Semester

Spring

Date of Graduation

2013

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Animal and Nutritional Sciences

Committee Chair

Kimberly M. Barnes

Committee Co-Chair

K. Marie Krause

Committee Member

Janet C. L. Tou

Abstract

Background: Fish oil (FO) is a marine source of n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexanaenoic acid (DHA), and has been shown to improve heart health.;Objective: The purpose of this study was to determine the cardiovascular effects of non-marine sources of n-3 fatty acids, algae oil (AO) and yeast oil (YO), as compared to fish oil (FO).;Methods: Male ICR mice (8 wk old, n=100) were randomly assigned to dietary treatment groups: soy oil (SO; 0 g/kg DHA or EPA), FO (7.03 g/kg DHA + 12.64 g/kg EPA), AO (7.03 g/kg DHA + 0.13 g/kg EPA), YO (0.018 g/kg DHA + 12.64 g/kg EPA), or AO+YO (7.05 g/kg DHA + 12.77 g/kg EPA) for 2 or 4 wks. Serum triglycerides (TG), total cholesterol (TC), and HDL-cholesterol (HDLC) were measured and non-HDL cholesterol (NHDLC) was calculated. Liver DHA and EPA concentration were determined. The liver mRNA expression was determined by real time RT-PCR for the following genes: apolipoprotein B100 (ApoB100), acyl-CoA:cholesterol acyltransferase (ACAT), diglyceride acyltransferase (DGAT), low-density lipoprotein receptor (LDLR), and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR). P < 0.05 is considered significant.;Results: The FO diet lowered all fractions of serum lipids and was the only diet to reduce TG. YO, alone and in combination with AO, reduced TC and NHDLC similar to FO at 4 wks. At both time points, FO-fed mice had significantly greater EPA and DHA incorporation into the liver than all other diet treatments. At both time points, SO-fed mice had significantly greater hepatic arachidonic acid (C20:4) concentrations than all other diet treatments. At both time points, FO-fed mice had significantly greater n-3 to n-6 ratios compared to all other diet treatments. There were no significant differences between any of the diet treatments at any time points in hepatic mRNA expression of ApoB100, ACAT, DGAT, and LDLR. However, at both time points the FO-fed mice had significantly down-regulated HMGCR expression compared to the SO-fed mice.;Conclusion: In conclusion, it appears that FO supplementation may be more beneficial for cardiovascular health due to its ability to decrease serum lipids and TGs, incorporate EPA and DHA into the liver, obtain a greater n-3 to n-6 ratio, and lower hepatic HMGCR mRNA expression.

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