Subchronic kretek smoke exposure induces myocardial p53 protein expression and associated inflammatory and fibrotic alterations in rats

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BSTRACT

Kretek smoke contains various toxic substances that are harmful to human health and has been associated with inflammation and structural alterations in multiple organs. However, its effects on cardiac tissue remain incompletely understood. This study aimed to evaluate myocardial histopathological alterations and p53 protein expression following subchronic kretek smoke exposure in rats. Male Rattus norvegicus Sprague–Dawley rats were randomly divided into two groups. Group I was exposed to normal air, while Group II was exposed to kretek smoke at a dose of 1 kretek/rat/day for 30 days. Cardiac tissues were examined using H&E and MT staining. IHC analysis was performed to assess myocardial p53 protein expression, while ultrastructural observations of the myocardium were conducted using SEM. Group II rats exhibited myocardial inflammation characterized by lymphocyte infiltration and increased collagen accumulation, whereas Group I rats showed no inflammatory changes and minimal collagen deposition. Myocardial p53 protein expression was significantly higher in Group II (224.68 ± 5.44 µm²) than in Group I (199.87 ± 13.35 µm²; P = 0.005). Ultrastructural myocardial alterations were observed in Group II but not in Group I. In conclusion, subchronic kretek smoke exposure increases myocardial p53 protein expression accompanied by inflammatory and fibrotic alterations.