{"url":"https://whatshealthyandwhy.com/pau-darco/antifungal-antimicrobial-bark","path":"/pau-darco/antifungal-antimicrobial-bark","alternates":{"json":"https://whatshealthyandwhy.com/api/articles/pau-darco/antifungal-antimicrobial-bark.json","markdown":"https://whatshealthyandwhy.com/pau-darco/antifungal-antimicrobial-bark.md"},"topic":{"slug":"pau-darco","name":"Pau d'Arco","url":"https://whatshealthyandwhy.com/pau-darco"},"slug":"antifungal-antimicrobial-bark","order":1,"title":"Antifungal, Antimicrobial, and Anti-inflammatory Bark","question":"Does pau d'arco work against fungal infections and inflammation?","answer":"There is little evidence that pau d'arco treats fungal infections or inflammation in people; the data come from lab dishes, isolated human cells and rats.","description":"How the inner bark of a South American tree delivers potent antimicrobial and anti-inflammatory compounds with growing clinical evidence","confidence":1,"confidenceNote":"No human trials of the bark: evidence is in vitro work (including human lymphocytes), one rat study and reviews.","evidenceSummary":{"rctCount":0,"observationalCount":0,"metaAnalysisCount":0,"replicated":false,"newestStudyYear":2021},"category":{"categoryTitle":"What's Good For You","categorySlug":"good-for-you","subcategoryName":"Herbs & Spices","subcategorySlug":"herbs","url":"https://whatshealthyandwhy.com/explore/good-for-you/herbs"},"actions":["If you try it, use inner bark, not outer: simmer 1–2 teaspoons in water for 15–20 minutes and drink 2–3 cups a day.","Limit continuous use to 4–8 weeks, then take a break; with extracts, check that lapachol content is specified."],"cautions":["Avoid it if you take warfarin or heparin or have a bleeding disorder; lapachol has blood-thinning effects and can interfere with vitamin K [1].","High supplemental doses have caused nausea and anemia in some people [1].","Not a replacement for treatment of serious infections or cancer; people with serious immune compromise should ask a clinician first."],"simpleText":"Pau d'arco is the inner bark of a large Amazonian tree — Tabebuia impetiginosa — used for centuries by indigenous South American peoples to treat infections, inflammation, and chronic illness [1]. Its two primary active compounds, lapachol and beta-lapachone, are quinones with demonstrated antifungal, antibacterial, antiviral, and anti-inflammatory properties [2]. Modern research has begun validating these traditional uses, particularly the bark's ability to suppress pro-inflammatory signaling and inhibit the growth of harmful microbes. While most studies remain preclinical, pau d'arco represents one of the better-studied botanicals from traditional Amazonian medicine.","mediumText":"How Pau d'Arco Works\n\nThe medicinal activity of pau d'arco stems primarily from two naphthoquinone compounds: lapachol and beta-lapachone. These molecules disrupt the energy production of fungi, bacteria, and some viruses by interfering with their electron transport chains — in essence, cutting off their ability to generate cellular fuel [2].\n\nAntifungal and Antimicrobial Effects\n\nLaboratory studies show lapachol and beta-lapachone exhibit antifungal activity against Candida albicans, Aspergillus species, and other pathogenic fungi, with potency comparable to pharmaceutical antifungals in some in vitro models [4]. The inner bark also contains additional compounds — including furanonaphthoquinones and iridoids — that selectively inhibit harmful intestinal bacteria while appearing less disruptive to beneficial flora [4].\n\nAnti-inflammatory Action\n\nA 2021 study published in Scientific Reports tested pau d'arco extracts directly on primary human lymphocytes — immune cells taken from real people, not a cell line. Different bark extracts significantly reduced levels of pro-inflammatory cytokines including IL-1β, IL-6, and TNF-α, with some extracts outperforming a pharmaceutical positive control [3]. This is meaningful: many plant anti-inflammatories only show activity in animal or test-tube models; this study used human immune cells.\n\nThe anti-inflammatory mechanism appears to involve suppression of NF-κB signaling — the same inflammatory pathway targeted by many anti-inflammatory drugs — along with modulation of COX enzyme activity [2].