Protective Role of Nano-Quercetin and Different Natural Extracts against Cardiotoxicity Induced by Glucocorticoids (Anti-COVID-19 Drugs): Molecular and Biochemical Studies

glucocorticoids such as azithromycin and dexamethasone. The study was designed to demonstrate the cardiotoxic consequences of anti-COVID-19 drugs and to clarify the protective role and mechanisms of different dietary natural extracts. Methods Forty-eight rats were divided into eight groups; Control, groups II-VI received 30 mg/kg azithromycin, 30 mg/kg dexamethasone and anti-COVID-19 protocol (30 mg /kg azithromycin, 30 mg/kg dexamethasone, 6.7 mg/kg vitamin C and 0.26 mg /kg zinc) orally for fourteen days, groups V-VIII received co-treatment of anti-COVID-19 protocol plus orally administration of 7.5 mg/kg Arabic gum, 4 ml/kg Nigella sativa oil, 83 µmol /kg nano-quercetin, and 500 mg/kg Thymus vulgaris extract, respectively for 14 days. Results anti COVID-19 drugs showed significant elevation in cardiac enzymes, malondialdehyde, nuclear factor-kappa B and interleukin-1 Beta besides a decrease in superoxide dismutase level. In addition, significant upregulation in expression levels of tumor necrosis factor-alpha, caspase-3 genes and alpha-smooth muscle actin in myocardial cells. However Arabic gum, Nigella sativa oil, nano-quercetin, and Thymus vulgaris extract co-treatments significantly improved these alterations and attenuated the expression of caspase-3, TNF-α genes and α-SMA protein. Conclusion: combined treatment with the examined dietary natural extracts especially nano quercetin established ameliorative effects against cardiotoxicity induced by anti-COVID-19 drugs through anti-inflammatory and anti-apoptotic effects.