Kudzu

• How It Works

  Although kudzu is used in traditional medicine, the evidence on whether it has benefit for any condition is unclear.

  Kudzu is an herb used in Chinese medicine to treat alcoholism, heart disease, menopausal symptoms, diabetes, fever, the common cold, and neck or eye pain. It is sometimes used in combination with other herbs. Lab studies suggest that kudzu has anti-inflammatory and neuroprotective properties. Compounds called isoflavones are thought to be responsible for its potential effects.

  Studies of kudzu in humans are limited and have mostly focused on whether it can reduce alcohol intake or menopausal symptoms. However, all of these studies enrolled small numbers of patients, and systematic reviews have determined that the evidence of benefit for any condition is unclear.

  Because animal and human studies suggest some estrogenic effects, individuals with hormone-sensitive cancers and those taking tamoxifen should avoid kudzu.

• Purported Uses
  • Menopausal symptoms
    Small clinical studies suggest that kudzu is a phytoestrogen that may help reduce menopausal symptoms, but a systematic review did not find benefit.
  • Alcohol abuse
    Kudzu may reduce alcohol intake and withdrawal, but these studies enrolled only a small number of patients, and a systematic review did not find benefit.
  • Diabetes
    Kudzu is used in traditional medicine to treat diabetes, but evidence is lacking.
  • Fever or common cold
    Kudzu is used in traditional medicine for these purposes, but human studies are lacking.
  • Neck or eye pain
    Kudzu is used in traditional medicine for these purposes. Although animal studies suggest kudzu may reduce inflammation and pain in combination with other herbs, human studies are lacking.
• Do Not Take If
  • You have hypersensitivity to kudzu.
  • You have hormone-sensitive cancer: Kudzu has estrogenic activity.
  • You are taking tamoxifen: Isoflavones in kudzu may interfere with the effects of tamoxifen which is used for estrogen-dependent breast cancer.
  • You are taking methotrexate: In animal studies, taking kudzu at the same time reduced elimination of the drug methotrexate, causing increased levels of the drug. Clinical relevance has yet to be determined.
  • You are taking antidiabetic medication: Animal studies suggest a key component in kudzu may increase the activity of these medications. Clinical relevance has yet to be determined.
• Side Effects

  Short-term effects on blood and liver tests occurred in a small study of postmenopausal women. A few other small studies reported no significant side effects.

  Case reports

  Kidney problems: In a middle-aged woman who consumed kudzu root juice to promote health and well-being for 10 days, and without evidence of any other causes. Symptoms of appetite loss, nausea, vomiting, and upper abdomen discomfort improved within several days after juice discontinuation and treatment.

  Liver injury: In a 55-year-old man previously in good health who was hospitalized with mild fever, brown urine, and elevated liver enzymes. Mistletoe and kudzu extracts which he took to promote general health were suspected, although it is uncertain whether either, both, or an interaction between the two caused these adverse effects.

• Scientific Name

  Pueraria mirifica, Pueraria thunbergiana, Pueraria lobata, Pueraria montana, Radix puerariae

• Clinical Summary

  Kudzu is a botanical used in traditional medicine to treat alcoholism, cardiovascular disease, menopausal symptoms, diabetes, fever, the common cold, and neck or eye pain. There are several species of kudzu and both the flowers and root extract are used for their medicinal properties. Isoflavones, the major components of kudzu, are thought to be responsible for its potential effects.

  In vitro, kudzu has demonstrated antiproliferative ⁽¹⁾, anti-inflammatory ⁽³⁾, and neuroprotective ^(16) (18) properties. In animal studies, feeding with kudzu root suppressed alcohol intake and withdrawal symptoms ⁽⁴⁾.

  Studies of kudzu in humans are limited and have mostly focused on its effects on alcohol consumption or climacteric symptoms. In heavy drinkers, data suggest kudzu may be a useful adjunct to reduce alcohol intake ^{(9) (19) (23)}. In moderate drinkers, it was shown to not disturb sleep wake/cycles, as can occur during withdrawal or with other medications that treat dependence ⁽²⁰⁾. In another small study, a single dose of kudzu extract reduced alcohol consumption ⁽²⁵⁾.

  Other preliminary studies suggest kudzu may improve symptoms such as hot flushes and night sweats in perimenopausal women ^{(5) (10) (21)}, and cognitive function in postmenopausal women ⁽⁶⁾. Although a topical P. mirifica gel improved vaginal symptoms in postmenopausal women, a conjugated estrogen cream was found to be more effective ⁽²⁶⁾. A recent systematic review of P. mirifica regarding efficacy for menopausal symptoms is inconclusive ⁽²⁷⁾. In addition, another systematic review determined that evidence on benefits for any condition with various species of kudzu are limited and unclear ⁽²⁸⁾.

  Because human and animal studies suggest some estrogenic effects ^{(5) (10) (11)}, individuals with hormone-sensitive cancers and those taking tamoxifen should avoid kudzu.

