Picao Pretois purportedly an antimicrobial, anti-inflammatory, hepatoprotective, antiulcerous antidiabetic


Family: Asteraceae

Genus: Bidens

Species: pilosa

Synonyms: Bidens adhaerescens, B. alausensis, B. chilensis, B. hirsuta, B. leucantha, B. montaubani, B. reflexa, B. scandicina, B. sundaica, Coreopsis leucantha, Kerneria pilosa

Common Names: Picão preto, carrapicho, amor seco, pirca, aceitilla, cadillo, chilca, pacunga, cuambu, erva-picão, alfiler, clavelito de monte, romerillo, saltillo, yema de huevo, z’aiguille, jarongan, ketul, pau-pau pasir, Spanish needles, bident herisse, herbe d’aiguille, zweizahn, bidente piloso, mozote, beggar’s tick.

Price: £22.50 – 1lb / 454 gm Bag [wp_eStore_add_to_cart id=129]

Parts Used: whole herb

From The Healing Power of Rainforest Herbs:

Main Actions Other Actions Standard Dosage
  • kills bacteria
  • dries secretions
Whole herb
  • kills viruses
  • increases urination
Decoction: 1/2 to 1 cup
  • kills germs
  • inhibits tumors
twice daily
  • kills leukemia cells
  • lowers blood sugar
Capsules: 2 g twice daily
  • kills yeast
  • promotes menstruation
Tincture: 2-3 ml twice daily
  • reduces inflammation
  • expels worms
  • protects liver
  • stimulates digestion
  • prevents ulcers
  • inhibits stomach acid
  • helps diabetes
  • reduces spasms
  • fights free radicals

Picão preto is a small, erect annual herb that grows to 1 m high. It has bright green leaves with serrated, prickly edges and produces small, yellow flowers and black fruit. Its root has a distinctive aroma similar to that of a carrot. It is indigenous to the Amazon rainforest and other tropical areas of South America, Africa, the Caribbean, and the Philippines. It is often considered a weed in many places. It is a southern cousin to Bidens tripartita, the European bur marigold, which has an ancient history in European herbal medicine. In Brazil, the plant is most commonly known as picão preto or carrapicho; in Peru it is known as amor seco or pirca.


Picão preto has a long history of use among the indigenous people of the Amazon, and virtually all parts of the plant are used. Generally the whole plant is uprooted and prepared in decoctions or infusions for internal use, and/or crushed into a paste or poultice for external use. In the Peruvian Amazon picão preto is used for aftosa (foot-and-mouth disease), angina, diabetes, menstrual disorders, hepatitis, laryngitis, intestinal worms and for internal and external inflammations. In Piura region of Peru, a decoction of the roots is used for alcoholic hepatitis and worms. The Cuna tribe mixes the crushed leaves with water to treat headaches. Near Pucallpa, Peru, the leaf is balled up and applied to a toothache; the leaves also are used for headaches. In other parts of the Amazon, a decoction of the plant is mixed with lemon juice and used to treat angina, hepatitis, sore throat, and water retention. The Exuma tribe grinds the sun-dried leaves with olive oil to make poultices for sores and lacerations and, in Tonga, an infusion of the flowers is used to treat upset stomach in food poisoning.

In Peruvian herbal medicine picão preto is employed to reduce inflammation, increase urination, and to support and protect the liver. It is commonly used there for hepatitis, conjunctivitis, abscesses, fungal infections, urinary infections, as a weight loss aid, and to stimulate childbirth. In Brazilian herbal medicine it is used for fevers, malaria, hepatitis, diabetes, sore throat, tonsillitis, obstructions in the liver and other liver disorders, urinary infections, and vaginal discharge and infections. An infusion or decoction of the entire plant is often gargled for tonsilitis and pharyngitis. Externally it is used for wounds, fungal infections, ulcers, diaper rash, insect bites, and hemorrhoids. Brazilian herbalists also report using picão preto to normalize insulin and bilirubin levels in the pancreas, liver, and blood. In Mexico the entire plant or leaf is used to treat diabetes, stomach disorders, hemorrhoids, hepatitis, nervous problems, and fever. It is used as a gargle for mouth blisters, and the juice of the plant is used in an external poultice for kidney and liver inflammation.


