Plant Comparison

Cranberry vs Japanese knotweed

A side-by-side comparison of two medicinal plants — every documented constituent, action, use, safety note and cited source, assembled automatically from the Omnia Sana database.

First plant
Second plant
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Plant ACranberryOxycoccus palustrisEricaceaeFull monograph →
Plant BJapanese knotweedReynoutria japonicaPolygonaceaeFull monograph →

At a glance

Cranberry and Japanese knotweed: they share 3 indicated uses (arthritis / joint pain, inflammation (general), skin irritation); 2 pharmacological actions in common.

CranberryJapanese knotweed
Constituents54
Pharmacological actions33
Indicated uses65
Safety notes22
Cited sources1414
Indicated uses
Only Cranberry
Infection (general)Urinary supportWounds
Shared (3)
Arthritis / joint painInflammation (general)Skin irritation
Only Japanese knotweed
Cancer (anticancer research)Cardiovascular / heart health
Pharmacological actions
Only Cranberry
Antimicrobial
Shared (2)
Anti-inflammatoryAntioxidant
Only Japanese knotweed
Anticancer (preclinical)

Evidence face-off — shared uses

ConditionCranberryJapanese knotweedVerdict
Arthritis / joint pain1/102/10Comparable evidence
Inflammation (general)2/107/10Stronger for Japanese knotweed
Skin irritation1/101/10Comparable evidence

Evidence scores (1–10) are computed from the tier of each cited source. “Comparable” means the two scores are within one point. Follow a score to its detailed sources.

Key Constituents

Proanthocyanidins (A-type PACs)[2, 4]

The A-type proanthocyanidins are considered responsible for inhibiting bacterial adhesion to the urinary tract lining.

Proanthocyanidins
Anthocyanins[4]

Red pigments and antioxidants of the fruit.

Anthocyanins
Flavonoids (quercetin, myricetin)[2]

Antioxidant flavonoids of the fruit.

QuercetinFlavonoids
Triterpenoids and phytosterols[3]

Minor lipophilic constituents of the fruit skin.

Phytosterols
Organic acids (quinic, citric, malic acid)[2]

Give the fruit its characteristic tartness and are traditionally credited with a mild urinary-acidifying effect.

Stilbenes (resveratrol, piceid)[1, 6]

Considered the principal bioactive constituents, responsible for much of the antioxidant, anti-inflammatory and cardioprotective activity attributed to this root.

Anthraquinones (emodin, physcion)[1]

Emodin has laxative and anti-inflammatory activity at typical concentrations but can cause gastrointestinal upset at high doses.

Anthraquinones
Polysaccharides[5]

Studied for immunomodulatory and other bioactivities.

Polysaccharides
Phenolic glycosides[8]

Minor phenolic constituents of the rhizome.

GlycosidesPhenolic compounds

Pharmacological Actions

Anti-inflammatory[1, 12, 13]
Antimicrobial[2, 4, 6, 10, 12, 13]
Antioxidant[1, 2, 4, 5, 12, 13]
Anti-inflammatory[1, 2, 3, 5, 6, 9, 11, 12, 13]
Anticancer (preclinical)[1, 3, 6, 7, 11, 12, 13]
Antioxidant[1, 3, 5, 6, 11, 12, 13]

Traditional & Indicated Uses

Arthritis / joint pain[12, 13]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Arthritis / joint pain
Infection (general)[2, 4, 6, 10, 12, 13]Traditional · 2/10

inferred from antimicrobial action

Evidence: 2
Label: Infection (general)
Inflammation (general)[1, 12, 13]Traditional · 2/10

inferred from anti-inflammatory action

Evidence: 2
Label: Inflammation (general)
Skin irritation[12, 13]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Skin irritation
Urinary support[1, 2, 11, 12, 13]Moderate · 5/10
Evidence: 5
Label: Urinary support
Wounds[12, 13]Traditional · 1/10

inferred from antimicrobial action

Evidence: 1
Label: Wounds
Arthritis / joint pain[9, 11, 12, 13]Traditional · 2/10

inferred from anti-inflammatory action

Evidence: 2
Label: Arthritis / joint pain
Cancer (anticancer research)[7]Traditional · 2/10