• Purported Uses
  • Alcoholism
  • Cold, fever
  • Diabetes
  • Pain
  • Menopause
• Mechanism of Action

  Anti-inflammatory properties are attributed to decreased prostaglandin E2 and tumor necrosis factor-alpha release, both of which are involved in inflammatory processes ⁽³⁾. The isoflavone tectorigenin demonstrated antiproliferative activity via cell differentiation and reduced expression of Bcl-2, an antiapoptotic protein ⁽¹⁾. In animal studies, peurarin may alleviate chronic alcoholic liver injury via inhibition of endotoxin gut-leakage, activation of Kupffer cells, and expression of lipopolysaccharide receptors ⁽²²⁾.

  In humans, benefits from kudzu on hot flashes, night sweats, and cognitive function are also attributed to isoflavones ^(5) (6). Puerarin particularly has been credited with influencing alcohol consumption patterns, although the mechanism by which this might occur is unknown ⁽¹⁹⁾.

• Contraindications
  • Hypersensitivity to kudzu ⁽²⁸⁾
  • Patients with estrogen receptor-positive (ER+) breast cancer ^(5) (10)
• Adverse Reactions

  In one small study of postmenopausal women, transient negative profiles including anemia and liver profiles ⁽⁵⁾. Other small studies reported no significant adverse effects ^{(9) (19) (20) (21) (23)}.

  Case reports

  Acute interstitial nephritis: In a middle-aged woman who consumed kudzu root juice to promote health and well-being for 10 days, and without evidence of any other causes ⁽²⁹⁾. Symptoms of appetite loss, nausea, vomiting, and epigastric discomfort, improved within several days after discontinuation and conservative treatment.

  Liver injury: In a 55-year-old man previously in good health who was hospitalized with mild fever, brown urine, and elevated AST/ALT levels. These adverse effects were attributed to the ingestion of mistletoe and kudzu extracts which he took to promote general health, although it is uncertain whether either, both, or an interaction between the two caused these adverse effects ⁽³⁰⁾.

• Herb-Drug Interactions
  • Tamoxifen: Human and animal studies suggest that kudzu has some estrogenic activity ^{(5) (10) (11)}. Therefore, it may antagonize the effects of tamoxifen, although clinical relevance has yet to be determined.
  • Methotrexate: In animal models, coadministration of a root decoction of kudzu reduced the elimination of methotrexate, resulting in increased methotrexate levels ⁽¹⁷⁾.
  • Antidiabetic drugs: Animal models suggest puerarin also has antihyperglycemic effects ⁽¹⁴⁾. Clinical relevance has yet to be determined.
  • Cytochrome P450 2D6: In vitro, puerarin inhibited activity of CYP2D6 and can alter the metabolism of drugs that are substrates of this enzyme ⁽¹⁵⁾. Clinical relevance has yet to be determined.
  • Cytochrome P450 1A2: In vitro, puerarin induced CYP1A2 and may affect the metabolism of some drugs that are substrates of this enzyme ⁽¹⁵⁾. Clinical relevance has yet to be determined.
• References

  1. Lee KT, et al. Tectorigenin, an isoflavone of Pueraria thunbergiana Benth., induces differentiation and apoptosis in human promyelocytic leukemia HL-60 cells. Biol Pharm Bull 2001; 24(10):1117-1121.

  2. Boue SM, et al. Evaluation of the estrogenic effects of legume extracts containing phytoestrogens. J Agric Food Chem 2003; 51(8):2193-2199.

  3. Kim IT, et al. Anti-inflammatory and anti-nociceptive effects of the extract from Kalopanax pictus, Pueraria thunbergiana and Rhus verniciflua. J Ethnopharmacol 2004; 94(1):165-173.

  4. Benlhabib E, et al. Kudzu root extract suppresses voluntary alcohol intake and alcohol withdrawal symptoms in P rats receiving free access to water and alcohol. J Med Food 2004; 7(2):168-179.

  5. Lamlertkittikul S and Chandeying V. Efficacy and safety of Pueraria mirifica (Kwao Kruea Khao) for the treatment of vasomotor symptoms in perimenopausal women: Phase II Study. J Med Assoc Thai 2004; 87(1):33-40.

  6. Woo J, et al. Comparison of Pueraria lobata with hormone replacement therapy in treating the adverse health consequences of menopause. Menopause 2003; 10(4):352-361.

  7. Jang MH, et al. Protective effects of puerariaeflos against ethanol-induced apoptosis on human neuroblastoma cell line SK-N-MC. Jpn J Pharmacol 2001; 87(4):338-342.

  8. MICROMEDEX(R) Healthcare Series. 120. 2004. Thomson MICROMEDEX.

  9. Lukas SE, et al. An Extract of the Chinese Herbal Root Kudzu Reduces Alcohol Drinking by Heavy Drinkers in a Naturalistic Setting. Alcohol Clin Exp Res. 2005;29(5):756-62.

  10. Chandeying V, Sangthawan M. Efficacy comparison of Pueraria mirifica (PM) against conjugated equine estrogen (CEE) with/without medroxyprogesterone acetate (MPA) in the treatment of climacteric symptoms in perimenopausal women: phase III study. J Med Assoc Thai. 2007 Sep;90(9):1720-6.

