الفهرس 
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Abstract
Aflatoxins are one of the principle groups closely related to mycotoxins that are produced in tropical and subtropical regions. The three main genera of fungi responsible for producing mycotoxins are Aspergillus, Fusarium, and Penicillium. Aspergillus flavus and Aspergillus parasiticus, are molds. They are a category of toxic substances belong to the most carcinogenic and mutagens substances known.
Aflatoxins are regularly found in commodities that are stored incorrectly including, rice, wheat, cottonseed, sunflower seeds, chili peppers, peanuts, sesame seeds, sweetcorn, tree nuts, and a variety of spices. Aflatoxins contaminate a variety of agricultural commodities in countries with hot and humid climates.
The mycotoxins that commonly occur in cereal grains and other products are not completely destroyed during food processing operations and can contaminate finished processed foods. Most aflatoxins are ingested most commonly. Furthermore, the most toxic species of aflatoxin, i.e., aflatoxin B1, can penetrate the skin. The existance of these types of molds does not always denote the presence of harmful levels of aflatoxin, but it does denote a significant level of risk. According to numerous researchers, worldwide, the change in climate varies, in the environment, both the temperature and the water activity (wa). This change in climate further affects the gene expression to form the aflatoxins. So, it can be concluded that, the temperature and water activity conditions control the extent of the development of the fungus which, in turn, affects the production of the aflatoxins. Aflatoxins B1, may produce damage to the blood components, such as, blood platelets, RBCs, and in general, aflatoxins have been accompanied by growth depression and many humoral alterations and cell immunity leading to affecting the hematological parameters.
Aim of the Work
At first, the aim of this work was “Studying the Physico-Chemical Effects of Aflatoxins Extracted from Cereal Wheat, on the Blood of Mice “.
For this purpose, fifty-two mice each weighing between (15-20 g) have been divided into three groups, as follows:
• group 1: Control group, 10 mice.
• group 2: 21 mice, the mice of this group have been injected with aflatoxins B1 IP, with concentration of 15 μg/kg.
• The animals of the second group, were divided into three equal sub-groups, each of 7 mice, and were sacrificed after 1, 7 and 15 days following the aflatoxin B1 injection. But the mice were not survived for the end point of the experiment after two weeks. Most of the animals were survived for one day and for one week after injection of the aflatoxins with the mentioned low concentration of aflatoxins B1 (μg/kg).
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• group 3: other 21 mice were injected with 30 μg/kg, and were sacrificied, also, after 1, 7 and 15 days following the aflatoxin B1 injection. But the animals of this group did not survive.
• The animals didn’t survive at using either of a single dose of 15 or 30 μg/kg. It was concluded from this experiment that, mice with our local species in Alexandria aren ’t resistant to aflatoxin B1.
Accordingly, 28 rats, were used as an experimental animal, with injections of aflatoxin B1 for 30 consecutive days, with daily concentration of 60 μg/kg. A total of 28 male albino rats were enrolled in this part divided into, two main groups, as follows:
group I: 7 rats served as a control group.
group II: Consist of 21 rats, each injected with aflatoxins B1 with daily concentration of 60 μg/Kg for 30 days. At the end of injection period, the rats were divided into three subgroups, each of 7 rats. These rats were sacrificed after, one day, one week, and two weeks, respectively. The blood of each rat was withdrawn for further analysis, as given in the original protocol, in addition to histopathological studies of rat livers, after the mentioned time schedule.
The results of the study, can be summarized as follows:
The Biochemical Analyses:
MDA: Significant difference existed between all groups, with increasing concentration starting from the control group until two weeks. With tendency to reach the control level, after two weeks.
TAC: Significant decrease between all groups with respect to the control, with increasing concentration starting from week one up-wards. With tendency to reach the control level, after two weeks.
Glucose: Significant decrease started after one day with more decrease in glucose level after one and two weeks, respectively.
Total proteins: Significant difference existed between all groups, with decreasing concentration started after one day, increasing concentration after one week, with tendency to reach the control level, after two weeks.
Liver Enzymes:
ALT: Significant difference existed between all groups, with increasing concentration starting from day one after injection, with respect to the control group, followed by decrease after one and two weeks, with tendency to reach the control level, after two weeks.
AST: Significant difference existed between all groups, with increasing concentration starting from day one after injection, up-wards, with respect to the control group, with no-tendency to reach the control level, after two weeks.
