Cholesterol Journal Articles

Record 5001 to 5020

Effect of monovalent cations on the binding of amino acids to cholesterol
Gere-Paszti, E., M. Prodan, et al. (2003), Pharmazie 58(1): 44-8.
Abstract: The nature of the interaction between amino acids and cholesterol was shown by reversed-phase thin-layer chromatography (RP-TLC) in the presence of monovalent cations of different concentration. The degree of interaction between amino acids and cholesterol was affected by different salt solutions and by applying cholesterol to the chromatographic plates at higher concentration. The relative strength of interaction was determined by statistical evaluation of the results in each case. The objectives of the investigations were to study the retention behaviour of biologically active amino acids on alumina supports impregnated with cholesterol and to characterize the effects of monovalent cations on the interaction between amino acids and cholesterol.

Effect of morning versus evening intake of simvastatin on the serum cholesterol level in patients with coronary artery disease
Lund, T. M., H. Torsvik, et al. (2002), Am J Cardiol 90(7): 784-6.

Effect of n-3 fatty acids on the key enzymes involved in cholesterol and triglyceride turnover in rat liver
al-Shurbaji, A., C. Larsson-Backstrom, et al. (1991), Lipids 26(5): 385-9.
Abstract: The effect of long-chain n-3 fatty acids on hepatic key enzymes of cholesterol metabolism and triglyceride biosynthesis was investigated in two rat models. In the first model, rats were intravenously infused for two weeks with a fat emulsion containing 20% of triglycerides in which either n-6 or n-3 fatty acids predominated. The treatment with n-3 fatty acids led to a reduction primarily of serum cholesterol (45%), but also of serum triglycerides (18%). HMG-CoA reductase activity and cholesterol 7 alpha-hydroxylase activity were reduced by 45% and 36%, respectively. There were no significant effects on diacylglycerol acyltransferase (DGAT) or phosphatidate phosphohydrolase (PAP) activities. In the second model, rats were fed a diet enriched with sucrose, coconut oil and either sunflower oil (n-6 fatty acids) or fish oil (long-chain n-3 fatty acid ethyl esters). The treatment with n-3 fatty acids decreased serum triglycerides (41%) and, to a lesser extent, serum cholesterol (17%). Neither glycerol 3-phosphate acyltransferase (GPAT) or DGAT were affected by n-3 fatty acids. In contrast, PAP activity was reduced by 26%. HMG-CoA reductase was not significantly affected, whereas cholesterol 7 alpha-hydroxylase activity was reduced by 36%. The results indicate that part of the TG-lowering effect of long-chain n-3 fatty acids may be mediated by inhibition of the soluble phosphatidate phosphohydrolase. The effect on serum cholesterol may be partly due to inhibition of HMG-CoA reductase.

Effect of naringin supplementation on cholesterol metabolism and antioxidant status in rats fed high cholesterol with different levels of vitamin E
Choi, M. S., K. M. Do, et al. (2001), Ann Nutr Metab 45(5): 193-201.
Abstract: Some bioflavonoids are potent antioxidants and have pharmacological effects similar to those of vitamin E. The interactive effect of naringin and vitamin E was studied with respect to cholesterol metabolism and antioxidant status. Naringin supplementation (0.1%, wt/wt) with comparable levels of vitamin E was given to rats with a high-cholesterol (1%, wt/wt) diet for 5 weeks. The amount of vitamin E included in naringin-free and naringin diets was a low (low-E) and a normal (normal-E) level. The naringin supplementation significantly lowered the concentrations of plasma cholesterol and triglyceride compared to the naringin-free group in low vitamin E-fed rats. HMG-CoA reductase activity was significantly lowered by naringin supplementation within both the low-vitamin E group (794.64 +/- 9.87 vs. 432.18 +/- 12.33 pmol/min/mg protein, mean +/- SE; p < 0.05) and normal-vitamin E group (358.82 +/- 11.4 vs. 218.22 +/- 9.47 pmol/min/mg protein, mean +/- SE; p < 0.05) compared to each of the naringin-free group. The HMG-CoA reductase activity was also significantly lowered by increased dietary vitamin E when compared within the naringin and naringin-free group, respectively. Neither dietary naringin nor vitamin E did significantly change the activities of hepatic antioxidant enzymes and plasma thiobarbituric acid-reactive substance level. These data indicate that naringin lowers the plasma lipid concentrations when the dietary vitamin E level is low. The HMG-CoA reductase-inhibitory effect of naringin was more potent when dietary vitamin E was at a normal level. These data may contribute to understanding the interactive effect of naringin and vitamin E on cholesterol biosynthesis in high-cholesterol-fed rats.

