Les protéines purifiées à partir de sardines améliorent les chiffres tensionnels, l’équilibre glycémique, les voies métaboliques anti-athérogènes et la capacité anti-oxydante, chez le rat obèse

Abstract

Aim of the studyThe effects of sardine by-products (SBy-P) and fillet proteins (SF-P) were compared to casein (Cas) ; these effects were assessed on blood pressure, glycemic control, reverse cholesterol transport, lipid peroxidation and total antioxidant capacity in obese rats. Materials and methodsEighteen male Wistar rats were subjected for three months, to a high-fat diet. The obese rats were divided into three groups and consumed the same high-fat diet for 28 days after addition of either, 20% SBy-P, SF-P or Cas. ResultsThe sardine proteins (SBy-P and SF-P) compared respectively to Cas, reduced diastolic (−14%, −11% P<0.05) and systolic pressures (−12%, −8% P<0.05), blood glucose (−24%, −21% P<0.05), glycated hemoglobin (−28%, −21% P<0.05), insulinemia (−29%, −18% P<0.05) and HOMA-IR index (−29%, −18% P<0.05). They improve the reverse cholesterol transport by increasing the lecithin: cholesterol acyltransferase (LCAT) activity (+43%, +30% P<0.05) and high-density lipoproteins in cholesterol esters (+108%, +88% P<0.05), and decreasing the atherogenicity ratios and membrane fluidity (P<0.05). Furthermore, SBy-P and SF-P induced a reduction of reactive thiobarbituric acid substances concentrations in heart (−45%, −25% P<0.05), aorta (−62%, −41% P<0.05), liver (−40%, −21% P<0.05) and adipose tissue (−50%, −37% P<0.05) with an improvement in antioxidant capacity. ConclusionSardine proteins, in particular those extracted from by-products, because of their hypotensive, hypoglycemic, anti-atherogenic and antioxidant properties, may have protective effects against the cardiovascular risk associated with obesity.