Picão preto is rich in flavonoids, terpenes, phenylpropanoids, lipids, and benzenoids. Even as early as 1979 and 1980, scientists demonstrated that specific chemicals found in the herb were toxic to bacteria and fungi. Many of the flavonoids in picão preto have been documented with antimalarial activity. In 1991, Swiss scientists isolated several known phytochemicals with antimicrobial and anti-inflammatory properties, which led them to infer that the presence of these compounds “may rationalize the use of this plant in traditional medicine in the treatment of wounds, against inflammation and against bacterial infection of the gastrointestinal tract.” New bioactive phytochemicals, discovered in 1996, showed activity against transformed human cell lines.

The plant chemicals in picão preto include: aesculetin, behenic acid, beta-sitosterol, borneol, butanedioic acid, butoxylinoleates, cadinols, caffeine, caffeoylic acids, capric acid, daucosterol, elaidic acid, erythronic acids, friedelans, friedelins, germacrene D, glucopyranoses, glucopyranosides, inositol, isoquercitrin, lauric acid, limonene, linoleic acids, lupeol, luteolin, muurolol, myristic acid, okanin-glucosides, palmitic acid, palmitoleic acid, paracoumaric acids, phenylheptatriynes, phytenoic acid, phytol, pilosola A, polyacetylenes, precocene I, pyranoses, quercetin, sandaracopimaradiols, squalene, stigmasterols, tannic acid, tetrahydroxyaurones, tocopherolquinones, tridecapentaynenes, tridecatetrayndienes, and vanillic acid.


Picão preto has been the subject of recent clinical research that has supported many of its uses in herbal medicine. A research group in Taiwan reported that a picão preto extract was capable of protecting the liver of rats from various introduced toxins known to cause liver injury. This research group had previously demonstrated picão preto’s anti-inflammatory actions in animals a year earlier (in 1995). In 1999, a Brazilian research group confirmed the anti-inflammatory activities in mice and attributed them to an immune modulation effect (noting the extract reduced the amount of pro-inflammatory immune cells in human blood in a previous study). In addition, other research demonstrated that a picão preto extract inhibited prostaglandin-synthesis and cyclooxygenase (COX) activities. Both are chemical processes in the body which are linked to inflammatory diseases (and provide the focus for newer “COX-inhibitor” classes of anti-inflammatory and arthritis pharmaceutical drugs).

Other areas of research have validated picão preto’s traditional use for ulcers and diabetes. Extracts of the leaf (as well as the entire plant) have clinically shown to protect rats against chemical- and bacteria-induced gastric lesions and ulcers and, also, to reduce gastric acid secretion. The activity noted in these studies was higher than that shown by two prescription anti-ulcer drugs. Other in vivo studies with rats and mice have demonstrated that picão preto has hypoglycemic activity and is able to improve insulin sensitivity which validates its long history in herbal medicine for diabetes. Researchers (in 2000) attributed the plant’s hypoglycemic properties to a group of glucoside chemicals found in the aerial parts of the plant. Picão preto was also documented to prevent hypertension in rats fed a high-fructose diet, and to lower the resulting (elevated) blood pressure and triglyceride levels. In hypertensive rats (including high dietary salt-induced hypertension), extracts of the plant significantly lowered blood pressure – without having an effect on heart rate and urine volume.19 A leaf extract was also shown to have smooth-muscle relaxant activity on the heart.

