Renoprotective action of L-carnitine in fructose-induced metabolic syndrome

Aim: Rats fed high dosage of fructose that form a well-known experimental model of the metabolic syndrome also display progressive renal disturbances. The present study evaluates the influence of L-carnitine (CA) administration on oxidant-antioxidant balance, protein damage and lipid levels in kidney of rats administered high dose of fructose. Methods: Adult male Wistar rats were divided into four groups of 10 rats each. Groups I and IV animals received starch-based control diet, while groups II and III rats were fed a high-fructose diet (60 g/100 g). Groups III and IV animals additionally received CA (300 mg/kg/day) for 60 days. The extent of lipid peroxidation, enzymatic and non-enzymatic antioxidants and lipid levels were measured after 60 days. The accumulation of nitrated and oxidatively modified proteins in kidney was also measured by immunohistochemical study with specific antibodies. Results: Fructose-fed rats exhibited increased levels of peroxidation end products, diminished antioxidant status, increased staining for the presence of 4-hydroxy-2-nonenal, 2,4-dinitrophenol and 3-nitrotyrosine protein adducts and lipid accumulation in kidney. CA administration attenuated these pathological renal alterations. Conclusions: The benefits of CA in this model suggest the therapeutic use of CA to counter the kidney changes associated with metabolic syndrome.