Pau D’arco

• How It Works

  Pau d’arco has antibacterial and anticancer activities in laboratory studies, but these effects have not been shown in humans.

  Pau d’arco is derived from the inner bark of several species of Tabebuia trees native to South America. Also known as taheebo or lapacho, it is used as a tea in traditional medicine for a wide range of ailments. In laboratory studies, compounds extracted from pau d’arco showed antibacterial, antifungal, anti-inflammatory, antidepressant, and anticancer properties. However, data from human studies are limited. The safety and effectiveness of these compounds for treating cancer remain unclear.

• Purported Uses
  • To treat cancer
    A small study done on 21 cancer patients did not show any benefits of pau d’arco. Side effects including nausea, vomiting, and blood-thinning were observed.
  • To treat infections
    Laboratory studies showed that pau d’arco has antibacterial and antifungal activities. It has not been tested in humans.
• Do Not Take If
  • You are taking anticoagulants/antiplatelet drugs: Theoretically, pau d’arco may increase the risk of bleeding with these drugs.
• Side Effects
  • Nausea, vomiting, urine discoloration.
  • Animal studies reported anemia, and reproductive and chromosomal abnormalities.
• Scientific Name

  Handroanthus impetiginosus, Tabebuia impetiginosa, Tabebuia avellanedae, Tabebuia heptaphylla

• Clinical Summary

  Pau d’arco is derived from the inner bark of several species of Tabebuia trees native to South America. Also known as taheebo or lapacho, it is used as a tea in traditional medicine for a wide range of ailments. Modern preparations in the form of oral tablets or capsules are marketed as dietary supplements to treat infections and cancer ^{(1) (2) (3) (4)}.

  In vitro and in vivo studies demonstrate antibacterial ^(5) (6), antifungal ⁽⁷⁾, antipsoriatic ⁽⁸⁾, immunomodulatory ^(9) (10), anti-inflammatory ^(11) (12), antidepressant ⁽¹³⁾, anticoagulant ^(10) (14) and anticancer ^{(1) (2) (3) (4) (15) (16)} properties. Human studies are needed to validate these effects.

  In a small single-arm study, the naphthoquinone lapachol, at the given dose, did not show clinical improvement in patients with chronic myelocytic leukemia. Side effects including nausea, vomiting, and prolongation of prothrombin were observed ⁽¹⁷⁾.

• Purported Uses
  • Cancer treatment
  • Antibacterial
  • Antifungal
• Mechanism of Action

  Lapachol and beta-lapachone, isolated from the inner bark of trees used to produce Pau d’arco, are thought to be the active constituents that are responsible for its pharmacological activities ⁽²⁰⁾. Beta-lapachone downregulates cyclooxygenase (COX-2) and telomerase activities ⁽¹⁾. It also induces apoptosis in cancer cells via mitochondrial signaling ⁽²⁾ or by activating caspases ^{(5) (9) (2)}. The antimetastatic activity of beta-lapachone occurs by inducing Egr-1, known to suppress metastasis, thereby decreasing the invasive ability of cancer cells ⁽⁴⁾. A water extract of Taheebo showed anti-proliferative effects on hormone-sensitive MCF7 breast cancer cells by modulating gene expression, thereby interfering with cell cycle progression. At high doses, it also has anti-estrogenic effects through the inhibition of estrogen receptor signaling ⁽¹⁶⁾. A methanolic extract of taheebo inhibited cell proliferation through the extracelluar signal regulated kinase (ERK1/2) mitogen activated protein kinase (MAPK) pathway ⁽¹⁰⁾.

  Lapachol’s anticoagulant activity is due to the inhibition of vitamin K epoxide and quinone reductases, an action similar to that of warfarin ⁽¹⁴⁾.

  However, it is important to note that the clinical effects of Pau d’arco are difficult to predict because they are influenced by several factors including variation in plant species or plant parts, extraction methods, bioavailability of the active compounds, dosages and routes of administration.

• Adverse Reactions

  Reported: Nausea, vomiting, urine discoloration ⁽¹⁷⁾
  Anemia: Animal studies showed that large, chronic dosing of lapachol can cause anemia ⁽²¹⁾.
  Reproductive toxicity: Short-term administration of lapachol caused significant reduction in the weight of seminal vesicle ⁽²²⁾.
  Lapachol also has fetotoxic effects ⁽²³⁾, and oral administration of lapachol caused chromosomal abnormalities ⁽²⁴⁾.

• Herb-Drug Interactions
  • Anticoagulant/antiplatelet drugs: Pau d’arco may increase their activity ^{(25) (14) (10)}
• Herb Lab Interactions
  • Lapochol may cause prolongation of prothrombin time^(17).
• References

  1. Lee JH, Cheong J, Park YM, et al. Down-regulation of cyclooxygenase-2 and telomerase activity by beta-lapachone in human prostate carcinoma cells. Pharmacol Res. Jun 2005;51(6):553-560. doi: 10.1016/j.phrs.2005.02.004

  2. Lee JI, Choi DY, Chung HS, et al. Beta-lapachone induces growth inhibition and apoptosis in bladder cancer cells by modulation of Bcl-2 family and activation of caspases. Exp Oncol. Mar 2006;28(1):30-35.

