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Eicosapentaenoic acid/docosahexaenoic acid 1:1 ratio improves histological alterations in obese rats with metabolic syndrome

Núria Taltavull1*, Mònica Muñoz-Cortés1, Laura Lluís1, Montserrat Jové2, Àngels Fortuño3, Eunice Molinar-Toribio4, Josep Lluís Torres4, Manuel Pazos5, Isabel Medina5 and M Rosa Nogués1

Author Affiliations

1 Unit of Pharmacology, Faculty of Medicine and Health Sciences, Rovira i Virgili University, Reus, Spain

2 Unit of Human Anatomy, Faculty of Medicine and Health Sciences, Rovira i Virgili University, Reus, Spain

3 Anatomical Pathology Service, Eldine Laboratory, Tarragona, Spain

4 Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), Barcelona, Spain

5 Institute of Marine Research-CSIC, Vigo, Spain

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Lipids in Health and Disease 2014, 13:31  doi:10.1186/1476-511X-13-31

Published: 11 February 2014



Marine polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been associated with improvement in the Metabolic Syndrome (MS). The aim of this study is to evaluate how three fish-oil diets with different eicosapentaenoic acid/docosahexaenoic acid ratios (EPA/DHA ratio) affect the histology of liver, kidney, adipose tissue and aorta in a preliminary morphological study. This work uses an animal model of metabolic syndrome in comparison with healthy animals in order to provide information about the best EPA:DHA ratio to prevent or to improve metabolic syndrome symptoms.


35 Wistar rats, as a control, and 35 spontaneously hypertensive obese rats (SHROB) were fed for 13 weeks with 3 different suplemmentation of fish oil containing EPA and DHA ratios (1:1, 2:1 and 1:2, respectively). All samples were stained with haematoxylin/eosin stain, except aorta samples, which were stained also with Verhoeff and van Gieson’s stain. A histological study was carried out to evaluate changes. These changes were statistically analyzed using SPSS IBM 19 software. The quantitative data were expressed by mean ± SD and were compared among groups and treatments using ANOVA with post-hoc tests for parametric data and the U-Mann–Whitney for non-parametric data. Qualitative data were expressed in frequencies, and compared with contingency tables using χ2 statistics.


EPA:DHA 1:1 treatment tended to improve the density and the wrinkling of elastic layers in SHROB rats. Only Wistar rats fed with EPA:DHA 1:1 treatment did not show mast cells in adipose tissue and has less kidney atrophy. In both strains EPA:DHA 1:1 treatment improved inflammation related parameters in liver and kidney.


EPA:DHA 1:1 treatment was the most beneficial treatment since improved many histological parameters in both groups of rats.

Metabolic syndrome; Omega-3-polyunsaturated fatty acids; EPA/DHA ratio; Histology; SHROB rats; Fish oils