Effect of CRP on Some of the in vitro Physicochemical Properties of LDL

Abstract &nbsp;&nbsp; BACKGROUND: Atherosclerosis is the most important underlying cause of cardiovascular diseases (CVD) which recently has been classified as an inflammatory disorder. Accumulation of large amounts of oxidized LDL in the intima during local inflammation reaction led to increase several factors such as C -reactive protein (CRP). It has also been reported that CRP is able to bind with modified forms of LDL as well as oxidized LDL. These findings suggest possible positive or negative involvement of this protein in atherogenesis. The main objective of the present study was to assess the influence of CRP on LDL oxidation and the possible physical \changes of LDL in the presence of CRP in vitro. &nbsp;&nbsp; METHODS: In this study, the susceptibility of purified LDL to oxidation was assayed by monitoring of formation of conjugated dienes in different physiological concentrations of CRP (0 - 0.5 -2&nbsp; &micro;g/ml) using a shimadzu spectrophotometer. Electrophoresis was used to determine the electrophoretic mobility of LDL in those conditions. &nbsp;&nbsp; RESULTS: CRP significantly reduced the susceptibility of Cu++ -induced LDL oxidation through increasing the lag timeand there was positive relationship between these findings and CRP concentration (P &lt; 0.05). CRP caused a significant reduction in the electrophotretic mobility of LDL compared to native LDL (n-LDL) (P&lt;0.05).&nbsp; &nbsp;&nbsp; CONCLUSION: A considerable reduction was shown in LDL oxidation, in higher concentration of CRP, via an unknown mechanism. The electrophoretic mobility of LDL, in the oxidative condition, decreases in the presence of CRP compared to n-LDL, which can be indicative of the effect of this protein on the physical and chemical properties of LDL. It seems that, other pathway than LDL oxidation is responsible for the effect of CRP on the atherogenesis processes. &nbsp; &nbsp;&nbsp; Keywords: Atherosclerosis, Creactive protein, Low-density lipoprotein, Inflammation. &nbsp;</p

Impacts of fresh lime juice and peel on atherosclerosis progression in an animal model

BACKGROUND: The main protective role of antioxidants in the progression of atherosclerosis has been shown in some studies. Therefore, this project evaluated the effects of Citrus aurantifolia (Christm) juice and peel on antioxidant activity and atherosclerosis progression in rabbits receiving a hypercholesterolemic diet. METHODS: Forty white New Zealand male rabbits were randomly allocated to four groups. All groups were on hypercholesterolemic diet for two months. While the first group was considered as the hypercholesterolemic control, groups 2 and 3 (intervention groups) received 5 ml/day lime juice and 1 g/day dried lime peel powder, respectively. Group 4 was fed a normal diet (normal control). Before and after the study, weight was measured and a fasting blood specimen was taken from the rabbits. Serum lipids analyses and antioxidant activity evaluations were then performed. The rabbits&rsquo; aorta and coronary arteries were separated and the presence of fatty streaks was studied. RESULTS: Comparing to the hypercholesterolemic control group (-25.2 &plusmn; 7.0), only the plasma total antioxidant capacity change was significantly more in rabbits supplemented with lime juice (16.3 &plusmn; 14.7) and peel (8.6 &plusmn; 7.1) (P = 0.008). The presence of fatty streaks in coronary arteries and aorta of the intervention groups [juice (0.2 &plusmn; 0.01); peel (0.0 &plusmn; 0.00)] was significantly decreased compared to the hypercholesterolemic control group (1.2 &plusmn; 0.4) (P &lt; 0.001). CONCLUSION: Based on our findings, Citrus aurantifolia peel and juice increase plasma antioxidant capacity in rabbits, and can thus prevent or decelerate the process of atherogenesis. However, lime peel is more effective than lime juice. &nbsp; Keywords: Animal, Atherosclerosis, Atherogenic Diet, Fatty Streak, Intervention, Lime &nbsp;&nbsp; Normal 0 false false false EN-US X-NONE AR-SA <!--[endif] --

Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

Introduction. Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health