Ashour M N, Salem S I, El-Gadban H M, Elwan N M, Basu T K
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada.
Eur J Clin Nutr. 1999 Aug;53(8):669-73. doi: 10.1038/sj.ejcn.1600830.
Free radicals are implicated in many diseases. The rise in free radicals associated with antioxidant deficiency results in tissue damage. The pathogenesis of oedema and anaemia commonly found in children with protein-energy malnutrition (PEM) has been suggested to be caused by an imbalance between the production of toxic radicals and their safe disposal. The aim of this study was to evaluate antioxidant status in children with PEM.
A total of 68 children (age range: 3 months to 3 years) living in Cairo, Egypt were recruited. Forty-six of these subjects had different degrees of PEM; they were admitted at the Abo-Elrish Hospital, Cairo. Of these, 26 children had kwashiorkor (KWO) and twenty had marasmus (MAR). Twenty-two age and sex matched healthy well-nourished children were recruited from the local community, and used as controls.
The antioxidant status of the study population was determined by measuring copper-zinc superoxide dismutase (Cu-Zn, SOD) in red blood cells, glutathione peroxidase (GPX) in whole blood, and ceruloplasmin in plasma. In addition, the plasma levels of trace-elements involving antioxidant activities, such as copper (Cu), zinc (Zn), and selenium (Se) were determined, along with a select group of vitamins. The latter included vitamin A (retinol), vitamin E (alpha-tocopherol) and vitamin C (ascorbic acid).
The mean whole blood GPX activity along with plasma levels of vitamins A, E and C as well as ceruloplasmin, Cu and Se were all lower in children with either KWO or MAR than their corresponding control subjects. The erythrocyte SOD activity, on the other hand, was increased while the plasma Zn concentrations were either increased or not changed in the malnourished children. It was of interest that while haemoglobin concentrations were decreased, the plasma free iron (Fe) levels were significantly increased in children with KWO.
The significant increase in red cell SOD activity associated with the decrease in plasma ceruloplasmin, antioxidant vitamins and the whole blood GPX activity in PEM children suggest that these children are potentially susceptible to high oxidative stress. An elevated plasma Fe concentrations, especially with KWO may augment the harmful effect of free radicals with a clinical consequence of oedema.
自由基与多种疾病有关。与抗氧化剂缺乏相关的自由基增加会导致组织损伤。蛋白质 - 能量营养不良(PEM)患儿中常见的水肿和贫血的发病机制被认为是由有毒自由基的产生与其安全清除之间的失衡引起的。本研究的目的是评估PEM患儿的抗氧化状态。
共招募了68名居住在埃及开罗的儿童(年龄范围:3个月至3岁)。其中46名受试者患有不同程度的PEM;他们在开罗的阿博 - 埃尔里什医院入院。其中,26名儿童患有夸希奥科病(KWO),20名患有消瘦症(MAR)。从当地社区招募了22名年龄和性别匹配的健康营养良好的儿童作为对照。
通过测量红细胞中的铜 - 锌超氧化物歧化酶(Cu - Zn,SOD)、全血中的谷胱甘肽过氧化物酶(GPX)和血浆中的铜蓝蛋白来确定研究人群的抗氧化状态。此外,还测定了参与抗氧化活性的微量元素如铜(Cu)、锌(Zn)和硒(Se)的血浆水平,以及一组选定的维生素。后者包括维生素A(视黄醇)、维生素E(α - 生育酚)和维生素C(抗坏血酸)。
KWO或MAR患儿的全血GPX平均活性以及血浆中维生素A、E和C以及铜蓝蛋白、Cu和Se的水平均低于相应的对照受试者。另一方面,红细胞SOD活性增加,而营养不良儿童的血浆Zn浓度要么增加要么不变。有趣的是,虽然血红蛋白浓度降低,但KWO患儿的血浆游离铁(Fe)水平显著升高。
PEM患儿红细胞SOD活性显著增加,同时血浆铜蓝蛋白、抗氧化维生素和全血GPX活性降低,这表明这些儿童可能易受高氧化应激影响。血浆Fe浓度升高,尤其是KWO患儿,可能会增强自由基的有害作用,导致水肿的临床后果。