الفهرس 
الغلافOnly 14 pages are availabe for public view
 |  | from | 176 |  |  |
| | | from | 176 | | |
Abstract
Ionizing radiation is known to induce oxidative stress through generation of reactive oxygen species resulting in imbalance of the pro-oxidant and antioxidant in the cells, which is suggested to culminate in cell death. The objective of the present study was to elucidate the role of oxidative stress, neurotransmitters alteration and mitochondrial damage in the severity of biochemical disorders in brain and kidney tissues of gamma irradiated rats. In addition, study the role of hesperidin (naturally occurring flavonoids) in modulating the severity of radiation-induced biochemical changes.
The results revealed that whole body y-irradiation of rats with single dose of 5Gy provoked oxidative stress in brain and kidney tissues identified by a significant increase in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glucose-6¬phosphate dehydrogenase (G-6-PDH) activities and glutathione (GSH) content on the 15t day post-irradiation, followed by a significant decrease on the ih and 14th day post-irradiation. Alteration in antioxidant biomarkers was concomitant with a significant increase in the content of oxidant biomarkers: thiobarbituric reactive substances (TBARS), protein carbonyls (CO) and advanced oxidation protein products (AOPPs), on the 1 st, ih and 14th day post-irradiation.
Whole body y-irradiation of rats resulted also in mitochondrial damage in brain and kidney tissues demonstrated by a significant decrease in glutamate dehydrogenase (GDH), and creatine phosphokinase (CPK) activities and a significant increase of calcium level as well as a significant decrease in the level of brain catecholamines (dopamine, norepinephrine and epinephrine), started in the 1 st day up to the 14th day post-irradiation as well as a significant increase of monoamine oxidase activity was recorded on the ih and 14th day post-irradiation. A significant decrease of serotonin content and a significant increase of 5-hydroxyindoleacetic acid was recorded on the ih and 14th day post-irradiation. A significant increase in brain serotonergic activity was recorded on the ih and 14th day post-irradiation indicating biochemical disorders in brain tissues. Furthermore, whole body y-irradiation of rats with 5Gy provoked a significant increase in the level of serum urea and creatinine indicating kidney dysfunction.
Supplementation of rats with hesperidin, via gavages, at a dose of 50 mg/day/kg body weight, either for 24 successive days before y¬irradiation or during 10 successive days before and 14 days after y¬irradiation has significantly modulated y-irradiation induced oxidative stress, mitochondrial damage and neurotransmitters alteration. The results were more significant when hesperidin was supplemented to rats before and after y-irradiation.
It could be concluded that through its antioxidant and free radical scavenging properties, hesperidin would minimize the severity of radiation-induced biochemical disorders in brain and kidney tissues.