Lingonberry juice negates the effects of a high salt diet on vascular function and low-grade inflammation

High salt in diet elevates blood pressure in man. Berries and fruits are regarded beneficial in antagonizing hypertension and related vascular complications. We aimed to test whether lingonberry juice shows beneficial and anti-inflammatory effects in salt induced hypertension rat model. Male Wistar-Kyoto rats were fed with 8% sodium chloride enriched pellets for 10 weeks having tap water or diluted lingonberry juice as drinking fluid. Blood pressure was recorded weekly and mesenteric artery functions tested ex vivo. Urine was collected in metabolic caging. Salt loading had only minor effects on blood pressure or endothelial function. Increased urine excretion of 8-isoprostane, cGMP and albumin reflected general or renal inflammation. Elevated expression (mRNA) of proinflammatory COX-2 by salt was normalized by lingonberry. Salt increased kidney, heart and left ventricle masses and changed serum chloride, alkaline phosphatase, albumin and lipid concentrations. Taken together the results show that l0 weeks' high-salt diet impaired kidney function of young rats without clear effect on blood pressure or vascular function. Lingonberry juice moderately reduced biomarkers of low-grade inflammation probably due to its high polyphenol concentrations.