Effect of natural and structurally modified bile acids on cholesterol metabolizing enzymes in rat liver microsomes. II
De Fabiani, E., M. Crestani, et al. (1991), Chem Phys Lipids 57(1): 97-101.
Abstract: The effect of ursodeoxycholic acid analogues bearing modifications at the side-chain moiety of the molecule was tested on cholesterol 7 alpha-hydroxylase and HMG-CoA reductase in rat liver microsomes. The compounds included 23 R,S mixture and the single isomers 23R and 23S of 23 methylursodeoxycholic acid (23-methyl UDCA), the isomeric mixture (cis + trans) of 3 alpha,7 beta-dihydroxy-20,22-methylen-5 beta-cholan-23-oic acid (norcypro-UDCA) and the corresponding single isomers. Each steroid was added to liver microsomes as the sodium salt, at concentrations ranging from 25 to 200 microM. Isomers 23R and 23S of 23-methyl-UDCA inhibited cholesterol 7 alpha-hydroxylase in a concentration-dependent manner. The inhibitory capacity was similar for the two isomers. The extent of inhibition of the analogues was greater than that of the parent compound UDCA. Shortening of the side-chain in norcypro-UDCA resulted in a partial loss of the inhibitory effect, as compared to cypro-UDCA (3 alpha,7 beta-dihydroxy-22,23-methylen-5 beta-cholan-24-oic acid). None of these bile acid derivatives affected the activity of the enzyme HMG-CoA reductase.

Effect of niacin and etofibrate association on subjects with coronary artery disease and serum high-density lipoprotein cholesterol <35 mg/dl
Sposito, A. C., B. Caramelli, et al. (1999), Am J Cardiol 83(1): 98-100, A8.
Abstract: Niacin treatment (alone) was compared with etofibrate and niacin combination to treat patients with high-density lipoprotein <35 mg/dl and without hypertriglyceridemia. The niacin and etofibrate combination proved to be safe and increased high-density lipoprotein cholesterol levels to 48%, which was 3 times higher than that obtained with niacin alone.

Effect of nifedipine on renal microvascular cholesterol accumulation and prostacyclin biosynthesis in cholesterol-fed rabbits
Kirschenbaum, M. A., D. D. Roh, et al. (1991), Atherosclerosis 91(3): 241-6.
Abstract: Studies, performed in rabbits, examined the effect of feeding a high cholesterol diet and/or a calcium antagonist, nifedipine, on renal microvascular prostacyclin biosynthesis and cholesterol accumulation. After 30 days, cholesterol-fed rabbits had elevated serum and tissue cholesterol levels associated with decreased microvascular prostacyclin biosynthesis and histologic evidence of microvascular and glomerular lipid accumulation. Nifedipine reduced tissue cholesterol levels, enhanced prostacyclin biosynthesis, and reduced the histologic evidence for lipid accumulation in renal microvessels and glomeruli. These studies suggest that calcium antagonists may have a beneficial effect in preventing the tissue cholesterol accumulation associated with a high-cholesterol diet and further suggest that these agents may have beneficial effects in the treatment of renal diseases associated with microvascular or glomerular lipid accumulation.