  11. Cherdshewasart W, Sriwatcharakul S, Malaivijitnond S. Variance of estrogenic activity of the phytoestrogen-rich plant. Maturitas. 2008 Dec 20;61(4):350-7.

  12. Penetar DM, Teter CJ, Ma Z, et al. Pharmacokinetic profile of the isoflavone puerarin after acute and repeated administration of a novel kudzu extract to human volunteers. J Altern Complement Med. 2006 Jul-Aug;12(6):543-8.

  13. Santosh N, Mohan K, Royana S, Yamini TB. Hepatotoxicity of tubers of Indian Kudzu (Pueraria tuberosa) in rats. Food Chem Toxicol. 2010 Apr;48(4):1066-71.

  14. Hsu FL, Liu IM, Kuo DH, et al. Antihyperglycemic effect of puerarin in streptozotocin-induced diabetic rats. J Nat Prod. 2003 Jun;66(6):788-92.

  15. Zheng J, Chen B, Jiang B, et al. The effects of puerarin on CYP2D6 and CYP1A2 activities in vivo. Arch Pharm Res. 2010 Feb;33(2):243-6.

  16. Zhu G, Wang X, Chen Y, et al. Puerarin protects dopaminergic neurons against 6-hydroxydopamine neurotoxicity via inhibiting apoptosis and upregulating glial cell line-derived neurotrophic factor in a rat model of Parkinson’s disease. Planta Med. 2010 Nov;76(16):1820-6.

  17. Chiang HM, Fang SH, Wen KC, et al. Life-threatening interaction between the root extract of Pueraria lobata and methotrexate in rats. Toxicol Appl Pharmacol. 2005 Dec 15;209(3):263-8.

  18. Xing G, Dong M, Li X, et al. Neuroprotective effects of puerarin against beta-amyloid-induced neurotoxicity in PC12 cells via a PI3K-dependent signaling pathway. Brain Res Bull. 2011 May 30;85(3-4):212-8.

  19. Penetar DM, Toto LH, Farmer SL, et al. The isoflavone puerarin reduces alcohol intake in heavy drinkers: A pilot study. Drug Alcohol Depend. 2012 Nov 1;126(1-2):251-6.

  20. Bracken BK, Penetar DM, Maclean RR, Lukas SE. Kudzu root extract does not perturb the sleep/wake cycle of moderate drinkers. J Altern Complement Med. 2011 Oct;17(10):961-6.

  21. Virojchaiwong P, Suvithayasiri V, Itharat A. Comparison of Pueraria mirifica 25 and 50 mg for menopausal symptoms. Arch Gynecol Obstet. 2011 Aug;284(2):411-9.

  22. Peng J, Cui T, Huang F, et al. Puerarin Ameliorates Experimental Alcoholic Liver Injury by Inhibition of Endotoxin Gut-leakage, kupffer Cell Activation and Lipopolysaccharide Receptors Expression. J Pharmacol Exp Ther. 2013 Mar;344(3):646-54.

  23. Lukas SE, Penetar D, Su Z, et al. A standardized kudzu extract (NPI-031) reduces alcohol consumption in nontreatment-seeking male heavy drinkers. Psychopharmacology (Berl). 2013 Mar;226(1):65-73.

  24. Jo SJ, Shin H, Paik SH, et al. Efficacy and Safety of Pueraria lobata Extract in Gray Hair Prevention: A Randomized, Double-Blind, Placebo-Controlled Study. Ann Dermatol. 2013 May;25(2):218-22.

  25. Penetar DM, Toto LH, Lee DY, et al. A single dose of kudzu extract reduces alcohol consumption in a binge drinking paradigm. Drug Alcohol Depend. Aug 1 2015;153:194-200.

  26. Suwanvesh N, Manonai J, Sophonsritsuk A, et al. Comparison of Pueraria mirifica gel and conjugated equine estrogen cream effects on vaginal health in postmenopausal women. Menopause. Feb 2017;24(2):210-215.

  27. Kongkaew C, Scholfield NC, Dhippayom T, et al. Efficacy and safety of Pueraria candollei var. mirifica (Airy Shaw & Suvat.) Niyomdham for menopausal women: A systematic review of clinical trials and the way forward. J Ethnopharmacol. Apr 24 2018;216:162-174.

  28. Ulbricht C, Costa D, Dam C, et al. An evidence-based systematic review of kudzu (Pueraria lobata) by the Natural Standard Research Collaboration. J Diet Suppl. Mar 2015;12(1):36-104.

  29. Jung JM, Kwon SH, Noh H, et al. Acute interstitial nephritis following kudzu root juice ingestion. Clin Nephrol. Oct 2013;80(4):298-300.

  30. Kim HJ, Kim H, Ahn JH, et al. Liver injury induced by herbal extracts containing mistletoe and kudzu. J Altern Complement Med. Mar 2015;21(3):180-185.