Research
The influence of feeding linoleic, gamma-linolenic and docosahexaenoic acid rich oils on rat brain tumor fatty acids composition and fatty acid binding protein 7 mRNA expression
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* Corresponding author: Fereydoun Siassi siassif@tums.ac.ir
1 Department of Nutrition and Biochemistry, Tehran University of Medical Sciences, Tehran, Iran
2 Department of Clinical Biochemistry, Tehran University of Medical Sciences, Tehran, Iran
3 Department of Biostatistics, Tehran University of Medical Sciences, Tehran, Iran
4 Department of Immunology, Tehran University of Medical Sciences, Tehran, Iran
5 Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran
6 Department of Medicinal Chemistry and Pharmaceutical Sceinces, Tehran University of Medical Sciences, Tehran, Iran
7 Department of Pathology of Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
8 Department of Physiology, Tehran University of Medical Sciences, Tehran, Iran
Lipids in Health and Disease 2008, 7:45 doi:10.1186/1476-511X-7-45
Published: 16 November 2008Abstract
Background
Experimental studies indicate that gamma linolenic acid (GLA) and docosahexaenoic acid (DHA) may inhibit glioma cells growth but effects of oral consumption of these fatty acids on brain tumor fatty acid composition have not been determined in vivo.
Methods
GLA oil (GLAO; 72% GLA), DHA oil (DHAO; 73% DHA) were fed to adult wistar rats (1 mL/rat/day) starting one week prior to C6 glioma cells implantation and continued for two weeks after implantation. Control group were fed same amount of high linoleic acid safflower oil (74–77% linoleic acid). Fatty acid composition of tumor samples was determined in a set of 8–12 animals in each group and serum fatty acid in 6 animals per each group. Gene expression of tumor fatty acid binding protein 7 (FABP7), epidermal growth factor receptor (EGFR), peroxisome proliferator activated receptor γ (PPAR-γ) and retinoid × receptor-α (RXR-α) were determined in a set of 18 animals per group.
Results
DHAO feeding increased EPA of brain tumors and decreased ratio of n-6/n-3 fatty acids. Serum levels of EPA were also increased in DHAO group. A similar trend in serum and tumor levels of DHA were observed in DHAO group but it did not achieve statistical significance. GLAO increased serum concentration of GLA but had no significant effect on tumor GLA or dihomo-gamma linolenic acid (DGLA) concentrations. Gene expression of FABP7 was up-regulated in tumors of DHAO group but no other significant effects were observed on EGFR, PPAR-γ or RXR-α expression, and expression of these genes in tumors of GLAO were not different from SFO group.
Conclusion
Dietary supplementation of DHA containing oil could be an effective way to increase levels of long chain n-3 fatty acids in brain tumors and this increase may be mediated partly by up-regulation of FABP7 expression.