Effect of nisoldipine on atherosclerosis in the cholesterol fed rabbit: endothelium dependent relaxation and aortic cholesterol content
Kappagoda, C. T., A. B. Thomson, et al. (1991), Cardiovasc Res 25(4): 270-82.
Abstract: STUDY OBJECTIVE--The aim was to determine the effect of the calcium channel blocker nisoldipine on the loss of endothelium dependent relaxation and the accumulation of cholesterol in the aorta produced by feeding a diet enriched with cholesterol. DESIGN--12 week old New Zealand white rabbits were assigned randomly to four groups with the following dietary and drug regimens: group A--standard diet + 2.5% cholesterol (n = 45); group B--standard diet + nisoldipine (n = 9); group C--standard diet + nisoldipine + 2.5% cholesterol (n = 9); group D--standard diet (n = 9). After 3 weeks the cholesterol supplements were stopped and all animals were given the standard rabbit diet. The animals in groups B and C were given nisoldipine (1 mg.kg-1.d-1) by mouth for the entire 7 week period. EXPERIMENTAL MATERIAL--Aortic tissue was removed for measurement of cholesterol content, endothelium dependent relaxation to acetylcholine, contractile responses to noradrenaline, relaxant responses to sodium nitrite, and sudan staining. Serum was obtained for measurement of cholesterol and triglyceride concentration. MEASUREMENTS AND MAIN RESULTS--At 7 weeks, endothelium dependent relaxation to acetylcholine was impaired in group A compared to group D, while that in group C was not. Aortic tissue cholesterol content in group A was significantly greater than in groups B, C, and D. At 15 weeks, ie, 12 weeks after reversal of the diet, endothelium dependent relaxation had recovered in the animals in group A. There was a significant reduction in the aortic cholesterol content at this stage. In two subgroups of A (groups A2 and A4) which were given nisoldipine immediately after and 4 weeks after cessation of cholesterol feeding respectively, the drug was found to have no influence upon restoration of endothelium dependent relaxation. However, the drug appeared to promote the retention of cholesterol within the aorta after cessation of cholesterol feeding. CONCLUSIONS--Nisoldipine protects against the accumulation of cholesterol and loss of endothelium dependent relaxation in the aorta of rabbits fed a diet supplemented with 2.5% cholesterol for three weeks. Administration of the drug after the lesions are established in the aorta also appears to retard the removal of cholesterol from the aorta.

Effect of non-ionic detergents on apparent enzyme mechanism: V121A mutant of Streptomyces cholesterol oxidase endowed with enhanced sensitivity towards detergents
Nishiya, Y., M. Yamashita, et al. (1998), Protein Eng 11(8): 609-11.
Abstract: One of the mutants of Streptomyces cholesterol oxidase with the Val121Ala mutation (V121A) was kinetically analysed. Although the reaction rate-substrate concentration curve of wild type follows a simple Michaelis-Menten equation, that of V121A is sigmoidal. The cooperativity was apparent and caused by non-ionic detergents that were used as a solvent of cholesterol. The concentration dependence of V121A on detergents was more significant than that of wild type, although the reaction rates of both enzymes decrease as the concentrations of detergents increase. Further experiments suggested that less hydrophobic interactions between V121A and detergents should be responsible for the apparent cooperativity. Since Val121 is in a hydrophobic loop located near the active site, the mutational effect is structurally discussed.

Effect of nonpharmacologic intervention on lowering plasma cholesterol levels
Brazdova, Z. and J. Fiala (2000), Vnitr Lek 46(9): 559-64.
Abstract: Our study focused on the effect of non-pharmacological intervention based on the modification of dietary habits and increasing physical activity on the level of total plasma cholesterol. SAMPLE AND METHODS: Intervented sample was created by 279 highly motivated healthy adults from Brno (168 women and 111 men) of average age 43.5 +/- 10.3 years and average level of total plasma cholesterol 6.1 +/- 0.75 mmol/l and HDL-cholesterol 1.04 +/- 0.14 mmol/l. After medical and life-style history assessment, followed by clinical and biochemical checking and evaluation the risk from the life-style and biochemical and clinical parameters, the participants were individually informed about recommendations. These recommendations regarded detailed changes of dietary habits, quantified by the recommended number of servings of basic food groups and sub-groups daily and also increasing physical activity. RESULTS: After 3 months the changes of biochemical parameters were evaluated. After our non-pharmacological intervention we founded significantly lower average level of total plasma cholesterol 5.36 +/- 1.24 mmol/l (p < 0.001) and higher level of HDL-cholesterol 1.16 +/- 0.14 mmol/l. The level of TG's did not change significantly neither in whole sample, nor in the sub/sample of women and men. 26% of our sample was resistant to the intervention (the difference in the total cholesterol level between 2 assessment was lower than 0.5 mmol/l). No significant difference was found between men and women regarding the reaction of plasma lipoproteins. DISCUSSION AND CONCLUSIONS: Our results justify the adequacy and appropriety of primary preventive advising focusing on decrease of the risk of premature death using non-pharmacological intervention in highly motivated people with good compliance and sufficient responsibility for their personal health.

