Dose-Dependent Protective Effect of L-Carnitine on Oxidative Stress in the Livers of Hyperthyroid Rats

Abstract

Objective: The present study was designed to investigate the dosedependent protective effect of L-carnitine (LC) on thyroid hormoneinduced oxidative stress in rat liver tissue. Materials and Methods:Twenty-one male Sprague Dawley rats were divided into four groups: control, hyperthyroidism, hyperthyroidism plus L-carnitine 100, and hyperthyroidism plus L-carnitine 500. Hyperthyroidism was induced in rats by injecting 250 μg of L-thyroxine/ kg body weight/day for twenty consecutive days. The activities of catalase (CAT), glutathione peroxidase (GPX) and myeloperoxidase (MPO) and the level of malondialdehyde (MDA) were measured in liver homogenates. Results:The liver CAT, GPX and MPO activities were significantly lower in the hyperthyroid rats than in the control group. Treating hyperthyroid rats with both low-dose (100 mg/kg) and high-dose (500 mg/kg) L-carnitine for 10 days resulted in a marked increase in the activities of the antioxidant enzymes in the liver tissue. Conclusion:The present study indicates that the low-dose L-carnitine application was sufficient to prevent L-thyroxine-induced oxidative stress in rat livers.Key Words: Catalase, glutathione peroxidase, L-carnitine, Liver, Malondialdehyde, Myeloperoxidase Özet Amaç: Bu çalışma rat karaciğer dokusunda tiroid hormonu ile uyarı-lan oksidatif stres üzerine L-karnitinin doza bağlı koruyucu etkilerini araştırmaktı. Gereç ve Yöntem:Yirmi bir erkek Sprague Dawley rat 4 gruba bö-lündü: Kontrol, hipertroidi, hipertiroidi + L-karnitine 100 ve hipertiroidi + L-karnitine 500. Hipertiroidi, yirmi gün boyunca ratlara 250 μg / kg dozunda L-Thyroxine enjeksiyonu uygulanarak oluşturuldu. Karaciğer homojenatlarında katalaz (CAT), glutatyon peroksidaz (GPX), myeloperoksidaz (MPO) aktiviteleri ve malondialdehit (MDA) düzeyleri ölçüldü. Bulgular:Kontrollerle karşılaştırıldığında hipertiroidili ratlarda karaciğer CAT, GPX ve MPO aktiviteleri belirgin olarak azaldı. 10 gün boyunca hem düşük doz (100 mg/kg) hem de yüksek doz (500 mg/ kg) L-karnitin uygulaması hipertiroidili ratlarda karaciğer antioksidan enzim aktivitelerinde belirgin bir artışa yol açtı.Sonuç: Bu çalışmanın sonuçları L-Tiroksin ile uyarılan rat karaciğerin-deki oksidatif stresi önlemek için düşük doz L-karnitin uygulamasının yeterli olduğunu göstermektedir.

Evaluation and physiopathology of minor transient shock wave lithotripsy – induced renal injury based on urinary biomarkers levels

“…Some agents, including bacteria, viruses, immune complexes, and reactive oxygen intermediates increase the tumor-necrosis-factor-α (TNF-α) level [ 18 , 19 ]. TNF-α is an inflammatory cytokine, which plays an essential role in many different kidney disease pathomechanisms [ 20 , 21 ].…”

“…Free-radical formation and following organ impairment may be assigned to shock wave lithotripsy in the same manner as in the ischemia-reperfusion model [ 17 , 39 ]. Hence, administration of antioxidants around procedure has a protective effect on renal function [ 17 , 19 , 40 , 41 ], which was proved, measuring differences in some urine biomarkers pre- and post-ESWL treatment. Stones located in soft tissues are crushed by the physical effects of shockwaves, which exert adverse effects on the surrounding tissues.…”

Impact of L-Carnitine on Bisphenol A-Induced Kidney Damage in Rats

“…Further, Ismail et al, (2012) stated that the administration of ginger and L-carnitine, either separately or in combination significantly increase the level of reduced glutathione. These protective effects of L-carnitine might result directly from antioxidant effects against oxygen radicals or from increased biosynthesis of enzymatic antioxidants, such as GSH and catalase (Yildirim et al, 2013).…”

Nutraceuticals in Thyroidology: A Review of in Vitro, and in Vivo Animal Studies

“…Four experimental groups were formed starting from 21 male Sprague Dawley rats: hyperthyroidism (n = 5), hyperthyroidism plus low dose L-carnitine (100 mg/kg/d for 10 days; n = 5), hyperthyroidism plus high dose L-carnitine (500 mg/Kg/d for 10 days; n = 5), and controls (0.2 mL/100 g body weight, subcutaneously, of 0.9% NaCl solution; n = 6) [10]. The injection of levothyroxine (L-T4) in a dose of 250 µg/kg body weight per day for 20 consecutive days was able to induce hyperthyroidism in rats.…”