Nettle

• How It Works

  Nettle was shown effective in relieving symptoms of benign prostatic hyperplasia (BPH), and osteoarthritis.

  Nettle is a perennial herbaceous flowering plant, native to Asia, Europe, and North America. The root is widely used to treat benign prostatic hypertrophy (BPH), allergies, arthritis, and inflammation. Nettle is usually combined with herbs such as saw palmetto and pygeum for the treatment of BPH.

  Data from clinical studies indicate benefits of nettle in the treatment of osteoarthritis of hip, knee, hand, gonarthritis, and in relieving symptoms associated with benign prostatic syndrome (BPS). A combination of saw palmetto and nettle greatly improved nocturnal voiding frequency compared to placebo, and was similar to tamsulosin or finasteride in patients with moderate to severe lower urinary tract symptoms (LUTS)/BPH. Nettle was shown to improve glycemic control in type-2 diabetic patients. It also showed anticancer effects in laboratory studies, but clinical trials have yet to be conducted.

• Purported Uses
  • To treat allergies
    Evidence is lacking to support this claim.
  • To treat arthritis
    Clinical trials support the topical use of nettle for arthritis of the hip, knee, and hand. Larger studies are needed to confirm these data.
  • To treat benign prostatic hypertrophy (BPH)
    When combined with other herbs, nettle has shown positive results in clinical trials.
  • To clear up chest congestion
    Evidence is lacking to support this claim.
  • To reduce inflammation
    Nettle may have anti-inflammatory activities, but clinical trials have yet to be conducted.
  • To calm muscle spasms
    Evidence is lacking to support this claim.
  • To treat urinary tract disorders and relieve difficult or painful urination
    Nettle was shown to have beneficial effects in clinical studies.
• Do Not Take If
  • You are taking diuretics: Nettle can have additive effects.
  • You are taking hypotensive drugs: Nettle has hypotensive action and may have additive effects.
  • You are taking cytochrome P450 substrate drugs: Nettle may increase the risk of side effects of these drugs.
• Side Effects
  • A case of enlarged breasts has been reported in a man following consumption of nettle tea.
  • Nipple discharge was reported in a woman after ingestion of nettle tea.
  • A breastfed, 17-day-old infant developed hives following the mother’s use of water boiled with stinging nettle to heal nipple cracks.
  • Low blood sugar was reported in a 78-year-old man after taking an herbal remedy containing nettle for benign prostatic hypertrophy.
  • Allergic rhinitis has been reported in 2 patients following exposure to nettle pollen
• Scientific Name

  Urtica dioica

• Clinical Summary

  Nettle is a perennial herbaceous flowering plant, native to Asia, Europe, and North America. The root is widely used to treat benign prostatic hypertrophy (BPH), allergies, arthritis, and inflammation. Nettle is usually combined with herbs such as saw palmetto and pygeum for the treatment of BPH. Several compounds have been isolated from nettle including flavonoid glycosides that appear to contribute to its biological effects, although the precise mechanism of action is unclear. In vitro and animal studies indicate that nettle extract has reno- ⁽¹⁾ and hepatoprotective ⁽²⁾ properties, and is effective against colitis in mice ⁽³⁾.

  Data from clinical trials suggest benefits of nettle in the treatment of osteoarthritis of hip, knee ⁽⁴⁾ hand ⁽⁵⁾ , gonarthritis ⁽²⁰⁾, and in ameliorating symptoms associated with benign prostatic syndrome (BPS) ^{(6) (7) (8)}. A combination of saw palmetto and nettle was reported to affect significant improvements in nocturnal voiding frequency compared to placebo, and was similar to tamsulosin or finasteride, in patients with moderate to severe lower urinary tract symptoms/BPH ⁽²¹⁾. In another study nettle was shown to improve glycemic control in type-2 diabetic patients ⁽⁹⁾.

  Nettle was also shown to have anti-proliferative effects in prostate cancer cells ⁽¹⁰⁾; to protect against cisplatin-induced toxicity ⁽¹¹⁾; to enhance the sensitivity of breast cancer cells to paclitaxel ⁽²²⁾; and to increase cisplatin cytotoxicity in non-small cell lung cancer cells ⁽²³⁾.

• Purported Uses
  • Allergies
  • Arthritis
  • Benign prostatic hypertrophy (BPH)
  • Chest congestion
  • Dysuria
  • Inflammation
  • Oily skin
  • Promote urination
  • Spasms
  • Urinary tract disorders
• Mechanism of Action

  In vitro studies show that nettle extract inhibits several inflammatory events that are responsible for the symptoms of seasonal allergies ⁽²⁾. They include the antagonist and negative agonist activity against the histamine-1 (H1) receptor, and inhibition of prostaglandin formation via inhibition of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and hematopoietic prostaglandin D2 synthase (HPGDS), which are key enzymes in pro-inflammatory pathways ⁽²⁾.