inferred from anticancer action

Evidence: 2
Label: Cancer (anticancer research)
Cardiovascular / heart health[6, 11, 12, 13]Traditional · 1/10
Evidence: 1
Label: Cardiovascular / heart health
Inflammation (general)[2, 11, 12, 13]Good · 7/10

inferred from anti-inflammatory action

Evidence: 7
Label: Inflammation (general)
Skin irritation[11, 12, 13]Traditional · 1/10

inferred from anti-inflammatory action

Evidence: 1
Label: Skin irritation

Safety, Cautions & Contraindications

Safety note[11, 12, 13]Info

Food amounts are generally considered safe (berries in meals, drinks, sauces). (Williams et al., 2023).

Safety note[11, 12, 13, 14]Info

Duke (2002) includes cranberry primarily at the experimental level for its astringent, diuretic, and antioxidant properties. Commission E has not approved cranberry for specific indications, though there is evidence supporting its role in preventing urinary tract infections (UTIs) by inhibiting bacterial adhesion to uroepithelial cells (proanthocyanidins). Duke notes the high vitamin C and organic acid content. Food-grade consumption is considered safe and beneficial as a urinary acidifier (Duke, 2002).

Safety note[11, 12, 13]Caution

Japanese knotweed root contains resveratrol and emodin; high doses of emodin may cause GI discomfort and have laxative effects. Not recommended during pregnancy (emodin has potential teratogenic effects in animal studies). May interact with anticoagulants and antiplatelet medications. Quality control of commercial preparations is important as invasive weed extracts vary significantly.

Safety note[11, 12, 13, 14]Info

Duke (2002) rates Japanese knotweed (listed as Hu-Zhang, Fallopia japonica) as +++ and highlights its rich content of resveratrol and emodin. Experimental evidence (score 1) supports COX-2 inhibitory, antioxidant, anti-inflammatory, hepatoprotective, and lipid-lowering activities — largely attributed to resveratrol. Duke notes its use in traditional Chinese medicine for fractures, burns, abscesses, and gynecological conditions. No significant clinical trials were available at time of publication, but resveratrol's biological activity is well-documented in vitro (Duke, 2002).

External Ids

Gbif: 11104128
Gbif: 2889173
Wikidata: Q18421053

Botanical Description

Low, creeping, evergreen dwarf shrub (Ericaceae) with slender, wiry stems that root at the nodes. Leaves are tiny, alternate, leathery and ovate with in-rolled margins, dark green above and whitish beneath. Flowers are small, pink and four-petalled, sharply reflexed backward so that the protruding stamens and style resemble a crane's head and neck - the origin of the name 'craneberry', later shortened to 'cranberry'. The fruit is a small, round, tart red berry.[8]

Height: Prostrate, mat-forming (stems trailing, rarely more than 10-20 cm above the moss)
Habit: Low, creeping, evergreen dwarf shrub
Leaves: Tiny, alternate, leathery, ovate, in-rolled margins, whitish beneath
Flowers: Small, pink, four-petalled, sharply reflexed (crane's-head shape)
Stem: Slender, wiry, trailing, rooting at the nodes
Root: Shallow fibrous roots adapted to waterlogged, acidic peat
Fruit: Small, round, tart red berry
Flowering Period: June-August

Vigorous, invasive rhizomatous perennial (Polygonaceae) with hollow, bamboo-like, jointed stems 1-3 m tall (occasionally taller), speckled reddish-purple. Leaves are broad, heart- to shovel-shaped with a flat base. Abundant sprays of small, creamy-white flowers appear in late summer, followed by small winged fruit.[6]

Height: 1-3 m (occasionally to 4 m+)
Habit: Vigorous, invasive, rhizomatous perennial
Leaves: Broad, heart- to shovel-shaped, flat-based
Flowers: Small, creamy-white, in abundant sprays
Stem: Hollow, bamboo-like, jointed, reddish-purple speckled
Root: Extensive, deep, aggressively spreading rhizome
Fruit: Small winged achenes
Flowering Period: August-October

Habitat

Native to boggy, acidic wetlands - sphagnum bogs and marshes - across northern and central Europe and northern Asia, requiring waterlogged, nutrient-poor, acidic peat soils.[8]

