Cardioprotective activity of Cladosiphon okamuranus fucoidan against isoproterenol induced myocardial infarction in rats.

Fucoidans, sulfated polysaccharides of brown algae, have attracted steady attention in the last few years as readily accessible biopolymers possessing a wide spectrum of biological activities. In this study, cardioprotective activity of fucoidan extracted from Cladosiphon okamuranus was evaluated in isoproterenol induced myocardial infarction in rats. Male Wistar albino rats (180±25 g) were divided in to four groups of six animals each as follows: Group (1) control, Group (2) isoproterenol alone, Group (3) fucoidan alone and Group (4) fucoidan+isoproterenol. To evaluate the efficacy of fucoidan treatment against isoproterenol induced myocardial damage, biochemical parameters and histopathological studies were carried out. Isoproterenol administration produced severe myocardial damage and high lipid peroxidation level. On the contrary, fucoidan treatment reduced myocardial damage, which has been reflected by improvement in parameters such as creatinine phosphokinase (CPK), lactate dehydrogenase (LDH), alanine transaminase (ALT) and aspartate transaminase (AST). In addition, fucoidan improved the antioxidant defence system in treated animals and considerably reduced the oxidative stress exerted by isoproterenol. The reduction in oxidative stress in Group (4) was evident from the lipid peroxidation and antioxidant activities. Furthermore, the increase in the levels of total cholesterol, triglycerides and low density lipoprotein (LDL) and decrease in the levels of high density lipoprotein (HDL) was significantly reversed in Group (4), when compared with Group (2). The histopathological studies also showed that fucoidan treatment significantly minimized the damage induced by isoproterenol. Thus, fucoidan provide cardioprotection against isoproterenol induced myocardial infarction in rats.