Anthocyanin-rich Purple Wheat Prolongs the Life Span of Caenorhabditis elegans Probably by Activating the DAF-16/FOXO Transcription Factor

Colored cereals attract public attention due to their potential antioxidant properties and corresponding health benefits. Purple wheat, rich in anthocyanins, is one of the newly developed cereals on the market. Cyanidin-3-O-glucoside (42.6%) is the predominant anthocyanin in purple wheat, followed by peonidin-3-O-glucoside (39.9%) and malvidin-3-O-galactoside (17.4%). To investigate the potential antiaging and antioxidant properties of purple wheat, the nematode Caenorhabditis elegans was chosen as an experimental model organism. It was found that an anthocyanin-rich methanolic extract of purple wheat extended the mean life span of wild type worms and of mev-1(hn1) mutants, which are sensitive to oxidative stress, by 10.5 and 9.2%, respectively. Life span extension depends on the transcription factor DAF-16; no significant increase of longevity was seen in daf-16 (mgDf50) mutant worms. Trans location of DAF-16/FOXO to the nucleus implies that the transcription factor DAF-16/FOXO was activated under purple wheat treatment by inhibition of the insulin/IGF-1-like signaling pathway which includes the insulin receptor DAF-2. Moreover, purple wheat increased stress response in C. elegans as well as reduced oxidative stress. Anthocyanins of purple wheat apparently exhibit beneficial effects in C. elegans. They may exert similar properties in humans, which is an issue to be explored in future studies.