AGT and atrial fibrillation: Zinc Protoporphyrin (ZnPP), an HO-1 inhibitor, reduced the anti-oxidative effect of neferine to some extent and subsequently abolished the beneficial effect of neferine on Ang II-induced AF.<h4>Conclusions</h4>These findings provide hitherto undocumented evidence that the protective role of neferine in Ang II-induced AF is dependent on HO-1.