Gallesia

Other Names

ajoajo-ajoárvore-de-alhocatinga-de-gambácebolãocipó-d'alhoCrateva gorarema Vell.Crateva gorazema Moq.Gallesia gorarema (Vell.) Moq.Gallesia gorazema (Vell.) Moq.Gallesia integrifoliaGallesia integrifolia (Spreng.) HarmsGallesia integrifolia var. ovata (O.C.Schmidt) NowickeGallesia ovata O.C.SchmidtGallesia scorododendrum Casar.garlic treegarlic woodgerebagoraremagorazemagororemaguararemaguarazemaguaremaibiracemaibiraremaimbiremaimburacemaiviraremajandiparamajandiparandubamuiraremapalo cebollapau-d'alhopau-d'alho-verdadeiropau-de-alhopau-de-mau-cheiropau-fedorentoThouinia integrifolia Spreng.ubaetéubiraremaubirarema-pau-d'alho

Synopsis

Gallesia integrifolia (Pau d'Alho / Garlic Wood): A Comprehensive Reference

Identity and Botanical Description

Taxonomic Classification

Accepted botanical name: Gallesia integrifolia (Spreng.) Harms. The species belongs to the family Phytolaccaceae. Gallesia integrifolia (Spreng) Harms, a member of the Phytolaccaceae family, is a species that remains relatively unexplored from both chemical and pharmacological perspectives. Historical synonyms documented in the taxonomic literature include Gallesia gorarema (Vell.) Moq., Gallesia scorododendrum Casar., Gallesia integrifolia var. ovata (O.C.Schmidt) Nowicke, Gallesia ovata O.C.Schmidt, and Thouinia integrifolia Spreng., reflecting the complex taxonomic history of the genus.

Common Names

Gallesia integrifolia (Phytolaccaceae) is commonly known as "pau-d'alho" in Brazil or "garlic plant" due to the strong scent of garlic peculiar to all parts of the plant. Commonly referred to as garlic-wood, árbol de ajo, or pau d'alho, G. integrifolia emits a distinct garlic-like odor attributed to its essential oils, which possess a high concentration of sulfur compounds. In Brazil it is additionally known as guararema.

Morphology and Habit

Gallesia integrifolia is an evergreen tree with a wide crown; it can grow up to 30 metres tall. The bole is short, but can be 70–140 cm in diameter. It is a perennial, heliophile, selective hygrophyte species that occurs in deep, humid and highly fertile soils.

Geographic Distribution

Gallesia integrifolia (Spreng.) Harms, Phytolaccaceae, is a native and endemic plant of Brazil that is widely distributed in the Amazon, Caatinga, Cerrado, and Atlantic rain forest. It is a Brazilian native tree occurring from Bahia to Paraná and characteristic of the Semideciduous Forest and the Paraná basin. Beyond Brazil, it also has a range extending into neighbouring South American countries: South America — Bolivia, Brazil, Peru, Ecuador — in seasonally dry forests at elevations up to 1,500 metres.

Plant Parts Used and Preparation Forms

The leaves, bark, and roots of Gallesia integrifolia are consumed in folk medicine through infusion, decoction, and topical preparation by crushing because of its pharmacological properties in several peripheral system disorders, including microbial infections. In research settings, investigators have isolated and tested the plant's essential oils (EOs) by steam or hydrodistillation and crude extracts (CEs) prepared by dynamic maceration in ethanol, hydroethanol, dichloromethane, and methanol from different plant organs (leaves, bark, roots, flowers, and fruits) separately.

Traditional and Historical Use

Cultures and Time Periods

This plant has been reported since 1821 for common treatments of orchitis, verminosis, and rheumatism. The bark decoction is used for the treatment of microbial infections among other diseases by different ethnic groups in Brazil, Peruvian Amazonians, Bolivia and Mosetene Indians.

