Tabebuia impetiginosa, T. avellanedae
• Pau d'Arco; Taheebo
Principal Proposed Uses
Other Proposed Use
• Bladder Infections; Colds and Flus; Cancer; Diarrhea; Psoriasis; Pain; Ulcers; Vaginal Infections; Yeast Hypersensitivity Syndrome ("Chronic Candida")
The inner bark of the lapacho tree plays a central role in the herbal medicine of several South American indigenous peoples. They use it to treat cancer as well as a great variety of infectious diseases.
There has been very little scientific investigation of lapacho as a whole herb. However, an enormous amount of scientific interest has focused on three constituents of lapacho: lapachol, lapachone, and isolapachone. The relevance of these findings to the use of lapacho itself remains unclear.
What Is Lapacho Used for Today?
Based on its traditional uses, lapacho is sometimes recommended by herbalists as a treatment for cancer . However, there is no reliable scientific evidence that the herb is effective. Test tube studies have found that lapachone can kill cancer cells by inhibiting an enzyme called topoisomerase , and there are hopes that effective anti-cancer drugs may eventually be produced through chemical modification of lapachone. 4-11 Nonetheless, this does not indicate that lapacho is effective against cancer in humans; it would be difficult to take enough of the herb to provide active levels of lapachone.
Similarly, test tube studies have found that constituents of lapacho (especially lapachone, isolapachone, and lapachol) may be able to kill various microorganisms, including various fungi and the parasites that cause schistosomiasis, malaria, and sleeping sickness. 12-16 These findings have led to the widespread belief that lapacho is useful against the yeast Candida albicans , a common cause of vaginitis , as well as the purported condition colloquially known as chronic candida ; unfortunately, the supporting research remains far too preliminary to meaningfully show clinical benefits.
Similarly, these studies have been twisted to support claims that lapacho is useful for many infections, including colds and flus and bladder infections . However, there are at least two problems with this reasoning. First, lapacho has been tested primarily against fungi and parasites; there is little evidence that it can kill viruses (the cause of colds) or bacteria (the cause of most bladder infections). Furthermore, even if lapacho can kill these microorganisms on direct contact, this does not imply that it would be effective if taken by mouth. Consider this analogy: wine easily kills the cold virus on direct contact, but if you drink wine when you have a cold you’re not likely to get well faster. Similarly, hundreds of herbal products kill microorganisms in the test tube, but fail to prove effective as systemic antibiotics. A substance taken by mouth has to survive the digestive tract and passage through the liver, and reach sufficient concentrations in the bloodstream to produce a meaningful effect. Few substances can do this without simultaneously proving toxic to the body; that’s why antibiotics were not invented until the 20th century and remain difficult to invent even today. Until lapacho’s potential effects as an oral antibiotic are examined directly, it is not reasonable to assume that the herb is likely to help systemic infections.
Lapacho and its constituents have also been investigated for potential use in the treatment of pain, 17psoriasis , 18 and ulcers ; 19 however, the evidence for benefit is as yet too preliminary to rely upon at all.
Lapacho contains many components that don't dissolve in water, so making tea from the herb is not the best idea. It's better to take capsulized powdered bark; a typical dose is 300 to 500 mg 3 times daily. The inner bark of the lapacho tree is said to be the most effective part of the plant.
When taken in normal dosages, lapacho has not been found to cause any obvious side effects. 3 However, full safety studies have not been performed. Furthermore, the anti-cancer actions of lapachone raise serious concerns about the safety of lapacho for pregnant women, because like cancer cells, cells of a developing fetus rapidly divide. Also, a study in animals found that lapachol caused fetal death. 20 For all these reasons, pregnant or nursing women should not use lapacho. Safety in young children or those with severe liver or kidney disease has also not been established.
1. Li CJ, Averboukh L, Pardee AB. beta-Lapachone, a novel DNA topoisomerase I inhibitor with a mode of action different from camptothecin. J Biol Chem . 1993;268:22463-22468.
