Suppressing Effects of Docosahexaenoic Acid-Containing Diets on Oxidative Stress and Fibrosis in 5/6 Nephrectomized Rats.

Abstract

Urinary albumin excretion gradually increases after nephrectomy, which eventually progresses toward renal failure. Our previous study had reported that arachidonic acid (ARA)- or/and docosahexaenoic acid (DHA)-containing diet attenuates the increasing urinary albumin excretion. The current study aimed to investigate the effects of ARA- or/and DHA-containing diets on oxidative stress and fibrosis that cause kidney injury in 5/6 nephrectomy rats. Sprague Dawley rats were randomly divided into control group, ARA group, DHA group, and ARA + DHA group. Rats underwent 5/6 kidney removal and were fed ARA or/and DHA containing diet each five groups continuously for 4 weeks. We collected urine, plasma, and kidney samples 4 weeks after surgery, and investigated the effects of ARA- and DHA-containing diets on oxidative stress, inflammation, and fibrosis in kidney. Urinary albumin excretion, indoxyl sulfate, reactive oxygen species, and tumor necrosis factor-α levels, and fibrosis in kidney were all increased upon nephrectomy; they were, however, attenuated after feeding the rats with DHA-containing diet. One possible mechanism of preventing chronic renal failure would be the suppression of indoxyl sulfate accumulation, oxidative stress, and kidney fibrosis arising due to nephrectomy. The results collectively suggested that DHA-containing diets can suppress the progression of renal failure.