Conditions Treated in Folk Medicine

Gallesia integrifolia, a notable species in the Atlantic Forest, has been traditionally employed in folk medicine for treating rheumatism, asthma, and worms. In traditional medicine, its leaves and bark are popularly used as a remedy for flu, cough, pneumonia, worms, gonorrhea, prostate tumors, and rheumatism. Tea from the leaves and stem bark is used to treat ulcers. Boiled leaves and stem bark are also used to treat intestinal worms and respiratory and lymphatic diseases. In traditional medicine, teas made from leaves and bark of Gallesia are used as antispasmodic, anthelmintic, antihemorrhagic and febrifuge agents. Crude leaves of this plant are also employed as a remedy in the treatment of abscesses, orchitis, gonorrhea and for rheumatic pain relief.

Preparation Methods in Traditional Use

Traditional preparations documented across Brazilian ethnic groups and Amazonian cultures include: (1) bark decoction for microbial and infectious conditions; (2) leaf and stem bark infusion (tea) for ulcers, respiratory ailments, and worms; (3) topical crushing preparations applied externally. Traditional medicine mainly focuses on the tree's bark.

Key Constituents and Active Compounds

Organosulfur Compounds (Essential Oils)

The most chemically distinctive feature of G. integrifolia is its extraordinary organosulfur content. EOs predominantly contained organosulfur compounds in flowers (96.29%), fruits (94.94%), and leaves (90.72%). The main compound identified was 2,2′-Disulfanediyldiethanethiol in the EOs of flowers (47.00%), leaves (41.82%), and fruits (44.39%). Other sulfur compounds identified by GC-MS in the essential oils include: 2,8-dithianonane (52.6%) in fruits, 3,5-dithiahexanol-5,5-dioxide (38.9%) in leaves, and methionine ethyl ester (45.3%) in flowers. Additional sulfur-containing molecules identified across tissues include 2,3,5-trithiahexane, 3,6-dithiaoctan-1,8-diol, methanethiol, 2,8-dithianonane, dimethyl disulfide, and lenthionine in fruits; methionine ethyl ester in flowers; and 3,5-dithiahexanol-5,5-dioxide in leaves.

Phenolic Compounds and Flavonoids (Bark and Crude Extracts)

Qualitative phytochemical analysis of the hydroethanolic bark extract (HEGi) revealed the presence of saponins, alkaloids, phenolic compounds and flavonoids. Phytochemical quantification of HEGi showed total phenolic content of 80.10 ± 0.62 mg GAE/g and flavonoid content of 16.10 ± 0.03 mg RE/g. HPLC fingerprint analysis revealed the presence of gallic acid, rutin, and morin.

Fatty Acids, Diterpenes, Phytosterols, and Vitamins

Phytochemical analysis of crude extracts from flowers and fruits of G. integrifolia indicated high concentrations of vitamin C and organosulfur compounds, and in leaves, high concentrations of phytol, fatty acids, and fatty acid esters. Oxygenated diterpenes were also found in flowers and leaves, as well as phytosterol and triterpenes in fruits. The major compounds of the ethanolic extract from G. integrifolia flowers were vitamin E (18.0%) and disulfide, ethyl iso-allocholate (10.6%); from fruits were vitamin E (20.9%), linolenic acid methyl ester (14.0%), and phytol (10.2%); whereas from leaves were phytol (30.9%), linolenic acid methyl ester (30.5%), and methyl palmitate (10.9%).

A Novel Natural Product from Roots

The dichloromethanic root extract (DRE) was assayed against herpes simplex viruses HSV-1 and HSV-2; only DRE was highly active against HSV-1. Phytochemical fractionation of DRE led to the isolation of 28-hydroxyoctacosyl ferulate, a novel natural product, which displayed strong antiviral activity against HSV-1 (EC₅₀ = 21.6 μg/mL) with a selective index above 9.

