Protective Effects of Houttuynia cordata Thunb. on Gentamicin-induced Oxidative Stress and Nephrotoxicity in Rats

Abstract

Development of a therapy providing protection from, or reversing gentamicin-sulfate (GS)-induced oxidative stress and nephrotoxicity would be of great clinical significance. The present study was designed to investigate the protective effects of Houttuynia cordata Thunb. (HC) against gentamicin sulfate-induced renal damage in rats. Twenty-eight Sprague-Dawley rats were divided into 4 equal groups as follows: group 1, control; group 2, GS 100 mg/kg/d, intraperitoneal (i.p.) injection; group 3, GS 100 mg/kg/d, i.p. + HC 500 mg/kg/d, oral; and group 4, GS 100 mg/kg/d i.p. + HC 1000 mg/kg/d, oral administration). Treatments were administered once daily for 12 d. After 12 d, biochemical and histopathological analyses were conducted to evaluate oxidative stress and renal nephrotoxicity. Serum levels of creatinine, malondialdehyde (MDA), and blood urea nitrogen (BUN), together with renal levels of MDA, glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) were quantified to evaluate antioxidant activity. Animals treated with GS alone showed a significant increase in serum levels of creatinine, BUN, and MDA, with decreased renal levels of GSH, SOD, and CAT. Treatment of rats with HC showed significant improvement in renal function, presumably as a result of decreased biochemical indices and oxidative stress parameters associated with GS-induced nephrotoxicity. Histopathological examination of the rat kidneys confirmed these observations. Therefore, the novel natural antioxidant HC may protect against GSinduced nephrotoxicity and oxidative stress in rats.

Keywords: Antioxidant; Gentamicin sulfate; Houttuynia cordata Thunb; Nephrotoxicity; Oxidative stress; Reactive oxygen species (ROS).

Fig. 1.. Photomicrograph of renal tissue of untreated, gentamicin and gentamicin plus Houttuynia cordata Thunb. (HC) treated rats (H & E stain, ×200). Normal histopathological view of renal section in control rats (A), The treatment with Gentamicin sulfate (100 mg/kg/day) showd degeneration, desquamation and extensive and marked necrosis in tubules (asterisk), massive hyaline casts in tubules (thin arrows), and inflammatory cells infiltration in intertubular area (thick arrow) (B), Section from rat treated with GS (100 mg/kg) plus HC (1000 mg/kg) reveal near to normal structure having mild hyaline cast (C), Section from rat treated with GS (100 mg/kg) plus HC (500mg/kg) show near to normal structure having moderate hyaline cast (D).