Effects of L-carnitine on renal function and oxidative stress in rats with doxorubicin-induced renal injury

Abstract

Effects of L-carnitine on nephrotoxicity and oxidative stress induced by doxorubicin (DOX) in rats were investigated. Rats were divided into 4 groups; group 1 (control: NSS injection); group 2 DOX injection (7.5 mg/kg, i.v.); group 3 DOX plus low dose (40 mg/kg) L-carnitine and group 4 DOX plus high dose (200 mg/kg) L-carnitine. Treatment with L-carnitine (40 and 200 mg/kg, per day) was performed 1 hour before doxorubicin injection and daily thereafter for 15 days. Nephrotic syndrome was induced by a single intravenous injection of doxorubicin. The results showed that rats in group 2 were associated with hypoalbuminemia, hyperlipidemia, high urinary excretion of protein and elevated plasma lipid peroxide, creatinine and urea nitrogen. Kidneys from group 2 rats had significant decreases in catalase (CAT) activity and elevated lipid peroxides. Doxorubicin significantly decreased glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and increased renal vascular resistance (RVR). In group 3 an 4 which received L-carnitine, plasma triglyceride, cholesterol, creatinine and plasma urea nitrogen declined. L-carnitine improved renal functions by elevated GFR and ERPF. The CAT activity in the kidneys of L-carnitine treated rats were increased significantly compared with group 2. From histopathologic results, there were glomerular capillary dilation, tubular dilation and loss of tubular cell in kidneys of group 2 rats. The lesions in glomerulus and tubule were less in rat receiving L-carnitine both low and high doses (group 3 and 4) compared with doxorubicin alone. In conclusion, L-carnitine can protect renal impairment functionally, biochemically and histopathologically with a corresponding reduction of oxidative stress.