The Effect of Soy Derived Phytoestrogens on Innate Immunity in the Nematode Caenorhabditis elegans
Authors:Breann De Santiago, Samantha Rodriguez, Peaches Ulrich
Mentor:Sylvia Vetrone, Assistant Professor of Biology, Whittier College
Nutraceuticals, such as phytoestrogens, are plant-derived substances that are thought to benefit human health. Phytoestrogens are estrogen like molecules that have been shown to decrease reactive oxygen species (ROS), decrease oxidative damage, and improve immunity in animal and human cells. These studies have demonstrated a correlation with the administration of phytoestrogens and improved life span. The nematode, Caenorhabditis elegans (C. elegans) is an excellent model for investigating interactions between host and pathogen, as they have a short life span and encompass an innate immune system homologous to some advanced organisms. We hypothesize that phytoestrogen administration to C. elegans will improve their bacterial resistance and these benefits might be mediated through the DAF-2 Insulin-like pathway. Therefore, in this study we examined the effect of phytoestrogens (daidzein, genistein, and daidzein/genistein) on innate immunity using the wild type (N2) and various C. elegans mutant strains (DAF-16, AGE-1, and AKT-1). The strains were treated with phytoestrogens from the egg stage of development, immunologically challenged with the bacterial pathogen Pseudomonas aeruginosa starting at the L4 stage, and monitored for mortality over an 80 hour period. Our preliminary findings show that the wildtype N2, along with the mutant DAF-16 and AGE-1 strains demonstrated a trend towards increased life span when treated with daidzein, genistein, or both as compared to the control group. Our results also showed that AKT-1 mutant strain had a statistically significant increased bacterial resistance when treated with the phytoestrogens as compared to the control (p<0.05). These findings suggest a beneficial potential of phytoestrogens for improving innate immunity in C. elegans. Similarly, as the mutant strains indicate a positive correlation, these benefits might be mediated through the DAF-2 Insulin-like pathway. Future efforts will focus on repeating our efforts to establish statistical significance of our findings and confirming the involvement of the DAF-2 Insulin-like pathway.