الفهرس | Only 14 pages are availabe for public view |
Abstract Ionizing radiation is a high-energy radiation that has the ability to break chemical bonds, cause ionization and produce free radicals which can result in biological damage. These free radicals can induce damage to critical macromolecules such as DNA. Cellular DNA damage leads to mutation and cancer. High levels of gamma radiation can induce mortality in mammals. Acrylonitrile (AN) is a synthetic colorless liquid, with onion- or garlic-like odor. It is used to make other chemicals such as plastics, synthetic rubber and acrylic fibers. AN and its metabolites can produce a wide array of toxicological effects in animals and humans. The present study was designed to evaluate the protective and antioxidant effects of hesperidin against the toxicity induced by the exposure to 6.5 Gy as a single shot of γ- radiation and /or acrylonitrile. The parameters studied in the current work were complete blood count, serum aspartate transaminase, alanine transaminase and alkaline phosphatase activities as well as levels of albumin, total proteins and glucose. In addition, total cholesterol, triacylglycerols, high Summary and conclusion ١٤٥ density lipoprotein cholesterol, low density lipoprotein cholesterol, urea and creatinine were also examined. Moreover, the antioxidant enzyme activities of catalase, SOD and GPx along with the GSH content and MDA concentration were also studied in both liver & kidney tissues. Furthermore, copper, zinc, selenium, iron, manganese and calcium contents were also determined. Eighty rats were divided into eight groups (10 rats of each) and classified as follows: group I: normal control group. group II (Hes group): rats received 200 mg hesperidin / kg body weight (three times per week) for 4 weeks, (prolonged oral administration by intragastric gavage). group III (γ-ray): rats exposed to 6.5Gy, as a single dose whole body gamma irradiation. group IV (γ-ray+ Hes): rats received hesperidin as in group II for 3 weeks, then exposed to gamma irradiation of 6.5 Gy (whole body irradiation) at day 21, followed by treatment with Hes for an additional week. group V (AN group): rats received 50 mg acrylonitrile / kg body weight orally for 4 weeks (twice per week). group VI (AN+ Hes): rats received 200 mg Hes/ kg body weight and 50 mg AN / kg body weight for 4 weeks. Summary and conclusion ١٤٦ group (VII) (γ-ray+ AN): rats received AN as in group Vand exposed to gamma irradiation of 6.5 Gy at day 21 of the treatment. group (VIII) (γ-ray+ AN+ Hes): rats received AN and Hes for 3 weeks, followed by gamma irradiation exposure at day 21, and then administered AN and Hes for an additional week. The results of the present study can be summarized as follows: 1- Administration of hesperidin alone exhibited non significant changes in most of the tested parameters except for Fe in kidney which had a highly significant decrease. 2- The exposure of rats to gamma radiation (6.5 Gy) led to a significant decrease in all parameters of CBC (Hb%, WBC’s, RBC’s, platelets and HCT %), albumin, total protein, HDL-C, TSC, (liver and kidney catalase, GPx, SOD and GSH), liver Cu, Se and Mn & Ca in kidney. In contrast, it caused a significant elevation in AST, ALT, ALP, glucose, urea, creatinine, cholesterol, triacylglycerols, LDL-C, liver MDA, kidney MDA, liver Fe & Zn and Se in kidney. 3- Administration of acrylonitrile alone led to the same results as gamma radiation except for the following: a) HCT only Summary and conclusion ١٤٧ recorded a decline; b) Cu level in liver had non significant change; c) Fe level in kidney showed a significant decrease while the others didn’t change. 4- The exposure of rats to γ- ray and AN togehter led to more disturbances in the majority of the estimated parameters. 5- Administration of hesperidin before and after gamma radiation and / or acrylonitrile exposure caused mitigation of most parameters. It could be conculded that hesperidin has antioxidant and radioprotective activities. |