5550
SHIMAA EL-SAYED RASHAD EL-SAYED
STUDY OF THE TOXICOGENOMIC EFFECT OF COMMON FOOD ADDITIVES USING SOME YEAST STRAINS
Yeast knockout, Comet assay, Cell lines, Flow cytometry, Real time-PCR, Neutral red assay.
A comet assay was performed to assess DNA damage in yeast deletion strains after treatment by the recommended concentrations of the food additives. yeast knockout haploid strains (YKO) strains exhibited a significant DNA damage (P < 0.05) which was observed by an increase in tail length, tail DNA% and tail moment as compared to the normal control strains. The results showed that food additives monosodium glutamate (MSG), sodium benzoate (SB) and saffron induced profound cytotoxicity in cancer cells, i.e., human lung cancer (A549), human breast cancer (MCF7), human colon cancer (Caco-2), respectively. In addition, those food additives generated cytotoxic activities on normal lung cell lines (Wi38), respectively. Flow cytometric analysis demonstrated that treatment of human hepatocellular carcinoma cells (Caco-2) cells with food additives increased G2/M phase cell cycle arrest. The quantitative real time-PCR was used to measure the mRNA levels of p53, Bax, and Bcl-2 genes. The data showed that food additives changed transcriptional levels of these related genes. The mRNA expression of p53 and Bax were up-regulated, but, the transcription of Bcl2 was significantly down-regulated compared to the control in Coca-3 cells. Protein-protein interaction maps provided a valuable framework for a better understanding of the functional organization of the proteome. To detect interacting pairs of human proteins (RAD51, RECQL, MLH1 and IGF2BP2) systematically, a protein matrix of human was screened by automated yeast knockout proteins (RAD51, SGS1, MLH1 and IMP2) interaction. The results revealed that food additives stimulated cytotoxicity by decreased cell viability in cancer and normal cell lines. Cell cycle blocking at the G2/M phase was evident. Moreover, induction of apoptosis via increased p53 and Bax mRNA expression levels accompanied with reduced Bcl2 gene expression which are correlated with apoptosis pathway was observed. Thus, the use of MSG, SB and Saffron could result in negative health biohazards to human beings. This calls for strict control of the threshold levels that should be permitted for the industrial products containing food additives as it could reflect biosafety hazards to human and environment.
2019
Ph.d
Ain Shams
Agriculture