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Hematological Data: CBC Data The HB, HCT, and RBCs levels suffered fluctuations, where they decreased significantly after one day, then increased significantly after one week and started to decline after two weeks to reach, relatively higher level, but with no significant difference with the control level. The mean corpuscular volume, MCV levels followed different route, where, it increased significantly after one day and started to decline after one week, to reach the control level after two weeks. The mean corpuscular hemoglobin, MCH, increased significantly after one day, and started to decline after one week and two weeks, but didn’t reach the control level after two weeks. The mean corpuscular hemoglobin concentration, MCHC, decreased, significantly, after one day, and increased after one week and decreased to much lower level after two weeks. This is, logically, due to the fact that the MCV increased after one day which leads to decreased of MCHC. The white blood cells, WBCs, started to increase significantly starting from day one and up-wards. This means that certain type of inflammation accompanied the aflatoxin injection. The inflammation persists within two weeks which is judged by the increase of lymphocytes and platelets until two weeks of aflatoxin injection. The relative viscosity of RBCs decreased continuously after one day and one week, but started to increase slowly after two weeks, with the level was still lower than the control level. This may indicate that aggregation occurred with blood cell components, leading to lower relative RBCs viscosity. The histopathology of rat’s liver The histopathology of rat’s liver after injection of aflatoxins B1 indicated that, the normal rat’s liver showed appearance of Kupffer cells, nucleated cells, and central vein with endothelial cell lining.
After one day of aflatoxin B1 injection, the liver showed widening and dilated central vein with ruptured endothelial cell lining, surrounding with large number of inflammatory cells. In addition, the liver showed degenerative hepatic cells with sever necrosis, dilated sinusoids, and pyknotic nuclei. After one weak of aflatoxin injection, the liver showed partial restoration of architecture. Hepatocytes arranged in cords, dilated sinusoids, and central vein with mild dilatation. Also, the portal tract was surrounded with some inflammatory cells with less marked degenerative changes in hepatocytes. After two weeks of aflatoxin injection, the liver showed dramatic improvement. Most of the liver sections showed regenerative hepatocytes with absence of necrosis and apoptosis. In addition, wide areas showed normal appearance of hepatocytes, well developed Kupffer cells and central vein.
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It is clear from these data that the rats were exposed to oxidative stress, which was clearly demonstrated in the increase in the concentration of MDA and a decrease in the total antioxidant capacity TAC. This is accompanied by changes in the hematological indices, liver enzymes and histological changes in the rat’s liver with tendency, in some cases, to recovery after two weeks.
Conclusion:
The data of the present study, through more shed on the effect of injection of aflatoxins B1 intraperitoneal to experimental animals. Two species of animals were employed in the study.
1- Mice animals were used in the first experiment trial, with two aflatoxin concentration injected intraperitoneal, namely; 15 μg/kg, and 30 μg/kg. With the first dose, most of the animals survived for utmost one week after injection. With the other dose, acute dose, the animals didn’t survive for 15 days of injection. The analyses of the mice blood received from the survived animals, didn’t show significant variation with respect to the control group. So, it was concluded that, mice with our local species in Alexandria aren’t resistant to aflatoxin injection.
2- Rat’s animals were used in the second experiment trial, with injection of aflatoxin B1, intraperitoneal, with daily dose of 60 μg/kg for consecutive 30 days. The data revealed significant changes in most of the studied parameters, especially after one day, at the end of the daily injection.
3- The rats were exposed to oxidative stress, as a result of injection with aflatoxins. The oxidative stress was clearly judged by, increase in MDA, decrease in TAC, with other changes in biochemical and hematological changes.
4- These variations go side by side with the histopathological variations which showed profound variation in the rat liver after one day of injection, with trend to recovery after one week and two weeks following the injection, in some and not in all cases.
Recommendations
from the present study it could recommended that
According to the present work data, the work of this study may be continued using another group of rats, to increase the follow up-period of the experiment to longer period than two weeks, because, a number of the studied parameters, still suffered significant changes even after two weeks and the levels didn’t approach the control level. The extended periods may add to our knowledge about the extent of aflatoxin B1 toxicity, using rats as an experimental animal.
• Another experiments, may also be carried out, to estimate the levels of aflatoxins in other human foods, which is necessary to describe the levels of aflatoxins B1 in human diet, to study the methods of minimizing the concentrations of aflatoxins B1, if present, in human diet.
• This work, opens new area, in studying the toxicity of aflatoxins B1 in other human nutrients, such as, liquid food, i.e., milk, and other types of meat and solid cereals.