(−)-Epicatechin administration protects kidneys against modifications induced by short-term l-NAME treatment in rats

Abstract

The aim of this work was to evaluate the protective effects of (−)-epicatechin on the kidneys of NO-deprived rats. Male Sprague Dawley rats were divided into three groups: control (C), receiving water and standard diet; L-NAME (L), receiving a solution of N(ω)-nitro-L-arginine methyl ester (L-NAME) (360 mg l⁻¹ in water) as a beverage and standard diet; and L-NAME-(−)-epicatechin (LE), receiving L-NAME solution as a beverage and standard diet supplemented with (−)-epicatechin (4 g kg⁻¹ diet). The L-group showed altered kidney function parameters, evaluated based on plasma urea and creatinine. In parallel, kidney oxidative stress markers, i.e. superoxide anion production, malondialdehyde content, and 3-nitrotyrosine protein adducts, were significantly increased in the L group. In addition, L-NAME treatment induced modifications in kidney NO bioavailability determinants: increased expression of NOX subunits (p47^phox, gp91^phox, NOXO1, and NOX4) and lowered NOS activity. (−)-Epicatechin administration restored kidney function parameters, oxidative stress markers, expression of p47^phox, gp91^phox, and NOX4 and NOS activity to control values. These results indicate that (−)-epicatechin can mitigate NO-mediated impairment of kidney function, in part due to its capacity to modulate NOXs, NOSs, and consequently oxidative stress, and NO bioavailability.