Summary of Chemical Compound Classes

Organosulfur compounds: Disulfides, trithianes, dithiolanes, thioethers, methionine esters — highly concentrated in essential oils of all plant parts.
Polyphenols: Gallic acid, rutin, morin (identified by HPLC in bark extract).
Flavonoids: Present in bark and crude extracts.
Alkaloids and saponins: Detected qualitatively in bark extract.
Phytol and fatty acid esters: Dominant in leaf crude extracts.
Triterpene glycosides and phytosterols: Identified in fruit crude extracts.
Vitamins C and E: Detected in flower and fruit crude extracts.
Oxygenated diterpenes: Found in flowers and leaves.
Novel ferulate ester: 28-hydroxyoctacosyl ferulate, isolated from root dichloromethane extract.

Proposed Mechanisms of Action

Antioxidant Mechanisms

The combination of a sterically hindered phenol and a sulfide group within a single molecule offers a unique approach to inhibit oxidative damage. In this combined delivery system, the hydroxy group of the phenolic moiety actively engages in reactions with peroxyl radicals, while the thioether group reacts with hydroperoxides, leading to the formation of sulfoxides (sulfones) and alcohols. Phenolic compounds directly intercept O₂ and hinder lipid peroxidation by capturing lipid alkoxy radicals. Moreover, the antioxidant effects of phenols can be attributed to their capacity to alter the kinetics of peroxidation. Modifying the lipid package and reducing membrane fluidity, they restrict the diffusion ability of free radicals and mitigate the peroxidation process.

Gastroprotective Mechanisms

The results of the essential oil (EOGi) study provide evidence that EOGi possesses potent gastroprotective and curative effects, probably attributable to its antioxidant, nitrergic, mucogenic, anti-secretory and anti-inflammatory effects. These are related at least in part to the presence of sulfur compounds, in particular the sesquiterpenes as (−)-alpha-santalene, the main components detected. EOGi gastroprotection was attenuated by indomethacin pre-treatment, suggesting involvement of the prostaglandin pathway in its cytoprotective mechanism.

Anticholinesterase and Insecticidal Mechanisms

Flower extract showed high activity against Aedes aegypti larvae (LC99.9 of 0.032 mg/mL) and highest inhibition of acetylcholinesterase enzyme (0.00019 mg/mL) ex situ. The flower extract presented anticholinesterase and larvicide activity 12.8% and 35.6% greater than the control temephos, respectively. The organosulfur compounds are understood to underlie both the insecticidal and antimicrobial activities. Gallesia integrifolia is known for its sulfur content, which plays a role in insecticidal and antimicrobial activities.

Scientific Evidence by Area of Use

1. Antimicrobial (Antibacterial) Activity

Evidence type: In vitro and in vivo (rodent) preclinical studies. No human clinical trials identified.

A 2016 study published in the Journal of Ethnopharmacology (PubMed PMID: 26945980) characterized the hydroethanolic bark extract (HEGi) in in vitro and in vivo models. HEGi is safe at the dose tested when used acutely, and it presented broad antibacterial effect, which supports its traditional use in the treatment of bacterial infections. It contains well-known important phytochemicals recognized to be active against bacterial pathogens in vitro. The ethanolic extract of G. integrifolia bark was active only against S. aureus among the four bacterial strains tested (E. coli, S. aureus, Salmonella enterica and P. aeruginosa) in earlier disc diffusion work. The 2016 study expanded testing and found broader activity attributable largely to the phenolic content (gallic acid, rutin, morin) and flavonoids.

Evidence strength: Preliminary. All results are in vitro or in rodents; no controlled human studies exist.

2. Antifungal Activity

Evidence type: In vitro testing against clinical isolates; molecular docking.