Effect of oat bran consumption on total serum cholesterol levels in healthy adults
Saudia, T. L., B. R. Barfield, et al. (1992), Mil Med 157(11): 567-8.
Abstract: The effect of oat bran on total nonfasting serum cholesterol levels in healthy adults was studied. Twenty volunteers whose cholesterol levels were greater than 200 mg/dl consumed 3 ounces of oat bran daily for 93 days in addition to their normal dietary intake. Rescreenings were conducted at days 31, 62, and 93. Repeated measures analysis of variance (ANOVA) revealed no significant difference in total serum cholesterol levels over the four consecutive screenings (a = 0.05, p = 0.054), although ANOVA for polynomial trends revealed a significant difference in total serum cholesterol levels across time (a = 0.05, p = 0.007) (quadratic effect). The interaction of gender with time revealed no significant difference. Thus, it is concluded from this study that daily addition of oat bran to the diet does not significantly lower total cholesterol levels for a sustained period of time.

Effect of oat bran on plasma cholesterol and bile acid excretion in nine subjects with ileostomies
Zhang, J. X., G. Hallmans, et al. (1992), Am J Clin Nutr 56(1): 99-105.
Abstract: A higher excretion of dry matter, fat, nitrogen, energy, and total bile acids in ileal effluents; a lower plasma low-density-lipoprotein (LDL) and total cholesterols (12.1% and 9.0% lower respectively); but no change in plasma high-density-lipoprotein (HDL) cholesterol or apolipoproteins A-I and B were observed in nine subjects with ileostomies when they consumed an oat-bran, bread-based, high-fiber diet (HFD) as compared with a wheat-flour, bread-based, low-fiber diet (LFD) for 3 wk with a crossover design. Of the nine subjects only the subjects with a low daily excretion of bile acids had an elevated excretion of total bile acids during the HFD compared with the LFD. Total cholesterol, LDL cholesterol, and apolipoprotein B in plasma also decreased by 11.3%, 15.3%, and 10.7%, respectively, after consumption of the HFD for 3 wk.

Effect of omega 3 fatty acid on plasma lipids, cholesterol and lipoprotein fatty acid content in NIDDM patients
Goh, Y. K., J. A. Jumpsen, et al. (1997), Diabetologia 40(1): 45-52.
Abstract: This study was conducted to examine the effect of omega 3 fatty acid supplementation on plasma lipid, cholesterol and lipoprotein fatty acid content of non-insulin-dependent diabetic individuals consuming a higher (0.65, n = 10) or lower (0.44, n = 18) ratio of dietary polyunsaturated to saturated fatty acid (P/S). The participants were initially given an olive oil supplement (placebo) equivalent to 35 mg of 18:1. kg body weight-1.day-1 for 3 months. This was followed by two omega 3 supplement periods in a randomized crossover. In these 3-month periods, participants were given a linseed oil supplement equivalent to 35 mg of 18:3 omega 3.kg body weight-1.day-1 or a fish oil supplement equivalent to 35 mg of 20:5 omega 3 + 22:6 omega 3.kg body weight-1. day-1. At the end of each supplement period, a blood sample was drawn from each participant for lipid, lipoprotein, insulin, glucagon and C-peptide analyses. At the end of each 3-month period a 7-day dietary record was completed to calculate dietary fat intake and P/S ratio. Results indicate that fish oil significantly reduced plasma triacylglycerol level (p < 0.05) and increased 20:5 omega 3 and 22:6 omega 3 content of all lipoprotein lipid classes. Linolenic acid supplementation had no effect on plasma triacylglycerol level, but it increased 18:3 omega 3 content of lipoprotein cholesterol ester fractions (p < 0.05). A slight increase in 20:5 omega 3, but not 22:6 omega 3, content was noted in lipoprotein lipid classes as a result of 18:3 omega 3 supplementation. LDL and HDL cholesterol, insulin, glucagon and C-peptide levels were not affected by either omega 3 supplement. It is concluded that a modest intake of omega 3 fatty acids, such as could be obtained from consuming fish regularly, will reduce plasma triglyceride level without affecting LDL or HDL cholesterol levels.