Picão preto has long been used in traditional medicine systems for infections of all kinds: from such upper respiratory tract infections as colds and flu to urinary tract infections and venereal diseases-and even infected wounds on the skin. Research has begun to confirm these uses in several in vitro microbial studies. In 1991, scientists in Egypt first documented picão preto’s antimicrobial activity against various pathogens. Other in vitro studies have demonstrated its antibacterial activity against a wide range of bacteria including Klebsiella pneumonia, Bacillus, Neisseria gonorrhea, Pseudomonas, Staphylococcus, and Salmonella. Extracts of the leaf also have been documented to have antimycobacterial activity towards Mycobacterium tuberculosis and M. smegmatis. A water extract of the leaf has shown significant anti-yeast activity towards Candida albicans. Much of picão preto’s antimicrobial actions have been attributed to a group of chemicals called polyacetylenes, which includes a chemical called phenylheptatriyne. Phenylheptatriyne has shown strong in vitro activity against numerous human and animal viruses, bacteria, fungi, and molds in very small amounts.

In the tropics, picão preto is also used for snakebite and malaria; research has confirmed these uses as well. Several studies have confirmed the plant’s antimalarial activity; it reduced malaria in animals by 43-66 percent, and in vitro by 90%. With regard to its status as a traditional snakebite remedy, one research group confirmed that a picão preto extract could protect mice from lethal injections of neurotoxic snake venom.

The last area of research has focused on picão preto’s anticancerous possibilities. Early research, in various in vitro assay systems designed to predict antitumor activity, indicated positive results in the early 1990s. Picão preto first was reported to have antileukemic actions in 1995. Then researchers from Taiwan reported (in 2001) that a simple hot-water extract of picão preto could inhibit the growth of five strains of human and mouse leukemia at less than 200 mcg per ml in vitro. They summarized their research by saying that picão preto “. . . may prove to be a useful medicinal plant for treating leukemia.”


Picão preto, one of South America’s well-known medicinal plants, is widely used for numerous conditions. Many of its indigenous uses for inflammation, hypertension, ulcers, diabetes and infections of all kinds are being validated and verified by modern research. Unfortunately, little is known of it in herbal medicine practices in the U.S. – and it is not widely available here. In South America, it is considered a safe plant to use; in the various animals studies performed to date, no toxic effects have been reported. Specific toxicology studies have shown no toxicity when dosages of (up to) 1 g per kg of body weight were injected into mice.

Picão Preto Plant Summary
Main Preparation Method: decoction or capsulesMain Actions (in order):
antimicrobial, anti-inflammatory, hepatoprotective (liver protector), antiulcerous, antidiabetic Main Uses: 

  1. as a broad-spectrum antimicrobial for various internal and external infections (caused by virus, bacteria, yeast, fungi)
  2. to tone, balance, strengthen, protect, and detoxify the liver
  3. for arthritis, rheumatism, and other inflammatory conditions
  4. for diabetes
  5. for stomach ulcers and digestive disorders

Properties/Actions Documented by Research:
anticandidal, anti-inflammatory, antiulcerous, antibacterial, anticoagulant (blood thinner), antifungal, antihepatotoxic (liver detoxifier), antileukemic, antimalarial, antioxidant, antitumorous, antivenin, antiviral, cardiotonic (tones, balances, strengthens the heart), COX-inhibitor (typically reduces inflammation), gastroprotective (protects the gastric tract), hepatoprotective (liver protector), hepatotonic (tones, balances, strengthens the liver), hypoglycemic, hypotensive (lowers blood pressure), immunomodulator (selectively modulates overactive immune cells), uterine stimulantOther Properties/Actions Documented by Traditional Use:
abortive, antidiabetic, antihemorrhagic (reduces bleeding), antiparasitic, antiseptic, antispasmodic, cough suppressant, astringent, bitter, carminative, diaphoretic (promotes sweating), diuretic, emollient, febrifuge (reduces fever), menstrual stimulant, stimulant, vermifuge (expels worms), wound healer

Cautions: It may potentiate the effects of antidiabetic, blood thinning, and high blood pressure drugs.







