الفهرس 
Acknowledgement
Chronic lead poisoningOnly 14 pages are availabe for public view
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Abstract
The present study was designed to provide base line information about the influence of Lead Acetate on DNA of hepatocytes. In addition, the antagonistic effect of Silymarin, Sesame oil and Ginger against damaged hepatocytes was evaluated. Lastly, the correlation between DNA damage and histopathological findings was also discussed. The research work was carried out on (100) adult male albino mice purchased from the Animal House of Faculty of Medicine-Assiut University.>Animals were categorized randomly into five equal groups,(20) mice each .Animals of the first group served as control negative group.All animals of other four groups received 30mg /kg.B.W. Lead Acetate with oral intubation twice weekly for eight weeks .The second group was considered as control positive. At the same time the third, fourth and fifth groups received oral intubation Silymarin (200mg /kg B.W.), Sesame oil (5ml/kg B.W.) and Ginger (60 mg/kgB.W.), respectively. At the end of experimental period. All mice were killed by decapitation and liver specimens were collected for Comet Assay analysis and histopathology.The protective effect of Ginger were prominently increased in comparison with the control positive group (10%, 60%) respectively.In silymarin –treated group the protective effect was nearly the same as Ginger-treated group as the percentage of DNA damaged cells was only (44%) while that of the normal cells reached (56%). In the Sesame oil -treated group, the protective effect was unfortunately decreased as the percentage of DNA damaged cells was 70%, while that of the normal cells was 30%.Effective of different treatments on the degree of DNA damage:Treatment of mice with silymarin significantly reduced the degree of DNA damage (46.65+_2.94)when compared with that of the exposed group to Lead Acetate only (61.54+_6.86).Treatment with Ginger significantly reduced the degree of DNA damage more than Silymarin (42.90+_3.00), but treatment of mice exposed to Lead Acetate with Sesame oil appeared to be had no effect on the degree of DNA damage (53.89+_5.77) when compared with animals exposed to Lead Acetate only.
Comparison between different types of treatments on hepatic DNA damage showed that using Ginger is better than Silymarin for treatment of hepatic DNA damage, while using Sesame oil had a limited value
Histopathological changes observed in the liver of control positive group (Lead Acetate onl):1. Changes occurred in the parenchymal cells of the liver were focal areas of hepatocellular degeneration and necrosis. these changes were always arranged midzonal ,centrilobular or periportal. 2. Prominent changes are observed in the hepatic vasulature in the form of severe dilatation and congestion of central and portal veins was also afrequent findings.3. Dilatation of hepatic sinusoids was diffuse and of variable degrees.4. Inflammatory cellular reactions were frequent and always seen around central veins as well as portal and periportal areas.5. Kupffer cell reaction was also frequent and mainly associated with dilatation of the hepatic sinusoids.6. Edema of the Disse spaces around the hepatic sinusoids and vasculature of the portal tract was prominent and frequently occurred.7. Mild changes of the bile duct system was infrequently reported and consisted of mild proliferation of biliary epithelium of small bile ducts and dilatation of the large bile duct which showed atrophied stretched epithelium.
Histopathological changes observed in the liver of third group (Lead Acetate plus Silmarin): 1. Silymarin had an ideal effect as it inhibited the toxic effect of lead on hepatocytes, nearly all cases have alittle histological changes. 2. Angiopathic changes were also inhibited by Silymarin as Avery few amount of blood vessels in portal tract was moderately congested.3. Mononuclear cell reactions were completely absent and kupffer cell reaction was only minimum.Histopathological changes observed in the liver of fourth group (Lead Acetate plus Sesame oil): Sesamem oil to a great extent prevented the toxic effect of Lead on hepatocytes but there was some histopathological changes., however the effect of Sesame oil on angiopathic changes was of moderate degree as the changes were only confined to the portal tract vasculature and to a least extent the central vein. These angiopathic changes varies from mild congestion, mild edema to thrombosis in the portal vein, vasculitis and accumulation of mononuclear inflammatory cells around the blood vessels, as well as kupffer cell reaction were of Avery mild degree and only seen in minute focal areas. Changes in the biliary epithelium were rare and of no significance.
Histopathological changes observed in the liver of fifth group (Lead Acetate plus Ginger):1. No changes in hepatic parenchymal cells were seen in any case.2. Onl histopathological changes were observed in hepatic vasculature and consisted of congestion of central and portal veins.3. Kupffer cell reaction was mild and focal.4. Edema of Disse spaces and dilatation of hepatic sinusoids were completely absent.5. Lymphoid cell raction in the portal tract was frequently observed and was considered as an immune potentiating effect of Ginger rather than the effect of lead toxicity. It had been concluded that lead acetate was a potent genotoxic substance to the hepatic cells of albino mice. three substance were tested in these studies to be used as an antigenotoxic substance namely Silymarin ,Sesame oil and Ginger.it had been concluded that Ginger were superior for its antigenotoxic effect followed by Silymarin ,while Sesame oil was the last one. The genotoxicity and histopathology of all studded groups were distinctly correlated with each one.