Japanese Knotweed

The most potent source of resveratrol is Polygonum cuspidatum or Japanese knotweed roots. There are other members of the polygonum family, including one used for making blue dye (Polygonum Tinctorium), Polygonum paleaceum, a Chinese folk medicine plant used for gastritis, duodenal ulcers, dysentery, wound, pain, hemorrhage and irregular menstruation, and Polygonum multiflorum thunb, another Chinese remedy.  The later caused a case of hepatitis Ann Intern Med 4/26/04. Polygonum punctatum is an herb known in Brazil as "erva-de-bicho" and is used to treat intestinal disorders.

There is a total absence of human research.  However, research on resveratrol and grapes suggests that knotweed resveratrols are beneficial.

Alzheimer's: Reduced Amyloid Beta Protein Toxicity in Mice: J Ethnopharm 2006 Mar 8;104(1-2):144-8. Similar: Zhongguo Zhong Yao Za Zhi 2004 Feb;29(2):176-9.

Brain: Polygonum multiflorum extracts improve cognitive performance in senescence accelerated mice: Chan YC. Providence University, Taichung, Taiwan. . Am J Chin Med 2003;31(2):171-9. Similar: J Nutr Sci Vitaminol (Tokyo) 2002 Dec;48(6):491-7.

Colitis: Tryptanthrin from Polygonum tinctorium Helped Mouse Inflammatory bowel disease: Colitis was induced by 5% dextran sodium sulfate. TRYP (100 mg/kg) from day 3 for 5 day reduced colon damage, however, colon injury resumed after treatment was stopped. However, mitogen-stimulated spleen cells from TRYP-treated colitic mice produced less interleukin 2 (IL-2) and less interferon-gamma. 90% of controls died from wasting disease; all the TRYP-treated mice survived. Micallef MJ, et al. Okayama, Japan. Int Immunopharm 2002 Mar;2(4):565-78.

Heart: Reduces Atherosclerosis in Rabbits: Treatment of NZW rabbits fed with high cholesterol diet with 100 mg/kg PMS attenuated the increase in plasma cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and plasma triglyceride. Treatment with 50 and 100 mg/kg PMS caused 43% and 60% decrease in atherosclerotic lesioned area ratio to total surface area. J Pharmacol Sci 2005 Nov;99(3):294-300.

Inflammation: Reduces Paw Edema in Rats: Pak J Pharm Sci 2005 Oct;18(4):13-8. 

Osteoporosis: Trans-resveratrol from Polygonum cuspidatum Lowers bone loss in ovariectomized rats: Liu ZP, et al. Beijing. J Med Food 2005 Spring;8(1):14-9.

Parkinson's: PME has a beneficial influence on parkinsonism induced by paraquat and MB in mouse study. Pharmacol Biochem Behav 2005 Oct;82(2):345-52.

Sperm: Knotweed extract Helped alkeran-induced changes in rat Sperm: Khotimchenko S, et al.  Russian Academy of Science. . Bull Exp Biol Med 2000 Dec;130(12):1156-8.

Stroke: Two Week Administration of Polygonum multiflorum Thunb. reduces cerebral ischemia-induced infarct volume in gerbils: Chan YC, et al. Providence University, Taichung, Taiwan. J Hypertens 2005 Feb;23(2):427-34.