  3. Kung HN, Chien CL, Chau GY, et al. Involvement of NO/cGMP signaling in the apoptotic and anti-angiogenic effects of beta-lapachone on endothelial cells in vitro. J Cell Physiol. May 2007;211(2):522-532. doi: 10.1002/jcp.20963

  4. Kim SO, Kwon JI, Jeong YK, et al. Induction of Egr-1 is associated with anti-metastatic and anti-invasive ability of beta-lapachone in human hepatocarcinoma cells. Biosci Biotechnol Biochem. Sep 2007;71(9):2169-2176. doi: 10.1271/bbb.70103

  5. Park BS, Lee HK, Lee SE, et al. Antibacterial activity of Tabebuia impetiginosa Martius ex DC (Taheebo) against Helicobacter pylori. J Ethnopharmacol. Apr 21 2006;105(1-2):255-262. doi: 10.1016/j.jep.2005.11.005

  6. Pereira EM, Machado Tde B, Leal IC, et al. Tabebuia avellanedae naphthoquinones: activity against methicillin-resistant staphylococcal strains, cytotoxic activity and in vivo dermal irritability analysis. Ann Clin Microbiol Antimicrob. 2006;5:5. doi: 10.1186/1476-0711-5-5

  7. Portillo A, Vila R, Freixa B, et al. Antifungal activity of Paraguayan plants used in traditional medicine. J Ethnopharmacol. Jun 2001;76(1):93-98.

  8. Muller K, Sellmer A, Wiegrebe W. Potential antipsoriatic agents: lapacho compounds as potent inhibitors of HaCaT cell growth. J Nat Prod. Aug 1999;62(8):1134-1136. doi: 10.1021/np990139r

  9. Bohler T, Nolting J, Gurragchaa P, et al. Tabebuia avellanedae extracts inhibit IL-2-independent T-lymphocyte activation and proliferation. Transpl Immunol. Feb 2008;18(4):319-323. doi: 10.1016/j.trim.2007.08.005

  10. Son DJ, Lim Y, Park YH, et al. Inhibitory effects of Tabebuia impetiginosa inner bark extract on platelet aggregation and vascular smooth muscle cell proliferation through suppressions of arachidonic acid liberation and ERK1/2 MAPK activation. J Ethnopharmacol. Nov 3 2006;108(1):148-151. doi: 10.1016/j.jep.2006.04.016

  11. Byeon SE, Chung JY, Lee YG, et al. In vitro and in vivo anti-inflammatory effects of taheebo, a water extract from the inner bark of Tabebuia avellanedae. J Ethnopharmacol. Sep 2 2008;119(1):145-152. doi: 10.1016/j.jep.2008.06.016

  12. Xu J, Wagoner G, Douglas JC, et al. Beta-Lapachone ameliorization of experimental autoimmune encephalomyelitis. J Neuroimmunol. Jan 15 2013;254(1-2):46-54. doi: 10.1016/j.jneuroim.2012.09.004

  13. Freitas AE, Budni J, Lobato KR, et al. Antidepressant-like action of the ethanolic extract from Tabebuia avellanedae in mice: evidence for the involvement of the monoaminergic system. Prog Neuropsychopharmacol Biol Psychiatry. Mar 17 2010;34(2):335-343. doi: 10.1016/j.pnpbp.2009.12.010

  14. Preusch PC, Suttie JW. Lapachol inhibition of vitamin K epoxide reductase and vitamin K quinone reductase. Arch Biochem Biophys. Nov 1 1984;234(2):405-412.

  15. Sunassee SN, Veale CG, Shunmoogam-Gounden N, et al. Cytotoxicity of lapachol, beta-lapachone and related synthetic 1,4-naphthoquinones against oesophageal cancer cells. Eur J Med Chem. Apr 2013;62:98-110. doi: 10.1016/j.ejmech.2012.12.048

  16. Mukherjee B, Telang N, Wong GY. Growth inhibition of estrogen receptor positive human breast cancer cells by Taheebo from the inner bark of Tabebuia avellandae tree. Int J Mol Med. Aug 2009;24(2):253-260.

  17. Block JB, Serpick AA, Miller W, et al. Early clinical studies with lapachol (NSC-11905). Cancer Chemother Rep 2. Dec 1974;4(4):27-28.

  18. Warashina T, Nagatani Y, Noro T. Further constituents from the bark of Tabebuia impetiginosa. Phytochemistry. Mar 2005;66(5):589-597. doi: 10.1016/j.phytochem.2005.01.005

  19. Koyama J, Morita I, Tagahara K, et al. Cyclopentene dialdehydes from Tabebuia impetiginosa. Phytochemistry. Apr 2000;53(8):869-872.

  20. Gomez Castellanos JR, Prieto JM, Heinrich M. Red Lapacho (Tabebuia impetiginosa)—a global ethnopharmacological commodity? Journal of ethnopharmacology. Jan 12 2009;121(1):1-13.

  21. Morrison RK, Brown DE, Oleson JJ, et al. Oral toxicology studies with lapachol. Toxicol Appl Pharmacol. Jul 1970;17(1):1-11.

  22. de Cassia da Silveira ESR, de Oliveira Guerra M. Reproductive toxicity of lapachol in adult male Wistar rats submitted to short-term treatment. Phytother Res. Jul 2007;21(7):658-662. doi: 10.1002/ptr.2141

  23. Felicio AC, Chang CV, Brandao MA, Peters VM, Guerra Mde O. Fetal growth in rats treated with lapachol. Contraception. Oct 2002;66(4):289-293.

  24. Maistro EL, Fernandes DM, Pereira FM, et al. Lapachol induces clastogenic effects in rats. Planta Med. Jun 2010;76(9):858-862. doi: 10.1055/s-0029-1240816.

  25. Norred CL, Brinker F. Potential coagulation effects of preoperative complementary and alternative medicines. Alternative therapies in health and medicine. Nov-Dec 2001;7(6):58-67.