Effects of Walnut on Lipid Profile as Well as the Expression of Sterol-Regulatory Element Binding Protein-1c(SREBP-1c) and Peroxisome Proliferator Activated Receptors <i>α</i> (PPAR<i>α</i>) in Diabetic Rat
- 1 Department of Laboratory Science, Islamic Azad University, Borūjerd, Iran
- 2 Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
- 3 Department of Laboratory Science, Islamic Azad University, Borūjerd, Iran
Abstract
Diabetes Mellitus has appeared as a universal burden. Studies have reported that mortality from Coronary Heart Disease (CHD) in diabetic patients is 2 - 4 times higher than nondiabetics. In this respect, walnut is a treatment which has beneficial effects on CHD risk factors. PPARα and SREBP-1c play an important role in the regulation of lipid metabolism. This study was aimed to evaluate the effects of walnut on lipid profile as well as SREBP-1c and PPARα protein levels in rats. Animals were randomly divided into 3 groups (n = 6); Group 1: Received chow only (control), Group 2: Diabetic rats + chow, Group 3: Diabetic rats + chow supplemented with 4% of whole walnuts. After four weeks rats were sacrificed, blood was collected; lipid profiles as well as SREBP-1c and PPARα protein levels were determined. Compared with diabetic rats walnut significantly decreased serum cholesterol (P < 0.01), LDL-c (P < 0.01), triglyceride (P < 0.001) and VLDL-c (P < 0.001) and also increased HDL-c (P < 0.05) compared with diabetic. Moreover, SREBP-1c protein level significantly decreased (P < 0.05) and PPARα significantly increased in walnut group compared with diabetic group (P < 0.05). The findings showed that walnut administration in diet clinically decreases atherosclerosis risk factors. Lipid profile reduction might be due to the rise of PPARα and the reduction of SREBP-1c by this medical treatment in liver.
- J. Stamler, O. Vaccaro, J. Neaton and D. Wentworth, “For the Multiple Risk Factor Intervention Trial Research Group: Diabetes, Other Risk Factors, and 12-Year Cardiovascular Mortality for Men Screened in the Multiple Risk Factor Intervention Trial,” Diabetes Care, Vol. 16, No. 2, 1993, pp. 434-444. doi:10.2337/diacare.16.2.434
- J. Sabate, E. G. Fraser, K. Burke, S. F. Knutsen, H. Bennett and K. D. Lindsted, “Effects of Walnut on Serum Lipid Levels and Blood Pressure in Normal Men,” New England Journal of Medicine, Vol. 328, No. 9, 1993, pp. 605-607. doi:10.1056/NEJM199303043280902
- P. A. Edwards, H. R. Kast and A. M. Anisfeld, “Bareing It all: The Adoption of LXR and FXR and Their Roles in Lipid Homeostasis,” Journal of Lipid Research, Vol. 43, No. 1, 2002, pp. 2-12.
- Z. Huang, X. Zhou, A. C. Nicholson, J. A. M. Gotto, D. P. Hajjar and J. Han, “Activation of Peroxisome Proliferator-Activated Receptor α in Mice Induces Expression of the Hepatic Low-Density Lipoprotein Receptor,” British Journal of Pharmacology, Vol. 155, No. 4, 2008, pp. 596-605. doi:10.1038/bjp.2008.331
- W. Friedewald and K. Leseg and D. Fredrickson, “Estimation of the Concentration of Low Density Lipoprotein Cholesterol in Plasma without Use of Preparative Centrifuge,” Clinical Chemistry, Vol. 18, 1972, pp. 499-502.
- M. A. Montanaro, A. M. Bernasconi, M. S. Gonzalez, O. J. Rimoldi and R. R. Brenner, “Effects of Feno?brate and Insulin on the Biosynthesis of Unsaturated Fatty Acids in Streptozotocin Diabetic Rats,” Prostaglandins, Leukotrienes and Essential Fatty Acids, Vol. 73, No. 5, 2005, pp. 369-378. doi:10.1016/j.plefa.2005.06.004
- S. J. Thornton, E. Wong, D. S. Lee and K. M. Wasan, “Effect of Dietary Fat on Hepatic Liver X Receptor Expression in P-Glycoprotein Deficient Mice: Implications for Cholesterol Metabolism,” Lipids in Health and Disease, Vol. 7, 2008, p. 21.
- A. P. Simopoulos, “The Importance of the Ratio of Omega-6/Omega-3 Essential Fatty Acids,” Biomed Pharmacother, Vol. 56, No. 8, 2002, pp. 365-379. doi:10.1016/S0753-3322(02)00253-6
- C. Crews, P. Hough, J. Godward, P. Brereton, M. Lees, S. Guiet and W. Winkelmann, “Study of the Main Constituents of Some Authentic Walnut Oils,” Journal of Agriculture and Food Chemistry, Vol. 53, No. 12, 2005, pp. 4853-4860. doi:10.1021/jf0478354
- T. Fukuda, H. Ito and T. Yoshida, “Antioxidative Polyphenols from Walnuts (Juglans regia L),” Phytochemistry, Vol. 63, No. 7, 2003, pp. 795-801. doi:10.1016/S0031-9422(03)00333-9