Cardiovascular disease is a leading cause of global mortality, accounting for 17 million deaths annually (Smith et al., 2004); atherosclerosis, in particular, is the main contributor for the pathogenesis of myocardial infarction. Dietary cholesterol in excess promotes coronary plaque formation, which increases the susceptibility to myocardial ischemia and aggravates ischemic heart disease (Schwartz et al., 2001; Yaoita et al., 2005). Elevated levels of plasma LDL and triglycerides, accompanied by reduced HDL levels, is often associated with an increased risk of coronary heart disease (CHD) (Fki et al., 2005; Smith et al., 2004). Atherosclerosis represents a state of heightened oxidative stress, characterized by lipid and protein oxidation (Stocker and Keaney, 2004). Several studies indicate that LDL oxidation in an early event of process. Indeed, oxLDL is cytotoxic to a variety of vascular cells (Morel et al., 1983), induces the synthesis of monocyte chemotatic protein-1 (Rajavashisth et al., 1990), recruits inflammatory cells (Navab et al., 1991) and stimulate the production of autoantibodies (Salonen et al., 1992).[wp_ad_camp_3]
The date palms (Phoenix dactylifera L.,) have been cultivated in the Middle East over at least 6000 years ago (Copley et al., 2001). Dates fruits have always played an important role in the economic and social lives of the people of these regions and they considered dates are a staple carbohydrate food (Al-Shahib and Marshall, 2003). They are also used in the production of local foods, beverages and spirits. Folk medicinal practices dates are considered as tonic and aphrodisiac. Recently, Al-Qarawi et al. (2005) reported its beneficial affect on experimentally induced gastric ulcers in rats. A first study, reported that date fruits has anti-tumor activity (Ishurd and Kennedy, 2005). It has proofed for antioxidant and anti-mutagenic properties (Vayalil, 2002; Mansouri et al., 2005). Dry date fruits are used in Indian traditional medicine after child birth as immunostimulants (Puri et al., 2000). Furthermore, Al-Shahib and Marshall, (2003) concluded that, in many ways, dates may be considered as an almost ideal food, providing a wide range of essential nutrients and potential health benefits.[wp_ad_camp_5]
The relation between coffee consumption and CVD has been extensively. Although many previous studies found no significant association between coffee and CHD (Kawachi et al., 1994; Willett et al., 1996), more recent results have been inconsistent. Case-control studies found a positive association between coffee consumption and risk of CHD (Tavani et al., 2001; Hammer et al., 2003), prospective cohort studies reported a lower risk among individuals with higher coffee consumption (Woodward and Tunstall-Pedoe, 1999; Kleemola et al., 2000). However, it has been reported that, boiled coffee enhances the serum cholesterol levels (Little et al., 1966; Bjelke, 1974). Scandinavian boiled coffee and Arabian coffee are prepared by boiling roasted ground coffee beans found to raise serum cholesterol levels in humans and in experimental animals (Zock et al., 1990; Urgert et al., 1995; Al-Kanhal et al., 1994). Dusseldorp et al. (1991) reported that, coffee boiling caused an increased extraction of hyphercholesterolemic lipid factor from coffee, which powerfully raises the serum cholesterol level.
The increase intake of gahwa (Arabian coffee) with dates along with a high cholesterol diet in Saudi population as well as increased incidence of CHD (Lewis and Russel, 1985; Al-Shoshan, 1992) has raised a concern about the effects of the Saudi diet on CHD risk. The present study has designed to evaluate the effect of dates, gahwa and their combination on lipid metabolism in hypercholesterolemic hamsters.[wp_ad_camp_2]
MATERIALS AND METHODS
This study has undertaken in College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia during 2006.
Animals: Thirty-six male golden Syrian hamsters of same age weighing 60-70 g were received from Experimental Animal Care Center, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia. All the animals were maintained under controlled condition of temperature (24±1°C), humidity (50-55%) and light (12 h light/dark) and were provided with chow and water ad lib. The animals were kept for one week in similar conditions as incubation period and were divided in six groups by taking 6 hamsters in each group. The groups are as follows: 1) Control (chow, manufactured by Grain Silos and Flour Mills Organization, Riyadh, Saudi Arabia), 2) Dates-diet (50% date pulp with chow w/w), 3) Dates-diet with gahwa (drinking water was replaced with gahwa), 4) Cholesterol-diet (1% cholesterol in chow w/w), 5) Date + cholesterol (1% cholesterol in dates-diet) and 6) Date + gahwa + cholesterol (1% cholesterol in dates-diet and gahwa replaced with drinking water).
Diets: Dates-diet: Khalas (a variety of date) date pulp was mixed with hamster chow power (1:1, w/w), made into pellets and air-dried.
Cholesterol-diet: One percent (w/w) cholesterol (BDH Chemicals, Poole, England) was mixed with hamster chow power, made into pellets and air-dried.
Gahwa: The gahwa was prepared by boiling 30 g of medium roasted grounded Arabian coffee (obtained from local market) in 1 L of water for 20 min, 5 g of grounded cardamom (Elettaria cardamomum Maton) was added to boiling coffee and continue for 5 more min. The gahwa was decanted to remove the sediments and used after cooled.
All the above dietary preparations were made every week and stored in refrigerator except gahwa. The treatments were continued for 13 weeks.[wp_ad_camp_1]
The aim of present study to evaluate the effect of dates, gahwa and their combination on lipid metabolism in hypercholesterolemic hamsters. The increase intake of dates and gahwa (Arabian coffee) along with a high cholesterol diet in Saudi population as well as increased incidence of cardiovascular disease (CVD) has raised a concern about the effects of the Saudi diet on CVD risk. Golden Syrian hamsters were divided into six groups (six animals in each) as follows: 1) control (chow), 2) Dates-diet (50% date pulp with chow), 3) Dates-diet + gahwa (replaced with drinking water), 4) cholesterol-diet (1% cholesterol in chow), 5) dates-diet + 1% cholesterol, 6) Dates-diet + gahwa + 1% cholesterol. All the above dietary preparations were made every week and supplemented for 13 consecutive weeks. Plasma lipid profile including total cholesterol, triglycerides (TC), Low Density Lipoprotein (LDL), High Density Lipoprotein (HDL) were estimated. Total cholesterol and TC were estimated in liver, heart and kidney tissues. The high cholesterol-diet caused significant increase in body and organs (liver and kidney) weights as compared to controls. Dates-diet, significantly reduced the body and liver weight that increased by the high cholesterol-diet. Plasma lipids were significantly elevated by high cholesterol-diet supplementation and this increase was significantly decreased by the dates-diet. However, hepatic TC levels further increased when dates were combined with high cholesterol-diet supplementation. Gahwa intake either with dates alone or with high cholesterol-diet was not induced any significant changes in lipid parameters. In conclusion, the dates lowering effects on body weights and plasma lipid profile shows its beneficial affects against atherosclerosis development in humans. Further investigations required for find out its potential constituents that affecting the CVD risk.[wp_ad_camp_4]