College of Life Science, Sichuan University, Chengdu, China.
J Agric Food Chem. 2009 Dec 9;57(23):11391-6. doi: 10.1021/jf902664f.
Natural polyphenols are major constituents of plant foods and herbs. Numerous studies have demonstrated that natural polyphenols inhibited amyloid formation and destabilized the preformed amyloid fibrils. However, the molecular mechanism for the antiamyloidogenesis of polyphenols is still unclear and remains to be further explored. In the present study, the preformed lysozyme fibrils were used as an in vitro model to study the disruptive effects of tea catechins on amyloid fibrils. Results showed that tea catechins induced the conversion of lysozyme fibrils to amorphous aggregates and inhibited fibril-induced hemolysis. Hydroquinone also showed disruptive effect on the fibrils, whereas phenol and two typical antioxidants, ascorbic acid and alpha-tocopherol, did not affect the fibrillar structure, suggesting that polyphenolic structure is essential for fibril deposition. Correlation analyses indicate that the fibril-depositing effects were related to both the antioxidative potency and hydrophobicity of tea catechins. These findings provide new evidence for comprehensive understanding of the interaction between natural polyphenols and amyloid fibrils.
天然多酚是植物性食物和草药的主要成分。大量研究表明，天然多酚可以抑制淀粉样蛋白的形成并使已形成的淀粉样纤维不稳定。然而，多酚抗淀粉样变的分子机制尚不清楚，仍有待进一步探索。在本研究中，预先形成的溶菌酶纤维被用作体外模型，以研究茶儿茶素对淀粉样纤维的破坏作用。结果表明，茶儿茶素诱导溶菌酶纤维向无定形聚集物转化，并抑制纤维诱导的溶血。对苯二酚也对纤维有破坏作用，而苯酚和两种典型的抗氧化剂抗坏血酸和α-生育酚则不影响纤维结构，表明多酚结构对纤维沉积是必需的。相关性分析表明，纤维沉积效应与儿茶素的抗氧化能力和疏水性有关。这些发现为全面理解天然多酚与淀粉样纤维之间的相互作用提供了新的证据。