Native to East Asia (Japan, China, Korea), now a notorious invasive species across Europe and North America, growing in disturbed ground, riverbanks, roadsides and waste land, spreading aggressively via an extensive rhizome network.[6]

Harvesting

Berries are hand-picked or wet-harvested (traditionally by hand-raking the bog) in autumn once fully ripe and deep red.[8]

Parts: Fruit
Season: Autumn

The rhizome/root, the main medicinal part, is dug in autumn or winter when resveratrol content is highest; young spring shoots (stems) are also edible and used. Strict containment is required when harvesting, given the plant's severe invasiveness.[6]

Parts: Root, Stem
Season: Root in autumn/winter; young stems in spring

Traditional Uses

Cranberry has a long northern-European and Native American tradition as a food and folk remedy for urinary complaints, valued for its tart, astringent, vitamin-C-rich fruit. Modern research on its proanthocyanidins supports a role in reducing bacterial adhesion in the urinary tract, consistent with the traditional use for cystitis and recurrent urinary tract infections.[2, 11]

Known as Hu Zhang in Traditional Chinese Medicine, Japanese knotweed root has a centuries-old use for inflammation, infections, jaundice and menstrual complaints. Modern interest centres on its resveratrol and emodin content, now studied (as Polygonum cuspidatum extract) for antioxidant, anti-inflammatory, cardioprotective and hepatoprotective activity, and more recently for supportive use in acute respiratory infections.[2, 3, 6]

Preparations

Juice[2]

Unsweetened juice, the traditional preparation used for urinary support.

Standardised extract capsule[2]

Proanthocyanidin-standardised extract, a concentrated form used in clinical trials for UTI prevention.

Decoction[6]

Dried rhizome simmered in water, the classic Traditional Chinese Medicine preparation.

Standardised resveratrol extract (capsule)[1]

The modern commercial supplement form, standardised for resveratrol content.

References

REF-0940, REF-0941, REF-0942, REF-0943, REF-0944, REF-0945, REF-0946, REF-0947, REF-0948, REF-0949
REF-0979, REF-0980, REF-0981, REF-0982, REF-0983, REF-0984, REF-0985, REF-0986, REF-0987, REF-0988

Lookalikes Review

Outcome: none-known
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07
Outcome: none-known
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07

Dosage

Not documented

Standardised extract[11, 12, 13]

Duke (2002) and general phytotherapy guidance treat this as an experimentally supported herb without a single agreed clinical dose; commercial resveratrol-standardised extracts should be dosed per product labelling. Educational reference only, not a prescription; avoid in pregnancy.