Traditional Preparation: In the tropics, generally one cup of a standard decoction 1-3 times daily depending on the condition that is being treated. Two to three ml of a 4:1 tincture twice daily or 2-3 g of powdered herb in tablets, capsules, or stirred into water (or juice) twice daily can be substituted, if desired. See Traditional Herbal Remedies Preparation Methods page if necessary for definitions.


Picão preto has evidenced weak uterine stimulant activity in guinea pigs. As such, it should not be used during pregnancy.

This plant contains several coumarin derivatives. Coumarins are a group of chemicals that thin the blood. Those on blood thinning medications such as Warfarin® should use picão preto with caution and monitor these possible effects.

Picão preto contains a small amount of naturally-occurring caffeine; it should not be used by those who are allergic or sensitive to caffeine.

The plant has been documented to lower blood sugar levels in several animal studies. Those with hypoglycemia or diabetes should only use picão preto under the supervision of a qualified health care professional and monitor their blood sugar levels accordingly.

Picão preto has been documented with hypotensive activity in several animal studies. People with heart conditions and those taking antihypertensive drugs should consult their doctors prior to using this plant to monitor these possible effects (as medications may need adjustment).

Drug Interactions: None clinically documented in humans; however, the use of this plant may potentiate antidiabetic, anticoagulant, and antihypertensive drugs (based on animal studies).

Africa for bleeding, blood clots, burns, cataracts, colitis, conjunctivitis, constipation, diarrhea, earache, eye disorders, food poisoning, hemorrhages, inflammation, malaria, pneumonia, postpartum hemorrhage, respiratory infections, rheumatism, sores, stomach pains, tuberculosis, worms, wounds, yaws, and as an antiseptic
Amazonia for angina, chills, diabetes, dysentery, edema, eye disorders, headache, hepatitis, jaundice, laryngitis, malaria, menstrual disorders, parasites, sore mouth, sore throat, stomachache, toothache, urinary insufficiency, worms, wounds
Bahamas for cancer, fever, heat-rash, itch, intestinal gas, lacerations, skin sores, water retention, wounds
Brazil for breast engorgement, cough, diabetes, diaper rash, dysentery, fever, fungal infections, gonorrhea, hemorrhoids, hepatitis, inflammation, insect bites, jaundice, lactation aid, liver tonic, liver obstructions, lung disorders, malaria, parasites, pharyngitis, rheumatism, sclerosis (glands), scurvy, sore throat, toothache, tonsillitis, ulcers, urinary infections, urinary insufficiency, vaginal infections, vaginal discharge, wounds, and as an antiseptic, astringent
for chest problems, toothaches, and to promote milk production, salivation, urination and menstruation
Ghana for allergies, bleeding, earaches, eye infections, hives
Haiti for angina, catarrh, diabetes, foot-and-mouth disease, mental disorders, milk production, nervous shock, stomatitis, tonsilitis, vomiting
Mexico for blood clots, chest problems, diabetes, fever, gastroenteritis, hemorrhoids, inflammation, jaundice, kidney, liver disorders, mouth blisters, nervous problems, snakebite, stomach problems, and as a antiseptic and diuretic
Panama for colds, headache, intestinal disorders, prostate tumors, rheumatism
Peru for abscesses, angina, anuria, baldness, bile stimulation, childbirth, chills, conjunctivitis, cystitis, diabetes, dysentery, edema, foot-and-mouth disease, fever, fungal infections, headache, hemorrhage, hepatitis, inflammation, jaundice, lacerations, laryngitis, liver problems, liver support, mouth sores, menstrual disorders, nephritis, nervous system disorders, pain, obesity, parasites, rheumatism, sores, sore throat, tonsilitis, toothache, urinary infections, urinary insufficiency, venereal diseases, weight loss, worms, wounds
Elsewhere for abortions, bleeding, blood cleansing, boils, bronchitis, burns, cancer, candida, colds, colic, colitis, conjunctivitis, coughs, cuts, diabetes, diarrhea, dysentery, eye problems, fever, flatulence, flu, food poisoning, gout, hair loss, hepatitis, hyperglycemia, hypertension, inflammation, intestinal infections, liver diseases, menstrual promotion, parasites, respiratory infections, rheumatism, skin problems, snakebite, stomach disorders, styptic, sweat promotion, thrush, toothache, ulcers, ulcerative colitis, urinary infections, urinary problems, worms, wounds, and as an antiseptic, astringent, diuretic


