الفهرس 
INTRODUCTION AND AIM OF WORKOnly 14 pages are availabe for public view
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Abstract
Echinacea purpurea (EP) is a purple cone flower containing phenols, caffeic acid derivatives, alkamides, flavonoids, and essential oils. The present study was designed to investigate the prophylactic and therapeutic effects effects of EP on gamma radiation-induced oxidative
stress in liver and testis tissues and some serum metabolic disturbances in parallel to histopathological changes in liver and testis tissues.
Rats received EP (50 mg/day/Kg body weight) by gavages for 28 successive days either before or after whole
body exposure to 3Gy gamma–radiation (one shot dose). A total of 50 rats were divided into 5 groups.
1- Control group: Rats received 1ml distilled water by gavages for 28 consecutive days.
2- EP-treated group: Rats received EP (50 mg/kg body weight/day) for 28 consecutive days and sacrificed 3 days post the last dose of EP.
3- Irradiated group: Rats were whole body exposed to 3 Gy gamma irradiation applied as one shot dose and sacrificed 3 days post irradiation .
4- EP + irradiated group: Rats received EP during 28 consecutive days by gavages before whole body exposure to gamma irradiation at 3 Gy and
sacrificed 3 days post irradiation .
5- Irradiated + EP group: Rats received EP during 28 consecutive days by gavages after whole body exposure to gamma irradiation at 3 Gy and
sacrificed 3days post the last dose of EP.
For biochemical analysis, blood was collected and sera obtained for testing ALT and AST activities, Glucose, Testosterone, Triglycerides, Total cholesterol, LDL-C, and HDL-C.
Oxidative stress was assessed in liver and testis tissues by measurement of TBARS content, SOD and CAT activities and GSH content.
For histological examination 6 μm thick serial paraffin sections of the liver and testis of rats from each group were prepared, stained with heamatoxylin and eosin and examined by Olympus light microscope.
The results obtained in the current study revealed that administration of EP to normal healthy rats has no effect on level TBARS, SOD and CAT activities as well as GSH content in the liver and testis compared to control.
Whole body gamma-irradiation of rats with 3 Gy provoked a significant increase (p<0.05) of TBARS level
associated to a significant decrease of SOD and CAT activities as well as GSH content indicating oxidative stress.
Administration of EP to rats either pre or post irradiation has significantly attenuated (p<0.05) radiationinduced
oxidative stress in the liver and testis compared to their values in irradiated group.
The results showed that administration of EP to normal healthy rats have no effects on serum lipid profile, glucose level, serum transaminase activities and testosterone level compared to the control values.
Whole body gamma irradiation provoked a significant increase (p<0.05) of serum total cholesterol, LDL-C and triglycerides and a significant decrease in HDL-C regarding their respective control values. Moreover, whole body gamma irradiation provoked a significant increase (p<0.05) of serum ALT and AST activities and testosterone level.
Administration of EP to rats either pre- or post– irradiation has significantly attenuated (p<0.05) radiation– induced alterations in serum lipid profile, glucose level, transaminase activities and testosterone level regarding their
respective values in the irradiated group.
However, the modulator role of EP modulatory was more pronounced when administered before irradiation.
The histopathological changes observed in the live correlate with the biochemical data of liver and testis of all control and test groups reflecting the degree of damage or repair induced by the various treatment.
The histopathologic examination in the liver of irradiated rats revealed widening and dilating central vein with ruptured endothelial lining layer, widened and dilated blood sinusoids and inflammatory cells surrounded it,
necrotic cells. Administration of EP pre- irradiation enhanced regeneration of hepatic cells which appeared with
normal rounded nuclei and cytoplasm and normal blood sinusoids. Administration of EP post- irradiation although enhancing regeneration of hepatic cells, the majority appeared with vacuolated cytoplasm, pyknotic and
karyolytic nuclei.
Histopathologic examination of testicular sections in irradiated rats showed fibrotic basement membrane,
irregular and necrotic spermatogoneal steps and haemorrhage.
Rats treated with EP before irradiation showed ameliorated and improved spermatogenesis steps, regenerated seminiferous tubules and interstitial cells.
Rats treated with EP after irradiation showed degenerated seminiferous tubules and interstitial cells.
Hence, the results of the current investigation prove the efficacy of EP in reducing radiation-induced tissue
damage in the liver and testis tissues. These results are attributed to the antioxidant and free radical scavenging
activity of EP.