Differential Expression of Genes Involved in Lipid Biosynthesis as Response to Diet. Protocol Development and Standardization for Syrian Hamster (Mesocricetus Auratus)-Edición Única
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Abstract
Development of coronary heart disease due to high cholesterol levels is a major
cause of death globally. This problem has been targeted by the aim in the reduction of
LDL cholesterol concentrations with therapeutic treatments such as statin drugs, which
are effective but expensive, and have shown to elicit side effects. Consequently,
research has been focused on finding and developing natural, healthier choices.
Nutrigenomics is the integration of genomic science with nutrition; this discipline helps
understand the effects of diet at the molecular level.
This study focused on the standardization of real-time RT-PCR protocols for
analyzing gene expression changes for lipid biosynthesis in hamsters as response to
diet. Specific primers were designed to evaluate genes that code for sterol regulatory
element-binding proteins-1 (SREBP-1), fatty acid synthase (FAS), and 3-hydroxy-3-
methyl-glutaryl-CoA reductase (HMGR). Hamsters were fed with diets supplemented
with sorghum bran and its methanolic extract from two plant varieties (Sumac and
Shawaya). Sorghum bicolor is rich in phytochemicals (flavonoids, anthocyanins,
tannins) which may have effects on cholesterol levels. After six-week feeding
treatment, total cholesterol, LDL, and HDL plasma concentrations were measured,
showing a slight increase in total cholesterol due mainly to a significant increase in
HDL levels for all sorghum treatments when compared to controls. Real-time RT-PCR
experiments showed that Shawaya extract diet up-regulated the gene expression of
these genes, and its extract showed some effects on SREBP-1 and HMGR in a gender
specific fashion. This work shows that phytochemicals from sorghum have an effect on
lipid metabolism that may be related in part to the expression of biosynthetic genes.
However, more investigation using a wider array of genes and enzyme activity data are
needed to have a better understanding of the impact of sorghum-supplemented diet on
mammals.