Hypericin (Hyp, HY) is a naturally occurring substance found in the common St. John’s Wort (Hypericum species) with antidepressive, antineoplastic and antiviral (human immunodeficiency and hepatitis C virus) activities. Hypericin has inhibitory effects on MAO (monoaminoxidase), PKC (protein kinase C), dopamine-beta-hydroxylase, reverse transcriptase, telomerase and CYP (cytochrome P450).