Evaluation of aluminium, manganese, copper and selenium effects on human islets amyloid polypeptide hormone aggregation.

Islet amyloid formation causes destruction of insulin-producing beta-cells of the pancreas. The subsequent lack of insulin leads to increased blood and urine glucose. In this research, the fluorimetric assay was used to examine the effects of aluminium and some nutritionally essential trace elements including, manganese, copper and selenium on amyloid formation of human peptide of amylin under near-physiological circumstances. Results obtained from in vitro study showed that after 120 h incubation by shaker incubator in 37 degrees C, copper and selenium at 8 microM inhibited amylin 8 microM from amyloid fibril formation by 22.1 and 11.3%, respectively (p<0.05) while the similar values of either aluminium and manganese promoted the formation of beta-pleated sheet structure by 19.3 and 13.2% respectively (p<0.05). If islet amyloid is cytotoxic to beta-cells then copper and selenium may be able to protect these cells against degeneration in diabetic patients especially in type 2 diabetes mellitus.