Proadifen (SKF-525A) is a non-selective inhibitor of cytochrome P450 enzymes, preventing some types of drug metabolism.

[1] It is also an inhibitor of neuronal nitric oxide synthase (NOS), CYP-dependent (cytochrome P450-dependent) arachidonate metabolism, transmembrane calcium influx, and platelet thromboxane synthesis.

Further documented effects include the blockade of ATP-sensitive inward rectifier potassium channel 8 (KIR6.1), and stimulation of endothelial cell prostacyclin production.

[2] Proadifen exerts apoptotic/anti-proliferate (tumour suppressing) effects in certain forms of cancer (HT-29 colon adenocarcinoma), believed to be caused by mediation of glycogen synthase kinase 3 β (GSK-3β).

In the same study administration of proadifen was demonstrated to produce time- and dose-dependent phosphatidylserine externalization, caspase-3 activation and PARP cleavage.