  Phenolic compounds derived from nettle were shown to inhibit alpha-glucosidase and alpha-amylase, chief enzymes involved in type-2 diabetes ⁽²⁴⁾. Inhibition of these enzymes results in decreasing the reabsorption of glucose in the intestine.

  A number of compounds in essential oil derived from nettle including carvacrol may have cytotoxic and genotoxic effects ⁽¹²⁾. And a methanolic extract of nettle was found to reduce experimentally induced prostatic hyperplasia in mice ⁽¹⁷⁾.

• Adverse Reactions
  • A case of gynecomastia was reported in a man following consumption of nettle tea ⁽¹⁵⁾.
  • Galactorrhea was reported in a woman after ingestion of nettle tea ⁽¹⁵⁾.
  • A breastfed, 17-day-old infant developed urticaria following the mother’s use of water boiled with stinging nettle to heal nipple cracks ⁽¹⁶⁾.
  • Hypoglycemia was reported in a 78-year-old man after taking an herbal remedy containing nettle for benign prostatic hypertrophy ⁽¹⁷⁾.
  • Allergic rhinitis has been reported in 2 patients following exposure to nettle pollen ⁽²⁵⁾.
  • Two adults who were severely stung following contact with Australian nettle tree required ICU admission. It took 2–3 weeks for them to return to normalcy, with urticaria and pain continuing for several months ⁽²⁶⁾.
• Herb-Drug Interactions
  • Cytochrome P450 substrates: Nettle inhibits cytochrome P450 enzymes and may affect the intracellular concentration of drugs metabolized by these enzymes ⁽¹⁸⁾.
  • Diuretics: Theoretically nettle may have an additive effect due to its diuretic activity ⁽¹⁹⁾.
  • Hypotensives: Nettle has hypotensive action and may enhance the effects of hypotensive drugs ⁽¹⁹⁾.
• References

  1. Sayhan MB, Kanter M, Oguz S, et al. Protective effect of Urtica dioica L. on renal ischemia/reperfusion injury in rat. J Mol Histol. Dec 2012;43(6):691-698. doi: 10.1007/s10735-012-9436-9

  2. Oguz S, Kanter M, Erboga M, et al. Protective effect of Urtica dioica on liver damage induced by biliary obstruction in rats. Toxicol Ind Health. Oct 2013;29(9):838-845. doi: 10.1177/0748233712445045

  3. Genc Z, Yarat A, Tunali-Akbay T, et al. The effect of stinging nettle (Urtica dioica) seed oil on experimental colitis in rats. J Med Food. Dec 2011;14(12):1554-1561. doi: 10.1089/jmf.2011.0028

  4. Jacquet A, Girodet PO, Pariente A, et al. Phytalgic, a food supplement, vs placebo in patients with osteoarthritis of the knee or hip: a randomised double-blind placebo-controlled clinical trial. Arthritis Res Ther. 2009;11(6):R192. doi: 10.1186/ar2891

  5. Randall C, Randall H, Dobbs F, et al. Randomized controlled trial of nettle sting for treatment of base-of-thumb pain. J R Soc Med. Jun 2000;93(6):305-309.

  6. Schneider T, Rubben H. [Stinging nettle root extract (Bazoton-uno) in long term treatment of benign prostatic syndrome (BPS). Results of a randomized, double-blind, placebo controlled multicenter study after 12 months]. Urologe A. Mar 2004;43(3):302-306. doi: 10.1007/s00120-004-0532-7

  7. Safarinejad MR. Urtica dioica for treatment of benign prostatic hyperplasia: a prospective, randomized, double-blind, placebo-controlled, crossover study. J Herb Pharmacother. 2005;5(4):1-11.

  8. Lopatkin N, Sivkov A, Schlafke S, et al. Efficacy and safety of a combination of Sabal and Urtica extract in lower urinary tract symptoms—long-term follow-up of a placebo-controlled, double-blind, multicenter trial. Int Urol Nephrol. 2007;39(4):1137-1146. doi: 10.1007/s11255-006-9173-7

  9. Kianbakht S, Khalighi-Sigaroodi F, Dabaghian FH. Improved glycemic control in patients with advanced type 2 diabetes mellitus taking Urtica dioica leaf extract: a randomized double-blind placebo-controlled clinical trial. Clin Lab. 2013;59(9-10):1071-1076.

