Promising cardioprotective effect of baicalin in doxorubicin-induced cardiotoxicity through targeting toll-like receptor 4/nuclear factor-κB and Wnt/β-catenin pathways

Abstract

Doxorubicin (Dox) is an indispensable chemotherapeutic agent associated with damaging cardiotoxicity. Baicalin (BA) is a flavonoid, extracted from the medicinal plant Scutellariae baicalensis Georgi. BA is well known for its anti-inflammatory and antioxidant effects. Our study investigated the potential effect of BA in attenuating Dox-induced cardiotoxicity. To this end, male Swiss albino mice were given BA (100 mg/kg/d, orally) for 4 wk and were challenged with Dox (six intraperitoneal doses, each 2.5 mg/kg, every other day with a final cumulative dose of 15 mg/kg). Serum activities of cardiac biomarkers (cardiac troponin-I, creatine kinase-membrane bound, lactate dehydrogenase, and aspartate aminotransferase) were assessed along with the histopathological examination of the heart tissues. Gene expression of Toll-like receptor 4 (TLR4) was analyzed by quantitative reverse transcription real-time polymerase chain reaction. Analysis of the protein levels of β-catenin and nuclear factor-κB (NF-κB) was done immunohistochemically. Cardiac Dickkopf-1 (DKK1) and interleukin-1beta (IL-1β) were quantified by enzyme-linked immuno-sorbent assay. Cardiac levels of reduced glutathione (GSH) and malondialdehyde (MDA) were detected spectrophotometrically. Pretreatment with BA significantly prevented Dox-induced elevation of serum activities of cardiac biomarkers and alterations to the heart. Moreover, BA suppressed the gene overexpression of cardiac TLR4 and subsequently prevented Dox-induced elevation of both cardiac NF-κB and IL-1β. BA also significantly reduced the cardiac levels of DKK1 and elevated the level of β-catenin. Dox-induced elevation of MDA and reduction of GSH were reversed by BA. BA exhibited a novel cardioprotective effect against Dox-induced cardiotoxicity. The cardioprotective effect was indicated through the inhibition of the inflammatory TLR4/NF-κB pathway and the activation of the protective Wnt/β-catenin pathway by the suppression of DKK1.

Keywords: Baicalin; Cardiotoxicity; DKK1; Doxorubicin; TLR4.