The Effect of Soy Derived Phytoestrogens on Innate Immunity in the Nematode Caenorhabditis elegans
Authors:Breann De Santiago, Peaches Ulrich
Mentor:Dr. Sylvia Vetrone, Assistant Professor of Biology, Whittier College
Nutraceuticals, such as phytoestrogens, are plant-derived substances that are thought to have many benefits that improve human health. Phytoestrogens are estrogen like molecules that have been shown to decrease reactive oxygen species (ROS), decrease oxidative damage, and improve immunity in both animal and human cells. Studies have also shown a correlation with improved life span. The nematode animal model, Caenorhabditis elegans (C. elegans) is an excellent model for research investigating interactions between host and pathogen, as they have a short life span and possess an innate immune system (mediated through the DAF-2 Insulin-like pathway) that is homologous to some advanced organisms. In this study, we investigated the effect of phytoestrogens (daidzein, genistein, or genistein/daidzein) on innate immunity using the wild type N2 strains and three mutant strains (AKT-1, DAF-16, and AGE-1) found to affect the DAF-2 Insulin-like pathway. The various strains were treated with phytoestrogens from the first stage of development until they reached the 2 day old adult stage, at which time they were immunologically challenged with the bacterial pathogen (Pseudomonas aeruginosa), and monitored for mortality over an 80 hour period. Our preliminary findings showed that phytoestrogen treated wildtype N2 strain showed a statistically significant reduced mortality when treated with daidzein, AKT-1 mutants had a statistically significant reduced mortality, and the AGE-1 mutants showed a statistically reduced mortality when treated with the phytoestrogen genistein. There was no statistically significant difference observed for the DAF-16 mutant strain. Taken together, our results indicate phytoestrogen administration to C. elegans is correlated with an improved immunity when challenged with pathogenic bacteria and that this improvement might be mediated through the DAF-2 Insulin-like pathway.