Effect of DHA plus EPA on oxidative stress and apoptosis induced by ischemia-reperfusion in rat kidneys

Apoptosis, as well as necrosis, has an important role in post-ischemic renal pathology. The effect of pretreatment with Docosahexaenoic acid+Eicosapentaenoic acid (DHA+EPA) on renal injury and apoptotic protein expression was evaluated. Right nephrectomy was completed on male Wistar rats (255-300g). The rats received DHA+EPA (200mg/kg/day) of distilled water orally for 14days before ischemia reperfusion (IR) or sham operation. A total of 81 rats were divided into three main groups with 6, 24 and 48h of post-operation or reperfusion period. Serum creatinine (SCr), BUN, creatinine clearance (CCr) and fractional excretion of sodium (FENa) were measured. Tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) activities, Bax and Bcl-2 protein expressions and renal histological injury were determined. SCr, BUN and FENa increased 6-48h of reperfusion (P<0.01). Tissue MDA content and Bax expression increased (P<0.01) and CAT and SOD activities decreased (P<0.05) in the IR group. DHA+EPA decreased SCr and BUN, FENa, tissue MDA levels (P<0.05 vs. IR) and increased CAT and SOD activities and Bcl-2 expression (P<0.05 vs. IR) for 6-48h after ischemia. IR induced mild (6h, P<0.05) and severe (24-48h, P<0.01) tissue damage. Mild-to-moderate tissue damage was observed in DHA+EPA groups from 6 to 48h of reperfusion period (P<0.05 vs. IR, 24-48h). In conclusion, the results suggest that pre-ischemic exposure to DHA+EPA could improve the outcome of early graft function by inhibition of IR-induced oxidative stress and apoptosis.