الفهرس 
Chapter I : IntroductionOnly 14 pages are availabe for public view
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Abstract
6. This study investigated the harmful effect of cholesterol on several biochemical blood parameters in white male albino rats feed on high fat diet for 14 weeks and administration of papaya fruits as a natural food. The study was applied on 90 white male albino rats of 4-6 weeks old and of average body weight 140-150 gm. Rats were housed in separate metal cages and kept at constant environmental and nutritional conditions throughout the periods of the experiment rat were divided into 3 groups by the way of:
• Group (I): Consists of 15 rats fed on normal ration and act as control.
• Group (II): Consists of 15 rats fed on normal diet and papaya fruit at a dose of 200 g/kg/day papaya fruit.
• Group (III): Consists of 60 rats were fed on high fat diet for about (14 weeks) Kempaiah and Srinivasan (2005). Rats were divided into 4 subgroups (15 rats) for each group.
- Hyperlipidemic: received high fat diet only.
- Hyperlipidemic + papaya 1: received high fat diet and papaya fruit at a dose of 100 g/kg/day papaya fruit.
- Hyperlipidemic + papaya 2: received high fat diet and 200 g/kg/day.
- Hyperlipidemic + papaya 3 received high fat diet and papaya fruit at a dose of 300 g/kg/day.
Sampling:-
A- Blood samples
Heparinized blood samples (20 IU/ ml) were collected from animals after 14 weeks for detection of hyperlipidemai, then blood samples and liver tissues were collected after 8, 9 and 10 weeks from the beginning of papaya treatment. The samples were collected in the morning after over night fasting from the retro-orbital plexus of eyes.
Blood samples were obtain in the dry, clean, screw and capped tubes and plasma was separated by centrifugation at 3000 rpm for 10 minutes. The clear plasma were aspirated carefully by Pasteur pipettes and transferred into dry, clean and sterile labeled tubes. Then kept in deep freezer at -20°c until used.
Then the following Biochemical analysis were performed for the following parameters:-
Total cholesterol, triglycerides (TG), plasma high-density lipoproteins cholesterol (HDL-ch), plasma low-density lipoproteins cholesterol (LDL-ch), very low-density lipoproteins cholesterol VLDL-ch, uric acid (UA), phospholipids (PL), non-estrified fatty acids (NEFA), malondialdhyde (MDA), lecithin cholesterol acetyl transferase (LCAT) activities, Vit. C, lipase enzyme. While glutathione redactase (GR), reduced glutathione (GSH), glutathione peroxidase (GPx) and catalase enzyme was done by sacrificed and take a samples of liver tissue from the albino male rats.
b- Tissue sampling
1- Biochemical analysis
After scarifying rats liver tissue specimens were taken immediately and washed several times with normal saline and kept for determination of (GR), (GSH), (GPx) and catalase enzyme activity.
Preparation of liver samples
1 gm of liver tissue specimen (weighted) was homogenized immediately with normal saline 0.9%. Then centrifuged at 3000 r.p.m. for 15 minutes. The supernatant fraction was seprated by Pasteur pipette and used freshly for data mentioned by Sinha (1972) and Beutler et al. (1963).
2- Histopathological examination:
Histopathological changes tissue specimens were taken from different organ including liver and aorta, the determination of such blood parameters as well as histopathological findings of liver and aorta may help to clarify the harmful effect and metabolic changes which may occurs as a result of the hypercholesterolemia and also useful in establishing the protective role of nutrient carica papaya on the harmful effect of cholesterol induced biochemical abnormalities rats (Bancroft and Stevens 1996).
1. Plasma total cholesterol:
• Hyperlipidemic rats showing significant increase in plasma total cholesterol concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of (100, 200 g/kg/day) showing a significant decrease of plasma cholesterol concentration after 8, 9 and 10 weeks from start of treatment in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in the plasma total cholesterol concentration when compared to hyperlipidemic rats.
• Hyperlipidemic rats treated with papaya at a dose of (300 gm/kg/day) showing significant decrease in plasma total cholesterol concentration when compared to hyperlipidemic rats administrated papaya at a dose of (100, 200 gm/kg/day).
2. Plasma triacylglycerols:
• Hyperlipidemic rats showing significant increase in plasma triacylglycerols concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing significant decrease in plasma triacylglycerols concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant decrease in plasma triacylglycerols concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in plasma triacylglycerols concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Hyperlipidemic rats treated with papaya at a dose of (300 gm/kg/day) showing significant decrease in plasma triacylglycerols concentration when compared to hyperlipidemic rats administrated papaya at a dose of (100, 200 gm/kg/day).