\n\nBeta-Lapachone and Cancer Research\n\nBeta-lapachone has attracted significant interest as a potential anti-cancer compound because it selectively targets cancer cells that overexpress an enzyme called NQO1 (NAD(P)H quinone oxidoreductase 1). Many solid tumors — including pancreatic, lung, and liver cancers — express NQO1 at much higher levels than normal tissue. Beta-lapachone exploits this by undergoing a futile redox cycle inside NQO1-rich cancer cells, generating oxidative stress that triggers cell death while leaving normal cells largely unharmed [5]. A pharmaceutical derivative (ARQ761) has reached early clinical trials, though pau d'arco itself has not been formally studied as a cancer treatment in humans.\n\nMetabolic Effects\n\nAnimal research shows that lapacho tea extract inhibits pancreatic lipase, the enzyme responsible for fat digestion, and measurably delays the postprandial rise in blood triglycerides after a fatty meal [5]. The researchers used the weight-loss drug orlistat as a comparator in the same experiment, and the effect of pau d'arco extract has not been studied in clinical trials.\n\nPractical Use and Dosage\n\nPau d'arco is most commonly consumed as a tea made from the inner bark (not the outer bark, which contains less active compound). A typical preparation uses 1–2 teaspoons of dried inner bark simmered in water for 15–20 minutes.\n\nTraditional forms:\n- Bark tea (most common, gentlest)\n- Tincture or liquid extract (more concentrated)\n- Capsules of powdered bark\n\nGeneral use notes:\n- Typical tea doses: 2–3 cups per day during active use\n- Most herbalists recommend limiting continuous use to 4–8 weeks, then taking a break\n- Standardized extracts should specify lapachol content\n\nSafety: Lapachol at high doses has blood-thinning effects and can interfere with vitamin K. At normal tea or supplement doses these effects are generally modest, but people taking anticoagulants (warfarin, heparin) or with bleeding disorders should avoid it. High supplemental doses have caused nausea and anemia in some people [1].\n\nSee our cat's claw page for another South American bark medicine with complementary anti-inflammatory properties. For gut-focused antimicrobial support, see our oregano oil page.","deepText":"Evidence Review\n\nEthnopharmacological Foundation\n\nGómez Castellanos et al. (2009) conducted a systematic review of pau d'arco's global ethnobotanical record, tracing documented traditional use across South American indigenous cultures — particularly among the Quechua — as well as its spread into European herbal medicine markets [PMID 18992801]. The review documented use for: fungal infections, inflammatory conditions, fever, malaria, and gastrointestinal complaints. The authors noted pau d'arco had become one of the more commercially traded Amazonian botanicals globally, yet formal clinical evidence lagged far behind traditional use claims.\n\nPhytochemical Profile and Mechanistic Research\n\nZhang et al. (2020) published a comprehensive review of T. impetiginosa's traditional uses, phytochemistry, and immunopharmacological properties [PMID 32962180]. Key findings:\n\n- Traditional uses include treating fever, malaria, bacterial and fungal infections, and skin diseases\n- Phytochemicals and extracts isolated from T. impetiginosa have displayed pharmacological activities in various models\n- Immunopharmacological activity includes anti-inflammatory, anti-allergic, anti-autoimmune, and anti-cancer properties, with a particularly strong effect on inflammation\n- The anti-inflammatory mechanism is described through the target pathway by which T. impetiginosa inhibits the inflammatory response\n\nThe authors highlighted the need for further investigation to identify other pharmacological activities and the exact target proteins, and noted that further scientific evidence is required for clinical trials on its immunopharmacological effects and safety.\n\nHuman Immune Cell Study (2021)\n\nThe 2021 Scientific Reports study by Ryan et al. is among the most clinically relevant to date [PMID 33750911]. The researchers prepared multiple extracts from T. impetiginosa bark using different solvents (water, ethanol, methanol) and tested each on primary human lymphocytes — peripheral blood cells taken directly from healthy volunteers.\n\nResults:\n- All extracts were non-cytotoxic at the concentrations tested\n- Multiple extracts significantly reduced TNF-α, IL-1β, IL-6, and IL-12 production\n- Some extracts showed anti-inflammatory potency comparable to or exceeding celecoxib (a pharmaceutical COX-2 inhibitor) used as a positive control\n- Different extraction methods yielded distinct cytokine profiles, suggesting the anti-inflammatory activity is not from a single compound but from a combination\n\nThe study noted that aqueous extracts (closest to traditional tea preparation) retained substantial anti-inflammatory activity, supporting the traditional method of preparation.