Histological and flow cytometric evaluation of astaxanthin's effects against cyclophosphamide induced heart injury in rats

Background: In this study, the protective effect of astaxanthin (AST), which is a strong antioxidant against adult rat heart damage caused by cyclophosphamide (CP), which has cytotoxic effects, was investigated. For this purpose, weight measurements, histopathologic and flow cytometric methods were used. Methods: Eighteen Sprague Dawley adult female rats were randomly divided into 3 equal groups as control, CP and CP+AST in the study. While no application is made to the control group, on the 7th day of the experiment, 200 mg/kg single dose of CP (dissolved in 2.5 ml physiologic saline, i.p.) was administered to CP group. On the first 7 days of the experiment, 25 mg/kg/day of AST (dissolved in 350 µl of olive oil, oral) and on the 7th day of the experiment, 200 mg/kg single dose of CP (dissolved in 2.5 ml physiologic saline, i.p.) was administered to the CP+AST group. On the 8th day of the experiment, the rats were sacrificed and the heart tissues were dissected. After dissection and washing the heart tissues with physiologic saline, they were weighed and recorded. Histopathological examinations were performed in one half of the tissues by Hematoxylin & Eosin (H&E), Masson Trichrome and Periodic Acid-Schiff (PAS) staining methods; In the other half, Annexin V and Anti-NOX2/gp91phox analyzes were performed by flow cytometry. Results: There was no significant difference between the groups in heart weight measurements. In histological examination of the heart sections belonging to the CP Group; degeneration in cardiomyocytes, hypereosinophilia, pycnotic nuclei, wavy fibers, perinuclear edema, vacuolization, contraction bands, separation in muscle fibers, vascular congestion and increased PAS (+) staining were observed. These findings were significantly reduced in the CP+AST group compared to the CP group. Masson Trichrome staining did not differ between the groups in terms of collagen accumulation. There was an increase in Annexin V and Anti-NOX2/gp91phox bound cell levels in CP group in flow cytometrically. With the AST pretreatment, compared to the CP group, in the CP+AST group Annexin V and Anti-NOX2/gp91phox bound cell level showed a marked decrease. Conclusions: In the light of the findings obtained, it can be said that CP affects the adult rat heart negatively and AST application prevents these negative effects of CP.