Effect of Chlorella Intake on the Development of Atherosclerosis and Spontaneous Thrombolytic Activity

Abstract

Background and Purpose: Thrombotic disease is a leading cause of death in industrialized countries. The development of atherosclerosis is a major underlying pathogenesis. Atherosclerotic lesions are largely related to abnormalities in lipid metabolism, and improvement of dietary habits is of great significance. Chlorella is a unicellular organism belonging to the green algae family, and is consumed worldwide as a functional food for the purpose of health promotion due to its excellent nutritional balance including high quality protein. In this study, we investigated the effects of long-term consumption of Chlorella as a food on the development of atherosclerosis and its ability to dissolve thrombi caused by the disruption of the atherosclerotic layer as a functional study of Chlorella. Methods: ApoE − / − and Ldlr − / − double-knockout mice were fed a chlorella-supplemented experimental diet for 14 weeks. The Entire aorta method was used to measure atherosclerosis development, and the area of sclerotic vessels was evaluated as a percentage of the total area of vessels. In addition, mRNA levels of lipid metabolism-related proteins in the liver and blood vessels were analyzed, as well as blood lipoprotein analysis. Spontaneous thrombolytic activity was measured by measuring the change in volume over time of thrombus formed in microvessel running over the cremaster muscle of the mice using the He-Ne laser-induced thrombus model. Results: There was no significant difference between the two groups in atherosclerosis development compared to the placebo group. However, a significant decrease in SREBP-1 mRNA level and a significant increase in mRNA levels of LXR and CPY71a were observed in the chlorella group. Cholesterol and TG levels in each lipoprotein fraction did not differ between the two groups. On the other hand, thrombolysis in vivo was not significantly different between the two groups in terms of thrombus volume at 60 minutes after thrombus formation. However, a trend toward decreased PAI-1 and TAFI mRNA expression levels was observed in the chlorella group. Conclusion: Intake of chlorella as a food suggested an effect on cholesterol catabolism, increased bile acid synthesis, improved lipid metabolism, and inhibited the development of atherosclerosis. Furthermore, it was suggested that chlorella may suppress the expression of fibrinolytic inhibitory factor and enhance thrombolytic activity.