Prolongevity effects of olive oil phenolic compounds: C. elegans as a model system

Abstract

Trabajo presentado al 4th Spanish Worm Meeting, celebrado en Carmona (Sevilla) del 14 al 15 de marzo de 2013.Tyrosol and hydroxytyrosol, in simple forms or in conjugates, are the main phenolic compounds present in Extra Virgin Olive Oil (EVOO), with reported protective effects in human health such as inhibition of LDL oxidation and platelet aggregation, among others. Nevertheless, the potential effects of these compounds on longevity in a whole organism had not been studied before. In order to investigate the effects of tyrosol and hydroxytyrosol on longevity, we decided to use the nematode Caenorhabditis elegans, a well characterized model organism which facilitates lifespan assays and molecular analyses. Our results demonstrate that one of the specific tyrosol concentrations assayed was able to induce a significant increase in the median lifespan of C. elegans. This phenol also delayed the onset of a typical marker of aging in these nematodes and increased survival to heat and oxidative stress. We also found that tyrosol induces a significant up-regulation of a small Heat Shock Protein (sHSPs) family gene, whose expression is highly controlled by the Insulin/Igf-1 (IIS) signaling pathway, known to modulate longevity in this and other organisms. In addition, we have performed lifespan assays with mutant strains which have provided useful information regarding the specific genetic requirements or molecular pathways involved in tyrosol effects in this model organism. In particular, the heat shock transcription factor (HSF-1) and the insulin pathway (DAF-2 and DAF-16) might be implicated in mediating tyrosol effects in lifespan. Together, our results suggest hormesis as a possible mechanism to explain the effects of tyrosol on longevity in C. elegans. Moreover, we have performed a proteomics analysis in order to identify C. elegans proteins that are differentially expressed in response to tyrosol treatment. In this sense, our preliminary data suggests additional mechanisms affected by this phenolic compound that might account for some of the described effects on longevity. In conclusion, our results so far demonstrate that a single phenolic compound from EVOO is able to promote longevity in an animal model. Our results suggest that this effect may be related to the ability of tyrosol to induce the expression of specific genes directly involved in key longevity regulation pathways.This work was funded by the Instituto de Estudios Giennenses (RFC/IEG 2009) and the University of Jaén (R1/13/2010/02).Peer Reviewe