A 2022 study (PubMed PMID: 35643209) evaluated antifungal activity of essential oils from leaves, flowers, and fruits of G. integrifolia against Candida species isolated from pregnant women with vulvovaginal candidiasis. Antifungal activity was determined by minimum inhibitory concentration (MIC) using broth microdilution against Candida spp., C. albicans, and C. tropicalis standard and clinical isolates. Nystatin and fluconazole were used as positive controls. Bioactive compounds of G. integrifolia presented antifungal activity against standard strains and Candida yeast species isolated from cultures of vaginal secretions from pregnant women. Leaves were more efficient against C. albicans, and flowers were more efficient against C. glabrata. Docking simulations suggested that phytol in leaves and flowers was responsible for the antimicrobial effect. The results suggest the potential therapeutic use of G. integrifolia, especially its leaves and flowers, against Candida and vulvovaginal candidiasis. Earlier work (Freixa et al., 1998) also reported that the dichloromethane and methanolic extracts of G. integrifolia bark had antifungal activity.

Evidence strength: Preliminary. Antifungal data derive from in vitro MIC testing and computational docking; no clinical trials in human subjects have been conducted.

3. Gastroprotective and Antiulcer Activity

Evidence type: In vitro and in vivo (rodent) preclinical studies.

A study published in 2017 (PubMed PMID: 28763752) specifically investigated the gastroprotective properties of the essential oil from the inner stem bark (EOGi). Gallesia integrifolia is a Brazilian Amazon tree whose bark decoction is popularly used to treat peptic ulcer. The gastroprotective effect of EOGi was assessed in acidified ethanol and piroxicam and ulcer healing on acetic acid-induced ulcer models in rodents. Anti-secretory, mucus, K⁺-ATP channels, prostaglandins (PGs), nitric oxide (NO), TNF-α, IL-1β, IL-10, catalase (CAT) and myeloperoxidase (MPO) activities and in vitro Helicobacter pylori action by EOGi were evaluated. EOGi exhibited cytotoxic effects only at 72 h and no acute toxicity. EOGi showed gastroprotective and ulcer healing effects.

Evidence strength: Preliminary (animal models only). No human studies have been performed.

4. Anti-inflammatory and Antinociceptive Activity

Evidence type: In vivo rodent experiments; cell-culture studies.

Dichloromethanic root (DRE) and ethanolic leaf (ELE) extracts displayed significant antinociceptive and anti-inflammatory activities in in vivo experiments with mice. A 2023 cell-culture study (published in Molecules, PMID: 37513277) evaluated EOs and CEs from flowers, leaves, and fruits. The anti-inflammatory activity IC₅₀ ranged from 36.00 to 268 µg/mL, and the cellular oxidation inhibition ranged from 69% to 82%. The majority of pharmacological and toxicological studies with this plant refer to antinociceptive and anti-inflammatory activities of leaf extracts. Antimicrobial activities of extracts derived from leaves, bark and root are also cited.

Evidence strength: Preliminary; restricted to animal models and cell cultures. No human data available.

5. Antiproliferative and Cytotoxic Activity (Cancer Cell Lines)

Evidence type: In vitro cancer cell line studies.

The antiproliferative potential was evaluated in gastric, colorectal, breast, and lung tumor cell lines and non-tumor VERO cells. The EOs and CEs demonstrated potential against the tumor cell lines tested (GI₅₀ between 51 and 230 µg/mL). The selectivity index values were greater than 1.0 (1.01 to 3.37), suggesting a relative safety profile. An additional study on the fruit essential oil (PubMed PMID: 34000931) reported cytotoxic activity against MCF-7 (GI₅₀ = 66 µg/mL), NCI-H-460 (GI₅₀ = 147 µg/mL), HeLa (GI₅₀ = 182 µg/mL) and HepG2 (GI₅₀ = 240 µg/mL).

Evidence strength: Very preliminary (in vitro only). Results are of mechanistic interest but do not constitute evidence of clinical anticancer benefit. No animal tumor models or human studies have been reported.

6. Antiviral Activity

Evidence type: In vitro cell-based antiviral assays.

