Amelioration of altered antioxidant enzymes activity and glomerulosclerosis by coenzyme Q10 in alloxan-induced diabetic rats ☆ Hassan Ahmadvand a, b, ⁎, Majid Tavafi c , Ali Khosrowbeygi b a Razi Herbal Researches Center, Lorestan University of Medical Sciences, Khoram Abad, Iran b Department of Biochemistry, Faculty of Medicine, Lorestan University of Medical Sciences, Khoram Abad, Iran c Department of Anatomy, Faculty of Medicine, Lorestan University of Medical Sciences, Khoram Abad, Iran abstract article info Article history: Received 26 March 2012 Received in revised form 3 June 2012 Accepted 4 June 2012 Available online 12 July 2012 Keywords: Diabetes Lipid peroxidation Rat Glomerulosclerosis Coenzyme Q10 Antioxidant enzymes activity Coenzyme Q10 is a natural antioxidant and scavenging free radicals. In the present study, we examined antioxidative activities of coenzyme Q10 and possible protective effect of coenzyme Q10 on in vivo and in vitro lipid peroxidation, antioxidant enzymes activity and glomerulosclerosis in alloxan-induced type 1 diabetic rats. Thirty Sprague–Dawley male rats were divided into three groups randomly: group 1 as control, group 2 as diabetic untreatment, and group 3 as treatments with coenzyme Q10 by 15 mg/kg i.p. daily, respectively. Diabetes was induced in the second and third groups by alloxan injection subcutaneously. After 8 weeks, animals were anaesthetized, liver and kidney were then removed immediately and used fresh or kept frozen until their lipid peroxidation analysis. Blood samples were also collected before killing to measure the lipid peroxidation and antioxidant enzymes activity. Kidney paraffin sections were prepared and stained by periodic acid-Schiff method. Glomerular volume and leukocyte infiltration were estimated by stereological rules and glomerular sclerosis was studied semi-quantitatively. Coenzyme Q10 significantly inhibited leukocyte infiltration, glomerulosclerosis and the levels of malondialdehyde (MDA) serum and kidney content in treated group compared with the diabetic untreated group. Coenzyme Q10 significantly inhibited LDL oxidation in vitro. Coenzyme Q10 significantly increased the serum levels of glutathione (GSH) and serum activity of catalase (CAT) and superoxide dismutase (SOD) in treated group compared with the diabetic untreated group. Coenzyme Q10 alleviates leukocyte infiltration and glomerulosclerosis and exerts beneficial effects on the lipid peroxidation and antioxidant enzymes activity in alloxan-induced type 1 diabetic rats. Crown Copyright © 2012 Published by Elsevier Inc. All rights reserved. 1. Introduction Oxidative stress is the imbalance between oxidant and antioxidant systems in favor of the former. Antioxidant systems include antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in addition to low molecular agents and dietary antioxidants. Clinical and experimental studies have shown that disturbing of oxidant–antioxidant balance system is involved in the pathogenesis of chronic diseases such as cancer (Barbosa, Bressan, Zulet, & Martínez Hernández, 2008) coronary heart disease, diabetes and many diabetic complications (Anderson et al., 2009). Hyperglycemia is confounded for the complications of diabetes because hyperglycemia directly causes glycation of proteins, lipids and nucleic acid then injures cells and induces lipid peroxidation (Lin & Sun, 2010). Also antioxidant and antioxidative enzyme activities reduce due to glycation or increase of lipid peroxidation products (Maritim, Sanders, & Watkins, 2003). A number of natural antioxidant such as vitamin E and phenolic compounds are known to have hypoglycemic, hypolipidemic or both activities (Drissi et al., 2004). Chemical drugs have many side effects; therefore, screening for new antidiabetic sources from natural antioxidants is still attractive because they are safe and good alternative for treatment of diabetes mellitus. A growing body of research indicates that nutritional deficiencies such as antioxidants contribute to the development of diabetes. Coenzyme Q10 is a natural human ubiquinone, and it has fundamental role in mitochondrial energy (ATP) production in the respiratory chain (Littarru & Tiano, 2007; Somayajulu et al., 2005). Coenzyme Q10 is also antioxidant, scavenging free radicals and inhibiting lipid peroxidation ( Bélanger, Mirault, Dewailly, Berthiaume, & Julien, 2008; Mabuchi et al., 2005; Niklowitz, Menke, Andler, & Okun, 2004). The antioxidant effect of coenzyme Q10 is greater than vitamin E (Niklowitz et al., 2004). Coenzyme Q10 is also known to enhance the availability of other antioxidants such as vitamin C, vitamin E and beta-carotene (Shekelle, Morton, & Hardy, 2003). Since the protective effects of coenzyme Q10 on glomerulo- sclerosis, lipid peroxidation status and antioxidant enzymes activity in alloxan-induced type 1 diabetic rats have not previously been Journal of Diabetes and Its Complications 26 (2012) 476–482 ☆ Conflict of Interest: None. ⁎ Corresponding author. Tel.: + 98 913 2267893, + 98 661 6200133; fax: + 98 661 6200133. E-mail address: hassan_a46@yahoo.com (H. Ahmadvand). 1056-8727/$ – see front matter. Crown Copyright © 2012 Published by Elsevier Inc. All rights reserved. doi:10.1016/j.jdiacomp.2012.06.004 Contents lists available at SciVerse ScienceDirect Journal of Diabetes and Its Complications journal homepage: WWW.JDCJOURNAL.COM