Cardioprotective effects and antioxidant status of Andrographis paniculata in isoproterenol-induced myocardial infarction in rats

Background:  Myocardial infarction has been regarded as one of the fastest killer diseases of modern-day man. Aim:  The protective effect of  Andrographis paniculata  on isoproterenol (ISO)-induced myocardial infarction in rats was investigated. Setting:  The study was carried out in a laboratory setting. Methods:  Animals were randomly divided into six groups of seven animals per group, and the treatment was as follows: normal control received normal saline for 9 days, isoproterenol group; three extract-treated groups in pre-treatment phase and an extract-treated group in post-treatment phase. The doses were given at 100, 200 and 400 mg/kg body weight for pre-treatment phase respectively while 200 mg/kg dose was given to the post-treatment phase group. Blood and heart tissues were collected for biochemical assays, haematological and histological analyses. Results:  Myocardial infarction was recorded in ISO group but was corrected by the extracts in both pre-treatment and post-treatment phases. The ISO group experienced a significant decrease in antioxidant parameters, whereas the extract at all doses caused a significant increase in the activities of in these parameters. The extract caused a significant decrease in malondialdehyde content and hydrogen peroxide generation, whereas reverse was the case for the ISO group. Although no significant histopathological changes were recorded for the extract, the ISO group showed marked histopathological changes. ISO caused higher expressions of cardiac C-reactive protein (CRP) and CTnI and decreased the expressions of IL-10β; but this was the opposite for the extract. Conclusion:  The ethanol leaf extract of  A. paniculata  significantly exhibits cardioprotective effects.