Dose-Dependent Cardioprotective Effect of Hemin in Doxorubicin-Induced Cardiotoxicity Via Nrf-2/HO-1 and TLR-5/NF-κB/TNF-α Signaling Pathways.

Doxorubicin (DOX) is one of the most widely used chemotherapeutic drugs, but its cardiotoxicity has been shown to be a dose-restricting factor during therapy. Finding new agents for reducing these complications is still in critical need. The current study aimed to evaluate the possible cardioprotective effect of hemin (HEM) in DOX-induced cardiotoxicity and exploring the role of toll like receptor-5/nuclear factor kappa-B/tumor necrosis factor-alpha (TLR-5/NF-κB/TNF-α) and nuclear factor erythroid 2-related factor-2/hemeoxygenase-1 (Nrf-2/HO-1) signaling pathways in mediating such effect. Wistar albino rats were randomly divided into five groups. They were administered DOX by interaperitoneal (i.p.) injection (15 mg/kg) on the 5th day of the experiment with or without HEM in different doses (2.5, 5, 10 mg/kg/day) i.p. for 7 days. Results showed that the DOX group had cardiotoxicity as manifested by a significant increase in cardiac enzymes, malondialdehyde (MDA), TLR-5, NF-κB, TNF-α, and cleaved caspase-3 levels with toxic histopathological changes. Based on these findings, HEM succeeded in reducing DOX-induced cardiotoxicity in a dose-dependent effect by stimulation of Nrf-2/HO-1 and inhibition of TLR-5/NF-κB/TNF-α pathways with subsequent antioxidant, anti-inflammatory, and anti-apoptotic effects.