Does Emodin in Knotweed make the latter a unsuitable source of resveratrol?

Japanese Knotweed

History

This plant is native to Eastern Japan, China and Korea. In the United States it is considered an invasive species as it is in most other countries. It is considered on of the worst invasive species in the world. The plant grows rapidly and displaces native species quickly with its large size and is difficult to eradicate due to the way it is able to propagate through it’s root system. Luckily the plant has some redeeming qualities, which should make it very desirable to harvest. It is known as a rich source of the antioxidant Resveratrol.

Function

In addition to the popular antioxidant Resveratrol, Japanese Knotweed also contains a chemical known as emodin.

Emodin has the ability to regulate bowel motility among other things. The Japanese used an alcohol extract of this plant as a natural laxative. Modern preparation from Japanese Knotweed, concentrated to maximize the Resveratrol, contain very little emodin.

The phytochemical Resveratrol has garnered considerable scientific attention for its potential to support healthy blood vessel function and promote heart health. A recent search for studies on Resveratrol through the national library of medicines database; PubMed, yielded over two thousand results.

http://www.gaiaherbs.com/products/ingredient/483/Japanese-Knotweed