Course content: The powerful and often well-known plant-derived drugs interact with molecular and cellular mechanisms in animals, including humans.  As an interdisciplinary approach between plant and animal cell biology, it covers, on the one hand, cellular signal transduction mechanisms in animals, concentrating on seven-transmembrane receptors (GPCRs) and ion channels, but also on cancer cell growth. On the other hand, it describes how and why plants produce these secondary metabolites.  The interplay between these topics is illustrated by elaboration on prominent plant-derived drugs that constitute potent plant toxins, pharmaceutically used drugs to treat human disease as well as so-called recreational drugs.