3. Plasma HDL-cholesterol (HDL-ch):
• Hyperlipidemic rats showing significant decrease in plasma HDL-ch concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of (100 g/kg/day) showing a significant increase in plasma HDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of (200, 300 gm/kg/day) showing a significant increase in plasma HDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
4. Plasma LDL-cholesterol (LDL-ch):
• Hyperlipidemic rats showing significant increase in plasma LDL-ch concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing significant decrease in plasma LDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant decrease in plasma LDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in plasma LDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
5. Plasma VLDL-cholesterol (VLDL-ch):
• Hyperlipidemic rats showing significant increase in plasma VLDL-ch concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing significant decrease in plasma VLDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant decrease in plasma VLDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in plasma VLDL-ch concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
6. Plasma phospholipids:
• Hyperlipidemic rats showing significant increase in plasma phospholipids concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing significant decrease in plasma phospholipids concentration all over the experiment stages in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of (200, 300 gm/kg/day) showing significant decrease in plasma phospholipids concentration all over the experiment stages in comparison with hyperlipidemic rats.
7. Plasma non esterfied fatty acid (NEFA):
• Hyperlipidemic rats showing significant decrease in plasma NEFA concentration when compared to control and papaya groups.
• Administration of papaya at a dose of (200, 300 gm/kg/day) to hyperlipidemic rats showing significant increase in plasma NEFA concentration all the time of experiment when compared to hyperlipidemic rats groups.
• Hyperlipidemic rats treated with papaya at a dose of (300 gm/kg/day) showing significant increase in plasma NEFA concentration when compared to hyperlipidemic rats administrated papaya at a dose of (100, 200 gm/ kg/ day).
8. Plasma L-malondialdhyde (L-MDA):
• Hyperlipidemic rats showing significant increase in plasma L-MDA concentration when compared to control and papaya groups.
• Administration of papaya at a dose of (100 gm/kg/day) to hyperlipidemic rats showing non significant change in plasma L-MDA concentration in week 8 of administration which is become a significant decrease after 9, 10 weeks in comparison to hyperlipidemic rats group.
• Administration of papaya at a dose of (200, 300 gm/kg/day) to hyperlipidemic rats showing significant decrease in plasma L-MDA concentration when compared to hyperlipidemic rats group all over the experimental period.
• Hyperlipidemic rats group administrated papaya at a dose of
(300 gm/kg/day) showing significant decrease in plasma L-MDA concentration when compared to hyperlipidemic rats administration papaya at a dose of (100, 200 gm/kg/day).
9. Plasma lecithin cholesterol acyl transferease (LCAT) activity:
• Administration of papaya to normal albino rats showing significant decrease in plasma LCAT activity when compared to the control group during all the periods of the experiment.
• Hyperlipidemic rats showing significant increase in plasma LCAT activity when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing significant decrease in plasma LCAT activity after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant decrease in plasma LCAT activity after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in plasma LCAT activity after 8, 9 and 10 weeks in comparison to hyperlipidemic rats during all the period of the experiment.
• Hyperlipidemic rats group administrated with papaya at a dose of
(300 gm/kg/day) showing significant decrease in plasma LCAT activity when compared to hyperlipidemic rats administration papaya at a dose of (100, 200 gm/kg/day).
10. Plasma Lipase activity:
• Administration of papaya to normal albino rats showing significant increase in plasma lipase activity when compared to the control group during all the periods of the experiment.
• Hyperlipidemic rats showing significant decrease in plasma in plasma lipase activity when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of (100, 200 gm/kg/day) showing significant increase in plasma lipase enzyme activity after 8, 9 and 10 weeks in comparison to hyperlipidemic group.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing a significant increase in plasma lipase enzyme activity after 8, 9 and 10 weeks in comparison with hyperlipidemic group.
• Hyperlipidemic rats group administrated papaya at a dose of
(300 gm/kg/day) showing significant increase in plasma lipase enzyme activity when compared to hyperlipidemic rats administration papaya at dose of (100-200 g/kg/day) all over the experiment period.
11. Plasma uric acid (UA):
• Hyperlipidemic rats showing significant increase in plasma uric acid concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of (100, 200 and 300 gm/kg/day) showing significant decrease in plasma uric acid concentration in comparison to hyperlipidemic group during all the period of the experiment.
• Administration of papaya at a dose of (300 gm/kg/day) to hyperlidemic rats showing non significant decrease after 8 weeks of papaya administration which become significant decrease in plasma uric acid concentration after 9 and 10 weeks in all the experiment stages in comparison to hyperlipidemic group.
• Admi~istration of pazaya at a dose of (300 gm/kg/day) to hyperlidemic rats showing non significant decrease in plasma uric acid concentration in week 10 during all the period of the experiment, while after 8 and 9 weeks there is significant increase in plasma uric acid concentration.
• Administration of papaya at a dose of (300 gm/kg/day) to hyperlidemic rats showing significant decrease in plasma uric acid concentration in comparison to hyperlipidemic group.
12. Plasma vitamin C:
• Hyperlipidemic rats showing non significant change in plasma vitamin C concentration when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of (100, 200 and 300 gm/kg/day) showing non significant change in plasma vitamin C concentration after 8, 9 and 10 weeks in comparison to hyperlipidemic group during all the period of the experiment.
