Genetic alterations induced by toxic effect of thermally oxidized oil and protective role of tomatoes and carrots in mice

Abstract

The present study was designed to investigate the genetic alterations and sperm abnormalities in male mice fed diet containing thermally oxidized sunflower oil repeatedly used for frying processes (FO). Also, tomatoes and carrots were added to FO diet to test their protecting ability against potential hazards caused by oxidized oil rich foods. The genetic alterations including DNA fragmentation and chromosome aberrations as well as changes of mRNA expression of some lipid metabolism related-proteins were determined. The results revealed that rate of DNA fragmentation was significantly higher in animals fed FO diet than those of animals fed normal oil diet (NO). On the other hand, the rates of DNA fragmentation decreased in animals fed FO diets plus low (5%) or high (10%) concentration of tomatoes (FOT1 or FOT2) or carrots (FOC1 or FOC2) compared with those fed FO diet. Chromosome examination showed that total structural aberrations increased significantly in animals fed FO diet than those fed NO diet. On the other hand, animals fed diets containing FO plus low or high concentration of tomatoes or carrots had significantly lower frequencies of total structural aberrations than those fed FO diet. Sperm studies showed a significant increase in the number of morphologically abnormal sperms and a significant decrease in the sperm count in animals fed FO diet compared with those fed NO diet. However, the animals fed diets containing low or high level of tomatoes or carrots showed significant decreases of sperm abnormalities. The mRNA expressions of the lipid metabolism related-genes, RBP, H-FABP and C-FABP were significantly higher in liver tissues of mice fed FO diet than those found in mice fed NO diet. However, the expression of all tested genes was down-regulated in FOT1 and FOT2 or FOC1 or FOC2 groups compared with those detected in the FO group. In conclusion, the present study adds evidence for a link between prolonged feeding intake of FO diet and induced mutagenic effects in animal cells. However, tomatoes and carrots proved to be good protective agents against hazards of such mutagenic foods. (Journal of American Science 2010;6(4):175-188). (ISSN: 1545-1003).