Korean mistletoe (Viscum album var. coloratum) extends the lifespan via FOXO activation induced by dSir2 in Drosophila melanogaster

Aim: We examined the underlying mechanisms associated with the longevity effects of Korean mistletoe extract (KME) in Drosophila melanogaster. Methods: We measured the lifespan of sirtuin, chico and foxo mutant flies fed KME, the expression of the forkhead box O (FOXO) target genes and insulin-like peptide genes, and the localization of FOXO in flies fed the KME. Results: The longevity effect of KME was abolished in sirtuin, chico and foxo null mutant flies. In addition, the expression of FOXO target genes and the localization of FOXO into nuclei were increased in flies fed KME, but the expression of the insulin-like peptide genes was decreased by KME supplementation. Conclusions: The results show that KME extends the fly lifespan through sirtuin-induced FOXO activation. We suggest that KME has potential use as a beneficial anti-aging and longevity supplement. Geriatr Gerontol Int 2021; 21: 725–731.