• There is a non significant change in plasma vitamin C concentration all over the period of experiment when compared weeks 8, 9, 10 during all the period of the experiment.
13. Glutathion reductase (GR) content:
• Hyperlipidemic rats showing significant increase in plasma GR content when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant decrease in GR content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in GR content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in GR content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats administrated papaya at a dose of (100 and 200 gm/kg/day).
14. Glutathione reduced (GSH) content:
• Hyperlipidemic rats showing significant decrease in GSH content when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing a non significant difference in GSH content after week 8 in comparison to hyperlipidemic rats while, there is significant increase in GSH content after 9 and 10 weeks.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant increase in GSH content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant increase in GSH content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Hyperlipidemic rats treated with papaya at a dose of (300 gm/kg/day) showing significant increase in GSH content when compared to hyperlipidemic rats administrated papaya at a dose of (100, 200 gm/kg/ day).
15. Glutathione peroxidase (GPx) content:
• Hyperlipidemic rats showing significant decrease in GPx content when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing significant increase in GPx content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant increase in GPx content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant increase in GPx content after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Hyperlipidemic rats treated with papaya at a dose of (300 gm/kg/day) showing significant increase in GPx content when compared to hyperlipidemic rats administrated papaya at a dose of (100, 200 gm/kg/ day).
16. Catalase activity:
• Hyperlipidemic rats showing significant increase in catalase activity when compared to control and papaya groups.
• Administration of hyperlipidemic rats with papaya at a dose of
(100 gm/kg/day) showing significant decrease in catalase activity after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(200 gm/kg/day) showing significant decrease in catalase activity after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
• Administration of hyperlipidemic rats with papaya at a dose of
(300 gm/kg/day) showing significant decrease in catalase activity after 8, 9 and 10 weeks in comparison to hyperlipidemic rats.
Histopathological examination
• The microscopical examination of the livers revealed normal histological appearance of the blood vessels and hepatocytes which arranged in radiating manner around the central veins similar to the control group. However, dilatation and congestion of the portal veins accompanied with hyperplasia of the bile ducts epithelium and mononuclear cellular aggregation in the portal areas mainly plasma cells and lymphocytes were also observed in some cases.
• Multifocally, the examined livers showed, fatty change of the hepatocyes, predominatly in the centrilobular zones of hepatic lobules, characterized by a circumferential zone of hepatocellular lipidosis surrounding the central veins. Occasionally, a pattern of central bridging degeneration characterized by connection of areas of fatty change between different lobules was seen. The degenerated hepatocyes exhibited marked enlargement of the cells by multiple variably sized discrete empty vacuoles (lipid type) that distend the cell cytoplasm, while the sinusoids were diffusely collapsed and bloodless. In advanced cases, the single large vacuoles of adjacent hepatocytes that displace the nucleus to the periphery coalesce forming irregular spaces or small fat cyst (Photo. 8). Moreover, the portal areas revealed focal areas of mononuclear cellular aggregation around the bile ducts.
• The heart showed fatty degeneration (fatty change) of some muscle fibers of atrial and ventricular wall or tunica media of blood vessels. The sarcoplasm of degenerated myocytes exhibited numerous variably sized discrete empty vacuoles. Occasionally, the degenerated myocytes were accompanied by myocytolysis of some muscle fibers.
• The examined livers of this group revealed histopathological changes similar to group III but milder in severity. Moderate numbers of the hepatocytes in the centrilobular zones of hepatic lobules showed fatty change characterized by enlargement of the cells by multiple variably sized discrete empty vacuoles (lipid type) that distend the cell cytoplasm. The heart showed also fatty change of some muscle fibers, similar to that observed in group III, characterized by numerous variably sized discrete empty vacuoles in the sarcoplasm of degenerated myocytes. Occasionally, the sarcoplasm of degenerated myocytes exhibited single large vacuoles that displace the nucleus to the periphery.
• The examined livers showed mild to moderate fatty change of the hepatocytes in the centrilobular zones of hepatic lobules. Rarely, coagulative necrosis of individual hepatocytes, characterized by retention of hepatic cell outline and shrunken hepatocytes with hypereosinophilic cytoplasm and pyknotic nuclei, were also detected in few cases. Moreover, mild hyperplasia of the lining epithelium of the bile ducts with periductal leucocytic cellular infiltration mainly lymphocytes and plasma cells were also detected. The heart showed moderate fatty change of some muscle fibers particularly in the subendocardial myocytes. Occasionally, moderate fatty change was also noticed in the tunica media of aorta and myocardial blood vessels.
• The microscopical examination of the livers revealed congestion of central veins with mild fatty change of the surrounding hepatocytes (centrilobular fatty change), while the hepatocytes in the periportal zone of hepatic lobules showed normal histological appearance. The portal areas revealed congestion of portal veins with moderate hyperplasia of the lining epithelium of the bile ducts and mononuclear cellular infiltration mainly lymphocytes and plasma cells. Moreover, the heart showed mild fatty change of some muscle fibers.