Document Type

Thesis

Date of Award

5-2016

School/College

College of Science, Engineering, and Technology (COSET)

Degree Name

MS in Environmental Toxicology

Abstract

Lipids over the years have been given far less relevance for the roles they play in the body. In recent times, the role of lipids are being studied and it is being brought to light that lipids play far more important roles in the body of living organisms than early stipulated. Lipids have been known for their role in the storage of energy and in the formation of cell membrane but right now; recent studies have shown lipids to have far more diverse and complex biological roles in the human body as they function as molecular messengers and signaling molecules in the body. Lipids are insoluble in water and are thus effective in the process ofsignaling that occurs between cells. This unique function oflipids births the reason for the lipidprofiling ofnematode, Caenorhabditis elegans as it is being used as an animal model in determining the effect exposure to environmental contaminants will have on lipids and its ability to function as a chemical messenger. Some environmental contaminants that we are mainly exposed to 1 2 are neurotoxins that affect the Central Nervous System and Peripheral Nervous System. Neurotoxins are known chemicals that affect the process ofsignaling that occurs between the neurons in the nervous system. Thus, C. elegans serves as a model organism in determining if any structural changes and modifications are seen in the profile of the lipids when they are exposed to environmental stressors. Instruments such as the LC-MS, GC-FID, LC Q-TOF/MS, GC Q-TOF MS are analytical instruments that are able to record accurate masses of the fatty acids and triglycerides due to their sensitivity and selectivity. Thus, if there is any alteration in the profile ofthe C. elegans fatty acids and/or lipids when they are subjected to the environmental stressors, these instruments will be able to detect even the minutest changes. Thus, the aim ofthis study is to determine the profile offatty acids to be used as a biomarker in determining the effect ofenvironmental stressors on the living organism. For this study, the environmental contaminant, which is being used is, pentachlorophenol (PCP). Pentachlorophenol is an organic compound, which is being used as a pesticide and an anti- fouling agent. Recent studies have shown pentachlorophenol to be carcinogenic and thus have been placed under the Class 2B; showing there is possible carcinogenicity in humans but there is strong evidence of carcinogenicity in animals. For this study, I utilized C. elegans as a model organism in order to determine the effect ofPCP on the fatty acid profile. This was done by analyzing the activity of Reactive Oxidative Species in the model organism that was exposed to PCP. It was observed that the level of free radical production as a result of reactive oxidative species (ROS) activity showed an increase as the concentration of 3 Pentachlorophenol increased. This was measured by the rate of florescence exhibited by C. elegans when exposed to different concentrations ranging from 5 ppm to 50 ppm using the Spectrofluorometer as an instrument for measurement. The fatty acid profile of C.elegans was analysed using the Gas Chromatography Mass Spectrometry (GC/MS) technique. It was seen that the fatty acid profile of the C. elegans exposed to 30 ppm of Pentachlorophenol showed the absence of some fatty acids that are important in the neurological development ofliving organisms as compared to the control experiment. One of such important fatty acids was Arachidonic acid (AA) which is of one the most abundant fatty acids in the hippocampal ofthe brain and plays a major role in neurological development. The destruction of these fatty acids was due to oxidative damage as a result of free radical formation and it is known that many ofthese fatty acids having different double bonds are more susceptible to oxidative damage

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