Avramovic N, Dragutinovic V, Krstic D, Colovic Mb, Trbovic A, de Luka S, Milovanovic I, Popovic T
Institute for Medical Research, University of Belgrade, Serbia.
Hippokratia. 2012 Jul;16(3):241-5.
The omega 3 fatty acids play an important role in many physiological processes. Their effect is well documented in neurodegenerative diseases and inflammatory diseases. Also, aging as a biophysiological process could be influenced by eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) components of fish oil. However there are not many studies showing the effect of PUFA (polyunsaturated FA) suplementation in eldery brain functions and the response to oxidative strees. The aim of this study was to investigate the effects of dietary omega-3 fatty acid supplementation on levels of lipid peroxidation and oxidant/antioxidant status of brain tissue in aged (24 months old) Wistar rats.
Animals were divided in two groups. Control group (n=8) was fed with standard laboratory food and received water ad libitum. Treated group (n=8) was also fed with standard laboratory food, water ad libitum and received fish oil capsules (EPA+DHA) for 6 weeks. Daily dose was 30mg EPA and 45mg DHA (capsules: 200mg EPA and 300mg DHA; in-house method). At the end of treatment animals were sacrificed and brains were collected and frozen on -80ºC. The levels of lipid peroxidation (malondialdehyde - MDA), activity of catalase (CAT) and activity of superoxide dismutase (SOD) were examined in cerebral cortex. Catalase activity was determined by measuring the decrease in absorbance (H2O2 degradation) at 240 nm for 3 min and expressed as U/mg protein. Total SOD (superoxide dismutase) activity was performed at room temperature according to the method of Misra and Fridovich. The extent of lipid peroxidation (LPO) was estimated as the concentration of thiobarbituric acid reactive product malondialdehyde (MDA) by using the method of Aruoma et al. The incorporation of fatty acids in cellular membranes was confirmed by gas chromatography.
Our results showed that lipid peroxidation significantly decreased in treated animal group, where MDA concentration was 0.38±0.001 vs. 0.43±0.001 nM/ml (p<0.05) in control. However SOD activity increased significantly in treated animal group 1.57±0.24 vs. 4.12±0.15 U/gHb/L (p<0.01) in control. CAT activity decreased in treated group but not significantly.
Incorporation of omega-3 fatty acids after their supplementation had beneficial effects on brain tissue. Omega-3 fatty acids increased activity of SOD and decreased lipid peroxidation. Changes in oxidative/antioxidative balance are a result of EPA and DHA effects on lipids and enzymes of antioxidative system.
ω-3脂肪酸在许多生理过程中发挥着重要作用。其在神经退行性疾病和炎症性疾病中的作用已有充分记录。此外，衰老作为一种生物生理过程，可能会受到鱼油中二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）成分的影响。然而，关于多不饱和脂肪酸（PUFA）补充剂对老年大脑功能及氧化应激反应影响的研究并不多。本研究的目的是调查膳食补充ω-3脂肪酸对老年（24月龄）Wistar大鼠脑组织脂质过氧化水平及氧化/抗氧化状态的影响。
将动物分为两组。对照组（n = 8）给予标准实验室饲料并随意饮水。治疗组（n = 8）同样给予标准实验室饲料、随意饮水，并接受鱼油胶囊（EPA + DHA）治疗6周。每日剂量为30mg EPA和45mg DHA（胶囊：200mg EPA和300mg DHA；内部方法）。治疗结束时处死动物，采集大脑并在-80℃冷冻。检测大脑皮质中脂质过氧化水平（丙二醛 - MDA）、过氧化氢酶（CAT）活性和超氧化物歧化酶（SOD）活性。通过测量240nm处吸光度的下降（H2O2降解）3分钟来测定CAT活性，并以U/mg蛋白质表示。总SOD（超氧化物歧化酶）活性根据Misra和Fridovich的方法在室温下进行测定。采用Aruoma等人提出的方法，通过测定硫代巴比妥酸反应产物丙二醛（MDA）的浓度来评估脂质过氧化程度（LPO）。通过气相色谱法确认脂肪酸在细胞膜中的掺入情况。
我们的结果表明，治疗组动物的脂质过氧化显著降低，其中MDA浓度为0.38±0.001 nM/ml，而对照组为0.43±0.001 nM/ml（p < 0.05）。然而，治疗组动物的SOD活性显著增加，为1.57±0.24 U/gHb/L，而对照组为4.12±0.15 U/gHb/L（p < 0.01）。治疗组的CAT活性降低，但不显著。
补充ω-3脂肪酸后其掺入对脑组织有有益影响。ω-3脂肪酸增加了SOD活性并降低了脂质过氧化。氧化/抗氧化平衡的变化是EPA和DHA对抗氧化系统的脂质和酶产生作用的结果。