The above text has been printed from The Healing Power of Rainforest Herbs by Leslie Taylor, copyrighted © 2005

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A complete Technical Data Report is available for this plant.

† The statements contained herein have not been evaluated by the Food and Drug Administration. The information contained in this plant database file is intended for education, entertainment and information purposes only. This information is not intended to be used to diagnose, prescribe or replace proper medical care. The plant described herein is not intended to treat, cure, diagnose, mitigate or prevent any disease. Please refer to our Conditions of Use for using this plant database file and web site.

Referenced Quotes on Picão Preto

The Green Pharmacy, James A. Duke, Rodale 1997

“Spanish needles (Bidens pilosa). This is a plant that belongs to the same botanical family as feverfew. It is a popular folk medicine in Taiwan for all sorts of illnessnes, from influenza to hepatitis. In one study with laboratory animals, Taiwanese scientists showed that this herb has significant anti-edemic and antiinflammatory activity. More research is needed here, but I’m intrigued, and I’m on the lookout for further reports of its effectiveness. Amazonian Ethnobotanical Dictionary, James A. Duke, et.al. CRC Press, 1994

Decoction mixed with lemon juice for angina, sore throat, water retention, hepatitis, dropsy. In Piura, the root decoction is used for alcoholic hepatitis and worms (FEO). Around Pucallpa, the leaf is balled up and applied to toothache. Leaves also used for headache (VDF). In Brazil it is used as a diuretic and to treat jaundice. Used for aftosa, angina, diabetes, dysentery, dysmenorrhea, edema, hepatitis, jaundice, laryngitis, worms (RAR).

Third-Party Research on Picão Preto

All available third-party research on picão preto can be found at PubMed. A partial listing of published research on picão preto is shown below: Anticancerous & Antileukemic Actions:

Sundararajan, P., et al. “Studies of anticancer and antipyretic activity of Bidens pilosa whole plant.” Afr. Health Sci. 2006 Mar; 6(1): 27-30.

Wu, L. W., et al. “Polyacetylenes function as anti-angiogenic agents.” Pharm. Res. 2004; 21(11): 2112-9.

Chang, J. S., et al. “Antileukemic activity of Bidens pilosa L. var. minor (Blume) Sherff and Houttuynia cordata Thunb.” Am. J. Chin. Med. 2001; 29(2): 303-12.

Wang, J., et al. “Inhibition of 5 compounds from Bidens bipinnata on leukemia cells in vitro.” Zhong Yao Cai. 1997; 20(5): 247-9.

Gupta, M. P., et al. “Screening of Panamanian medicinal plants for brine shrimp toxicity, crown gall tumor inhibition, cytotoxicity and DNA intercalation.” Int. J. Pharmacog. 1996; 34(1): 19–27.

Alvarez, L., et al. “Bioactive polyacetylenes from Bidens pilosa.” Planta Med. 1996; 62(4): 355–57.

Wat, C. K., et al. “Ultraviolet-mediated cytotoxic activity of phenylheptatriyne from Bidens pilosa L.” J. Nat. Prod. 1979; 42(1): 103–11.

Immunomodulator, Antioxidant & Cellular Protective Actions:

Chiang, Y. M., et al. “Cytopiloyne, a novel polyacetylenic glucoside from Bidens pilosa, functions as a T helper cell modulator.” J. Ethnopharmacol. 2006 Oct 19;

Yang, H. L., et al. “Protection from oxidative damage using Bidens pilosa extracts in normal human erythrocytes.” Food Chem. Toxicol. 2006 Sep; 44(9): 1513-21.

