ABSTRACT
LDL oxidation and oxidative stress are closely related to atherosclerosis. Therefore, natural antioxidants have been studied as promising candidates. In the present study, the LDL oxidation inhibition activity of bioactive compounds from Halimeda incrassata seaweed. associated to antioxidant capacity, was evaluated in vitro. Experimental work was conducted with lyophilized aqueous extract and phenolic-rich fractions of the seaweed and their effect on LDL oxidation was evaluated using heparin-precipitated LDL (hep-LDL) with exposure to Cu2+ ions and AAPH as the free radical generator. H. incrassata had a protective effect for hep-LDL in both systems and the presence of phenolic compounds contributed to the activity where phenolic-rich fractions showed significant capacity for inhibition of oxidation mediated by Cu2+ ions. The observed effect could be related to the antioxidant potential of polar fractions evidenced by reducing activity and DPPH radical scavenging. The results obtained in vitro further support the antioxidant and LDL oxidation inhibition properties of H. incrassata and further knowledge toward future phytotherapeutic application of the seaweed.
A oxidação da LDL e o estresse oxidativo estão intimamente relacionados com a aterosclerose. Por isso, os antioxidantes naturais têm sido estudados como candidatos promissores. No presente trabalho foi avaliada in vitro a capacidade de inibição da oxidação da LDL pelos compostos bioativos da alga Halimeda incrassata em associação à capacidade antioxidante. O trabalho experimental foi conduzido com extratos polares (extrato aquoso liofilizado e frações ricas em fenólicos) e seu efeito na oxidação da LDL foi avaliado usando LDL precipitada com heparina (hep-LDL), oxidada com íons de Cu2+ e AAPH, como geradores de radicais livres. A H. incrassata apresentou efeito protetor para hep-LDL em ambos sistemas e a presença de compostos fenólicos contribuiu para a atividade em que as frações ricas em fenólicos demonstram capacidade significativa em inibir a oxidação mediada pelos íons de Cu2+. O efeito observado deve estar relacionado com o potencial antioxidante das frações polares medido pela atividade redutora e varredura do radical DPPH. Os resultados obtidos demonstram as propriedades antioxidantes e de inibição da oxidação da LDL da H. incrassata e podem contribuir para as evidências de futuras aplicações fitoterapêuticas desta alga.
Subject(s)
Seaweed/classification , Receptors, Oxidized LDL , Polyphenols/pharmacokinetics , Lipoproteins/pharmacology , Antioxidants/pharmacologyABSTRACT
Atherosclerosis represents a major cause of death in the world. It is known that Lipofundin 20% induces atherosclerotic lesions in rabbits, but its effects on serum lipids behaviour and redox environment have not been addressed. In this study, New Zealand rabbits were treated with 2 mL/kg of Lipofundin for 8 days. Then, redox biomarkers and serum lipids were determined spectrophotometrically. On the other hand, the development of atherosclerotic lesions was confirmed by eosin/hematoxylin staining and electron microscopy. At the end of the experiment, total cholesterol, triglycerides, cholesterol-LDL, and cholesterol-HDL levels were significantly increased. Also, a high index of biomolecules damage, a disruption of both enzymatic and nonenzymatic defenses, and a reduction of nitric oxide were observed. Our data demonstrated that Lipofundin 20% induces hyperlipidemia, which promotes an oxidative stress state. Due to the importance of these phenomena as risk factors for atherogenesis, we suggest that Lipofundin induces atherosclerosis mainly through these mechanisms.
ABSTRACT
La oxidación de las lipoproteínas de baja densidad (LDLox) es un evento importante en el desarrollo y progresión de la aterosclerosis y la respuesta inmune contra estas moléculas puede modular la aterogénesis. La relación entre los autoanticuerpos anti-LDLox y la cardiopatía isquémica (CI) es aún controversial. En el presente estudio se determinaron los valores de las IgM e IgG anti-LDLox, en 20 pacientes a quienes se les indicó una coronariografía por alguna razón en la consulta de cardiología. Se tomó como grupo control a 10 voluntarios jóvenes sanos trabajadores del Centro de Inmunología Molecular. Los niveles de anticuerpos de tipo IgM contra las LDLox no fueron diferentes entre los pacientes sin evidencia de CI y los sujetos jóvenes sanos. En cambio, los niveles de IgM anti-LDLox de estos grupos fueron estadísticamente superiores a los del grupo de pacientes con evidencia de CI. Nuestros resultados, aunque preliminares, sustentan la hipótesis de que este tipo de autoanticuerpos pudiera estar inversamente asociado con la presencia de aterosclerosis
Low-density lipoprotein (LDL) oxidation is an important event in atherosclerosis development. The relationship between oxidized LDL (oxLDL) autoantibodies and coronary artery disease (CAD) remains controversial. IgM and IgG autoantibodies to oxLDL were measured in twenty patients undergoing clinically indicated coronary angiography, and in ten young healthy volunteers from the Center of Molecular Immunology. The levels of IgM autoantibodies to oxLDL did not differ between no CAD patients and healthy subjects, but the levels of IgM autoantibodies to oxLDL of these two groups were higher compared with the one of CAD patient group. Our results, although preliminary, supports the hypothesis that this kind of Abs might be inversely associated with the presence of atherosclerosis
Subject(s)
Autoantibodies , Diagnostic Imaging/methods , Coronary Artery Disease/diagnosis , Myocardial Ischemia/diagnosis , Receptors, Oxidized LDL , Coronary VesselsABSTRACT
La oxidación de las lipoproteínas de baja densidad (LDLox) es un evento importante en el desarrollo y progresión de la aterosclerosis y la respuesta inmune contra estas moléculas puede modular la aterogénesis. La relación entre los autoanticuerpos anti-LDLox y la cardiopatía isquémica (CI) es aún controversial. En el presente estudio se determinaron los valores de las IgM e IgG anti-LDLox, en 20 pacientes a quienes se les indicó una coronariografía por alguna razón en la consulta de cardiología. Se tomó como grupo control a 10 voluntarios jóvenes sanos trabajadores del Centro de Inmunología Molecular. Los niveles de anticuerpos de tipo IgM contra las LDLox no fueron diferentes entre los pacientes sin evidencia de CI y los sujetos jóvenes sanos. En cambio, los niveles de IgM anti-LDLox de estos grupos fueron estadísticamente superiores a los del grupo de pacientes con evidencia de CI. Nuestros resultados, aunque preliminares, sustentan la hipótesis de que este tipo de autoanticuerpos pudiera estar inversamente asociado con la presencia de aterosclerosis(AU)
Low-density lipoprotein (LDL) oxidation is an important event in atherosclerosis development. The relationship between oxidized LDL (oxLDL) autoantibodies and coronary artery disease (CAD) remains controversial. IgM and IgG autoantibodies to oxLDL were measured in twenty patients undergoing clinically indicated coronary angiography, and in ten young healthy volunteers from the Center of Molecular Immunology. The levels of IgM autoantibodies to oxLDL did not differ between no CAD patients and healthy subjects, but the levels of IgM autoantibodies to oxLDL of these two groups were higher compared with the one of CAD patient group. Our results, although preliminary, supports the hypothesis that this kind of Abs might be inversely associated with the presence of atherosclerosis(AU)