The dichloromethanic root extract (DRE) was tested against herpes simplex viruses HSV-1 and HSV-2; only DRE was highly active, showing a selective antiviral effect against HSV-1. Phytochemical fractionation of DRE led to the isolation of 28-hydroxyoctacosyl ferulate, a novel natural product, which displayed strong antiviral activity against HSV-1 (EC₅₀ = 21.6 μg/mL) with a selective index above 9. These results suggest that the plant Gallesia is a potential candidate for the development of novel anti-herpetic phytomedicines.

Evidence strength: Very preliminary (in vitro). No in vivo or human data exist.

7. Antimycobacterial Activity

Evidence type: In vitro antimycobacterial assays.

Gallesia integrifolia essential oils (EOs) and crude extracts (CEs) were tested for their anti-Mycobacterium tuberculosis and anti-nontuberculous mycobacteria activity. Minimum inhibitory concentration (MIC) of EOs ranged from 15.63 to 62.5 μg/mL against M. tuberculosis and 62.5 to >250 μg/mL against nontuberculous mycobacteria. CEs showed low activity. All EOs tested demonstrated synergism with antituberculosis drugs. The cytotoxicity of EOs and CEs, in different cell lines, showed selectivity index from 2.2 to 9.8 and >0.056 to 2.0, respectively. G. integrifolia EOs are a candidate for the development of new therapeutic options in the treatment of tuberculosis and other mycobacterial diseases.

Evidence strength: Preliminary (in vitro only). The noted synergism with established antituberculosis drugs is a finding of interest, but no animal or human validation exists.

8. Larvicidal and Insecticidal Activity (Aedes aegypti)

Evidence type: In vitro and ex situ bioassays.

The essential oils showed high activity against larvae, and low for pupae. The flower extract showed highly active larvicidal results, with LC99.9 of 0.032 mg/mL and LC99.9 of 0.969 mg/mL on A. aegypti larvae and pupae, respectively, and the highest inhibition of acetylcholinesterase enzyme (0.00019 mg/mL) ex situ. This study opens new perspectives on the use of extracts from G. integrifolia as a bioinsecticide alternative for the control of A. aegypti larvae and pupae.

Evidence strength: Preliminary laboratory bioassay data. No field trials or human application studies exist. This area of research is primarily of agrochemical and public health interest rather than direct dietary supplement relevance.

9. Acaricidal Activity Against Cattle Tick (Rhipicephalus microplus)

Evidence type: In vitro bioassays.

The objective of the acaricidal study was to evaluate the acaricidal and larvicidal activities of essential oil (EO) from fruits, leaves and flowers of garlic wood on cattle tick [Rhipicephalus (Boophilus) microplus]. The results showed greater larvicidal activity of crude extracts from flowers and fruits (LC99.9 = 15.82 mg/mL and LC99.9 = 16.13 mg/mL, respectively). Essential oils of fruits, leaves, and flowers showed acaricidal and larvicidal activity against R. microplus, and minor allelopathic effects of the essential oil against Bidens pilosa L. seeds were also reported.

Evidence strength: Preliminary in vitro only. No in vivo (veterinary) or clinical data exist.

Body Systems and Health Areas Associated with Gallesia integrifolia

Infectious disease / antimicrobial: Bacteria, fungi (Candida), mycobacteria (M. tuberculosis), and viruses (HSV-1).
Gastrointestinal system: Peptic ulcer and gastric protection (traditional use and rodent pharmacology).
Immune/inflammatory system: Anti-inflammatory and antinociceptive effects demonstrated in rodent models and macrophage cultures.
Oncology (preclinical only): Antiproliferative activity against gastric, colorectal, breast, lung, cervical (HeLa), and hepatocellular (HepG2) cancer cell lines in vitro.
Respiratory system: Traditionally used for flu, cough, and pneumonia; no controlled pharmacological data specific to respiratory pathways.
Reproductive/urogenital system: Traditional use for gonorrhea and orchitis; in vitro antifungal data against vaginal Candida isolates.
Musculoskeletal system: Traditional use for rheumatic pain; antinociceptive data in rodent models.
Parasitology/Ectoparasites: Larvicidal and acaricidal activity against disease-vector mosquitoes and cattle ticks in laboratory bioassays.

