Fiesta flower

Other Names

Acmella oleraceaagrião do Brasilagrião do ParáAkarkarAkarkaraAnacyclus pyrethrariusArizona FiestaflowerBerro de ParaBidens acmelloidesBidens fervidaBidens fixaBidens fuscaBidens oleraceaBlue Fiesta-flowerBlue FiestaflowerBrazil cressBrede mafanebuzz buttonsCotula pyrethrariaCresson de ParaDesert Fiestaflowerelectric daisyEllisia auritaeyeball plantHemmugalujambujambújambú do rioNemophila auritapará cresspara cressparacresspeek-a-boo plantpellitoryPhak khratPholistoma auritumPholistoma auritum var. arizonicumPholistoma auritum var. auritumpimenteiraPipulkaPirazhaPyrethrum spilanthussalad cressSichuan buttonsSpilanthes acmellaSpilanthes acmella var. oleraceaSpilanthes fuscaSpilanthes oleraceaSpilanthes oleracea var. fuscaSpilanthes radicansspot plantSzechuan buttonstingflowerstoothache plantViticella aurita

Synopsis

Fiesta Flower (Acmella oleracea / Spilanthes acmella): A Comprehensive Reference

Nomenclature and Taxonomic Disambiguation

The common name "fiesta flower" is shared by two botanically unrelated plants, and this creates an important distinction that any scholarly treatment must address at the outset.

The first plant bearing this name is Pholistoma auritum (Lindley) Lilja. Pholistoma auritum is a species of flowering plant in the family Hydrophyllaceae, known by the common name blue fiestaflower. It is native to California, southern Nevada, and Arizona, where it can be found in many types of habitat, from mountain talus to coastal bluffs to desert scrub. The scientific name loosely translates as "scaly mouth with ears" — pholis being Greek for scale and stoma for mouth. As the common name suggests, young Spanish señoritas are said to have decorated their party gowns with sprays of fiesta flowers, which, because of their peculiar spiny hairs, adhere tightly to fabric. Pholistoma auritum has no documented history as a dietary supplement, medicinal preparation, or pharmacologically studied botanical. No peer-reviewed research, government monograph, pharmacopeial entry, or evidence database contains medicinal or supplement data for this species.

The second plant — and the subject of this article — is Acmella oleracea (L.) R. K. Jansen, which is marketed and studied under the common names "fiesta flower," "toothache plant," "jambu," "paracress," "eyeball plant," "spot flower," and "buzz button." This plant has a long history of use in traditional medicine, particularly in South America, Asia, and Africa. In the dietary supplement industry, the name "fiesta flower" is used commercially for Acmella oleracea preparations, and it is this species for which substantive ethnobotanical documentation and peer-reviewed scientific investigation exist. All content below pertains exclusively to Acmella oleracea and its closely related synonym Spilanthes acmella.

Identity and Botanical Description

Accepted Botanical Names and Synonyms

Acmella oleracea (L.) R. K. Jansen is a member of the Asteraceae family, an annual herb characterized by its yellow-to-red cylindrical discoid capitula. Due to the distinct appearance of its central discoid, which turns red, it is commonly referred to by various names such as eyeball plant, spot flower, and buzz button. It is widely known as the "toothache plant" owing to its exceptional ethnomedicinal efficacy in relieving dental pain, and is also called "paracress," a term derived from the Pará region of Brazil, its place of origin, meaning "cress-like vegetable."

Taxonomically, the species has undergone several reclassifications. Acmella oleracea (L.) R.K. Jansen bears the basionym Spilanthes oleracea and the synonym Spilanthes acmella var. oleracea, and belongs to the family Asteraceae. The specific epithet oleracea means "vegetable/herbal" in Latin. Reports of taxonomic misapplication are common in the literature: there have been documented instances of taxonomic misapplication in identifying A. oleracea across different countries, and several species within the genus Acmella — which contain spilanthol to some extent — exhibit similar analgesic and anesthetic properties, making categorizing ethnobotanical uses strictly by country challenging.

Morphology

This herbaceous plant is native to rainy, humid regions of Brazil. It is winter-hardy in US Zones 9–11; although a perennial in its native region, it should be treated as an annual or overwintered indoors in areas that may receive frost. Acmella oleracea is believed to have originated in Brazil and has now spread throughout tropical America, Africa, and India. The oldest record of cultivation is from St. Vincent in the Caribbean in 1791.

