Tea catechins induce the conversion of preformed lysozyme amyloid fibrils to amorphous aggregates.

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.