Dairam Amichand, Fogel Ronen, Daya Santy, Limson Janice L
Department of Biochemistry, Microbiology and Biotechnology and Faculty of Pharmacy, Rhodes University, PO Box 94, Grahamstown, South Africa.
J Agric Food Chem. 2008 May 14;56(9):3350-6. doi: 10.1021/jf0734931. Epub 2008 Apr 19.
Research demonstrates that antioxidants and metal chelators may be of beneficial use in the treatment of neurodegenerative diseases, such as Alzheimer's disease (AD). This study investigated the antioxidant and metal-binding properties of curcumin, capsaicin, and S-allylcysteine, which are major components found in commonly used dietary spice ingredients turmeric, chilli, and garlic, respectively. The DPPH assay demonstrates that these compounds readily scavenge free radicals. These compounds significantly curtail iron- (Fe2+) and quinolinic acid (QA)-induced lipid peroxidation and potently scavenge the superoxide anion generated by 1 mM cyanide in rat brain homogenate. The ferrozine assay was used to measure the extent of Fe2+ chelation, and electrochemistry was employed to measure the Fe3+ binding activity of curcumin, capsaicin, and S-allylcysteine. Both assays demonstrate that these compounds bind Fe2+ and Fe3+ and prevent the redox cycling of iron, suggesting that this may be an additional method through which these agents reduce Fe2+-induced lipid peroxidation. This study demonstrates the antioxidant and metal-binding properties of these spice ingredients, and it is hereby postulate that these compounds have important implications in the prevention or treatment of neurodegenerative diseases such as AD.
研究表明，抗氧化剂和金属螯合剂可能对治疗神经退行性疾病（如阿尔茨海默病，AD）有益。本研究调查了姜黄素、辣椒素和S-烯丙基半胱氨酸的抗氧化和金属结合特性，它们分别是常用膳食香料成分姜黄、辣椒和大蒜中的主要成分。DPPH试验表明，这些化合物能迅速清除自由基。这些化合物能显著减少铁（Fe2+）和喹啉酸（QA）诱导的脂质过氧化，并有效清除大鼠脑匀浆中1 mM氰化物产生的超氧阴离子。采用亚铁嗪法测定Fe2+螯合程度，用电化学方法测定姜黄素、辣椒素和S-烯丙基半胱氨酸的Fe3+结合活性。两种试验均表明，这些化合物能结合Fe2+和Fe3+，并阻止铁的氧化还原循环，这表明这可能是这些药物减少Fe2+诱导的脂质过氧化的另一种方式。本研究证明了这些香料成分的抗氧化和金属结合特性，据此推测这些化合物对预防或治疗AD等神经退行性疾病具有重要意义。