Dosage Forms and Doses Reported in Studies

No standardized human dosage has been established. All dosing information below is drawn directly from preclinical studies:

Acute toxicity testing (rodents): In the Alamar blue assay, no cytotoxic effect of HEGi in CHO-K1 cells was observed up to 200 µg/mL, and no signs or symptoms of acute toxicity were observed in mice of both sexes at higher doses of up to 2000 mg/kg, p.o.
Antiproliferative (cancer cell lines): EOs and CEs demonstrated potential against the tumor cell lines tested, with GI₅₀ between 51 and 230 µg/mL.
Anti-inflammatory (macrophage cell culture): Anti-inflammatory activity IC₅₀ ranged from 36.00 to 268 µg/mL.
Antimycobacterial (in vitro): Minimum inhibitory concentration (MIC) of EOs ranged from 15.63 to 62.5 μg/mL against M. tuberculosis and 62.5 to >250 μg/mL against nontuberculous mycobacteria.
Antiviral (in vitro): The isolated compound 28-hydroxyoctacosyl ferulate displayed strong antiviral activity against HSV-1 (EC₅₀ = 21.6 μg/mL) with a selective index above 9.
Larvicidal (flower extract, A. aegypti): LC99.9 of 0.032 mg/mL on larvae and 0.969 mg/mL on pupae.
Acaricidal (crude extract, R. microplus): Greater larvicidal activity of crude extracts from flowers (LC99.9 = 15.82 mg/mL) and fruits (LC99.9 = 16.13 mg/mL).

Safety Considerations

Preclinical Toxicology (Available Data)

No cytotoxic effect of HEGi in CHO-K1 cells was observed up to 200 µg/mL, and no signs or symptoms of acute toxicity were observed in mice of both sexes at higher doses of up to 2000 mg/kg, p.o. Results showed that HEGi can be considered as non-cytotoxic under the conditions tested.

EOGi (essential oil from inner stem bark) exhibited cytotoxic effects only at 72 hours and no acute toxicity in the tested rodent models.

For the antiproliferative and antimycobacterial essential oil fractions, selectivity index (SI) values were calculated to gauge relative safety. The selectivity index values for antiproliferative effects were greater than 1.0 (1.01 to 3.37), suggesting a relative safety profile. For antimycobacterial activity, cytotoxicity of EOs in different cell lines showed a selectivity index from 2.2 to 9.8. These SI values indicate modest selectivity, meaning that the concentrations active against pathogens or tumor cells are in some cases close to concentrations that show toxicity in non-target cells — a known concern in natural product development.

Absence of Human Safety Data

The presence of various molecules in different parts of the plant likely confers this species' fungicidal action, but scientific evidence is lacking. No human pharmacokinetic, tolerability, or safety studies have been published. The plant has not been evaluated by major regulatory bodies (EMA, FDA, EFSA) for use as a dietary supplement or herbal medicine. There are no published data on drug interactions, effects in pregnancy, or chronic-use toxicity in humans.

Phytochemical Complexity and Variation

Differences in essential oil composition may result from phenological changes and regional rainfall patterns observed over years of studies with this species. This phytochemical variability means that no single composition can be guaranteed across harvests, seasons, or geographic origins, which is a relevant quality-control consideration.

Current State of Research

Gallesia integrifolia is a species that remains relatively unexplored from both chemical and pharmacological perspectives. Further research is necessary to fully understand the potential of this species. All pharmacological evidence to date is derived from in vitro cell assays, rodent models, and ex situ bioassays. No randomized controlled trials, observational cohort studies, or any other form of clinical investigation in human subjects has been published for any indication. The entire body of evidence supporting bioactivity claims for G. integrifolia is therefore classified as preliminary and preclinical.

References

Health Conditions

Health conditions that Gallesia may help support.

No conditions available.

Body Systems

Body systems that Gallesia may help support.

No body systems available.