EFFECTS OF SODIUM BENOZATE ON FAT DEPOSITION AND GROWTH IN CAENORHABDITIS ELEGANS

Abstract

Clinical observation has proposed the linkage between the occurrence of obesity and slow weight loss with daily exposure to common food additives such as sodium benzoate. However, well-controlled laboratory experiments on this topic have been lacking; the dose-response relationship of sodium benzoate and obesity occurrence and/or slow weight loss has not been established; the potential mechanism of such linkage has not been explored. The insulin-signaling and fatty acid synthesis pathways in the model organism Caenorhabditis elegans (C. elegans) are highly conserved with higher organism including humans and thereby has been widely utilized to study obesity and aging related mechanisms. Scientific literature links the insulin pathway of C. elegans to growth, development, longevity, behavior, and metabolism in the organism. C. elegans is also a perfect model for exploring the genetics of fat storage. Thereby, C. elegans was used as a model organism to study the effects of sodium benzoate exposure on fat storage and on the gene expression of major players in insulin signaling and fatty acid synthesis pathway, as well as, key nuclear hormone receptor genes. This study demonstrated that C. elegans growth was greatly affected over time with exposure to sodium benzoate. This study could not provide a clear conclusion about the effects of sodium benzoate on fat deposition. Sodium benzoate exposure also led to the down-regulation of one nuclear hormone receptor gene, and two genes involved in fatty acid synthesis. After 72 hours of exposure, all treatment groups were larger than the control group, with the highest treatment causing significantly more growth. After 72 hours of exposure all treatment groups showed higher fluorescence values than the control group, with the lowest treatment group demonstrating significantly higher fluorescence levels than the control group. Three genes of interest were significantly downregulated after 24 hours exposure: nhr-50, fat-1, and elo-5. These findings indicate that sodium benzoate exposure is significantly impacting the model organism C. elegans and could be significantly impacting humans as well.