Effect of oral curcumin administration on serum peroxides and cholesterol levels in human volunteers
Soni, K. B. and R. Kuttan (1992), Indian J Physiol Pharmacol 36(4): 273-5.
Abstract: The effect of curcumin administration in reducing the serum levels of cholesterol and lipid peroxides was studied in ten healthy human volunteers, receiving 500 mg of curcumin per day for 7 days. A significant decrease in the level of serum lipid peroxides (33%), increase in HDL Cholesterol (29%), and a decrease in total serum cholesterol (11.63%) were noted. As curcumin reduced serum lipid peroxides and serum cholesterol, the study of curcumin as a chemopreventive substance against arterial diseases is suggested.

Effect of orally administered Eubacterium coprostanoligenes ATCC 51222 on plasma cholesterol concentration in laying hens
Li, L., C. A. Baumann, et al. (1996), Poult Sci 75(6): 743-5.
Abstract: Thirty normocholesterolemic laying hens were used to investigate the effect of oral administration of Eubacterium coprostanoligenes on plasma cholesterol concentrations. Hens were divided randomly into three treatment groups (active, inactive, and control) with 10 hens in each group. The active group received 0.5 mL of E. coprostanoligenes suspension (approximately 2 x 10(7) cells per milliliter) daily for 4 wk; the inactive group received the same dosage of killed (boiled) bacterial suspension; and the control group received no supplemental bacteria. After bacterial feeding, the coprostanol to cholesterol ratio in feces of the active group was significantly greater than ratios of the inactive and control groups, indicating that E. coprostanoligenes was colonized in the intestine of hens and was converting intestinal cholesterol to coprostanol. Plasma cholesterol concentrations, however, were not affected by the bacterial treatment.

Effect of oryzanol on cholesterol absorption & biliary & fecal bile acids in rats
Seetharamaiah, G. S. and N. Chandrasekhara (1990), Indian J Med Res 92: 471-5.
Abstract: Effect of oryzanol on biliary secretion of cholesterol, phospholipid and bile acids and fecal excretion of cholesterol and bile acids was examined in male albino rats. Feeding oryzanol at 0.5 per cent level with the control diet did not cause any change in bile flow and composition. On feeding oryzanol with high cholesterol diet, the bile flow and total bile acid output were increased by 12 and 18 per cent respectively, while biliary cholesterol and phospholipids remained unchanged. The increased bile acid secretion was mainly due to taurocholic acid. In rats fed oryzanol along with high cholesterol diet, there was a significant increase in the fecal excretion of cholesterol (28%) and of bile acids (29%), whereas cholesterol absorption was lowered by 20 per cent.

Effect of oxidized cholesterol derivatives on lymphokine stimulated differentiation of macrophages and primary allogenic mixed human lymphocyte culture
Musatov, M. I., M. I. Dushkin, et al. (1997), Biull Eksp Biol Med 124(12): 655-7.

Effect of oxidized cholesterol on age-associated changes to immune parameters in spleen lymphocytes and peritoneal exudate cells derived from rats
Osada, K., K. Minehira, et al. (2000), Biosci Biotechnol Biochem 64(5): 1047-51.
Abstract: The effects of oxidized cholesterol on immune parameters were examined by using spleen lymphocytes and peritoneal exudate cells (PEC) derived from 5-week- (Young) and 9-month-old (Adult) rats. The immunoglobulin (Ig) G and IgM production was inhibited by oxidized cholesterol in the rats of both ages when lymphocytes were exposed to 30 micrograms/ml of oxidized cholesterol for 24 hr. The intracellular IgA level was also lowered by 30 micrograms/ml of oxidized cholesterol, irrespective of age. In contrast, IgE production was significantly increased by the addition of 30 micrograms/ml of oxidized cholesterol in only young lymphocytes. Moreover, oxidized cholesterol enhanced the intracellular histamine accumulation in only adult PEC, although the total histamine level produced by PEC was similar in the rats of both ages. These results thus suggest the possibility that oxidized cholesterol can have different effects on the age-related modulation of immune functions such as Igs production and histamine release.

