الفهرس 
Introduction and Aim of the WorkOnly 14 pages are availabe for public view
Abstract
Cardiovascular diseases including myocardial infarctions, myocarditis, strokes, coronary artery disease, chronic granulomatous disease, atherosclerotic cardiovascular disease, etc. can be regarded as the severe health trouble round the globe. The reasons behind the heart related complications have been well chalked our so far.
Atherosclerosis, a chronic disease of arteries and prime culprit of cardiovascular diseases, has been a leading cause of mortality worldwide for many years. It is an inflammatory disease in which lipids accumulate on the walls of blood vessels, thickening and clogging these vessels. Atherosclerosis is a multifactorial disease influenced by genetics, lifestyle and environmental factors. Despite therapeutic advances that reduce the risk of cardiovascular events, atherosclerosis-related diseases remain the leading cause of mortality worldwide.
A broad spectrum of traditional cardiovascular risk factors associated with atherosclerosis includes hypertension, hyperlipidemia, diabetes mellitus, obesity and smoking. These factors to some extent explain the pathogenesis of atherosclerosis, but are not completely implicated in cardiovascular diseases.
At the present, anti-atherosclerosis therapies targeting the traditional risk factors include first-line antiplatelet drugs, hypoglycemic drugs and lipid-lowering agents. Despite the standard and efficacious conventional therapies, cardiovascular diseases risk still persists in patients, which may be partially attributed to complex etiology of atherosclerosis.
There is a pressing need to improve our understanding of atherosclerosis and develop effective approaches targeting underlying mechanisms.
Holothuria polii is a common Mediterranean Sea cucumber which lives in the sublittoral zone. It has a high content in proteins, micronutrients, polyunsaturated acids but is very low in lipids. It is therefore a “functional” and nutraceutical food for human consumption. Also, it has been highlighted as a potential source of bioactive compounds with significant antifungal, anti-inflammatory and antibacterial activity. This suggests that research on H. polii aquaculture could have high applicative aspects on several fronts.
The objective of this study was to evaluate the anti-atherogenic activity of sea cucumber extracts (Holothuria Polii) in rats fed on atherogenic diet as well as to assess the involvement of oxidative damage in atherosclerotic development. To achieve this target, firstly the extract was prepared by the aqueous and mixed methods. Then, the concentration of proteins, carbohydrates, lipids, amino acids, phenolic compounds and vitamins were determined. Secondly, the atherogenic diet was prepared to be used throughout the study.
A total of 64 normal healthy Swiss albino rats were divided to 2 main groups A (Normal) and B (Atherogenic).
group A: consisted of 24 rats that were subdivided into three equally sized groups as follows:
group 1 (Normal Control): Normal animals fed a standard animal chow for eight consecutive weeks.
group 2 (Aqueous Extract): Normal animals fed a standard animal chow and orally administered with the aqueous extract for eight consecutive weeks.
group 3 (Mixed Extract): Normal animals fed a standard animal chow and orally administered with the mixed extract for eight consecutive weeks.
group B: consisted of 40 rats and were subdivided into 5 equally sized groups as follows:
group I (Atherogenic): Normal animals fed the high fat diet for eight consecutive weeks serving as negative control group.
group II (Aqueous Extract + Atherogenic): The animals were fed the high fat diet along with an oral challenge of the aqueous extract for eight consecutive weeks serving as a protective group.
group III (Mixed Extract + Atherogenic): The animals were fed the high fat diet along with an oral challenge of the mixed extract for eight consecutive weeks serving as a protective group.
group IV (Atherogenic + Aqueous Extract): The animals were fed the high fat diet for eight consecutive weeks followed by an oral administration of the aqueous extract for further eight consecutive weeks serving as therapeutic group.
group V (Atherogenic + Mixed Extract): The animals were fed the high fat diet for eight consecutive weeks followed by an oral administration of the mixed extract for further eight consecutive weeks serving as therapeutic group.
At the end of the experiment, the animals were weighed then sacrificed after a fast of 12h. Blood samples were withdrawn, then serum was prepared aliquoted and stored at -20°C until analysis. Serum was used to determine the lipid profile, Lecithin cholesterol acyltransferase (LCAT), cardiac troponin-inhibitory subunit (cTn-I), aspartate aminotransferase (AST) activity and lactate dehydrogenase (LDH) activity
The liver and the heart were dissected out, rinsed in isotonic sterile saline, blotted dry with a filter paper and weighed. Small specimens of the liver and the heart were fixed in 10% formalin solution for histological examination.
Results of the present study have demonstrated that the aqueous extract of sea cucumber H. polii possesses an anti-oxidative activity in a dose dependent manner. The HPLC analysis of sea cucumber aqueous extract revealed the presence of thirteen phenolic components, four water-soluble vitamins and 16 amino acids. Oral supplementation of normal rats with aqueous or mixed extract showed no significant effect on any of the studied biochemical parameters. Oral supplementation of atherogenic rats with aqueous or mixed extract of sea cucumber caused a highly significant reduction in serum levels of total lipids, triacylglycerol, total cholesterol, VLDL-C, LDL-C and the atherogenic indices which were markedly elevated in the atherogenic group. By contrast, sharp significant elevations in serum HDL-C and LCAT levels were observed, which were markedly decreased in rats fed atherogenic diet. On the other hand, the atherogenic diet elevated the heart markers, such as troponin I level, AST and LDH activities. Treating the atherogenic rats with aqueous or mixed sea cucumber extract produced marked reductions in serum levels of troponin I and both of AST and LDH activities. Histopathological examination of heart tissue, blood vessels and liver tissue of rats fed atherogenic diet revealed cardiomyocyte necrosis with extensive and diffuse vacuolar degeneration with sub-endothelial deposition of foamy macrophages and disruption of medial layer of blood vessels. In addition to numerous glycogenated nuclei, microvesicular steatosis with eccentrically located nuclei, ballooning degeneration of hepatocytes that appeared markedly swollen with the presence of megamitochondria and fibroblastic proliferation. Administration of aqueous or mixed extract of sea cucumber along with the atherogenic diet showed an improvement in heart tissue, blood vessels and liver tissue of treated rats, which was augmented in the protective group.
Data obtained from this study suggests that oral supplementation with sea cucumber extract substantially alleviated atherosclerosis through regulating oxidative stress and cholesterol metabolism, and thus, may be beneficial in the treatment of patients with cardiovascular disease.