This study aimed to compare the protective or therapeutic effects of silymarin and/or boric acid against myocardial infarction induced by isoproterenol. Distilled water was given orally by gavage to the GI and GII groups for fourteen days. The GIII group was received silymarin (100mg/kg), while the GIV group was given boric acid (100mg/kg) for 14 days. In the last group, both silymarin and boric acid were given orally (gavage) for fourteen days. On the thirteenth and fourteenth days of the study, while isotonic water was applied to the GI group, isoproterenol (85mg/kg) was applied to the other groups subcutaneously. Plasma ALT, AST, Ca, CK, CHO, TP, Ing P, IL-6, IL-12, PAL-1, and sPLA2 parameters were evaluated. Histopathological examination was performed on the heart, lung, liver, kidney, spleen, cerebrum, and cerebellum tissues taken from mice. The CK level was found to be significantly lower in the GIII and GV groups compared to the GII group (P