Effects of apolipoprotein B-100 on the metabolism of a lipid microemulsion model in rats

In previous studies, it was shown that lipid microemulsions resembling LDL (LDE) but not containing protein, acquire apolipoprotein E when injected into the bloodstream and bind to LDL receptors (LDLR) using this protein as ligand. Aiming to evaluate the effects of apolipoprotein (apo) B-100 on the catabolism of these microemulsions, LDE with incorporated apo B-100 (LDE-apoB) and native LDL, all labeled with radioactive lipids were studied after intraarterial injection into Wistar rats. Plasma decay curves of the labels were determined in samples collected over 10 h and tissue uptake was assayed from organs excised from the animals sacrificed 24 h after injection. LDE-apo B had a fractional clearance rate (FCR) similar to native LDL (0.40 and 0.33, respectively) but both had FCR pronouncedly smaller than LDE (0.56, P<0.01). Liver was the main uptake site for LDE, LDE-apoB, and native LDL, but LDE-apoB and native LDL had lower hepatic uptake rates than LDE. Pre-treatment of the rats with 17 alpha-ethinylestradiol, known to upregulate LDLR, accelerated the removal from plasma of both LDE and LDE-apoB, but the effect was greater upon LDE than LDE-apoB. These differences in metabolic behavior documented in vivo can be interpreted by the lower affinity of LDLR for apo B-100 than for apo E, demonstrated in in vitro studies. Therefore, our study shows in vivo that, in comparison with apo E, apo B is a less efficient ligand to remove lipid particles such as microemulsions or lipoproteins from the intravascular compartment. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Long-term orange juice consumption is associated with low LDL-cholesterol and apolipoprotein B in normal and moderately hypercholesterolemic subjects

Abstract. Background: This study investigated the hypothesis that long-term orange juice consumption (≥ 12 months) was associated with low risk factors for cardiovascular disease in adult men and women with normal and moderately high cholesterol blood levels. Methods. The sample consisted of 103 men (18-66 y) and 26 women (18-65 y); all were employees of an orange juice factory with daily access to free orange juice. The results showed that 41% of the individuals consumed 2 cups (480 mL) of orange juice per day for at least twelve months, while 59% of the volunteers are non-consumers of orange juice. Results: Orange juice consumers with normal serum lipid levels had significantly lower total cholesterol (-11%, p <0.001), LDL-cholesterol (-18%, p < 0.001), apolipoprotein B (apo B) (-12%, p < 0.01) and LDL/HDL ratio (-12%, p < 0.04) in comparison to non-consumers, as did the consumers with moderate hypercholesterolemia: lower total cholesterol (-5%, p <0.02), LDL-cholesterol (-12%, p <0.03), apolipoprotein B (-12%, p <0.01) and LDL/HDL ratio (-16%, p <0.05) in comparison the non-consumers counterparts. Serum levels of homocysteine, HDL- cholesterol and apolipoprotein A-1, body composition and the dietary intake of food energy and macronutrients did not differ among orange juice consumers and non-consumers, but vitamin C and folate intake was higher in orange juice consumers. Conclusion: Long-term orange juice consumers had lower levels of total cholesterol, LDL-cholesterol, apo B and LDL/HDL ratio and an improvement of folate and vitamin C in their diet. © 2013 Aptekmann and Cesar; licensee BioMed Central Ltd.

Suco de laranja reduz o colesterol em indivíduos normolipidêmicos

Objetivos Neste estudo foi investigado o efeito do consumo habitual de suco de laranja no perfil dos lípides e lipoproteínas em homens e mulheres normolipidêmicos. Métodos Todos os voluntários (n=29) consumiram 750mL/dia de suco de laranja durante 60 dias. Variáveis bioquímicas como perfil lipídico, apolipoproteínas, glicose, paraoxonase1 e o tamanho de HDL foram medidas antes e após o período de suplementação com suco de laranja. Também foram realizadas medidas antropométricas e inquéritos dietéticos. Resultados O consumo crônico de suco de laranja reduziu significativamente o colesterol total nos homens (11%, p<0,05) e nas mulheres (10%, p<0,05) e o LDL-C nos homens e mulheres (15%, p<0,05). O HDL-C e a apoA-I também diminuíram, refletindo a redução do colesterol total. Os triacilgliceróis, apo B, PON1, tamanho da HDL, IMC, gordura corporal e circunferência abdominal não foram modificados com o tratamento com suco de laranja. Conclusão Neste estudo, mostrou-se que o suco de laranja apresenta propriedade redutora sobre o colesterol, e foi sugerido que a associação dos flavonóides cítricos com a vitamina C previne o estresse oxidativo e o desenvolvimento da aterosclerose.

Beneficial effects of diclofenac therapy on serum lipids, oxidized low-density lipoprotein and antioxidant defenses in rats

To study the effects of diclofenac, a nonselective nonsteroidal anti-inflammatory drug (NSAID), on lipid profile, oxidized low-density-lipoprotein (Ox-LDL), serum antioxidant defenses and markers of oxidative stress, male Wistar rats were divided into two groups (n = 10): (C) receiving intramuscularly a single daily dose of saline (NaCl 0.9%), and (AI) receiving intramuscularly a single daily dose of 10 mg/kg diclofenac sodium (C14H10C12NNaO2). After 28 days diclofenac-treated rats had lower Ox-LDL, apoprotein B (apo-B), apo-B/LDL-cholesterol and lipid hydroperoxide than C. Total antioxidant substances and superoxide dismutase were increased in diclofenac-treated rats, while no significant changes were observed in catalase, glutathione peroxidase and nitric oxide. A perincubation test done to examine the possibility of mechanism-based activation showed that diclofenac had no effect on maximal superoxide dismutase velocity, but significantly reduced the Michaelis-Menten (K-M) constant, indicating that diclofenac induced SOD activation increasing substrate linkage affinity to the enzyme-catalytic site. In conclusion, diclofenac had beneficial effects decreasing Ox-LDL and improving antioxidant defense. It appears that the application of this agent may be feasible and beneficial for serum antioxidant protection, which certainly would bring new insights on dyslipidemia control. (C) 2008 Elsevier B.V. All rights reserved.

Atividade protetora cardiovascular do suco de laranja vermelha em indivíduos adultos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proteção cardiovascular e papel antioxidante do suco de laranja em indivíduos com execesso de peso

Pós-graduação em Alimentos e Nutrição - FCFAR

Estudo da influência dos genótipos 1 e 3 do vírus da hepatite C sobre os indicadores do metabolismo lipídico em hepatopatas crônicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do consumo de suco de laranja no perfil sérico dos lípides, apolipoproteínas e homocisteína em homens normais e hiperlipidêmicos

Pós-graduação em Alimentos e Nutrição - FCFAR

Avaliação comparativa da eficácia da terapia de reposição hormonal de baixa dose isolada ou associada à sinvastatina no perfil lipídico e lipoprotéico em mulheres sintomáticas e dislipidêmicas na pós-menopausa

Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB

Comparison between apo and complexed structures of bothropstoxin-I reveals the role of Lys122 and Ca2+-binding loop region for the catalytically inactive Lys49-PLA(2)s

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)