Galhardi F, Mesquita K, Monserrat J M, Barros D M
Instituto de Ciências Biológicas, Universidade Federal do Rio GrandeRio Grande, RS, Brazil.
Food Chem Toxicol. 2009 Oct;47(10):2655-60. doi: 10.1016/j.fct.2009.07.030. Epub 2009 Aug 6.
Silymarin (SM), the active complex of milk thistle, is a lipophilic fruit extract and is composed of several isomer flavonolignans. Flavonoids are antioxidants found molecules capable of intercepting reactive oxygen species (ROS). The oxidative stress (OS) is caused by imbalance between antioxidant defenses and production of ROS causing oxidative damage to macromolecules. Brain is susceptible to oxidative stress and it is associated with age-related brain dysfunction. This study evaluated the effect of SM on biochemical parameters that evaluate OS in aged and young rat brain. For measures of OS were used measures of total oxyradical scavenging capacity (ACAP) through the concentration of ROS by fluorescence, lipid peroxidation (LPO), via FOX and TBARS, proteins oxidation by Western blot (WB). Rats were treated with SM at doses of 200 and 400mg/kg/day (SM200 and SM400). The LPO analyzed through FOX was increased in the hippocampus of aged animals treated with SM400, but in the cortex of young and aged, the highest dose of SM decreased LPO analyzed through TBARS. Both doses have seemed most effective in the reduction of oxidized proteins in aged brain. These results suggest that SM may contribute to the prevention of aged-related and pathological degenerative processes in the brain.
水飞蓟素（SM）是水飞蓟的活性复合物，是一种亲脂性果实提取物，由几种异构黄酮木脂素组成。黄酮类化合物是能够拦截活性氧（ROS）的抗氧化剂分子。氧化应激（OS）是由抗氧化防御与ROS产生之间的失衡引起的，ROS会对大分子造成氧化损伤。大脑易受氧化应激影响，且与年龄相关的脑功能障碍有关。本研究评估了水飞蓟素对评估老年和年轻大鼠大脑氧化应激的生化参数的影响。对于氧化应激的测量，通过荧光法测定ROS浓度来测量总氧自由基清除能力（ACAP），通过FOX和硫代巴比妥酸反应物（TBARS）测定脂质过氧化（LPO），通过蛋白质印迹法（WB）测定蛋白质氧化。大鼠分别以200和400mg/kg/天的剂量接受水飞蓟素治疗（SM200和SM400）。通过FOX分析，接受SM400治疗的老年动物海马体中的LPO增加，但在年轻和老年动物的皮质中，最高剂量的水飞蓟素通过TBARS分析降低了LPO。两种剂量在减少老年大脑中的氧化蛋白方面似乎最有效。这些结果表明，水飞蓟素可能有助于预防大脑中与年龄相关的和病理性退行性过程。
