Praeruptorin A, a naturally existing pyranocumarin, is isolated from the dried root of Peucedanum praeruptorum Dunn. Praeruptorin A inhibits p38/Akt-c-Fos-NFATc1 signaling and PLCγ-independent Ca2+ oscillation. Praeruptorin A can significantly upregulates multidrug resistance-associated protein 2 expression via the constitutive androstane receptor-mediated pathway in vitro, and this should be taken as an herb-drug interaction.