Pau d’Arco

Pau d arco Multiple chronic conditions (scant evidence)... 

Latin American lapacho tree, Pau d Arco Tabebuia spp., Bigncmiaceae, Ang.), an Andean traditional tea... 

The naphthoquinones with acid hydroxyl function like lapachol are easily extracted with bases. They are also extracted in a Soxhlet apparatus with EtOH, and the resulting extract is then exhaustively extracted with AcOEt to yield a residue rich in naphthoquinones [115-116]. The naphthoquinones are mainly isolated from the wood and heartwood but there some examples of isolation from the roots [46, 48, 53, 58, 65, 66, 75, 78]. The study of commercial herbal products sold as Taheebo, Pau d Arco, Lapacho, and Ipe roxo carried out by Girard et al [117], showed important differences in the content of lapachol and other related naphthoquinones present in extracts of Tabebuia ssp Tabebuia rosea, T. cassinoides, T. impetiginosa, and T. chrisantha. Similar works using HPLC techniques have been carried out by Awang et al. [118]. 

Biological investigations over the last years have shown that many of the medicinal properties claimed for Lapacho, Taheebo, Pau D Arco or Ipe Roxo are attibuted to the active components lapachol, a-lapachone, P-lapachone and their derivatives. 

Figure 2 Lapachol occurs in the heartwood of many Tabebuia species. Its interfence in oxidative processes has been documented. Its metabolite fi-lapachone inhibits enzymes associated with DNA replication. However the use of Tabebuia bark (pau d arco) as a cancer preventative can hardly be attributed to these activities.

K. Jones, Pau d Arco, Immune Power from the Rain Forest , Healing Arts Press, Rochester, VT, 1995, pp. 13-14. 

A 28-year-old man presented with jaundice after taking six tablets of skullcap (together with zinc and pau d arco) daily for the previous 6 months to help his multiple sclerosis. His liver enzjmes were raised and hepatitis A, B, and C serologies were negative. He developed progressive liver failure and received a transplant but died shortly after. His explanted hver showed fibrous stenosis and obliteration of most of the terminal venules with extensive perivenular fibrosis, indicative of veno-occlusive disease. 

Lewis, W., Okunade, A., and Elvin-Lewis, M. 2004a. Pau d Arco or Lapacho (Tabebuia) . Marcel Dekker. 

Bloodroot is also used sometimes as a cure for cancer, e.g., in a substance called Compound-X, and likewise used is chaparral or creosote bush or greasewood, as it is variously called, and which will be detailed subsequently. At the least, a couple of other reported cancer cures hail from South America, namely, pau d arco and cundurango or condurango, the condor vine, to be further discussed. Still another is called cat s claw, or urn de goto, also to be discussed.)... 

A formula provided by herbalist Michael Tierra has multiple ingredients (Walters, 1993, p. 139). Its principal components are chaparral and echinacea (or purple coneflower), plus red clover blossoms, cascara sagrada, astralagus, ginseng roots, and other herbs. Another formula supphed has chaparral, echinacea root, pau d arco, and red clover blossoms. Echinacea root itself is apparently in renewed favor as an anticancer agent. 

Bignoniaceae (Tabebuia imptetiginosa and Tabebuia spp., some species of which are known as pau d arco and contain the phenylnaphthoquinone anticancer compound lapachol)... 

In Leslie Taylor s section concerning pan d arco, there are comments that adulteration or substitutions are often made. Thus, a main anticancer constituent is the compound lapachol, which may be in concentrations of 2 to 7% in true pau d arco, whereas other related species may have none. Moreover, in the chemical analysis of 12 commercially available products, only 1 showed even trace amounts. Either substitutions had been made, or there was degradation during processing, transport, and storage. And whereas most research studies have been confined to the heartwood, most commercially available products contain the inner and outer bark of the tree, which is stripped at the sawmills from the ten or so species that are logged. The call is for standardized extracts that guarantee the lapachol and naphthoquinone content. 

Much of the research related to pau d arco has been done on the compound lapachol, which is reported by one reference to be present in the heartwood at a concentration of 2 to 7%, with less in the bark (Taylor 2005). An analysis of commercial pau d arco wood and bark products, however, indicated that the lapachol content in the wood was 0.001%, with no lapachol detected in bark products (Awang et al. 1994). Similarly, no lapachol was identified in an aqueous extract of pau d arco inner bark (Steinert et al. 1996). Publications... 

Occupational asthma and allergic contact dermatitis have been reported in woodworkers exposed to pau d arco dust (Algranti et al. 2005 Estlander et al. 2001). 

While animal studies indicated mixed effects of the compound lapachol see Editors Note) in pregnant animals, no information on the safety of pau d arco in pregnancy or lactation was identified in the scientific or traditional literature. Although this review did not identify any concerns for use while pregnant or nursing, safety has not been conclusively established. 

No LD50 of pau d arco concentrated aqueous extract could be determined at doses up to 5 g/kg orally administered to mice (de Miranda et al. 2001). 

Awang, D., B. Dawson, J. Ethier, et al. 1994. Naphthoquinone constituents of commercial lapacho/pau d arco/taheebo products. /. Herbs Spices Med. Plants 2(4) 27-43. 

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