Hypocholesterolemic Effects of Phenolic Extracts and Purified Hydroxytyrosol Recovered from Olive Mill Wastewater in Rats Fed a Cholesterol-Rich Diet
- 12 January 2007
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of Agricultural and Food Chemistry
- Vol. 55 (3), 624-631
- https://doi.org/10.1021/jf0623586
Abstract
In our previous studies, a phenolic-rich extract of olive mill wastewaters (OMW) was prepared under optimal conditions, using a continuous countercurrent extraction unit, and hydroxytyrosol was purified from the obtained OMW extract. The antioxidant activity of OMW extract and hydroxytyrosol was determined by a series of models in vitro. In this study, the hypocholesterolemic effects of hydroxytyrosol and OMW extract in rats fed a cholesterol-rich diet were tested. Wistar rats, fed a standard laboratory diet or a cholesterol-rich diet for 16 weeks, were used. Serum lipid levels, as well as thiobarbituric acid reactive substances (TBARS) and superoxide dismutase and catalase activities in liver were examined. Cholesterol-rich diet-induced hypercholesterolemia was manifested in the elevation of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Administration of a low-dose (2.5 mg/kg of body weight) of hydroxytyrosol and a high-dose (10 mg/kg of body weight) of OMW extract significantly lowered the serum levels of TC and LDL-C while increasing the serum levels of high-density lipoprotein cholesterol (HDL-C). Furthermore, the TBARS contents in liver, heart, kidney, and aorta decreased significantly after oral administration of hydroxytyrosol and OMW extract as compared with those of rats fed a cholesterol-rich diet. In addition, OMW phenolics increased CAT and SOD activities in liver. These results suggested that the hypocholesterolemic effect of hydroxytyrosol and OMW extract might be due to their abilities to lower serum TC and LDL-C levels as well as slowing the lipid peroxidation process and enhancing antioxidant enzyme activity. Keywords: Antioxidant enzymes; cholesterol-fed rat; hydroxytyrosol; hypocholesterolemic; olive mill wastewaters extract; serum lipid levelsKeywords
This publication has 33 references indexed in Scilit:
- Isolation and evaluation of antioxidants from leaves of a Tunisian cultivar olive treeEuropean Journal of Lipid Science and Technology, 2005
- Apple procyanidins decrease cholesterol esterification and lipoprotein secretion in Caco-2/TC7 enterocytesJournal of Lipid Research, 2005
- Identification and Antioxidant Potential of Flavonoids and Low Molecular Weight Phenols in Olive Cultivar Chemlali Growing in TunisiaJournal of Agricultural and Food Chemistry, 2004
- High-Density Lipoprotein Cholesterol and Coronary Heart DiseaseCardiology in Review, 2004
- Effect of Different Olive Oils on Bile Excretion in Rats Fed Cholesterol-Containing and Cholesterol-Free DietsJournal of Agricultural and Food Chemistry, 2003
- Long-Term Effects of Vitamin E, Vitamin C, and Combined Supplementation on Urinary 7-Hydro-8-Oxo-2′-Deoxyguanosine, Serum Cholesterol Oxidation Products, and Oxidation Resistance of Lipids in Nondepleted MenArteriosclerosis, Thrombosis, and Vascular Biology, 2000
- Free Radical-Scavenging Properties of Olive Oil PolyphenolsBiochemical and Biophysical Research Communications, 1998
- The role of oxidized lipoproteins in atherogenesisFree Radical Biology & Medicine, 1996
- Glutathione, glutathione-dependent and antioxidant enzymes in mussel, Mytilus galloprovincialis, exposed to metals under field and laboratory conditions: implications for the use of biochemical biomarkersAquatic Toxicology, 1995
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976