Petiveria alliacea (Anamu): A Comprehensive Reference
1. Identity and Botanical Description
Scientific Classification and Nomenclature
Petiveria alliacea L. belongs to the family Phytolaccaceae and is a plant species widely distributed in the Amazon region but also found in various regions of the Americas, including the Caribbean islands and Mexico. Known synonyms include Mapa graveolens, P. corrientina, P. foetida, P. graveolens, P. hexandria, and P. paraguayensis.
Morphology
It is characterized as an herbaceous plant with a height ranging from 5 to 150 cm, featuring an erect, cylindrical stem and branches. The flowers are small, arranged in axillary or terminal spikes 15–40 cm long, graceful, small, hermaphrodite, with four petals, white, greenish-white, or light pink; the fruit is about 8 mm long, cuneate, striated, with six terminal bristles and a solitary, linear seed.
Common Names
The plant is known by many common names depending on region: Anamu (Dominican Republic, Puerto Rico); Tipi (Brazil); Guinea Hen Weed and Garlic Weed (Jamaica); Mapurite and Gully Root (Trinidad); Apacin (Guatemala); Mucura (Peru). It is also known by the names 'mucuracaá', 'guiné', and 'pipi'.
Geographic Distribution
Petiveria alliacea L. commonly grows in the tropical regions of the Americas such as the Amazon forest, Central America, Caribbean islands and Mexico, as well as specific regions of Africa. It is described as a perennial shrub prevalent in South and Central America, and in some areas of Africa and the southeastern United States.
Plant Parts Used and Common Preparations
Leaves, stems, and roots are all used, with roots generally considered stronger than aerial parts. Ethnobotanical uses include the treatment of respiratory disorders, fever, venereal diseases, and influenza; nutritional uses include the powder as herbal concoctions in the form of extracts, teas, and capsules. Preparation methods vary by region but commonly include leaf infusions, root powders mixed into teas, or whole-plant extracts, though dosages differ based on local customs and the severity of symptoms.
2. Traditional and Historical Use
Indigenous and Folk Medicine in the Americas
Petiveria alliacea has been used in traditional medicine for the treatment of various central nervous system (CNS) disorders, such as anxiety, pain, memory deficits, and seizures, as well as for its anaesthetic and sedative properties. Indigenous groups in the Amazonia region of South America have incorporated the plant into their healing traditions for centuries, employing it for a broad spectrum of ailments including earaches, headaches, and inflammatory conditions like rheumatism.
Brazilian folk medicine attributes to the hot water infusion of its roots or leaves the following pharmacological properties: antipyretic, antispasmodic, abortifacient, antirrheumatic, diuretic, analgesic, and sedative. In Brazilian folk medicine specifically, it serves as an antispasmodic, diuretic, menstrual promoter, and stimulant.
In Jamaica and other Caribbean islands, where it is called guinea hen weed, the plant is frequently used to treat headaches, respiratory issues, and general infections through infusions of leaves or roots.
In traditional medicine, P. alliacea finds application in various therapeutic approaches, among which stand out antispasmodic, diuretic, abortive, hypoglycemic, anti-inflammatory, and anticancer activity, in addition to central nervous system activities, such as anxiolytic effects, and use in the treatment of dementia and nervous disorders.
Ritual and Religious Use
The use of this species for religious ceremonies has been reported since the era of slavery in the Americas. Its incorporation into syncretic ceremonies—including house cleansings, altar work, and offerings—extends to contexts such as despacho rituals in Andean-influenced practice, where aromatic plants are assembled to restore balance and protection.
Traditional Use in Africa
P. alliacea grows in Africa and tropical America, where it is popularly known as "tipim", "tipi", and "guiné". The leaves are used in folk medicine as diuretic, sedative, or analgesic.
Traditional Use in Central America
Ethnobotanical uses include the treatment of respiratory disorders, fever, venereal diseases, and influenza, with the powder used as herbal concoctions in the form of extracts, teas, and capsules intentionally for boosting immune systems. In Colombia, in some countries of Central and South America, aqueous and alcoholic infusions have been used to treat leukemias and breast cancer.
