Cocoa supplementation reduces amyloid-beta1–42 (Aβ1–42) induced deficits in a transgenic C. elegans

Abstract

BACKGROUND: Cocoa, a significant contributor of polyphenols to the western diet has been shown to be effective against Aβ induced toxicity in vitro. However, the effects of long-term cocoa supplementation on Aβ induced behavioural deficits, particularly on the short-term memory loss observed in human AD are not well defined. OBJECTIVE: This study characterized the phenotype of a pan-neuronal Aβ expressing C. elegans strain and investigated the effects of long-term cocoa supplementation on Aβ induced behavioural deficits including short-term memory loss and lifespan. METHODS: Cocoa powder was supplemented to the E. coli OP50 diet of C. elegans starting from L1 stage until they die. Neuronally controlled processes including locomotion, learning and memory were studied at different stages of the lifespan. In addition, lifespan was evaluated with different cocoa doses. Aβ fibril levels were determined with Thioflavin T. RESULTS: Aβ expressing worms showed a reduced growth, a reduced maximum speed at old age, short-term memory deficits at middle age and a reduced lifespan. Cocoa-supplementation reversed the deficits in growth, maximum speed, short-term memory loss and lifespan to reach similar levels to control counterparts while reducing the Aβ fibril levels. CONCLUSIONS: Long-term cocoa supplementation seemed to improve Aβ induced deficits in C. elegans.