الفهرس 
Introduction & Aim of the WorkOnly 14 pages are availabe for public view
 |  | from | 215 |  |  |
| | | from | 215 | | |
Abstract
The present study tried to evaluate the effects of high cholesterol & high fat diets on the structure of adult & aged rat hippocampus (which is essential for the memory & learning processes) & the possible protective role of curcumin.
Sixty male albino rats were used in this study. They were classified equally according to age into adult & aged groups. Each group was divided equally into three groups; Group I: that was further subdivided into negative and sham control subgroups; Group II: that was further subdivided into cholesterol and cholesterol with curcumin subgroups; Group III: that was further subdivided into unsaturated fat and unsaturated fat with curcumin subgroups.
All types of diet were given to rats as: 15 gm / rat / day for adult rats and 20 gm / rat / day for aged rats for eight weeks. Curcumin was added to different types of diet as (5 gm/ kg diet).
All rats were weighed before & after the experiment. At the end of the experiment all rats were fasted for 12 hours, anaesthetized, and blood samples and brain specimens were collected for biochemical analysis and histopathological studies respectively.
The collected blood samples were used to detect: HDL, LDL, total cholesterol and triglycerides serum levels. The serial coronal sections of the brain were stained with H & E, Toluidine blue, Golgi cox and GFAP immunohistochemical stains. Also the morphometric measurements were done by the image analyzer for detection of the number of pyramidal cells in the hippocampus and thickness of the hippocampus.
Summary & conclusion
- 2 -
Examination of sections of the hippocampus revealed that:
In the adult control group, the hippocampus of adult balanced diet and adult balanced diet with curcumin fed rats showed similar normal hippocamal structure.
High cholesterol diet feeding to adult rats resulted in disturbed arrangement of the pyramidal cell layer with significant decrease in the number of the pyramidal cells. Many pyramidal cells became shrunken, eosinophilic, swollen or showed central chromatolysis. The cells showed absence of the dendrites and moderate disintegration of axons. Some cells also showed decrease of their Nissl substance content. Moreover, there was an increase in the number and size of astrocytes with visible long processes; (reactive astrocytes). Some blood vessels showed thickening of their walls while others showed thinning of the walls with subendothelial edema. There was also peripheral degeneration and small vacuolations in the neuropil.
High fat diet feeding to adult rats resulted in a little disturbed arrangement of pyramidal cell layer with significant decrease in the number of the pyramidal cells. Some pyramidal cells were shrunken or eosinophilic. Others had vacuolated nuclei with absent or eccentric nucleoli or had ghost like appearance. The cells had normal contour but with absent dendrites. There was a decrease of Nissl substance content in many of the pyramidal cells with moderate increase in the number and size of astrocytes. Also, there was notable vascularisation of the hippocampus, with the appearance of congested thin walled blood vessels. Peripheral degeneration and vacuolation (spongiosis) were observed in the neuropil.
In the aged control rats, many changes of senility were observed as decrease in the hippocampal thickness, increased vascularization inside the hippocampal
Summary & conclusion
- 3 -
sulcus, senile neuritic plaques, lipofuscin pigmentation, granulovacuolar degeneration and Hirano bodies. The neuropil showed spongiosis with increase in number and size of astrocytes. The pyramidal cell layer showed slight disturbed arrangement with significant decrease in the pyramidal cell number. Some pyramidal cells were shrunken while others showed abnormal distinct cell boundaries. The cells had irregular triangular bodies, short axons & few non branched dendrites. An observable decrease in Nissl substance density was seen.
Both high cholesterol diet and high unsaturated fat diet feeding to aged rats pronounced the pathological features of senility in addition to their characteristic features. Also, the appearance of Lewy bodies in both groups assured dementia.
Addition of curcumin to the experimental groups showed clinical, biochemical, histopathological, morphometric and immunohistochemical improvements. The improvements were marked in adult than in aged rats and in high unsaturated fat diet than in high cholesterol diet fed rats.