿胀,电镜下超微形态变异较明显,膜、嵴均有溶解、断裂现象,甚至整个线粒体崩解,出现空泡化.胶囊组和冲剂组大鼠下丘脑中5-HT、5-HTAA、HOPAC和GABA浓度均明显低于对照组(P＜0.05).结论 复方氨基酸维生素制剂可通过降低下丘脑超微结构改变和神经递质水平来提高中枢抗疲劳能力.     

Lipophilic Micronutrients and Adipose Tissue Biology

Lipophilic micronutrients (LM) constitute a large family of molecules including several vitamins (A, D, E, K) and carotenoids. Their ability to regulate gene expression is becoming increasingly clear and constitutes an important part of nutrigenomics. Interestingly, adipose tissue is not only a main storage site for these molecules within the body, but it is also subjected to the regulatory effects of LM. Indeed, several gene regulations have been described in adipose tissue that could strongly impact its biology with respect to the modulation of adipogenesis, inflammatory status, or energy homeostasis and metabolism, among others. The repercussions in terms of health effects of such regulations in the context of obesity and associated pathologies represent an exciting and emerging field of research. The present review will focus on the regulatory effects of vitamin A, D, E and K as well as carotenoids on adipose tissue biology and physiology, notably in the context of obesity and associated disorders.     

Vitamin and mineral status in elderly patients with chronic obstructive pulmonary disease

Introduction: Eating problems are common in patients with chronic obstructive pulmonary disease (COPD), and intake of micronutrients might be lower than recommended. Objective: To study dietary intake, serum and urinary concentration of trace elements and vitamins in elderly underweight patients with established severe COPD. Methods: Outpatients at a university clinic for lung medicine, with COPD, 70–85 years old, with no other serious disease, and with a body mass index (BMI) of ≤20 kg/m² and an FEV₁of <50 % predicted were recruited. Body composition and bone density were evaluated with dual energy X‐ray absorptiometry. Dietary intake was studied by a trained dietitian using diet‐history interview. Blood and urine samples were analysed for various vitamins and trace elements. Results: Seventeen of 30 recruited patients took part. Osteoporosis or osteopaenia was found in 16 patients. Dietary intake of energy and macronutrients was in line with recommendations for healthy individuals. Intake of protein did not meet recommendations for COPD patients. Intake of polyunsaturated fatty acids was lower than recommended and intake of saturated fatty acids was higher than recommended. Mean intake of vitamin D and folic acid was far below recommendations. Serum concentrations for folic acid and methylmalonate and plasma concentrations for homocysteine were below normal in several patients. Conclusion: Intake of vitamin D and calcium is often low in older COPD patients, which might contribute to osteoporosis. Low intake of folic acid might also be a problem. The results support prophylaxis with calcium, vitamin D and folic acid. Please cite this paper as: Andersson I, Grönberg A, Slinde F, Bosaeus I and Larsson S. Vitamin and mineral status in elderly patients with chronic obstructive pulmonary disease. The Clinical Respiratory Journal 2007;1:23–29.     

Protective effect of some vitamins against the toxic action of ethanol on liver regeneration induced by partial hepatectomy in rats