References & Sources

  1. Shareef, S.M., Khaleel, R.A. and Maryoosh, T.M (2024) 'Nephroprotective effect of cranberry (Vaccinium oxycoccos) in streptozocin-induced diabetic nephropathy in mice', Drug Metabolism and Personalized Therapy, 39(1), pp. 35-45. doi:10.1515/dmpt-2023-0092 Preclinical
    https://doi.org/10.1515/dmpt-2023-0092
  2. Jurikova, T., Skrovankova, S., Mlcek, J., Balla, S. and Snopek, L (2018) 'Bioactive Compounds, Antioxidant Activity, and Biological Effects of European Cranberry (Vaccinium oxycoccos)', Molecules, 24(1), pp. 24. doi:10.3390/molecules24010024 Traditional / reference
    https://doi.org/10.3390/molecules24010024
  3. Sedbare, R., Raudone, L., Zvikas, V., Viskelis, J. and others (2022) 'Development and Validation of the UPLC-DAD Methodology for the Detection of Triterpenoids and Phytosterols in Fruit Samples of Vaccinium macrocarpon Aiton and Vaccinium oxycoccos L', Molecules, 27(14), pp. 4403. doi:10.3390/molecules27144403 Preclinical
    https://doi.org/10.3390/molecules27144403
  4. Sedbare, R., Sprainaityte, S., Baublys, G., Viskelis, J. and Janulis, V (2023) 'Phytochemical Composition of Cranberry (Vaccinium oxycoccos L.) Fruits Growing in Protected Areas of Lithuania', Plants (Basel), 12(10), pp. 1974. doi:10.3390/plants12101974 Preclinical
    https://doi.org/10.3390/plants12101974
  5. Brown, P.N., Turi, C.E., Shipley, P.R. and Murch, S.J (2012) 'Comparisons of large (Vaccinium macrocarpon Ait.) and small (Vaccinium oxycoccos L., Vaccinium vitis-idaea L.) cranberry in British Columbia by phytochemical determination, antioxidant potential, and metabolomic profiling with chemometric analysis', Planta Medica, 78(6), pp. 630-640. doi:10.1055/s-0031-1298239 Preclinical
    https://doi.org/10.1055/s-0031-1298239
  6. Harini, K., Janani, K., Teja, K.V., Mohan, C. and Sukumar, M (2022) 'Formulation and evaluation of oral disintegrating films using a natural ingredient against Streptococcus mutans', Journal of Conservative Dentistry, 25(2), pp. 128-134. doi:10.4103/jcd.jcd_143_21 Preclinical
    https://doi.org/10.4103/jcd.jcd_143_21
  7. Cesoniene, L., Daubaras, R., Jasutiene, I., Vencloviene, J. and Miliauskiene, I (2011) 'Evaluation of the biochemical components and chromatic properties of the juice of Vaccinium macrocarpon Aiton and Vaccinium oxycoccos L', Plant Foods for Human Nutrition, 66(3), pp. 238-244. doi:10.1007/s11130-011-0241-5 Preclinical
    https://doi.org/10.1007/s11130-011-0241-5
  8. Van Rossum, F., Vereecken, N.J., Bredat, E. and Michez, D (2012) 'Pollen dispersal and fruit production in Vaccinium oxycoccos and comparison with its sympatric congener V. uliginosum', Plant Biology, 15(2), pp. 344-352. doi:10.1111/j.1438-8677.2012.00646.x Preclinical
    https://doi.org/10.1111/j.1438-8677.2012.00646.x
  9. Kawash, J., Colt, K., Hartwick, N.T., Abramson, B.W. and others (2022) 'Contrasting a reference cranberry genome to a crop wild relative provides insights into adaptation, domestication, and breeding', PLoS One, 17(3), pp. e0264966. doi:10.1371/journal.pone.0264966 Preclinical
    https://doi.org/10.1371/journal.pone.0264966
  10. Stobnicka, A. and Gniewosz, M (2017) 'Antimicrobial protection of minced pork meat with the use of Swamp Cranberry (Vaccinium oxycoccos L.) fruit and pomace extracts', Journal of Food Science and Technology, 55(1), pp. 62-71. doi:10.1007/s13197-017-2770-x Preclinical
    https://doi.org/10.1007/s13197-017-2770-x
  11. Hooton, T.M., Vecchio, M., Iroz, A., Tack, I., Dornic, Q., Seksek, I. and Lotan, Y (2018) 'Effect of increased daily water intake in premenopausal women with recurrent urinary tract infections: a randomized clinical trial', 178(11), pp. 1509--1515. doi:10.1001/jamainternmed.2018.4204 Randomized trial
    https://doi.org/10.1001/jamainternmed.2018.4204
  12. Jepson, R.G., Williams, G. and Craig, J.C (2012) 'Cranberries for preventing urinary tract infections'. Traditional / reference
    https://scholar.google.com/scholar?q=Cranberries%20for%20preventing%20urinary%20tract%20infections
  13. Royal Botanic Gardens, Kew (n.d.). Available at: https://powo.science.kew.org Traditional / reference
    https://powo.science.kew.org
