Humulus lupus (Hops)

A climbing perennial vine, the flowers of which are used as a flavoring agent in beer.  Hops contains a range of flavonoids, including 8-prenylnaringenin – a potent phytoestrogen.  Hops also exhibits chemopreventive activity, as an inhibitor of CYP1A1 - a liver (Phase I) enzyme that activates chemical carcinogens.  Hops extract – in combination with valerian – has been studied as a sleep aid.  Compounds isolated from hops also possess cytotoxic, anti-aromatase and antioxidant activities in-vitro, although in-vivo research remains to be done.