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Role of naturally-occurring plant sterols on intestinal cholesterol absorption and plasmatic levels

Papel de los esteroles vegetales de la dieta sobre la absorción intestinal de colesterol y sus niveles plasmáticos (minirrevisión)

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Abstract

Cardiovascular disease is a major health problem in developed countries although its incidence is relatively lower in Mediterranean countries which is partly ascribed to dietary habits. Epidemiologic evidence shows that elevated serum cholesterol, specifically low-density lipoprotein cholesterol (c-LDL), increases cardiovascular disease. Phytosterols are bioactive compounds, found in all vegetable foods, which inhibit intestinal cholesterol absorption and, therefore, have a serum cholesterollowering effect. Intestinal cholesterol absorption is a multistep process where, plant sterols and stanols may act:a) attenuating the NPC1L1 gene expression, which may result in a lower cholesterol uptake from the lumen;b) lowering the cholesterol esterification rate by the ACAT2 (acyl-CoA cholesterol acyltransferase) and, consequently, the amount of cholesterol secreted via the chylomicrons andc) upregulating the expression of ABC-transporters ABCG5 and ABCG8 in intestinal cells, which may result in an increased excretion of cholesterol by the enterocyte back in the lumen. Many clinical trials proved that commercial products enriched with phytosterols reduce cholesterol levels. Likewise, recent studies show that phytosterols present in natural food matrices are also effective and could be an important component of cardioprotective dietary patterns such as the Mediterranean diet.

Resumen

Le enfermedad cardiovascular es un problema de salud importante en los países desarrollados, aunque su incidencia es relativamente menor en los países mediterráneos lo que es parcialmente atribuible a los hábitos dietéticos. Existen evidencias epidemiológicas que muestran que el colesterol sérico elevado, específicamente el colesterol ligado a las lipoproteínas de baja densidad (c-LDL), incrementa la enfermedad cardiovascular. Los fitosteroles son compuestos bioactivos, presentes en todos los alimentos de origen vegetal, que inhiben la absorción intestinal de colesterol y, por lo tanto, tienen un efecto reductor en el colesterol sérico. La absorción intestinal de colesterol es un proceso multi-etapa donde los esteroles y estanoles vegetales pueden actuar de diversas formas:a) atenuando la expresión del gen NPC1L1, lo que puede suponer una disminución del ingreso de colesterol desde el lumen intestinal;b) disminuyendo la tasa de esterificación del colesterol por la ACAT2 (acil-CoA colesterol aciltransferasa) y, en consecuencia, la cantidad de colesterol excretada vía quilomicrones yc) aumentando la expresión de los ABC-transportadores ABCG5 y ABCG8 en las células intestinales, lo que puede derivar en una excreción incrementada de colesterol desde el enterocito hacia el lumen. Diversos ensayos clínicos han demostrado que los productos comerciales enriquecidos con fitosteroles reducen los niveles de colesterol. Sin embargo, estudios recientes muestran que los fitosteroles presentes en matrices alimentarias naturales también pueden ser bioactivos y podrían ser un componente importante de los patrones dietéticos cardioprotectores como es la dieta Mediterránea.

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Sanclemente, T., Marques-Lopes, I., Puzo, J. et al. Role of naturally-occurring plant sterols on intestinal cholesterol absorption and plasmatic levels. J Physiol Biochem 65, 87–98 (2009). https://doi.org/10.1007/BF03165972

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