Red-beet betalain pigment inhibits amyloid-β aggregation and toxicity in amyloid-β expressing Caenorhabditis elegans model

Abstract

BACKGROUNDBetalain pigments are mainly produced by plants in the order Caryophyllales. Recent interest in the biological functions of betalain pigments has increased with antioxidant, anti-inflammatory, and anticancer activities reported. RESULTSWe investigated the effects of betalain pigments derived from red-beet on amyloid-{beta} (A{beta}) aggregation, a cause of Alzheimers disease. Inhibition of A{beta} aggregation against A{beta}40 and A{beta}42 by betalain pigments in vitro was demonstrated by the Thioflavin T fluorescence assay, circular dichroism spectroscopy analysis and transmission electron microscopic observations. Moreover, we examined the ability of betalain pigments to interfere with A{beta} toxicity by using the transgenic Caenorhabditis elegans strain CL2006, which expresses the human A{beta}42 protein intracellularly within the body wall muscle and responds to A{beta}-toxicity with paralysis. Treatment with 50 M betalain pigments significantly delayed the paralysis of Caenorhabditis elegans. CONCLUSIONThese results suggest that betalain pigments reduce A{beta}-induced toxicity by inhibiting A{beta} aggregation and may lead to their use as inhibitors of A{beta} aggregation.