COMPARATIVE INVESTIGATION OF ORANGE JUICE AND VITAMIN C ON GENE EXPRESSION IN NEURONAL TISSUES OF SPRAGUE DAWLEY RATS

Abstract

The comparative effects of Vitamin C and Citrus sinensis (orange) juice on the gene
expression levels of superoxide dismutase (Sod), tumour necrosis factor receptor
(Tnfr), p53 protein, and progesterone receptor (Pgr) genes were evaluated in rat
neuronal tissues. Experimental rats were given 5mllKg body weight offreshly extracted
orange juice or 20mg Vitamin C IKg body weight. Control animals were fed with rat
chow and water. After 71" day administration, brain tissues were collected in liquid
nitrogen and total RNA was extracted using Qiagen Rneasy extraction kit. 1 OOng of
normalized RNA samples were converted to cDNA with Oligo-dT primers. PCR
Primer pairs were designed using Primer 3 and NCB! primer blast tool. SYBR green
Real time PCR relative quantification was done using High yield Taq Polymerase
Kit and SYBR green dye. The orange juice extract contained I5.84mg Vitamin C, .
J3.67g total sugar; 0.02 mg sodium, 0.15 mg iron, 11.48 mg magnesium, 44.20 mg
calcium, 4.76 mg potassium, 0.75 mg zinc, and 22.9 mg phosphorus. Relative
quantification gene expression assays in the rats showed a 400 fold change in Tnfr
and 38 fold change ill p53 gene in the orange administered group in comparison to
the Vitamin C administered group and control group. Vitamin C caused a 420 fold
change in the expression of Pgr gene in comparison with the orange administered
group. Our findings showed that, orange juice administered rats showed higher levels
of gene expressions of Tnfr and p53 genes, thereby suggesting brain tumour
preventing ability of oranges.