The yellow and maroon cone-shaped flowers are produced throughout the growing season. The leaves are rich in vitamins A, C, and K, lutein, and magnesium. Analytical research has revealed remarkable chemical complexity: analytical research on the chemical compositions responsible for its biological activities has led to the identification of approximately 120 secondary metabolites.

Common Forms and Preparations

In both traditional and contemporary contexts, multiple plant parts and preparation types are employed. The whole plant is used as a medicinal remedy in various parts of the world. The leaves and inflorescence are used as household medicine in the northern region of Brazil to treat oral and throat diseases. In commercial supplement and cosmetic contexts, preparations include:

Hydroethanolic and ethanolic extracts of the aerial parts (leaves and flowers), used in oral care products and topical anesthetics
Mucoadhesive films containing crude jambu extract, developed for oral mucosal anesthesia
Ointments and gels for topical dental application
Jambu oleoresin, an intense preparation used as a food flavoring
Isolated spilanthol, the principal active compound, used in cosmetics and oral care formulations

Spilanthol, the representative bioactive compound of the species, has seen a significant increase in patent registrations. Its applications are being widely explored in oral care products, personal care items, detergents, and the food and beverage industry. Acmella oleracea, commonly known as jambu or paracress, is an herbaceous species with high agronomic potential and strong cultural significance. In Brazil, and particularly in the Amazon, jambu holds a distinctive place in regional cuisine, featuring not only in traditional dishes but also in the development of value-added products such as jambu-infused cachaça and gin.

Traditional and Historical Use

South America — Pre-Columbian Through Modern Folk Medicine

In South America, particularly among indigenous groups in the Amazon region, Acmella oleracea has been used since pre-Columbian times for treating oral ailments, with leaves or flowers chewed directly to alleviate toothache due to their numbing effect or prepared as decoctions for stomatitis and snakebites. Traditional practices also include its application for malaria, rheumatism, tuberculosis, fever, and digestive issues, often through infusions or poultices.

Jambu, the traditional name for acmella, has been used for centuries to treat oral pain because of its analgesic properties. The leaves and inflorescence are used as household medicine in the northern region of Brazil to treat oral and throat diseases. In the northern parts of Brazil, this flower is also added to vegetables during cooking. The flowers were traditionally chewed by people living in the Amazon to relieve mouth, tooth, and throat pains, hence the common name of "toothache plant."

Historically, the plant has been claimed to cure scurvy. Other traditional uses include treatment for snakebite, tuberculosis, rheumatism, malaria, and other fevers. A decoction of the plant has been used in Brazil as an antiseptic.

Africa and Asia

In Africa and Asia, the plant features prominently in folk medicine for similar conditions, with infusions used to treat malaria, rheumatism, and tuberculosis, as well as fever and digestive disorders. It has been employed as a diuretic and anti-inflammatory agent for wounds, typically via topical applications or teas prepared from the aerial parts.

Historically, this plant has been integral to traditional medicine systems such as Ayurveda and Traditional Chinese Medicine (TCM), prized for its powerful analgesic and anti-inflammatory properties. The "Thai toothache plant," which is used for toothaches but often documented as A. oleracea in the literature, has been reported to treat as many as 14 different symptoms depending on the ethnicity.

Breadth of Ethnopharmacological Applications

Various parts of the plant have been employed to treat wounds, stomachaches, skin diseases, and muscular pain, or to serve as laxatives, anthelmintics, and appetite enhancers. When limited to A. oleracea, the most frequent application of the plant is for toothache relief. The traditional preparation forms documented in the ethnobotanical literature include direct chewing of fresh flowers and leaves, infusions (teas) from aerial parts, decoctions, poultices applied topically to wounds, and topical application of expressed plant juice.

Traditional dosages among indigenous and folk practitioners generally involve 1–2 grams of dried herb steeped in tea, administered 1–3 times daily for internal use. These figures are ethnobotanical records rather than clinically validated dosing regimens.

