International Journal of Biological Macromolecules 51 (2012) 783–787 Contents lists available at SciVerse ScienceDirect International Journal of Biological Macromolecules jo u r n al hom epa ge: ww w.elsevier.com/locate/ijbiomac Dietary chitosan supplementation attenuates isoprenaline-induced oxidative stress in rat myocardium R. Anandan a , B. Ganesan a,∗ , T. Obulesu a , S. Mathew a , R.S. Kumar a , P.T. Lakshmanan a , A.A. Zynudheen b a Biochemistry and Nutrition Division, Central Institute of Fisheries Technology, Matsyapuri (PO), Cochin 682029, Kerala, India b Fish Processing Division, Central Institute of Fisheries Technology, Matsyapuri (PO), Cochin 682029, Kerala, India a r t i c l e i n f o Article history: Received 18 June 2012 Received in revised form 11 July 2012 Accepted 15 July 2012 Available online 22 July 2012 Keywords: Chitosan Lipid peroxidation Antioxidant status Oxidative stress Cardio-protective activity a b s t r a c t Despite considerable advances in diagnosis and management over the last three decades, acute myocar- dial infarction continues to be a major public health problem. It is predicted that ischemic heart diseases will constitute the major disease-burden worldwide in the year 2020. In the present study, an attempt has been made to examine the effects of dietary chitosan supplementation on lipid peroxidation and cardiac antioxidant defense system in isoprenaline-induced myocardial infarction in rats, an animal model of myocardial infarction in man. Dietary chitosan intake significantly attenuated the isoprenaline-induced lipid peroxidation and maintained the level of reduced glutathione at near normal. Its administration demonstrated an antioxidant effect by maintaining the activities of myocardial glutathione depen- dent antioxidant enzymes (glutathione peroxidase and glutathione-S-transferase) and antiperoxidative enzymes (superoxide dismutase and catalase) at levels comparable to that of controls. The results of the present study indicate that the salubrious effects of dietary supplementation of chitosan is probably related to a counteraction of free radicals and/or to normal maintenance of the activities of free rad- ical enzymes and the level of GSH, which protect myocardial membrane against oxidative damage by decreasing lipid peroxidation. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Myocardial infarction is a major public health concern and the leading cause of death all over the world. A better understanding of the processes involved in myocardial infarction has stimulated the search for new drugs, which could limit the myocardial injury. Nat- ural products have been the starting point for the discovery of many important modern drugs. This fact has led to chemical and pharma- cological investigations and general biological screening programs for natural products all over the world. The consumption of diets rich in seafood is associated with a reduced risk of vascular dis- eases and certain cancers [1]. While some of the beneficial effects of seafood can be attributed to the essential nutrients they provide, these foods can also contain many other valuable compounds. Chi- tosan, an important polysaccharide of marine origin, is prepared from the shells of prawns, krill, oysters, fungi and insects [2]. It is a polymer of -(1-4)-d-glucosamine and it is chemically sim- ilar to that of the plant fiber, cellulose (Fig. 1). Previous reports [3,4] have shown that the dietary supplementation of chitosan is capable of ameliorating high fat diet-induced hyperlipidemia in experimental animals. Earlier Anandan et al. [5] investigated the ∗ Corresponding author. Tel.: +91 9446986089; fax: +91 0484 2668212. E-mail address: ganesancift@rediffmail.com (B. Ganesan). antiulcer effect of chitosan against HCl–ethanol mixture induced peptic ulcer in rats. It has been reported to possess antilipidemic [6], antioxidant [7] and membrane stabilizing properties [8]. Though the beneficial effects of chitosan have been extensively studied, the cardioprotective effect of chitosan on antioxidant defense system in experimentally induced myocardial infarction condition has not yet been explored. Myocardial disorders induced by isoprenaline [isoproterenol], a synthetic catecholamine and -adrenergic agonist (Fig. 2), have been reported to show many metabolic and morphologic aberra- tions in the heart of experimental animals similar to those seen in human myocardial ischemia [9] and therefore isoproterenol- induced changes can be used as a model for studying the effects of protective agents on the processing of myocardial infarction. Alterations in tissue defense systems including chem- ical scavengers or antioxidant molecules and the antioxidant enzymes catalase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase have been reported in isoprenaline- induced myocardial infarction [9,10]. Excessive accumulation of lipids in the heart tissue is one of the major disorders encountered in isoproterenol-induced myocardial infarction condition [11,12]. Administration of isoproterenol has already been reported to pro- mote lipolysis both in the adipose tissue and myocardium [9,13]. A growing body of evidence is emerging which suggests that reactive oxygen-derived radicals play a crucial role in the pathogenesis of 0141-8130/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ijbiomac.2012.07.016