Comparing the Effect of Flaxseed and Fish Oils on Acute Ischemia-Reperfusion Injury in the Rat Kidney

Polyunsaturated fatty acids (PUFAs) are useful in reducing the deleterious effects of ischemia-reperfusion (IR). This study was designed to compare the impacts of treatment with flaxseed oil (FLO), rich in linoleic and alpha-linolenic acids, and fish oil containing long PUFAs, as well as eicosapentaenoic and docosahexaenoic acids (DHAs), on IR injury in the rat kidney. In this experimental study, 32 male Wistar rats were randomly divided into 4 groups (8 rats each) including Sham, IR, FLO, and fish oil (FO). Correspondingly, experimental groups were administered saline and flaxseed or FO at doses of 0.4 g/kg by gavage. After 4 weeks, the rats underwent right nephrectomy and 45-minute clamping of the left renal arteries followed by 24 hours reperfusion. Renal function was assessed by measuring the serum creatinine (Cr) and blood urea nitrogen (BUN) levels. The oxidative stress and serum aspartate aminotransferase (AST) activity were measured. Each kidney was sectioned into 2 equal parts. One part was used for pathological evaluations after hematoxylin-eosin staining and the other one was applied in assaying the malondialdehyde (MDA) level. Serum Cr and BUN levels, AST activity, and tissue MDA content increased in the IR group. Both FO and FLO decreased tissue MDA levels (P < 0.05 vs. IR), but could not lead to a significant reduction in the levels of the renal markers. In addition, histological damages which were increased following the IR were markedly reduced by these 2 oils. Generally, FLO and FO may provide protection against IR-induced renal injury and oxidative stress. However, these effects were not significant between the 2 supplementations.