Shikimic acid, a phenolic acid reverses isoproterenol-induced myocardial infarction in rat model

Background

Myocardial infarction (MI), a leading cause of death in ischemic heart disease, may be mitigated by natural phenolic acids due to their antioxidant properties. This study investigates the cardioprotective role of shikimic acid (SA) against isoproterenol (ISO)-induced myocardial infarction in rats.

Methods

Rats were divided into six groups; all received ISO (85 mg/kg/day, s.c) on days 6 and 7, except the control (normal saline). Groups III-V received SA (10, 30, and 50 mg/kg/day, i.p) for seven days, while group VI was given atenolol (10 mg/kg/day, i.p). In-vitro studies were performed on isolated rat aortic rings and right atrium.

Results

SA pretreatment significantly prevented ISO-induced ECG changes (ST elevation, pathological Q wave), reduced cardiac biomarkers (cTnI, CPK, LDH, AST), improved heart histology, and increased tissue viability. Similarly, SA also showed a significant vasorelaxant effect against phenylephrine-induced precontraction, probably by inhibiting the receptor operated Ca²⁺ channels without having effect on voltage-dependent Ca²⁺ channels. SA showed mild negative chronotropic and ionotropic effects, potentially reducing MI-related cardiac workload.

Conclusion

These results indicate that SA preventing MI in rats through improving ECG, cardiac biomarkers and histopathological changes; the effect of SA may be attributed to the decrease in Ca²⁺movement and cardiac workload.