Pajk Tanja, Rezar Vida, Levart Alenka, Salobir Janez
Institute of Nutrition, Biotechnical Faculty, University of Ljubljana, Domzale, Slovenia.
Nutrition. 2006 Apr;22(4):376-84. doi: 10.1016/j.nut.2005.08.010. Epub 2006 Jan 18.
The present study investigated the potency of apples, strawberries, and tomatoes in decreasing oxidative stress in pigs as a model for humans.
Forty-eight growing pigs were individually penned in metabolic cages and divided into six groups. All groups received isocaloric daily rations composed of a basal diet supplemented with starch, linseed oil, linseed oil and apples, linseed oil and strawberries, linseed oil and tomatoes, or linseed oil, apples, strawberries and tomatoes. Oxidative stress was evaluated at the beginning and at the end of the 22-d experimental period by measuring the degree of DNA damage in mononuclear blood cells, the concentration of malondialdehyde (MDA) in plasma, the MDA excretion rate, the concentration of tocopherols in plasma, plasma total antioxidant status, and erythrocyte glutathione peroxidase concentration.
The results confirmed that the linseed oil diet significantly increased MDA formation in the body and DNA damage to mononuclear blood cells in comparison with the starch diet. Although the MDA concentration in plasma was significantly decreased in all fruit groups, urine MDA excretion rate was decreased only in the linseed oil/apple and linseed oil/apple/strawberry/tomato groups. Supplementation with fruit significantly decreased DNA damage, was more pronounced in the linseed oil/apple and linseed oil/apple/strawberry/tomato groups. Significantly lower glutathione peroxidase concentrations were observed only in the linseed oil/strawberry group.
Our findings support the hypothesis that supplementation with apples, strawberries, or tomatoes effectively decreases oxidative stress by decreasing MDA formation in the body and by protecting mononuclear blood cells against increased DNA damage. This effect was particularly pronounced in the group supplemented with a fruit mixture; among the single fruit supplements, the most beneficial effect was obtained with apples.
本研究以猪作为人类的模型，探究苹果、草莓和番茄在降低氧化应激方面的效能。
48头生长猪被单独饲养在代谢笼中，并分为六组。所有组均接受由基础日粮组成的等热量日粮，基础日粮补充有淀粉、亚麻籽油、亚麻籽油和苹果、亚麻籽油和草莓、亚麻籽油和番茄，或亚麻籽油、苹果、草莓和番茄。在22天实验期开始和结束时，通过测量单核血细胞中DNA损伤程度、血浆中丙二醛（MDA）浓度、MDA排泄率、血浆中生育酚浓度、血浆总抗氧化状态以及红细胞谷胱甘肽过氧化物酶浓度来评估氧化应激。
结果证实，与淀粉日粮相比，亚麻籽油菜日粮显著增加了体内MDA的形成以及对单核血细胞的DNA损伤。尽管所有水果组血浆中MDA浓度均显著降低，但仅在亚麻籽油/苹果组和亚麻籽油/苹果/草莓/番茄组中尿MDA排泄率降低。补充水果显著降低了DNA损伤，在亚麻籽油/苹果组和亚麻籽油/苹果/草莓/番茄组中更为明显。仅在亚麻籽油/草莓组中观察到显著较低的谷胱甘肽过氧化物酶浓度。
我们的研究结果支持以下假设，即补充苹果、草莓或番茄可通过减少体内MDA的形成以及保护单核血细胞免受DNA损伤增加的影响，有效降低氧化应激。这种效果在补充水果混合物的组中尤为明显；在单一水果补充剂中，苹果的有益效果最为显著。