3. Key Chemical Constituents and Active Compounds
Overview of Phytochemical Diversity
Phytochemistry studies of P. alliacea indicate that this plant contains a diversity of biologically active compounds, with qualitative and quantitative variations of the major compounds depending on the region of collection and the harvest season, such as essential oil (Petiverina), saponinic glycosides, isoarborinol-triterpene, isoarborinol-acetate, isoarborinol-cinnamate, steroids, alkaloids, flavonoids, and tannins.
Sulfur-Containing Compounds (Signature Constituents)
The most chemically distinctive and pharmacologically significant compounds in P. alliacea are its organosulfur components. The sulfur compounds reported for Petiveria alliacea include thiobenzaldehyde S-oxide, dibenzyl sulfide, S-(2-hydroxyethyl)-phenylmetanethiosulfinate, glutamyl-S-benzyl cysteine, and dibenzyltrisulfide. It is likely that these compounds are produced by petiverins (benzyl sulfoxides) degradation during the plant extraction process, and are associated with antitumor activity.
The plant also contains sulfur-containing amino acids such as S-benzyl cysteine sulfoxide and S-(2-hydroxyethyl)-cysteine sulfoxide. Dibenzyl trisulfide (DTS) is a lipophilic compound having immunomodulatory and cytotoxic activity associated with the cytoskeleton.
Root-Specific Chemistry
Root chemical analyses have revealed coumarins, benzyl-hydroxy-ethyl-trisulphide, benzaldehyde, benzoic acid, dibenzyl trisulphide, potassium nitrate, β-sitosterol, isoarborinol, isoarborinol-acetate, isoarborinol-cinnamate, polyphenols, trithiolaniacine, glucose, and glycine.
Flavonoids, Triterpenes, and Other Classes
Compounds isolated and reported for Petiveria alliacea include flavonoids such as astilbin, myricitrin, and engeletin; triterpenes such as barbinervic acid and α-friedelinol; steroids such as daucosterol; lipids such as lignoceric acid, nonadecanoic acid, and oleic acid; and other compounds such as allantoin and coumarin.
Phytochemical investigation has also led to the identification of stigmasterol, stigmastenol, stigmastanol, loliolide, 3-hydroxy-5,6-epoxy-β-ionone, and benzyl-β-glucopyranoside, several of which were described for the first time in this species.
Essential Oil Composition
Research on the essential oil of P. alliacea from Nigeria revealed that phytol was a major constituent, and potent anti-inflammatory activity of the essential oil may be attributed to its high content of citronellol, (Z,Z)-α-farnesol, and phytol.
Phenolic Compounds
Chemical analyses of the ethanolic extract have revealed a rich content of phenolic compounds such as protocatechuic acid, cinnamic acid, and catechin epicatechin.
4. Established and Proposed Mechanisms of Action
Anti-Inflammatory Mechanisms
Anti-inflammatory effects have been investigated through the production of several cytokines, chemokines, and expression of nuclear factor-kappa B (NF-κB) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. An ethanol extract precipitated with water (PW) significantly suppressed the secretion of prostaglandin E2, leukotriene C4, interleukin (IL)-1β, IL-6, IL-10, interferon gamma, and nitric oxide (NO). These antioxidant and anti-inflammatory activities can be attributed in part to the presence of dibenzyl disulfide, dibenzyl trisulfide pinitol, coumarin, myricetin, glutamyl-S-benzyl cysteine, and petiveriins A and B.
Researchers have demonstrated COX-1 inhibitory properties for P. alliacea extracts, noting cyclooxygenase-1 inhibitors are a class of anti-arthritis agents.
Anticancer Mechanisms
In one study, P. alliacea was shown to mediate changes in glycolytic enzyme expression causing a decrease in glucose uptake and lactate production, thereby inducing apoptosis in breast adenocarcinoma cells. The plant could inhibit glycolysis and oxidative phosphorylation (OXPHOS), modulating tumor metabolism, making it a potential treatment for tumors with altered metabolism.
