Curcumin prevents potassium dichromate (K₂Cr₂O₇)-induced renal hypoxia

Curcumin exhibits several therapeutic properties. Potassium dichromate (K₂Cr₂O₇)-induced nephropathy is associated with oxidative stress. Reactive oxygen species production affects renal oxygenation that may participate in the progression of renal damage. The aim of the present work was to elucidate whether K₂Cr₂O₇-induced nephropathy is associated to partial O₂ pressure (pO₂) impairment and if curcumin is able to prevent it. Four groups of rats were studied: control group; K₂Cr₂O₇ group (12.5 mg/kg, s.c.); curcumin + K₂Cr₂O₇ group, in which animals were treated with curcumin (400 mg/kg/day, p.o.) for 10 days before K₂Cr₂O₇ injection; and curcumin group. All animals were sacrificed 48 h after the end of the treatments. K₂Cr₂O₇ administration increased renal function markers and decreased glomerular filtration rate, pO₂ and renal perfusion. Concerning hemodynamic parameters, K₂Cr₂O₇ increased mean arterial pressure and renal vascular resistance and reduced renal blood flow. The hemodynamic changes were attributed to decreased availability of nitric oxide and increased 3-nitrotyrosine levels. Moreover, increased superoxide anion production and vascular endothelial growth factor levels were observed after K₂Cr₂O₇ administration. Curcumin attenuated all the above-described alterations. Our results suggest that the protective effects of curcumin in K₂Cr₂O₇-induced nephropathy are associated with its ability to prevent O₂ supply reduction.