  10. Konrad L, Muller HH, Lenz C, et al. Antiproliferative effect on human prostate cancer cells by a stinging nettle root (Urtica dioica) extract. Planta Med. Feb 2000;66(1):44-47. doi: 10.1055/s-2000-11117

  11. Ozkol H, Musa D, Tuluce Y, et al. Ameliorative influence of Urtica dioica L against cisplatin-induced toxicity in mice bearing Ehrlich ascites carcinoma. Drug Chem Toxicol. Jul 2012;35(3):251-257. doi: 10.3109/01480545.2011.598531

  12. Gul S, Demirci B, Baser KH, et al. Chemical composition and in vitro cytotoxic, genotoxic effects of essential oil from Urtica dioica L. Bull Environ Contam Toxicol. May 2012;88(5):666-671. doi: 10.1007/s00128-012-0535-9

  13. Roschek B, Jr., Fink RC, McMichael M, et al. Nettle extract (Urtica dioica) affects key receptors and enzymes associated with allergic rhinitis. Phytother Res. Jul 2009;23(7):920-926. doi: 10.1002/ptr.2763

  14. Lichius JJ, Renneberg H, Blaschek W, et al. The inhibiting effects of components of stinging nettle roots on experimentally induced prostatic hyperplasia in mice. Planta Med. Oct 1999;65(7):666-668. doi: 10.1055/s-2006-960844

  15. Sahin M, Yilmaz H, Gursoy A, et al. Gynaecomastia in a man and hyperoestrogenism in a woman due to ingestion of nettle (Urtica dioica). N Z Med J. 2007;120(1265):U2803.

  16. Uslu S, Bulbul A, Diler B, et al. Urticaria due to Urtica dioica in a neonate. Eur J Pediatr. Mar 2011;170(3):401-403. doi: 10.1007/s00431-010-1327-z

  17. Edgcumbe DP, McAuley D. Hypoglycaemia related to ingestion of a herbal remedy. Eur J Emerg Med. Aug 2008;15(4):236-237. doi: 10.1097/MEJ.0b013e3282f4d178

  18. Ozen T, Korkmaz H. Modulatory effect of Urtica dioica L. (Urticaceae) leaf extract on biotransformation enzyme systems, antioxidant enzymes, lactate dehydrogenase and lipid peroxidation in mice. Phytomedicine. 2003;10(5):405-415. doi: 10.1078/0944-7113-00275

  19. Tahri A, Yamani S, Legssyer A, et al. Acute diuretic, natriuretic and hypotensive effects of a continuous perfusion of aqueous extract of Urtica dioica in the rat. J Ethnopharmacol. Nov 2000;73(1-2):95-100.

  20. Moré M, Gruenwald J, Pohl U, Uebelhack R. A Rosa canina – Urtica dioica – Harpagophytum procumbens/zeyheri Combination Significantly Reduces Gonarthritis Symptoms in a Randomized, Placebo-Controlled Double-Blind Study. Planta Med. 2017 Dec;83(18):1384-1391.

  21. Oelke M, Berges R, Schläfke S, Burkart M. Fixed-dose combination PRO 160/120 of sabal and urtica extracts improves nocturia in men with LUTS suggestive of BPH: re-evaluation of four controlled clinical studies. World J Urol. 2014 Oct;32(5):1149-54.

  22. Mohammadi A, Mansoori B, Aghapour M, Shirjang S, Nami S, Baradaran B. The Urtica dioica extract enhances sensitivity of paclitaxel drug to MDA-MB-468 breast cancer cells Biomed Pharmacother. 2016 Oct;83:835-842.

  23. D’Abrosca B, Ciaramella V, Graziani V, et al. Urtica dioica L. inhibits proliferation and enhances cisplatin cytotoxicity in NSCLC cells via Endoplasmic Reticulum-stress mediated apoptosis. Sci Rep. 2019 Mar 21;9(1):4986.

  24. Bouchentouf S, Said G, Kambouche N, Kress S. Identification of phenolic compounds from nettle as new candidate inhibitors of main enzymes responsible on type-II diabetes. Curr Drug Discov Technol. 2018 Aug 28.

  25. Tiotiu A, Brazdova A, Longé C, et al. Urtica dioica pollen allergy: Clinical, biological, and allergomics analysis. Ann Allergy Asthma Immunol. 2016 Nov;117(5):527-534.

  26. Maor D, Little M. Skin contact with a stinging tree requiring intensive care unit admission. Contact Dermatitis. 2017 Nov;77(5):335-337.