Although DTS showed good cytotoxic activity, its high toxicity even affecting normal cells has not allowed its clinical and therapeutic use.
Immunomodulatory Mechanisms
Dibenzyl trisulfide is an immunomodulatory compound isolated from Petiveria. Immunomodulatory properties have been documented to enhance cytokine production and immune response, supporting its proposed use in cancer therapy.
Antinociceptive Mechanisms
In animal models, root crude aqueous extract showed an antinociceptive effect in acetic acid–, acetylcholine–, and hypertonic saline–induced abdominal constrictions, but not in hot-plate and tail-flick tests, and did not produce any CNS depressor effect. In a formalin model study, all extracts at doses from 10 to 316 mg/kg significantly reduced the pain response in both phases of the formalin model, with values of 50–60% for the inflammatory response.
5. Scientific Evidence by Area of Use
5.1 Pain and Inflammation
Animal and in vitro evidence: Studies done in laboratories and in animals have shown that P. alliacea can prevent certain infections, reduce inflammation and pain, and regulate cancer cell growth; however, this has not been confirmed in humans.
Human clinical evidence: The first published clinical study on the species was "The effectiveness of tipi in the treatment of hip and knee osteoarthritis—A preliminary report" by Ferraz et al. and "Evaluation of antinociceptive effect of Petiveria alliacea (guiné) in animals" by de Lima et al., both published in a supplementary volume of the Brazilian journal Memórias do Instituto Oswaldo Cruz in 1991. Interestingly, this first study was a randomized clinical trial that explored a P. alliacea infusion as a therapeutic alternative for osteoarthritis, which promoted superior pain relief compared to placebo despite having a reduced sample.
However, a subsequent assessment yielded conflicting results. A small study done in patients with osteoarthritis did not show benefits of P. alliacea compared with placebo. Specifically, one small clinical trial found that P. alliacea is no more effective than a placebo in arthritic patients with hip and knee pain.
A Cochrane-indexed review of oral herbal therapies for osteoarthritis included Petiveria alliacea (tipi tea, aqueous extract) among the monoherbal products studied. Overall, the evidence for analgesia and anti-inflammation in humans is weak and conflicting, with no adequately powered, rigorously controlled trials available.
5.2 Antimicrobial, Antifungal, and Antiviral Activity
In vitro, extracts of this herb demonstrated antimicrobial, antifungal, antiviral, antiprotozoal, and immunomodulatory properties. The herb is rich in sulfur-containing compounds that possess a broad-spectrum of in vitro antimicrobial activity against pathogenic fungi and bacteria at low concentrations.
P. alliacea showed active inhibition of bovine viral diarrhea virus replication in vitro. All antimicrobial and antiviral evidence is confined to cell-culture and laboratory studies; no human clinical trials on infectious disease have been conducted.
5.3 Oncology / Anticancer Activity
Preclinical evidence: P. alliacea showed cytotoxicity and antiproliferative activity against cancer cell lines through sophisticated machinery of cellular damage in vitro. Data on its cytotoxic effects are conflicting. There is ethnopharmacological evidence that Petiveria alliacea can have antitumor activity; however, the mechanism of its cytotoxic activity is not well understood. Multiple in vitro biological activities of an ethyl acetate soluble plant fraction have been assessed over several tumor cell lines.
Clinical evidence — Phase Ib/II Trial (ongoing): A prospective, open-label, Phase I/randomized, double-blind single-center Phase II study has been designed to evaluate the safety and efficacy of a standardized Esperanza extract in patients with metastatic gastrointestinal tumors and acute leukemias. In Stage 1, the study will determine the maximum tolerated dose (MTD) and assess safety. In Stage 2, safety at the MTD will be evaluated, and the efficacy of the Esperanza extract will be explored in both metastatic gastric tumors and acute leukemias. Quality of life improvement will be the primary outcome in the gastric tumor group, while different efficacy outcomes will be assessed in the acute leukemia group. This trial is registered in the US National Library of Medicine with identifier NCT05587088, registered October 19th, 2022.
