The effect of piceatannol on cell survival and markers of mitochondrial function

According to the United Nations, the world population is increasingly becoming older; the number of people aged 60 and over is predicted to double by 2050 and triple by 2100. However, an increase in life expectancy is not necessarily synonymous with an increase in general health. Improving health in older individuals is an important goal to reach to address the aging of the population. In this work, we investigated the effect of the potential health improving polyphenol, piceatannol on cell viability and mitochondrial content using two well established cell lines, COS7 and HEK293. We also began to explore the impact of piceatannol on proteins involved in mitochondrial protein import. In order to quantify cell viability, we counted living cells based on their exclusion of trypan blue. To estimate the mitochondrial content of the cells we measured citrate synthase activity, a marker of mitochondrial number. Citrate synthase is an enzyme of the Krebs cycle located in the matrix of the mitochondria. To assess the protein level of proteins involved in mitochondrial protein import we used Western Blotting. It is a method to detect protein based on the interaction between an antibody and an antigen of the protein. In this work, we found that cell viability was reduced by the highest concentrations of piceatannol tested in COS7 cells. In addition, piceatannol increased mitochondrial content in this cell type. HEK293 cell viability was not influenced by piceatannol, but mitochondrial content decreased within treated cells. Using Western blotting techniques, we successfully detected two proteins involved in mitochondrial protein import, Tim23 and Hsp60. However, the level of these proteins varied between replicates. This thesis follows the lines of the increasing interest of piceatannol as a molecule to improve health. More research is needed to fully understand the mechanisms of action of this polyphenol.