Preventive effect of nerolidol on isoproterenol induced myocardial damage in Wistar rats: Evidences from biochemical and histopathological studies.

The present study aimed at investigating the protective effects of nerolidol (NRD) against myocardial infarction (MI) induced by isoproterenol (ISO) in Wistar rats. The rats were randomly divided into five groups, each group consisting of six rats. Group I were treated as control rats, group II received NRD (200 mg/kg b.w.) by intragastric intubation for 21 days, group III received ISO (60 mg/kg b.w) subcutaneously (s.c) for two consecutive days on 22nd and 23rd day, group IV and V received NRD (100 and 200 mg/kg b.w) as in group II and additionally ISO was given for two consecutive days (22nd and 23rd). On 24th day all the rats were sacrificed by cervical dislocation and the blood and heart samples were collected. In the present study, ISO-induced myocardial damage was indicated by the changes in body weight, heart weight and the cardiac and hepatic marker enzymes such as creatine kinase (CK), creatine kinase-MB (CK-MB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and troponin T and I (cTnT, cTnI) in the serum. In addition, the levels of lipid peroxidation products such as thiobarbituric acid reactive substances (TBARS), conjugated dines (CD), and lipid hydroperoxides (LHPs) increased significantly in the plasma and heart tissue. Activities of enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) in erythrocytes and heart tissue and the levels of nonenzymatic antioxidants like vitamin C, vitamin E, and reduced glutathione (GSH) in plasma and heart tissue were decreased in ISO-induced rats. Histopathological observations were also supported with the biochemical parameters. Pretreatment with NRD at different doses (100 and 200 mg/kg b.w) for 21 days prevented the above changes induced by ISO. The 200 mg/kg b.w of NRD was more pronounced than the other dose and brought back all the above parameters near to normalcy.