  14. Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
    https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition
  1. Dong, X., Fu, J., Yin, X., Cao, S. and others (2016) 'Emodin: A Review of its Pharmacology, Toxicity and Pharmacokinetics', Phytotherapy Research, 30(8), pp. 1207-1218. doi:10.1002/ptr.5631 Traditional / reference
    https://doi.org/10.1002/ptr.5631
  2. Wang, S., Yang, Y., Sun, L., Qiao, G. and others (2022) 'Reynoutria japonica Houtt for Acute Respiratory Tract Infections in Adults and Children: A Systematic Review', Frontiers in Pharmacology, 13, pp. 787032. doi:10.3389/fphar.2022.787032 Meta-analysis / review
    https://doi.org/10.3389/fphar.2022.787032
  3. Ke, Y., Zhan, L., Lu, T., Zhou, C. and others (2023) 'Advances for pharmacological activities of Polygonum cuspidatum (Reynoutria japonica) - A review', Pharmaceutical Biology, 61(1), pp. 177-188. doi:10.1080/13880209.2022.2158349 Traditional / reference
    https://doi.org/10.1080/13880209.2022.2158349
  4. Zhang, Q., Zhao, Y., Zhang, M., Zhang, Y. and others (2021) 'Bioactive amides from Reynoutria japonica', Journal of Asian Natural Products Research, 23(3), pp. 228-234. doi:10.1080/10286020.2021.1873298 Preclinical
    https://doi.org/10.1080/10286020.2021.1873298
  5. Lai, Y., Zhou, C., Huang, P., Dong, Z. and others (2024) 'Polygonum cuspidatum polysaccharide: A review of its extraction and purification, structure analysis, and biological activity', Journal of Ethnopharmacology, 331, pp. 118079. doi:10.1016/j.jep.2024.118079 Traditional / reference
    https://doi.org/10.1016/j.jep.2024.118079
  6. Peng, W., Qin, R., Li, X. and Zhou, H (2013) 'Botany, phytochemistry, pharmacology, and potential application of Polygonum cuspidatum Sieb. et Zucc.: a review', Journal of Ethnopharmacology, 148(3), pp. 729-745. doi:10.1016/j.jep.2013.05.007 Traditional / reference
    https://doi.org/10.1016/j.jep.2013.05.007
  7. Wang, X., Liang, L., Yan, J., Li, Z. and others (2023) 'Citri Reticulatae Pericarpium-Reynoutria japonica Houtt. herb pair suppresses breast cancer liver metastasis by targeting ECM1-mediated cholesterol biosynthesis pathway', Phytomedicine, 116, pp. 154896. doi:10.1016/j.phymed.2023.154896 Preclinical
    https://doi.org/10.1016/j.phymed.2023.154896
  8. Jiang, Y., Liu, Y., Zhang, X. and others (2020) 'New phenolic glycosides from Reynoutria japonica', Journal of Asian Natural Products Research, 22(1), pp. 17-23. doi:10.1080/10286020.2019.1646730 Preclinical
    https://doi.org/10.1080/10286020.2019.1646730
  9. Liu, Y., Wang, J., Li, Q. and others (2024) 'The Possibility of Polygonum cuspidatum against Osteoarthritis based on Network Pharmacology', Current Computer-Aided Drug Design, 20(2), pp. 121-133. doi:10.2174/1573409919666230403114131 Preclinical
    https://doi.org/10.2174/1573409919666230403114131
  10. Espinosa-Andrews, H., Morales-Hernandez, N., Garcia-Marquez, E. and others (2025) 'Physicochemical and rheological characteristics of commercial Greek-style yogurt enriched with Polygonum cuspidatum roots or the P. cuspidatum beta-cyclodextrin inclusion complex', Food Research International, 203, pp. 115854. doi:10.1016/j.foodres.2025.115854 Preclinical
    https://doi.org/10.1016/j.foodres.2025.115854
  11. Burns, J., Yokota, T., Ashihara, H., Lean, M.E.J. and Crozier, A (2002) 'Plant foods and herbal sources of resveratrol', 50(11), pp. 3337--3340. doi:10.1021/jf0112973 Traditional / reference
    https://doi.org/10.1021/jf0112973
  12. Royal Botanic Gardens, Kew (n.d.). Available at: https://powo.science.kew.org Traditional / reference
    https://powo.science.kew.org
  13. World Health Organization (2007) 'WHO Monographs on Selected Medicinal Plants'. Traditional / reference
    https://scholar.google.com/scholar?q=WHO%20Monographs%20on%20Selected%20Medicinal%20Plants
  14. Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
    https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition

Generated automatically from the Omnia Sana plant database and its cited sources. For educational purposes only — not medical advice. Always consult a qualified practitioner before using medicinal plants.