Japanese Knotweed (Fallopia japonica)

Traditional Indications

In Traditional Chinese Medicine Japanese knotweed Fallopia japonica syn Polygonum Cuspidatum is known as Bian Xu 扁蓄. Bian Xu is bitter and cold and enters the Bladder channel to promotes urination and dispels Damp Heat in the Bladder (1).


Japanese knotweed has long been used in Japan and China as a traditional herbal remedy and is an important source of the antioxidant resveratrol (2). Resveratrol has been the subject of intense interest in recent years due to a range of unique anti-aging properties (3).

These include cardiovascular benefits via increased nitric oxide production. The results of a study demonstrate that the addition of RESV to standard antihypertensive therapy is sufficient to reduce blood pressure to normal levels, without the need for additional antihypertensive drugs (4). Aging selectively suppresses vasoactive intestinal peptide messenger RNA expression (5). Resveratrol down-regulates vasoactive peptides (6).

Resveratrol protects against diet-induced atherosclerosis by reducing low-density lipoprotein cholesterol and inhibiting inflammation in apolipoprotein E-deficient mice (7).

Resveratrol is safe and well tolerated and was associated with significant increases in the numbers of circulating γδ T cells and regulatory T cells and results in small, yet significant, decreases in the plasma levels of the proinflammatory cytokines TNF-α and MCP-1 and a significant increase in the plasma antioxidant activity (8).

The amyloid hypothesis suggests that the progressive accumulation and deposition of central nervous system amyloid with aging is the proximate cause of Alzheimer’s disease (AD). Thus, targeting molecular mechanisms of aging may represent a viable treatment approach. Caloric restriction prevents diseases of aging, including AD, in animal models, perhaps by activation of sirtuins. The sirtuins (such as mammalian SIRT1) are deacetylases that link energy balance (NAD+/NADH) to regulation of gene transcription. Resveratrol is a potent activator of SIRT1, and thus may mimic caloric restriction to prevent diseases of aging (9). Resveratrol promotes clearance of Alzheimer's disease amyloid-beta peptides (10).

The anticancer molecular mechanisms of resveratrol are well understood in relation to in vitro and in vivo studies. Resveratrol appears to have many anti-tumour effects on different cancer cells in vitro (11). Molecular mechanisms of resveratrol involved signalling pathways related to extracellular growth factors and receptor tyrosine kinases; formation of multiprotein complexes and cell metabolism; cell proliferation and genome instability; cytoplasmic tyrosine kinase signalling (cytokine, integrin, and developmental pathways); signal transduction by the transforming growth factor-β super-family; apoptosis and inflammation; and immune surveillance and hormone signalling (12). Resistance of cancer cells to chemotherapy is controlled by the decrease of intracellular drug accumulation, increase of detoxification, and diminished propensity of cancer cells to undergo apoptosis.

Fallopia japonica can modulate the function of ATP-binding cassette (ABC) drug transporters. ABC membrane transporters with intracellular metabolic enzymes contribute to the complex and unresolved phenomenon of multidrug resistance (MDR). Natural products as alternative medicines have great potential to discover new MDR inhibitors with diverse modes of action. Fallopia japonica can modulate MDR to overcome MDR in cancer cells (13).

The polyphenol resveratrol is a naturally occurring highly powerful antioxidant and is particularly known for its antiaging effects. Sources of resveratrol in food include the skin of grapes, blueberries, raspberries, mulberries, and peanuts. A randomised double-blind placebo-controlled proof-of-concept trial of resveratrol for outpatient treatment of mild COVID-19 published in Scientific Reports found that resveratrol recipients had a lower incidence compared to placebo of: hospitalization, COVID-19 related accident and Emergency (A&E) visits and pneumonia (14).


 1. Lotus S. Bian Xu (Knotweed, Polygonum). 2019.
2. Burns J, Yokota T, Ashihara H, Lean ME, Crozier A. Plant foods and herbal sources of resveratrol. Journal of agricultural and food chemistry. 2002;50(11):3337-40.
3. Baxter RA. Anti-aging properties of resveratrol: review and report of a potent new antioxidant skin care formulation. Journal of cosmetic dermatology. 2008;7(1):2-7.
4. Theodotou M, Fokianos K, Mouzouridou A, Konstantinou C, Aristotelous A, Prodromou D, et al. The effect of resveratrol on hypertension: A clinical trial. Experimental and therapeutic medicine. 2017;13(1):295-301.
5. Duncan MJ, Herron JM, Hill SA. Aging selectively suppresses vasoactive intestinal peptide messenger RNA expression in the suprachiasmatic nucleus of the Syrian hamster. Molecular Brain Research. 2001;87(2):196-203.
6. Bastianetto S, Dumont Y, Duranton A, Vercauteren F, Breton L, Quirion R. Protective action of resveratrol in human skin: possible involvement of specific receptor binding sites. PLoS One. 2010;5(9):e12935.
7. Chang G-R, Chen P-L, Hou P-H, Mao FC. Resveratrol protects against diet-induced atherosclerosis by reducing low-density lipoprotein cholesterol and inhibiting inflammation in apolipoprotein E-deficient mice. Iranian journal of basic medical sciences. 2015;18(11):1063-71.
8. Espinoza JL, Trung LQ, Inaoka PT, Yamada K, An DT, Mizuno S, et al. The Repeated Administration of Resveratrol Has Measurable Effects on Circulating T-Cell Subsets in Humans. Oxidative medicine and cellular longevity. 2017;2017:6781872-.
9. Sawda C, Moussa C, Turner RS. Resveratrol for Alzheimer's disease. Annals of the New York Academy of Sciences. 2017;1403(1):142-9.
10. Marambaud P, Zhao H, Davies P. Resveratrol promotes clearance of Alzheimer's disease amyloid-beta peptides. The Journal of biological chemistry. 2005;280(45):37377-82.
11. Carter LG, D'Orazio JA, Pearson KJ. Resveratrol and cancer: focus on in vivo evidence. Endocrine-related cancer.21(3):R209-R25.
12. Varoni EM, Lo Faro AF, Sharifi-Rad J, Iriti M. Anticancer Molecular Mechanisms of Resveratrol. Frontiers in nutrition. 2016;3:8-.
13. Eid SY, El-Readi MZ, Ashour ML, Wink M. Fallopia japonica, a Natural Modulator, Can Overcome Multidrug Resistance in Cancer Cells. Evidence-based complementary and alternative medicine : eCAM. 2015;2015:868424-.
14. McCreary MR, Schnell PM, Rhoda DA. Randomized double-blind placebo-controlled proof-of-concept trial of resveratrol for outpatient treatment of mild coronavirus disease (COVID-19). Scientific Reports. 2022;12(1):10978.


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