The role of nutritional additives in prevention: dietary supplementation with Spirulina reduces myocardial damage and improves cardiac function post-myocardial infarction in swine
Authors: Sutelman P , Vilahur G , Casani L , Badimon L 
Published: November 2020

Abstract

Introduction
The outcome of acute ST-elevation myocardial infarction depends, to a large extent, on the size of the infarct. Myocardial damage due to infarction involves several pathogenic mechanisms among which excessive generation of reactive oxygen species and an exacerbated inflammatory reaction play a critical role. Spirulina is a dietary supplement made from blue-green algae (Arthrospira platensis) used to manage weight loss and metabolic syndrome disorders. In addition, Spirulina has experimentally shown to exert anti-oxidant and anti-inflammatory properties because its composition rich in antioxidants, polyunsaturated fatty acids, essential amino-acids, and minerals.

Purpose
The purpose of the present study was to investigate whether dietary supplementation with Spirulina may serve as a cardioprotective agent by attenuating cardiac damage and ventricular dysfunction due to myocardial infarction in a highly translatable animal model.

Methods
Pigs (n=10) were fed a normocholesterolemic diet supplemented with Spirulina (1 gr/animal/bid; n=5) or placebo (n=5) for 10 days and then they were subjected to myocardial infarction by means of 1.5h balloon occlusion of the mid left anterior descending coronary artery. Thereafter animals were reperfused for 2.5h and then sacrificed. Infarct size was assessed by TTC staining and ischemic and non-ischemic myocardial tissue was obtained for molecular analysis of cardioprotective kinases, anti-apoptotic- and anti-inflammatory- related markers. Biochemical analyses (lipid levels, kidney and liver parameters) and weight gain were monitored throughout the study.

Results
Supplementation with Spirulina led to an absolute significant reduction in infarct size of 10±1% of the left ventricle (LV) as compared to control animals (p&lt;0.05). At a functional level, all animals displayed comparable LV ejection fraction (LVEF) prior-MI induction (control: 64.5±2.6%; Spirulina: 61.5±2.6%). However, after 2.5h of reperfusion control animals showed a worsening of 18.2±2.0% LVEF whereas it was only of 7.2±2.5% in Spirulina-administered pigs (60% relative improvement vs. controls; p&lt;0.05). At a molecular level, Spirulina administered animals showed higher expression of PI3K, Bcl-2, and Cox-2 and reduced content of MCP-1 in the jeopardized myocardium. Supplementation with Spirulina for 10 days markedly reduced total- cholesterol by 25% (p&lt;0.04), LDL- cholesterol by 47% (p&lt;0.05), enhanced HDL-cholesterol concentration by 79% (p&lt;0.03) and limited weight gain (p&lt;0.05) as compared to controls. Kidney and liver enzymes were found to be within the physiological range.

Conclusion
Supplementation with Spirulina, beyond its proven benefits in weight loss and lipid profile, exerts cardioprotection by inducing myocardial survival kinases, and triggering cytoprotective and anti-inflammatory mechanisms, thereby limiting cardiac damage and improving ventricular contractility post-MI.

Funding Acknowledgement
Type of funding source: Public grant(s) – National budget only. Main funding source(s): Ministerio de Ciencia Innovacion y Universidades / Instituto de Salud Carlos III