Effect of oxLDL on the uptake and clearance rate of cholesterol in vascular smooth muscle cells originated from human apoAI transgenic mice
Zeng, Y., G. F. Zhao, et al. (2001), Zhongguo Yi Xue Ke Xue Yuan Xue Bao 23(4): 328-32.
Abstract: OBJECTIVE: Study on (1) inhibition of oxidized low density lipoprotein (oxLDL) effect on the uptake and clearance of intra-cellular 3H-cholesterol in vascular smooth muscle cells (v-SMC) originated from the human-apoAI transgenic mice (C57BL/6); (2) change of human-apolipoprotein AI (h-apoAI) mRNA expression in v-SMC after oxLDL stimulation and the protective effect of expressed h-apoAI on v-SMC against oxLDL intoxication. METHODS: (1) v-SMC isolated from human apoAI transgenic mice possessing a recombined gene connected beforehand with a mouse metallothionein-I (MT-I) as the promoter; (2) study of h-apoAI mRNA expression from v-SMC of the transgenic mice by RT-PCR and Northern blot. RESULTS: oxLDL (30 micrograms/ml) strongly promoted v-SMC proliferation. No difference found on 3H-cholesterol uptake between smooth muscle from normal mouse aorta (n-SMC) and smooth muscle cells from transgenic mouse aorta (tr-SMC) of the control groups, the uptake rates of both kinds of SMC rose 100% after oxLDL stimulation. The efflux rates of 3H-cholesterol in tr-SMC were much higher than those of n-SMC (40%-50%). After oxLDL stimulation, the clearance rates fell by 28% and 10% respectively for n-SMC and tr-SMC. The result of RT-PCR and Northern blot showed a marked increase of h-apoAI gene expression after oxLDL stimulation. CONCLUSIONS: Expression of h-apoAI gene in C57BL/6 mice enables to decrease the accumulation of cholesterol in v-SMC. tr-SMC are capable to alleviate the harmful effect of oxLDL on v-SMC due to the increase of h-apoAI expression.

Effect of oxLDL on the uptake and clearance rate of cholesterol in v-SMC originated from human apoA1 transgenic mice
Zeng, Y., G. Zhao, et al. (2002), Chin Med J (Engl) 115(4): 584-8.
Abstract: OBJECTIVE: To study the inhibition effect of oxLDL on the uptake and clearance of intra-cellular (3)H-cholesterol in v-SMC from the human-apoA1 transgenic mice (C57BL/6) and the changes in human-apoA1 mRNA expression in v-SMC from human apoA1 transgenic mice after oxLDL stimulation. METHODS: v-SMC originally isolated from human apoA1 transgenic mice connected with a recombined mouse metallothionein-I (MT-I) promoter was used, and the effect of oxLDL on the uptake and clearance of intracellular (3)H-cholesterol was studied in v-SMC of the transgenic and control mice respectively, the study of h-apoA I mRNA expression from v-SMC of the transgenic mice were done by RT-PCR and Northern blot. RESULTS: oxLDL (30 microg/ml) strongly promoted the SMC proliferation. No difference was found in (3)H-cholesterol uptake between nSMC and trSMC, and the uptake rates of both kinds of SMC rose 100% after oxLDL stimulation. The efflux rates of (3)H-cholesterol in trSMC were much higher than those of nSMC (40% - 50%). After oxLDL stimulation, the clearance rates fell by 28% and 10%, respectively, for nSMC and trSMC. The result of RT-PCR and Northern blot showed that h-apoA1 gene expression was markedly increased by the stimulation of oxLDL. CONCLUSION: Expression of the h-apoA1 gene in C57BL/6 mice enables them to reduce the accumulation of cholesterol in v-SMC. The trSMC can alleviate the harmful effect of oxLDL due to the increase of h-apoA1 expression.

Cholesterol Articles and Abstracts

Cholesterol Journal Articles