Japanese knotweed

Japanese knotweed, for example, was introduced into British gardens in 1825, as "a plant of sterling merit." It is now Britain s most troublesome weed, and a serious problem in parts of North America, too. 

A similar effect is now as well ascribed to resveratrol, aphytoalexin from the skin of black grapes, and to the Japanese knotweed (Polygonum cuspidatum). The active compound, widely used in traditional Chinese herhal medicine, prevents the increased expression of human cyclooxygenase-2 and hence a higher COX-2 activity. 

The major dietary sources of stilbenes include grapes, wine, soya and peanut products. Trans-resveratrol and its glucoside are found in especially high amounts in the Itadori plant Polygonum cuspidatum), which is also known as Japanese knotweed (Burns etcd. 2002). It is an extremely noxious weed that has invaded many areas of Europe and North America. 

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