Key Constituents and Active Compounds

N-Alkylamides: Spilanthol (Affinin)

The dominant bioactive compound in Acmella oleracea is the N-alkylamide spilanthol (also called affinin; chemical formula C₁₄H₂₃NO). Bioactive activities are attributed to numerous bioactive compounds, including phytosterols, phenolic compounds, and N-alkylamides, with spilanthol responsible for many activities, primarily anesthetic. This sensation is caused by the action of spilanthol, an isobutylamide compound that promotes local anesthetic action treating toothache.

Spilanthol is found in higher concentrations in the flowers of the plant than in the leaves. HPLC analysis revealed that spilanthol was found to be maximum in flowers (18.44 mg/g), compared to other parts of the plant as well as several other Acmella (syn: Spilanthes) species. Compounds that induce tingling sensations associated with topical application or chewing of jambu include spilanthol, and to a lesser degree acmellonate. Taste-activating alkamide compounds that induce a salivary response have also been identified.

Fatty acid amides, such as spilanthol, are particularly notable for their taste-active properties and involvement in saliva-inducing mechanisms. Spilanthol is closely related to sanshool, which is the chemical in Szechuan pepper.

Other Secondary Metabolites

Alkamides are secondary metabolites with anti-inflammatory, immunomodulatory, and cannabinomimetic effects. Other bioactive compounds found in A. oleracea are triterpenes, coumarins, phenolic acids, stigmasterol, and myrcyl alcohol, which have various known functions in the human body, mainly anti-inflammatory, antimicrobial, antioxidant, antidiabetic, hepatoprotective, and anticarcinogenic functions.

The most common substances identified in the plant include 9,12,15-octadecatrienoic acid (14%), 3,7,11,15-tetramethylhexadec-2-en-1-ol (16%), cedrene (10.65%), pentadecanoic acid (8%), and trans (beta)-caryophyllene (3.28%), among other components. The main chemical classes found in the plant include sesquiterpenes, steroidals, terpene alcohols, polyenoic fatty acids, palmitic acid ethyl esters, and hydrocarbons.

Acmella oleracea flowers contain significant amounts of alkylamides, 3-acetylaleuritolic acid, β-sitostenone, scopoletin, vanillic acid, trans-ferulic acid, and trans-isoferulic acid.

Estimation of phenolics and flavonoids in the extract by spectrophotometry revealed that phenolics content was highest in the flower extract (5.58 mg GAE/g), whereas flavonoid content was found maximum in the leaf extract (31.65 mg QE/g).

Rhamnogalacturonan

A structurally distinct class of compound also present in A. oleracea is the polysaccharide rhamnogalacturonan. Potential mechanisms for gastroprotective effects with rhamnogalacturonan, a polysaccharide isolated from A. oleracea, include protectively binding to the mucosal surface, increasing mucus synthesis, scavenging radicals, and diminishing secretions of acid and pepsin. Other research suggests rhamnogalacturonan promotes restoration of epithelial continuity via epithelial cell proliferation and enhances mucin production to promote gastric ulcer healing.

Established Mechanisms of Action

Local Anesthetic and Analgesic Action

In an acute pain mouse model, Acmella oleracea has been reported to have antiallodynic and anti-oedematogenic activities due to alkylamides, and in particular spilanthol. The molecular mechanism has been described for spilanthol as modulator of TRPA1 receptors and as TRPV1 antagonist, thus promoting analgesic effects.

Spilanthol extract reduces the perception of pain by targeting the pain-mediating receptors CB1, CB2, and TRPV1. Antinociceptive effects have been attributed to anti-inflammatory properties and engagement of opioid receptors. Key bioactive compounds, including spilanthol, act on pathways involving cannabinoid and TRPV1 receptors, supporting their application in chronic inflammatory pain management.

Anti-Inflammatory Pathways

Hexane and chloroform extracts of Spilanthes acmella were found to suppress nitric oxide production in stimulated macrophages at 80 mcg/mL by 72% and 85%, respectively. Isolated spilanthol demonstrated dose-dependent prevention of macrophage activation with 60% and 20% production of nitric oxide at 90 and 360 μM concentrations, respectively. These inhibitory properties were accompanied by less nitric oxide synthetase and cyclooxygenase-2 mRNA and protein content, less cytokine production from macrophages, and less NF-κB activation in the nucleus.

