الفهرس | Only 14 pages are availabe for public view |
Abstract Additives are found in many types of food and we often consume them unknowingly. Thus, it is very important to study the biological consequences of using food coloring agents. For the time being, people are becoming more aware of the possible danger of these additives that have no nutritional value. Taking into account the concentration indicated as the equivalent ADI for human. The present study showed the toxic effect of some synthetic coloring agent during organogenesis phase of chick embryonic development due to single dose in the 6th day of incubation and the ameliorative role of Cur as natural coloring agent had against this toxicity. The target organs under investigation were liver, kidney and endoskeleton of embryos. Based on that, five integrated approaches, namely, morphologoical, skeletal, histological, immuno-histochemical and molecular were utilized. 1- Morphological and morphometric investigation: this included body, liver and kidney weights as well as crown-rump length and mortality rate of chick embryos. In addition, the external feature of embryos. The investigation displayed that administration of Cur as natural color decrease in mortality rate and normal growth parameter. But, administration of both SY and TZ as synthetic color led to increase in mortality rate, reduction in growth parameter including crown-rump length, body weight but increase in liver and kidney weights. There was a high frequency in malformation of skin, head, trunk and limbs of embryos of both SY and Tz groups. Meanwhile, embryos injected with both Cur and SY or Tz groups showed salient improvement in terms of mortality rate, shape, length and weights of both body and organs of embryos. 2- Skeletal investigation: this included examining the double stained endo-skeleton system of 20-day-old chick embryos of all groups. No malformation of bone in natural color groups was observed. On the other hand, several malformations as excencephaly, clindoctyle and flexed toes as well as sharp lack of ossification and reduction in the length of ossified pats of long bone were seen in embryos injected with SY and Tz in 6th day of incubation. Furthermore, administration of Cur after SY and Tz resulted in an evident decrease in skeletal malformation compared to SY and Tz groups. 3- Histological investigation: this involved the histological structure of the liver and kidney of chick embryos of different groups. The liver of Cur groups displayed normal histological structure. On the other hand liver of SY and Tz treated groups showed massive change throughout the lobule with cellular vacuolization, leucocytic infiltration, dilatation in central vein with haemorrhagic conditions, fibrosis and hyalinization of hepatocyte especially in SY groups. Also, microgranuloma in hepatocyte of Tz groups was observed. The liver of combined groups showed an evident ameliorative result. Otherwise, the kidney of Cur groups displayed no pathological effect. But, kidney of SY and Tz injected groups revealed dilatation in convoluted renal tubules and the lining epithelium showed degenerative changes, oedema especially in SY groups and hyalinization of tubules with presence of fibrosis, as well as hypertrophy of renal glomeruli showed in Tz groups. In the kidney of combined SY, Tz and Cur, despite the presence of mild tubular degeneration and epithelial vacuolization in renal tubules, glomeruli maintained better morphology compared with SY and Tz groups. 4- Immuno-histochemical investigation: this involved investigation of the pattern of expression of proapoptotic marker Caspase-3 in the liver and kidney of embryos of different groups. The Cur treated groups showed decrease in expression of Caspase-3 of both liver and kidney cells but, SY and Tz treated embryos showed increase in the expression of Caspase-3. While, co-adminestration of Cur resulted in decreased expression in Caspase-3in the liver and kidney of both groups. 5- Molecular investigation: this involved two parts: A- Determination of DNA fragmentation by gel electrophoresis: the cells of Cur treated group showed no damage in DNA. On the other hand, the cells of both SY and Tz injected group revealed extensive DNA fragmentation compared with control. The cells taken from combined groups displayed some DNA fragmentation but less than SY and Tz groups. B- Detection of DNA damage and measurement of cell cycle distribution: this has been done using flow cytometry and applied on liver and kidney of coloring agent. In accordance with the mentioned present investigation, low percentage of DNA damage and normal trend of cell cycle in Cur group. While, treated groups with SY and Tz showed high percentage in DNA damage in the cells and arrested S phase of cell cycle. The combined groups with Cur revealed amelioration effect in percentage of DNA damage and in the cell cycle trend of both groups. |