Laboratory studies showed that P. alliacea can be toxic to some cancer cells, but more data are needed. It has not been studied in humans in completed efficacy trials. Evidence strength: preliminary preclinical only; one ongoing Phase Ib/II trial as of 2023.
5.4 Central Nervous System (Anxiolytic, Anticonvulsant, Antidepressant, Cognitive)
Crude extracts, fractions and phytochemical constituents isolated from various parts of P. alliacea show a wide spectrum of neuropharmacological activities including anxiolytic, antidepressant, antinociceptive, and anti-seizure properties, and as cognitive enhancers.
The whole plant extracts have anxiolytic effects, whereas an extract of aerial parts showed anxiogenic properties, and root extracts showed anticonvulsant effects in mice. The finding that different preparations can produce opposite effects (anxiolytic versus anxiogenic) underscores the complexity of the plant's CNS pharmacology and the importance of preparation specifics. All CNS evidence is from animal and in vitro models; no human clinical trials for CNS indications have been published.
5.5 Hypoglycemic / Antidiabetic Activity
Extracts from P. alliacea leaves and stems showed hypoglycemic effects in mice. An older animal study suggests P. alliacea may have additive hypoglycemic effects with antidiabetic drugs; clinical relevance has yet to be determined. However, in one preclinical study, the aqueous and hexane extracts demonstrated no significant reduction of fasting blood glucose (FBG) and no significant improvement of glucose tolerance in normal rats. Evidence is mixed and confined to animal models; no human clinical data exist.
5.6 Immunomodulation
This species is a medicinal plant with important pharmacological properties including anti-inflammatory, antinociceptive, hypoglycemic, and anesthetic activities, in addition to its wide use in the treatment of epilepsy, anxiety, and poor memory. Nutritional uses include the use of the powder as herbal concoctions intentionally for boosting immune systems; reported pharmacological activities include antimicrobial, anti-inflammatory, antidiabetic, anticancer, immunostimulating, and antinociceptive activities. All immunomodulatory data come from in vitro studies and animal models.
5.7 Overall Strength of Evidence
After 32 years following the first 1991 randomized clinical trial on the species, no further clinical trials related to the species had been identified as of the 2023 bibliometric review. The single registered Phase Ib/II oncology trial (NCT05587088) is the only active human study. The overwhelming majority of evidence for P. alliacea is preclinical—in vitro and animal studies—and should be characterized as preliminary throughout all therapeutic areas.
6. Body Systems and Health Areas
- Musculoskeletal system: P. alliacea is used in traditional medicine as an antirheumatic, antispasmodic, and analgesic for pain relief.
- Central nervous system: Traditional use for anxiety, pain, memory deficits, seizures, as well as anaesthetic and sedative properties.
- Immune system: In vitro, extracts demonstrated antimicrobial, antifungal, antiviral, antiprotozoal, and immunomodulatory properties.
- Endocrine / metabolic system: Wide use in the treatment of epilepsy, anxiety, poor memory, and hypoglycemic activity.
- Reproductive system: Traditionally used as an abortifacient in folk medicine.
- Oncology: Widely used in folk medicine to treat inflammation, infection, and as an anticancer agent.
- Respiratory system: Ethnobotanical uses include the treatment of respiratory disorders, fever, venereal diseases, and influenza.
- Renal/urinary system: The roots and leaves have been used as antispasmodic, sedative, diuretic, and antihelminthic agents.
7. Dosage Forms and Dosages Reported in Studies
In one study evaluating hypoglycaemic activity, P. alliacea has ethno-traditional use as a hypoglycaemic agent in Jamaica; aerial parts were evaluated using aqueous and hexane extracts prepared from leaves and tested for hypoglycaemic activity, with an acute administration of the extracts at 200 and 400 mg/kg body weight evaluated in normoglycaemic rats.