AIM： To investigate the effects of vitamins （A, C and E） on liver injury induced by ethanol administration during liver regeneration in rats. METHODS： Male Wistar rats subjected to 70% partial hepatectomy were divided into five groups （groups 1-5）. During the experiment, animals of Group 1 drank only water. The other four groups （2-5） drank 30 mL of ethanol/L of water. Group 3 additionally received vitamin A, those of group 4 vitamin C and those of group 5 received vitamin E. Subsequently serum alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, albumin and bilirubin were measured colorimetrically. Lipid peroxidation （thiobarbituric-acid reactive substances, TBARS） both in plasma and liver was measured, as well as liver mass gain assessment and total DNA. RESULTS： Compared with sham group, serum AST and ALT increased significantly under ethanol treatment （43% and 93%, respectively, with P 〈 0.05）. Vitamin C and vitamin E treatment attenuated the ethanol-induced increases in ALT and AST activity. Ethanol treatment also decreased serum albumin concentration compared to sham group （3.1 ± 0.4 g/dL vs 4.5 ± 0.2 g/dL; P 〈 0.05）. During liver regeneration vitamins C and E significantly ameliorated liver injury for ethanol administration in hepatic lipid peroxidation （4.92 nmol/mg and 4.25 nmol/mg vs 14.78 nmol/mg, respectively, with P 〈 0.05）. In association with hepatic injury, ethanol administration caused a significant increase in both hepatic and plasma lipid peroxidation. Vitamins （C and E） treatment attenuated hepatic and plasma lipid peroxidation. CONCLUSION： Vitamins C and E protect against liver injury and dysfunction, attenuate lipid peroxidation, and thus appear to be significantly more effective than vitamin A against ethanol-mediated toxic effects during liver regeneration.     

Physical activity is inversely associated with total homocysteine levels, independent of C677T MTHFR genotype and plasma B vitamins

The homocysteine level is considered to be a product of genetic and lifestyle interactions, mainly mutated methylenetetrahydrofolate reductase (MTHFR) and the intake of folate, vitamin B12 and pyridoxine, and their blood levels. Physical activity has been associated with lower homocysteine levels in some population studies, especially among elderly subjects. To further elucidate the observed association between homocysteine and physical activity, while accounting for the effect of the MTHFR C677T genotype, and of plasma levels of folate and B12 vitamins, a cross-sectional study of 620 males and females, aged 70.5 ± 6.8 years, was carried out. Information on lifestyle habits was collected and laboratory examinations of 12-h fasting total plasma homocysteine, folate, and vitamin B12, as well as DNA analysis for MTHFR C677T variant, were performed. Median total homocysteine values were 11.4 μmol/l for males and 9.4 for females; p < 0.001. Smoking and ethnic origin were not found to be associated with homocysteine levels. Physically active subjects had significantly lower total homocysteine levels when adjusted for sex (p = 0.01). Significant inverse correlations were found between body mass index, plasma folate, B12 and homocysteine levels. Homocysteine levels of the CC, CT and TT genotypes were 9.7, 10.6 and 10.2 μmol/l, respectively (p = 0.002, controlling for sex). In a multiple linear regression model, a sedentary lifestyle increased homocysteine levels by 7% as compared to an active one (p = 0.03) controlling for sex, age, body mass index, folate, vitamin B12, and C677T genotype, all of which were also found to be significantly associated with homocysteine levels. Any level of physical activity was found to be independently associated with lower homocysteine levels in an elderly population, controlling for MTHFR genotype, plasma B-vitamins, age, sex, smoking and BMI. This study emphasizes the importance of maintaining a physically active lifestyle in the elderly.     

Dietary intake and micronutrient deficiency in children with cancer

Data regarding micronutrient deficiencies in children with cancer are lacking. We measured micronutrients in a subset of children with cancer (n = 23) participating in a randomized trial of the neutropenic diet. Ninety‐six percent of children had ≥1 micronutrient deficiency and 39% had ≥3 micronutrient deficiencies. Eighty‐six percent of children had vitamin C deficiency, 87% had 25‐hydroxyvitamin D deficiency, 50% had zinc deficiency, and 13% had vitamin A deficiency. Dietary intake did not correlate with micronutrient deficiency status. More data are needed regarding the prevalence and etiology of micronutrient deficiencies in children with cancer to further understand their implications and treatment.     

