LAUSR

ABSTRACT Background Nano selenium (Nano Sel) has many therapeutic properties including antioxidant, anticancer, and anti-inflammatory actions. Objective Impacts of Nano Sel administration against cardiac fibrosis and heart and aorta tissue oxidative damage observed in hypothyroid rats were explored. Methods The animals were randomly grouped and treated as: 1) Control; 2) Propylthiouracil (PTU) in which PTU was added to the drinking water (0.05%) to induce hypothyroidism; 3–5) PTU-Nano Sel 50, PTU-Nano Sel 100, and PTU-Nano Sel 150 groups, which received daily PTU plus 50,100 or 150 µg/kg of Nano Sel for 6 weeks intraperitoneally. The heart and aorta tissues were removed under deep anesthesia and then biochemical parameters including malondialdehyde (MDA), total thiol groups, catalase (CAT), and superoxide dismutase (SOD), as well as cardiac fibrosis were assessed. Results Hypothyroidism induced by PTU was remarkably associated with myocardial hypertrophy and perivascular fibrosis in Masson’s trichrome staining. Moreover, hypothyroidism increased MDA level, while it subtracted total thiol group content and activity of SOD and CAT. Treatment with Nano Sel recovered hypothyroidism-induced cardiac fibrosis in the histological assessment. Nano Sel also promoted CAT and SOD activity and thiol content, whereas alleviated MDA levels in the heart and aorta tissues. Conclusion Results propose that administration of Nano Sel exerts a protective role in the cardio vascular system via preventing cardiac fibrosis and inhibiting oxidative stress.