Curcumin alleviates colistin-induced nephrotoxicity and neurotoxicity in rats via attenuation of oxidative stress, inflammation and apoptosis

Colistin is an effective antibiotic against multidrug-resistant (MDR) gram-negative bacterial infections; however, nephrotoxic and neurotoxic effects are fundamental dose-limiting factors for this treatment. This study was conducted to assess the potential protective effects of curcumin, a phenolic constituent of turmeric, against colistin-induced nephrotoxicity and neurotoxicity, and the possible mechanisms underlying any effect. Twenty-four adult male albino rats were randomly classified into 4 equal groups; the control group (orally received saline solution), the curcumin-treated group (orally administered 200 mg curcumin/kg/day), the colistin-treated group (IP administered 300,000 IU colistin/kg/day) and the concurrent group (orally received 200 mg curcumin/kg/day concurrently with colistin injection); all rats were treated for 6 successive days. Colistin administration significantly increased serum creatinine, urea and uric acid levels as well as brain gamma butyric acid (GABA) concentrations. In renal and brain tissues, colistin significantly increased malondialdehyde (MDA), nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and caspase-3 expression levels. In addition, colistin significantly decreased catalase (CAT), glutathione (GSH), and B-cell lymphoma 2 (Bcl-2) expressions. Curcumin administration in colistin-treated rats partially restored each of these altered biochemical, antioxidant, inflammatory and apoptotic markers. Histopathological changes in renal and brain tissues were also alleviated by curcumin co-treatment. Our study reveals a critical role of oxidative damage, inflammation and apoptosis in colistin-induced nephrotoxicity and neurotoxicity and showed that they were markedly ameliorated by curcumin co-administration. Therefore, curcumin could represent a promising agent for prevention of colistin-induced nephrotoxicity and neurotoxicity.