Health Care Professional Information

Scientific Name
Tabebuia impetiginosa, Tabebuia avellanedae, Tabebuia heptaphylla
Common Name

Ipe-Roxo, lapacho, purple lapacho, trumpet bush, taheebo, lapacho tree

Clinical Summary

Pau d'arco is a tree native to South America. Preparations derived from the bark have been traditionally used to treat bacterial, fungal, or viral infections, and cancer. Quinones have been identified as the main active constituents (1) (2) (3) (4).

In vitro and in vivo studies of compounds isolated from pau d'arco demonstrate antibacterial (5) (6) (7) (8), antifungal (9), antipsoriatic (10), immunomodulatory (11) (12), anti-inflammatory (13) (14), antidepressant (15), anticoagulant (16), anticancer (1) (2) (3) (4) (17), and antimetastatic (4) properties. Taheebo extract from the inner bark of pau d'arco selectively inhibits growth of ER positive breast cancer cells (18), but human studies are needed to validate these effects.

In a small single-arm study, the isolated naphthoquinone lapachol failed to show any effects on patients with non-leukemic tumors or chronic myelocytic leukemia (19).

Purported Uses
  • Cancer treatment
  • Antibacterial
  • Antifungal
  • Naphthoquinones: lapachol, xyloidone; beta-lapachone
  • Anthroquinones: tabebuin
  • Flavonoids: Quercetin
  • Glycosides: Iridoid, lignan, isocoumarin, phenylthanoid, phenolic
  • Cyclopentene dialdehydes
    (5) (20) (21)
Mechanism of Action

The anticoagulant effect of lapachol is due to the inhibition of vitamin K epoxide and quinone reductases (16).

The anticancer activity of beta-lapachone, an isolated quinone compound, may be due to downregulation of cyclooxygenase (COX-2) and telomerase activities (1). Beta-lapachone also induces apoptosis in cancer cells via mitochondrial-signaling (2) or by activating caspases (5) (11) (22). The antimetastatic activity of beta-lapachone occurs by inducing Egr-1, known to suppress metastasis, thereby decreasing the invasive ability of cancer cells (4).


Women who are pregnant or trying to conceive should avoid pau d’arco (25).

Adverse Reactions

Reported: Nausea, vomiting, urine discoloration (19).

In animal studies
With large, chronic dosing of lapachol (23).
Reproductive toxicity: Short-term administration of lapachol caused significant reduction in seminal vesicle weight (24). Lapachol also has an abortifacient effect (25).
Clastogenic effects: Oral administration of lapachol caused chromosomal abnormalities (26).

Herb-Drug Interactions

Warfarin: Theoretically, pau d’arco may enhance the activity of anticoagulants (16) (19).
Vitamin K: Lapachol may inhibit the action of vitamin K (16) (19).

Dosage (Inside MSKCC Only)
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  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. Anesini C, Perez C. Screening of plants used in Argentine folk medicine for antimicrobial activity. J Ethnopharmacol. Jun 1993;39(2):119-128.
  7. Park BS, Kim JR, Lee SE, et al. Selective growth-inhibiting effects of compounds identified in Tabebuia impetiginosa inner bark on human intestinal bacteria. J Agric Food Chem. Feb 23 2005;53(4):1152-1157. doi: 10.1021/jf0486038
  8. 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
  9. 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.
  10. 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
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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.
  17. 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
  18. 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.
  19. 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.
  20. 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
  21. Koyama J, Morita I, Tagahara K, et al. Cyclopentene dialdehydes from Tabebuia impetiginosa. Phytochemistry. Apr 2000;53(8):869-872.
  22. Woo HJ, Park KY, Rhu CH, et al. Beta-lapachone, a quinone isolated from Tabebuia avellanedae, induces apoptosis in HepG2 hepatoma cell line through induction of Bax and activation of caspase. J Med Food. Summer 2006;9(2):161-168. doi: 10.1089/jmf.2006.9.161
  23. Morrison RK, Brown DE, Oleson JJ, et al. Oral toxicology studies with lapachol. Toxicol Appl Pharmacol. Jul 1970;17(1):1-11.
  24. 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
  25. Guerra Mde O, Mazoni AS, Brandao MA, et al. Toxicology of lapachol in rats: embryolethality. Braz J Biol. Feb 2001;61(1):171-174.
  26. 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

Consumer Information

How It Works

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

Pau d'arco, a tree native to South America, has been used 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, the safety and effectiveness of these compounds has not been confirmed in humans.

Purported Uses
  • To treat cancer
    A small study done on 21 cancer patients did not show any benefits of pau d'arco.
  • 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: In theory, pau d’arco may increase bleeding risk with these drugs.
You are taking vitamin K: Lapachol in pau d’arco may inhibit the activity of this supplement.
You are pregnant or trying to conceive: There have been reproductive toxicities in animal models.

Side Effects
  • Nausea, vomiting, urine discoloration.
  • Animal studies also noted anemia and reproductive and chromosome abnormalities.
  • There is also the theoretical potential for enhanced bleeding risk.
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