Protective Effects of Pyrroloquinoline Quinone in Isoproterenol-Induced Myocardial Infarction in Rats

Cardiovascular diseases remain the leading cause of mortality worldwide, with myocardial infarction (MI) representing one of the most severe manifestations. Oxidative stress, inflammation, and apoptosis are major contributors to myocardial injury. Pyrroloquinoline quinone (PQQ), a potent redox cofactor, has demonstrated antioxidant and cytoprotective properties; however, its effects on isoproterenol (ISO)-induced myocardial injury remain unclear. This study investigated the cardioprotective effects of PQQ in an ISO-induced MI rat model using biochemical, histopathological, and immunohistochemical analyses. Thirty-two male Wistar rats were divided into four groups: Control, PQQ, ISO-MI, and ISO-MI+PQQ. MI was induced by subcutaneous ISO administration (85 mg/kg) for two consecutive days, while PQQ (3 mg/kg) was administered orally for 14 days. ISO significantly increased Troponin T levels and caused myocardial necrosis, edema, inflammation, and fibrosis. PQQ treatment significantly attenuated myocardial damage, reduced Troponin T levels, increased CAT activity, and improved oxidative balance. Immunohistochemical findings showed decreased BAX expression in the PQQ-treated group. These findings indicate that PQQ may have beneficial effects in this experimental model; however, further studies are required to clarify these effects and their potential clinical relevance.