2. Guiraud P, Steiman R, Campos-Takaki GM, et al. Comparison of antibacterial and antifungal activities of lapachol and beta-lapachone. Planta Med . 1994;60:373-374.
3. Oswald EH. Lapacho. Br J Phytother . 1993/1994;3:112-117.
4. Bailly C. Topoisomerase I poisons and suppressors as anticancer drugs. Curr Med Chem. 2000;7:39-58.
5. Dolan ME, Frydman B, Thompson CB, et al. Effects of 1,2-naphthoquinones on human tumor cell growth and lack of cross-resistance with other anticancer agents. Anticancer Drugs. 1998;9:437-448.
6. Huang L, Pardee AB. Beta-lapachone induces cell cycle arrest and apoptosis in human colon cancer cells. Mol Med. 1999;5:711-720.
7. Hueber A, Esser P, Heimann K, et al. The topoisomerase I inhibitors, camptothecin and beta-lapachone, induce apoptosis of human retinal pigment epithelial cells. Exp Eye Res. 1998;67:525-530.
8. Krishnan P, Bastow KF. Novel mechanism of cellular DNA topoisomerase II inhibition by the pyranonaphthoquinone derivatives alpha-lapachone and beta-lapachone. Cancer Chemother Pharmacol. 2001;47:187-198.
9. Li Y, Li CJ, Yu D, Pardee AB. Potent induction of apoptosis by beta-lapachone in human multiple myeloma cell lines and patient cells. Mol Med. 2000;6:1008-1015.
10. Neder K, Marton LJ, Liu LF. Reaction of beta-lapachone and related naphthoquinones with 2-mercaptoethanol: a biomimetic model of topoisomerase II poisoning by quinones. Cell Mol Biol. 1998;44:465-474.
11. Planchon SM, Pink JJ, Tagliarino C, et al. Beta-lapachone-induced apoptosis in human prostate cancer cells: involvement of NQO1/xip3. Exp Cell Res. 2001;267:95-106.
12. Carvalho LH, Rocha EM, Raslan DS, et al. In vitro activity of natural and synthetic naphthoquinones against erythrocytic stages of Plamodium falciparum . Braz J Med Biol Res . 1988;21:485-487.
13. Guiraud P, Steiman R, Campos-Takaki GM, et al. Comparison of antibacterial and antifungal activities of lapachol and beta-lapachone. Planta Med. 1994;60:373-374.
14. Lima NM, dos Santos AF, Porfirio Z, et al. Toxicity of lapachol and isolapachol and their potassium salts against Biomphalaria glabrata , Schistosoma mansoni cercariae , Artemia salina and Tilapia nilotica . Acta Trop. 2002;83:43-47.
15. Portillo A, Vila R, Freixa B, Adzet T, Canigueral S. Antifungal activity of Paraguayan plants used in traditional medicine. J Ethnopharmacol. 2001;76:93-98.
16. Santos AF, Ferraz PA, de Abreu FC, et al. Molluscicidal and trypanocidal activities of lapachol derivatives. Planta Med. 2001;67:92-93.
17. Miranda FG, Vilar JC, Alves IA, Cavalcanti SC, Antoniolli AR. Antinociceptive and antiedematogenic properties and acute toxicity of Tabebuia avellanedae Lor. ex Griseb. inner bark aqueous extract. BMC Pharmacol. 2001;1:6.
18. Muller K, Sellmer A, Wiegrebe W. Potential antipsoriatic agents: lapacho compounds as potent inhibitors of HaCaT cell growth. J Nat Prod. 1999;62:1134-1136.
19. Goel RK, Pathak NK, Biswas M, et al. Effect of lapachol, a naphthaquinone isolated from Tectona grandis , on experimental peptic ulcer and gastric secretion. J Pharm Pharmacol. 1987;39:138-140.
20. Guerra MO, Mazoni AS, Brandao MA, Peters VM. Interceptive effect of lapachol in rats. Contraception. 1999;60:305-307.
Last reviewed August 2013 by EBSCO CAM Review Board
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