Sodium Alginate Oligosaccharides Attenuate Hypertension and Associated Kidney Damage in Dahl Salt-Sensitive Rats Fed a High-Salt Diet

Abstract

Objectives: In this article, the antihypertensive effects of sodium alginate oligosaccharides, enzymatic products of high molecular natural alginate from sea weeds, in Dahl salt-sensitive (Dahl S) rats were investigated. Material and Methods: Dahl S rats fed a high-salt (4% NaCl) diet were treated with sodium alginate oligosaccharides (4% or 8% w/w) for 7 weeks. Systolic blood pressure (SBP) was measured by the tail-cuff method, and hypertensive cardiovascular benefits and kidney damage were assessed. Glomerular function and morphological sclerosis were determined. Results: SBP increased in an age-dependent manner in the untreated Dahl S rats. Sodium alginate oligosaccharide treatment attenuated the increase in SBP in a dose-dependent manner. The heart and aortic walls weighed less in the rats treated with sodium alginate oligosaccharides than in the untreated rats. The SBP reduction was associated with a decrease in urinary protein excretion and an increase in the creatinine clearance rate. Sodium alginate oligosaccharides significantly attenuated hypertensive glomerular sclerosis and arterial injury in the kidney. Fractional excretion of sodium (FENa) decreased in low-salt Dahl S rats and increased with a salt challenge. The alginate oligosaccharides decreased FENa in high-salt Dahl S rats. Conclusions: The results of this study suggest that sodium alginate oligosaccharides attenuate salt-induced hypertension in Dahl S rats. This reduction is associated with decreases in cardiovascular and renal damage.

• alginate
• salt-induced hypertension
• kidney
• Dahl rats

ACKNOWLEDGMENT

The authors acknowledge Ms. Naoko Suzuki for morphological investigation.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.