In animal models, spilanthol isolated from S. acmella reduced inflammatory responses via NF-κB inactivation. Hyperglycemic stimulation in vascular smooth muscle cells promoted the expression of inflammatory parameters including chymase, NO, CAT, and SOD activity, all of them attenuated by the presence of extracts and spilanthol. The administration of extracts or spilanthol significantly inhibited edema formation, NO production, and cell tissue infiltration in the formalin test, without causing kidney and liver toxicity.

Gastroprotective Mechanism

A type of molecule that the plant contains, rhamnogalacturonan, was isolated and shown to inhibit stomach ulcers, making gastroprotective implications a possibility for the toothache plant.

Cosmetic / Neuromodulatory Action

The Applicant (in the relevant patent) observed that spilanthol, notably in the form of an Acmella oleracea extract, was able to effectively inhibit contractile activity in subcutaneous face muscles. The active compound spilanthol acts as a natural alternative to Botox because of its botulinum toxin-like action of stopping the subcutaneous muscles, especially those in the face, from contracting. This mechanism underlies the growing interest in topical spilanthol preparations in cosmetics, though independent large-scale clinical verification remains limited.

Scientific Evidence by Area of Use

1. Oral / Dental Anesthesia

Evidence rating: Preliminary human clinical data; small controlled trials; most studies preclinical or animal-based.

Spilanthes acmella, commonly known as the toothache plant, has been used as Ayurvedic medicine in dentistry for a long time. It is found to have anti-microbial, analgesic, and local anesthetic action. This medicinal plant has been studied for its local anesthetic applications in humans and animals.

One of the most closely studied human applications is topical dental anesthesia. A clinical study published in Revista Odonto Ciência investigated the effectiveness and safety of Acmella oleracea ointment as a topical anesthetic for buccal mucosa. The study aimed to determine the effectiveness and safety of Acmella oleracea ointment used as a topical anesthetic. The topical agent was applied to dried buccal mucosa, a short needle was inserted in the mucobuccal fold above the maxillary canine eminence, and each volunteer served as their own control. Pain was measured with a visual analogue scale and by heart rate. A one-way analysis of variance followed by a Kruskal-Wallis test showed no statistically significant differences in the effectiveness of the two Acmella oleracea ointment concentrations studied compared to the benzocaine 20% control. Acmella oleracea ointment was effective and safe in reducing the pain from needle insertion. Acmella oleracea ointment demonstrated similar effectiveness to benzocaine 20% for topical anesthesia, with no reported adverse reactions during procedures.

A 2025 randomized crossover clinical trial investigated the combination of lidocaine–prilocaine with Acmella oleracea (jambu) extract. A randomized, blinded, crossover clinical trial was conducted with 40 healthy volunteers who received six formulations, including a combination of LDC 2.5% + PLC 2.5% + jambu extract 20%.

Researchers have also developed mucoadhesive films for oral use. Researchers developed an anesthetic mucoadhesive film containing Acmella oleracea (jambu) extract for topical use on oral mucosa using ethanolic extracts from aerial parts. Three mucoadhesive films were developed using 10% or 20% crude jambu extract and 10% extract treated with activated carbon. The films were characterized for uniformity, thickness, pH, and spilanthol content, with stability evaluated over 120 days. The permeation study revealed that the spilanthol from 10% JBC presented higher flux and permeability coefficient values compared to 10% or 20% JB. Moreover, 10% JBC showed better topical anesthetic efficacy than the other films. Mucoadhesive film containing crude extract of jambu treated with activated carbon was identified as a potential alternative for oral, topical use, encouraging future clinical studies.

A narrative review published in 2023 summarized available evidence: this finding demonstrated the effectiveness of S. acmella in blocking pain produced by the anesthetic needle puncture. Therefore, S. acmella or A. oleracea gel can be used as a safe and effective local topical anesthetic for oral mucosa. However, these conclusions are based on a small body of primarily small-scale clinical and preclinical studies, and large-scale randomized controlled trials are absent from the literature.

2. Systemic Anti-Inflammatory and Analgesic Effects

Evidence rating: Predominantly preclinical (in vitro and animal models); no large-scale human clinical trials.

The aim of one major review was to provide an overview of the knowledge of Acmella oleracea and its activities, particularly anti-inflammatory, anti-oxidant, and analgesic. These activities are attributed to numerous bioactive compounds, including phytosterols, phenolic compounds, and N-alkylamides. This review included 99 eligible studies to consider these activities of Acmella.