Abajo, C., et al. “In vitro study of the antioxidant and immunomodulatory activity of aqueous infusion of Bidens pilosa.” J. Ethnopharmacol. 2004 Aug; 93(2-3): 319-23.

Chang, S. L., et al. “Polyacetylenic compounds and butanol fraction from Bidens pilosa can modulate the differentiation of helper T cells and prevent autoimmune diabetes in non-obese diabetic mice.” Planta Med. 2004; 70(11):1045-51.

Chiang, Y. M., et al. “Metabolite profiling and chemopreventive bioactivity of plant extracts from Bidens pilosa.” J. Ethnopharmacol. 2004 Dec; 95(2-3): 409-19.

Usami, E., et al. “Assessment of antioxidant activity of natural compound by water- and lipid-soluble antioxidant factor” Yakugaku Zasshi. 2004; 124(11): 847-50.

Chin, H. W., et al. “The hepatoprotective effects of Taiwan folk medicine ‘ham-hong-chho’ in rats.” Am. J. Chin. Med. 1996; 24(3–4): 231–40.

Anti-inflammatory, Muscle Relaxant, & Pain-Relieving Actions:

Yoshida, N., et al. “Bidens pilosa suppresses interleukin-1beta-induced cyclooxygenase-2 expression through the inhibition of mitogen activated protein kinases phosphorylation in normal human dermal fibroblasts.” J. Dermatol. 2006; 33(10): 676-83.

Chiang, Y. M., et al. “Ethyl caffeate suppresses NF-kappaB activation and its downstream inflammatory mediators, iNOS, COX-2, and PGE2 in vitro or in mouse skin.” Br. J. Pharmacol. 2005 Oct; 146(3): 352-63.

Nguelefack, T. B., et al. “Relaxant effects of the neutral extract of the leaves of Bidens pilosa Linn on isolated rat vascular smooth muscle.” Phytother. Res. 2005; 19(3): 207-10.

Chang, C. L., et al. “The distinct effects of a butanol fraction of Bidens pilosa plant extract on the development of Th1-mediated diabetes and Th2-mediated air way inflammation in mice.” J. Biomed. Sci. 2005; 12(1): 79-89.

Pereira, R. L., et al. “Immunosuppressive and anti-inflammatory effects of methanolic extract and the polyacetylene isolated from Bidens pilosa L.” Immunopharmacology. 1999; 43(1): 31–7.

Jager, A. K., et al. “Screening of Zulu medicinal plants for prostaglandin-synthesis inhibitors” J. Ethnopharmacol. 1996; 52(2): 95–100.

Chih, H. W., et al. “Anti-inflammatory activity of Taiwan folk medicine ‘ham-hong-chho’ in rats.” Am. J. Chin. Med. 1995; 23(3–4): 273–78.

Antimicrobial Actions:

Rojas, J. J., et al. “Screening for antimicrobial activity of ten medicinal plants used in Colombian folkloric medicine: A possible alternative in the treatment of non-nosocomial infections.” BMC Complement. Altern. Med. 2006 Feb; 6(1): 2.

Khan, M. R., et al. “Anti-microbial activity of Bidens pilosa, Bischofia javanica, Elmerillia papuana and Sigesbekia orientalis.” Fitoterapia. 2001; 72(6): 662–65.

Chariandy, C. M., et al. “Screening of medicinal plants from Trinidad and Tobago for antimicrobial and insecticidal properties.” J. Ethnopharmacol. 1999; 64(3): 265–70.

Rabe, T. “Antibacterial activity of South African plants used for medicinal purposes.” J. Ethnopharmacol. 1997; 56(1): 81–7.

van Puyvelde, L., et al. “In vitro inhibition of mycobacteria by Rwandese medicinal plants.” Phytother. Res. 1994; 8(2): 65–9.