In a study of antinociceptive activity in mice, all extracts at doses from 10 to 316 mg/kg significantly reduced the pain response in both phases of the formalin model, with values of 50–60% for the inflammatory response. Toxicological studies (LD50) exhibited that all extracts did not cause any mortality up to the 2000 mg/kg dose level.
In the human trial framework, a Phase I/randomized double-blind Phase II study is designed to evaluate the Esperanza extract; Stage 1 will determine the maximum tolerated dose (MTD) and assess safety, while Stage 2 will evaluate safety at the MTD and explore efficacy in metastatic gastric tumors and acute leukemias. Specific human dosage figures from completed human trials are not established in the published literature.
A double-blind cross-over trial in osteoarthritis used a preparation described as "Tipi, a popular analgesic tea" by Ferraz et al. (1991), studied in Brazil. Precise dosage information from this trial is not reported in accessible secondary literature.
8. Safety Considerations and Drug Interactions
Reproductive Toxicity and Pregnancy
Information regarding safety and efficacy of P. alliacea in pregnancy and lactation is lacking, and methanol extracts of anamu can cause uterine contractions, which can lead to miscarriage. Studies have demonstrated that use of the plant could stimulate contractions of the uterus, which may result in miscarriage; therefore, pregnant women and those trying to conceive should avoid its use.
Genotoxic and Mutagenic Potential
In vitro and in vivo assays showed that petiveria has mutagenic effects. A decreased cell viability in wild-type and ogg1 yeast strains was demonstrated, and all fractions of the extract exerted a mutagenic effect on the ogg1 strain. Toxic effects have already been described, whose mechanisms of action require further studies.
Chronic Toxicity
Despite its beneficial pharmacological properties, P. alliacea is also known to exert toxic effects on the CNS, and deaths after one year of chronic exposure to this plant have been reported.
Cytochrome P450 Drug Interactions
Dibenzyl trisulfide (DTS) isolated from Petiveria alliacea inhibits CYP1A2, CYP2C19, and CYP3A4 and may affect the blood levels of drugs metabolized by these enzymes; clinical relevance has yet to be determined.
Anticoagulant Interaction
Low concentrations of coumarin have been found in the plant; hence, its use may result in thinning of the blood and should not be taken by persons with pre-existing blood conditions such as hemophilia or those on blood-thinning medications such as warfarin.
Hypoglycemic Drug Interaction
Animal studies have shown that P. alliacea has a hypoglycemic effect, so individuals with hypoglycemia or diabetes should exercise caution regarding its use.
CNS Toxicity Concerns
Although DTS showed good cytotoxic activity, its high toxicity even affecting normal cells has not allowed its use in clinical and therapeutic applications. No studies have evaluated herb–herb interactions or herb–drug interactions with P. alliacea. Potential adverse reactions of P. alliacea are not well understood, as no adverse reactions have been systematically reported from controlled human studies.
9. Current Research Status
A comprehensive bibliometric analysis using conventional metrics combined with a critical content review of P. alliacea's pharmacological and toxicological properties has been conducted to identify gaps in the existing literature. This investigation identified a total of 55 articles meeting the inclusion criteria. Analysis of keyword co-occurrence revealed that "Petiveria alliacea", "plant extract", and "guatemala" were the most frequently encountered terms; in vitro and in vivo were the predominant study types observed.
Many traditional uses of P. alliacea have now been partially validated by modern pharmacology research, and available data support the emergence of P. alliacea as a potential source for the treatment of different CNS disorders including anxiety, depression, pain, epilepsy, and memory impairments. However, robust human clinical evidence across all indications remains absent, with the exception of a small, inconclusive early osteoarthritis trial and the ongoing oncology Phase Ib/II protocol registered in 2022.
The ongoing PA001 trial aims to evaluate the safety profile of the Esperanza extract in patients with metastatic gastrointestinal tumors and acute leukemias, while exploring its potential efficacy in conjunction with standard treatment for these pathologies.
References
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