Giant knotweed - an excellent source of the potent antioxidant resveratrol - is a plant that is characterized by its hollow stems and its wide, oval-shaped leaves. The Japanese knotweed plant also grows a profusion of small, white flowers during the late summer and early fall. Once only found in Asia, Japanese knotweed is now cultivated and prized around the world for its high quantities of resveratrol, and contemporary medical uses supported by clinical results include acute microbial infections or viral hepatitis, chemo-or radiation-induced leukoytopenia, atherosclerosis, and hyperlipidemia.
Giant knotweed extract has exhibited antitussive, antihistaminic, hypotensive, vasodilating, cytotoxic, and antioxidant properties, among others. Giant knotweed extract is also a concentrated source of resveratrol, an antioxidant phenol produces in response to fungi. Resveratrol has also show antimutagenic activity in bioassays conducted on bacteria in vitro.