Desta, B. “Ethiopian traditional herbal drugs. Part II: Antimicrobial activity of 63 medicinal plants.” J. Ethnopharmacol. 1993; 39(2): 129–39.

Sarg, T. M., et al. “Constituents and biological activity of Bidens pilosa l grown in Egypt.” Acta. Pharm. Hung. 1991; 61(6): 317–23.

Geissberger, P., et al. “Constituents of Bidens pilosa L.: do the components found so far explain the use of this plant in traditional medicine?” Acta Trop. 1991; 48(4): 251–61.

Hudson, J. B., et al. “Investigation of the antiviral action of the photoactive compound phenylheptatriyne.” Photochem. Photobiol. 1986; 43(1): 27–33.

Boily, Y., et al. “Screening of medicinal plants of Rwanda (central Africa) for antimicrobial activity.” J. Ethnopharmacol. 1986; 16(1): 1–13.

Bondarenko, A. S., et al. “The antimicrobial properties of the polyacetylene antibiotic phenylheptatriyne.” Mikrobiol. Zh. 1985; 47(2): 81–3.

Hudson, J. B., et al. “Nature of the interaction between the photoactive compound phenylheptatriyne and animal viruses.” Photochem. Photobiol. 1982; 36(2): 181–85.

Arnason, T., et al. “Photosensitization of Escherichia coli and Saccharomyces cerevisiae by phenylheptatriyne from Bidens pilosa.” Can. J. Microbiol. 1980; 26(6): 698–705.

Antidiabetic & Hypoglycemic Actions:

Lans, C. A. “Ethnomedicines used in Trinidad and Tobago for urinary problems and diabetes mellitus.” J. Ethnobiol. Ethnomedicine. 2006 Oct; 2: 45.

Chang, C.L., et al. “The distinct effects of a butanol fraction of Bidens pilosa plant extract on the development of Th1-mediated diabetes and Th2-mediated air way inflammation in mice.” J. Biomed. Sci. 2005; 12(1): 79-89.

Alarcon-Aguilar, F. J., et al. “Investigation on the hypoglycaemic effects of extracts of four Mexican medicinal plants in normal and alloxan-diabetic mice.” Phytother. Res. 2002; 16(4): 383–86.

Ubillas, R. P. “Antihyperglycemic acetylenic glucosides from Bidens pilosa.” Planta Med. 2000; 66(1): 82–3.

Alarcon-Aguilara, F. J., et al. “Study of the anti-hyperglycemic effect of plants used as antidiabetics.” J. Ethnopharmacol. 1998; 61(2): 101–10.

Perez, R. M., et al. “A study of the hypoglycemic effect of some Mexican plants.” J. Ethnopharmacol. 1984; 12(3): 253–62.

Hypotensive Actions:

Dimo, T., et al. “Leaf methanol extract of Bidens pilosa prevents and attenuates the hypertension induced by high-fructose diet in Wister rats.” J. Ethnopharmacol. 2002; 83(3): 183–91.

Dimo, T., et al. “Effects of the aqueous and methylene chloride extracts of Bidens pilosa leaf on fructose-hypertensive rats.” J. Ethnopharmacol. 2001; 76(3): 215–21.

Dimo, T., et al. “Hypotensive effects of a methanol extract from Bidens pilosa Linn. on hypertensive rats.” C. R. Acad. Sci. Paris 1999; 322(4): 323–29.

Dimo, T., et al. “Effects of leaf aqueous extract of Bidens pilosa (Asteraceae) on KCL- and norepinephrine-induced contractions of rat aorta.” J. Ethnopharmacol. 1998; 60(2): 179–82.

Anti-ulcer & Anti-diarrhea Actions:

Lans, C. “Comparison of plants used for skin and stomach problems in Trinidad and Tobago with Asian ethnomedicine.” J. Ethnobiol. Ethnomedicine. 2007 Jan; 3(1): 3.

