Abstract

Human Islet amyloid polypeptide gathering in the β-cell of the pancreas has been implicated in the pathology of type 2 diabetes. Inhibition of the formation of amylin fibrils could be therapeutic aims for the treatment of type 2 diabetes mellitus. In this study, the fluorimetric assay was used to examine the role of two herbal polyphenol compounds including Rosmarinic acid and Curcumin on amyloid formation and destabilization of human amylin amyloid under near-physiological circumstances. The results showed that after 192 h incubation by shaker incubator at 37°C, Rosmarinic acid at 10 and 40 µM repressed amylin amyloid formation by 18.6 and 19.3% respectively (P<0.05), and the similar values of Curcumin inhibited the formation of β-sheet structure by 17.2 and 29.9%, respectively (P<0.05). The obtained data also confirmed that amyloidal sheet opening was induced by Rosmarinic acid and Curcumin significantly (P<0.05). It   was concluded that islet amyloid cytotoxicity to β-cells may be reduced by these two herbal extracts and these compounds should be key molecules for the development of the therapeutics for diabetes mellitus.

Key words: Amylin, diabetes, rosmarinic acid, curcumin, amyloid.