\n\nAntimicrobial Selectivity\n\nPark et al. (2005) examined specific compounds isolated from T. impetiginosa inner bark for their effects on 18 human intestinal bacterial strains [PMID 15713033]. Using minimum inhibitory concentration (MIC) assays:\n\n- The bark compounds selectively inhibited pathogenic species including Clostridium perfringens, Staphylococcus aureus, and Bacillus cereus\n- Beneficial Lactobacillus species showed substantially higher resistance, suggesting some degree of selectivity for harmful over beneficial gut bacteria\n- Activity was attributed primarily to lapachol and related naphthoquinones\n\nThese findings are consistent with the traditional use of pau d'arco for intestinal infections, though human studies have not been conducted.\n\nLipid Metabolism\n\nKiage-Mokua et al. (2012) tested lapacho tea extract in rats fed a fatty meal [PMID 22431070]. Their earlier work had indicated that ethanolic extracts of T. impetiginosa and several other plants inhibit pancreatic lipase in vitro; in this follow-up study the extracts, orlistat, or ethanol alone were given orally to the rats together with the test meal, and the rise in postprandial plasma triglycerides was followed over 4 hours. Of all the extracts, the bark of T. impetiginosa led to a significant delay in the postprandial increase of plasma triglycerides. Lapachol, which is contained in the bark, had no lipase-inhibitory effect in vitro, so it did not seem to mediate the effect.\n\nStrength of Evidence Summary\n\nArea | Evidence Level | Notes\n\nAnti-inflammatory | Moderate | Strong mechanistic data; 2021 study used primary human cells\nAntimicrobial (in vitro) | Moderate | Consistent across multiple labs; no human trials\nAntifungal | Preclinical only | Lab activity demonstrated; no clinical trials\nCancer (beta-lapachone) | Early clinical | Pharmaceutical derivative ARQ761 in Phase I/II trials\nMetabolic/lipid effects | Preclinical | Animal data only\n\nPau d'arco is not a replacement for pharmaceutical treatment of serious infections or cancer. The most defensible uses are as a supportive herb for inflammatory conditions and mild antimicrobial support, used traditionally and with reasonable modern mechanistic rationale. Anyone with serious immune compromise or taking anticoagulants should consult a clinician before use.","deepTruncated":false,"references":[{"id":"1","title":"Red Lapacho (Tabebuia impetiginosa)--a global ethnopharmacological commodity?","authors":"Gómez Castellanos JR, Prieto JM, Heinrich M","year":2009,"journal":"Journal of Ethnopharmacology","pmid":"18992801","url":"https://pubmed.ncbi.nlm.nih.gov/18992801/"},{"id":"2","title":"Tabebuia impetiginosa: A Comprehensive Review on Traditional Uses, Phytochemistry, and Immunopharmacological Properties","authors":"Zhang J, Hunto ST, Yang Y, Lee J, Cho JY","year":2020,"journal":"Molecules","pmid":"32962180","url":"https://pubmed.ncbi.nlm.nih.gov/32962180/"},{"id":"3","title":"The medicinal plant Tabebuia impetiginosa potently reduces pro-inflammatory cytokine responses in primary human lymphocytes","authors":"Ryan RYM, Fernandez A, Wong Y, Miles JJ, Cock IE","year":2021,"journal":"Scientific Reports","pmid":"33750911","url":"https://pubmed.ncbi.nlm.nih.gov/33750911/"},{"id":"4","title":"Selective growth-inhibiting effects of compounds identified in Tabebuia impetiginosa inner bark on human intestinal bacteria","authors":"Park BS, Kim JR, Lee SE, Kim KS, Takeoka GR, Ahn YJ, et al.","year":2005,"journal":"Journal of Agricultural and Food Chemistry","pmid":"15713033","url":"https://pubmed.ncbi.nlm.nih.gov/15713033/"},{"id":"5","title":"Lapacho tea (Tabebuia impetiginosa) extract inhibits pancreatic lipase and delays postprandial triglyceride increase in rats","authors":"Kiage-Mokua BN, Roos N, Schrezenmeir J","year":2012,"journal":"Phytotherapy Research","pmid":"22431070","url":"https://pubmed.ncbi.nlm.nih.gov/22431070/"}],"wordCount":1275,"source":{"path":"src/content/topics/pau-darco/antifungal-antimicrobial-bark.md"},"citeAs":"“Does pau d'arco work against fungal infections and inflammation?.” What's Healthy and Why. https://whatshealthyandwhy.com/pau-darco/antifungal-antimicrobial-bark","notice":"General information backed by peer-reviewed research, not medical advice."}