No abstract

The small intestine displays numerous morphological and functional alterations after exposure to ionizing radiations. Oxidative stress and changes in monoamines levels may contribute toward some of these alterations. The objective of the current work is to evaluate the efficacy of lycopene on radiation-induced damage in the small intestine. Lycopene (5 mg/kg BW) was given to male albino rats, via gavages for 7 days before whole body exposure to gamma ray (6 Gy). Irradiated animals, sacrificed 7 days after irradiation, showed sloughing villi, ulcers, and ruptured goblet cells, shrinkage of submucosa layers, more fibers and fibroblasts. Histopathological changes were associated with a significant increase in thiobarbituric acid reactive substances (TBARS) and alteration in xanthine oxidoreductase system (XOR). In parallel, significant decreases in reduced glutathione (GSH) content, superoxide dismutase (SOD) and catalase (CAT) activities were recorded. Gamma irradiation has also induced a significant decrease in the level of monoamines: serotonin (5-HT), dopamine (DA), norepinephrine (NE), and epinephrine (EPI) associated with an increase in monoamine-oxidase (MAO) activity. Lycopene pretreatment has significantly improved the oxidant/antioxidant status, which was associated with significant regeneration of the small intestine, and improved monoamines levels. Based on these results, it is concluded that lycopene may protect the small intestine against radiation-induced damage.

Oxidative stress, apoptosis, and fibrosis may play a major role in the development of radiationinduced liver damage. Betaine, a native compound widely present in beetroot, was reported to possess hepato-protective properties. The objective of this study was to investigate the influence of betaine on radiation-induced liver damage. Animals were exposed to 9 Gy applied in 3 doses of 3 Gy/wk. Betaine (400 mg/kg/d), was orally supplemented to rats after the first radiation dose, and daily during the irradiation period. Animals were sacrificed 1 day after the last dose of radiation. The results showed that irradiation has induced oxidative stress in the liver denoted by a significant elevation in malondialdehyde, protein carbonyl, and 8-hydroxy-2-deoxyguanosine with a significant reduction in catalase activity and glutathione (GSH) content. The activity of the detoxification enzyme cytochrome P450 (CYP450) increased while GSH transferase (GSH-T) decreased. The activity of the apoptotic marker caspase-3 increased concomitant with increased hyaluronic acid, hydroxyproline, laminin (LN), and collagen IV. These alterations were associated with a significant increase of gamma-glutamyl transferase, alkaline phosphatase and alanine and aspartate aminotransferase markers of liver dysfunction. Betaine treatment has significantly attenuated oxidative stress, decreased the activity of CYP450, enhanced GSH-T, reduced the activity of caspase-3, and the level of fibrotic markers concomitant with a significant improvement of liver function. In conclusion, betaine through its antioxidant activity and by enhancing liver detoxification and reducing apoptosis may alleviate the progression of liver fibrosis and exert a beneficial impact on radiation-induced liver damage.

Whole body exposure to ionizing radiation induces the formation of reactive oxygen species (ROS) in different tissues provoking oxidative damage, organ dysfunction and metabolic disturbances. The present study was designed to determine the possible protective effect of grape seed extract (GSE), rich in proanthocyanidins against gamma-radiation-induced oxidative stress in heart and pancreas tissues associated with serum metabolic disturbances. Irradiated rats were whole body exposed to 5 Gy gamma-radiation. GSE-treated irradiated rats received 100 mg GSE/kg/day, by gavage, for 14 days before irradiation. The animals were killed on days 1, 14 and 28 after irradiation. Significant decreases of SOD, CAT and GSH-Px activities associated with significant increases of TBARS levels were recorded in both tissues after irradiation. GSE administration pre-irradiation significantly attenuated the radiation-induced oxidative stress in heart tissues which was substantiated by a significant amelioration of serum LDH, CPK and AST activities. GSE treatment also attenuated the oxidative stress in pancreas tissues which was associated with a significant improvement in radiation-induced hyperglycemia and hyperinsulinemia. In conclusion, the present data demonstrate that GSE would protect the heart and pancreas tissues from oxidative damage induced by ionizing irradiation.

It could be concluded that hesperidin might attenuate the severity of radiation-induced biochemical disorders in brain tissues.