Atta, A. H., et al. “Evaluation of some medicinal plant extracts for antidiarrhoeal activity.” Phytother. Res. 2005 Jun; 19(6): 481-5.

Tan, P. V., et al. “Effects of methanol, cyclohexane and methylene chloride extracts of Bidens pilosa on various gastric ulcer models in rats.” J. Ethnopharmacol. 2000; 73(3): 415–21.

Alvarez, A., et al. “Gastric antisecretory and antiulcer activities of an ethanolic extract of Bidens pilosa L. var. radiata Schult. Bip.” J. Ethnopharmacol. 1999; 67(3): 333–40.

Avalos, A. A., et al. “Influence of extracts from leaves and stem of Bidens pilosa on experimental ulcerogenesis in rats.” Rev. Cubana Farm. 1984; 18(2): 143–50.

Anti-allery & Antihistamine Actions:

Wang, N. L., et al. “Two neolignan glucosides and antihistamine release activities from Bidens parviflora WILLD.” Chem. Pharm. Bull. 2006 Aug; 54(8): 1190-2.

Fever-Reducing Actions:

Sundararajan, P., et al. “Studies of anticancer and antipyretic activity of Bidens pilosa whole plant.” Afr. Health Sci. 2006 Mar; 6(1): 27-30.

Antimalarial Actions:

Oliveira, F.Q., et al. “New evidences of antimalarial activity of Bidens pilosa roots extract correlated with polyacetylene and flavonoids.” J. Ethnopharmacol. 2004 Jul; 93(1): 39-42.

Andrade-Neto, V. F., et al. “Antimalarial activity of Bidens pilosa L. (Asteraceae) ethanol extracts from wild plants collected in various localities or plants cultivated in humus soil.” Phytother. Res. 2004; 18(8): 634-9.

Krettli, A. U., et al. “The search for new antimalarial drugs from plants used to treat fever and malaria or plants randomly selected; a review.” Mem. Inst. Oswaldo Cruz 2001; 96(8): 1033–42.

Krettli, A. U., et al. “New antimalarial drugs: A search based on plants used in popular medicine to treat fever and malaria.” Folha. Med. 2001; 120(2): 119–26.

Brandao, M. G. L., et al. “Antimalarial activity of extracts and fractions from Bidens pilosa and other Bidens species (Asteraceae) correlated with the presence of acetylene and flavonoid compound.” Eur. J. Pharmacol. 1997; 57(2): 131–38.

Ingredients: 100% pure picão preto (Bidens pilosa) whole herb (root, leaf, stem, and flowers). No binders, fillers or additives are used. It is a wild harvested product—grown naturally in the Brazilian Amazon without any pesticides or fertilizers.

Suggested Use: This plant is best prepared as a decoction. Use one teaspoon of powder for each cup of water. Bring to a boil and gently boil in a covered pot for 20 minutes. Allow to cool and settle for 10 minutes and strain warm liquid into a cup (leaving the settled powder in the bottom of the pan). It is traditionally taken in 1 cup dosages, 2-3 twice daily. For more complete instructions on preparing herbal decoctions, see the Methods for Preparing Herbal Remedies Page.


Not to be used during pregnancy or while breast-feeding.

This plant contains several coumarin derivatives.Those on coumadin blood thinning medications should use with caution and monitor these possible effects.

Picão preto contains a small amount of naturally-occurring caffeine; it should not be used by those who are allergic or sensitive to caffeine.

This plant has been documented to lower blood sugar levels in several animal studies. It is probably contraindicated in persons with hypoglycemia and people with diabetes should monitor their blood sugar levels accordingly.

Picão preto has been documented with hypotensive activity in several animal studies. It is probably contraindicated for persons with low blood pressure.

Drug Interactions: None reported, however, this plant might increase or enhance the effect of high blood pressure, blood thinning and antidiabetic drugs.

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