Water-Soluble Vitamins and Trace Elements Losses during On-Line Hemodiafiltration

Maintenance hemodialysis induces water-soluble vitamins and trace elements losses, which is why recommendations regarding potential supplementation were provided, but mainly based on conventional hemodialysis. This study′s aim was to measure the water–soluble vitamins and trace element losses during one on-line post-dilution hemodiafiltration (HDF) session. Thirty-nine patients under maintenance HDF were enrolled. We used the Theraflux^® sampler (Theradial Corp., Orvault, France) to analyze the full session dialysate mass transfer. Blood and dialysate samples were collected before and after one HDF session to measure B1, B2, B6, B9, B12, C vitamins, zinc, and selenium concentrations. Values significantly decreased for B1 (20.2%), B2 (13%), B6 (25.4%), B9 (32.6%), C (66.6%) and selenium (6.7%). No significant differences were found for vitamin B12 and zinc. The dialysate losses per session were 1.12 ± 0.88 mg for vitamin B1, 0.28 ± 0.30 mg for B2, 0.33 ± 0.09 mg for B6, 0.3 ± 0.18 mg for B9, 147.5 ± 145.50 mg for C and 25.75 ± 6.91 mg for zinc. Vitamin B12 and selenium were under detection values. In conclusion, during a standard 4hr-HDF session, we found important losses for vitamin B1, B6, B9, C and zinc, suggesting the need for regular monitoring of plasma levels and systematic supplementation of these compounds.     

Investigating the Effects of a Multinutrient Supplement on Cognition,Mood and Biochemical Markers in Middle-Aged Adults with ‘Optimal’ and ‘Sub-Optimal’ Diets: A Randomized Double Blind Placebo Controlled Trial

Background: Previous randomized controlled trials examining cognitive and mood effects of combination multivitamin supplements in healthy, non-clinical adults have reported mixed results. One purported explanation for this is that the dietary status of participants at the start of supplement interventions may influence the magnitude of the effect of supplementation. Methods: In this study, we evaluated the effect of a multinutrient formula containing B group vitamins, Bacopa monniera and Ginkgo biloba on memory, attention, mood and biochemical markers of nutrient status in middle-aged adults (M = 52.84 years, n = 141) with ‘optimal’ and ‘sub-optimal’ diets over 12 weeks. We hypothesised that active supplementation would differentially improve memory and attention in those with a ‘sub-optimal’ diet. Results: Mixed model, repeated measures analysis revealed that, in comparison to placebo, active treatment was associated with significant increases in B vitamin status (B1, B6, B12). Regarding behavioural outcomes there was no significant benefit to memory (F(1, 113.51) = 0.53, p = 0.470) nor attention (F(1,113.77) = 1.89, p = 0.171) in the whole cohort. Contrary to our hypothesis, there was a significant beneficial effect of supplementation on attentional performance in individuals with an ‘optimal’ diet prior to supplementation (F(1,57.25) = 4.94, p = 0.030). In the absence of a main effect of supplementation across the entire cohort, there were also a number of significant three-way interactions (treatment by time by diet group) detected in secondary outcomes including lower state anxiety and mental fatigue in those with an ‘optimal’ diet. Conclusion: These findings suggest that the cognitive benefit of B vitamin and herbal supplementation may be dependent on diet quality, supporting the concepts of ‘co-nutrient optimisation’ and interdependency of nutrients. This warrants further investigation. This study advocates characterising the diet of participants prior to supplementation as it may influence the effect of a nutraceutical intervention.     

Micronutrients

Micronutrients are essential dietary components and play a fundamental role in the prevention of disease. 30 are essential and cannot be synthesized by the body on a daily basis, making dietary sources critical. Micronutrients have an array of biochemical functions which are fundamental in the homoeostatic regulation of body function. It is at any point in a metabolic pathway that the chemical reaction may be unable to continue along its nature cascading pathway because the essential micronutrient is lacking. The normal metabolic regulation of the body will have been disturbed and ill health may occur due to the absence of a specific micronutrients. Several population groups with specific nutritional requirements, complex social, environmental and economic circumstances may be at risk of inadequate micronutrient intakes due to poor consumption or excessive losses, and hence maybe unable to meet their recommended requirements of micronutrients. This group may benefit from micronutrient supplements. Infants/children are a specific population group who are at risk of micronutrient deficiency states making adequate intakes essential to ensure normal growth and development. The paediatric group will be discussed here, with reference to current recommendations for their micronutrient and supplementation requirements based on current evidence available to advisory groups.