Studies reported in this review confirmed anti-inflammatory and antioxidant activities of Acmella, postulating that transcription factors of the NF-κB family trigger the transcription of iNOS and COX-2 and several other downstream inflammatory mediators. The research is mostly limited to data from rat subjects. The results show that the extract not only reduces the perception of pain, but also the physical presence of inflammation, in a similar manner to popular anti-pain and anti-inflammation drugs like acetaminophen and ibuprofen.

A study examining inflammatory vestibulodynia in an animal model found promising results. Researchers tested the effects of an Acmella oleracea and Boswellia serrata combination in CFA-induced vestibulodynia using behavioral testing, immunohistochemical, and electrophysiological techniques. The results demonstrated the efficacy of the combined treatment in modulating pain sensitivity with significant reduction of spinal biochemical modifications. Spilanthol may directly act on specific potassium channels (K2P, TREK) that are involved in pain chronification. Further investigations are needed for better understanding the mechanisms through which Acmella exerts analgesic effects.

3. Gastroprotective Effects

Evidence rating: Preclinical only; no human data.

Rhamnogalacturonan, isolated from the plant, was shown to inhibit stomach ulcers in preclinical models, making gastroprotective implications a possibility for the toothache plant. Potential mechanisms for gastroprotective effects include protectively binding to the mucosal surface, increasing mucus synthesis, scavenging radicals, and diminishing secretions of acid and pepsin. Other research suggests rhamnogalacturonan promotes restoration of epithelial continuity via epithelial cell proliferation and enhances mucin production to promote gastric ulcer healing. Human data are lacking.

4. Immunomodulatory Effects

Evidence rating: In vitro and animal data only; no human clinical trials.

Alkamides, including spilanthol, are secondary metabolites with documented anti-inflammatory, immunomodulatory, and cannabinomimetic effects in laboratory settings. Preliminary research has examined the plant's possible antioxidant and immunomodulatory effects, which may contribute to overall wellness. However, while these early findings are promising, comprehensive human clinical trials are still limited.

5. Antimicrobial and Antifungal Activity

Evidence rating: In vitro data; no human clinical trials.

Research indicates that A. oleracea contains phytochemicals, including spilanthol, which exhibit diverse pharmacological activities including antibacterial and antifungal effects. Some in vitro and animal studies suggest that extracts from Acmella oleracea could support oral health by inhibiting the growth of harmful bacteria and reducing gum inflammation. These findings are preliminary and have not been replicated in clinical settings.

6. Diuretic Activity

Evidence rating: Animal studies; no human clinical trials.

Extracts and phytoconstituents isolated from this plant have been shown to produce different pharmacological responses, which include anticonvulsant, analgesic, anti-inflammatory, vasodilation, diuretic, and antimalarial effects in animal models. The diuretic potential of A. oleracea has not been evaluated in human clinical trials.

7. Cosmetic / Skin Anti-Aging Applications

Evidence rating: Small in vivo studies in human volunteers; industry-sponsored or limited-scale; moderate-quality evidence for topical use.

Spilanthol, notably in the form of an Acmella oleracea extract, was observed to effectively inhibit contractile activity in subcutaneous face muscles. This finding underpins the cosmetic application sometimes described as "natural botox." Acmella oleracea extract has become increasingly popular in natural cosmetics for the purpose of generating a natural face lift. When applied to the face on the skin, the muscles of the skin surface relax, thus preventing the movements that cause expression lines and wrinkles.

A study on urban Chinese women aged 20–45 found that a product with supramolecular retinol and acmella oleracea extract significantly reduced dark circles, fine wrinkles, and improved skin firmness over six weeks. In vivo tests on human volunteers demonstrated safety and effectiveness of an acmella oleracea-containing serum, showing no skin irritation and a noticeable reduction in wrinkles after two weeks. These studies tend to be small in scale, use combined formulations that make it difficult to isolate the effect of A. oleracea alone, and are often sponsored by commercial interests, all of which limit the strength of conclusions that can be drawn.

As a medicinal plant, A. oleracea is considered to have great potential, both topically and internally, due to its main lipophilic N-alkylamide, spilanthol (affinin), the most abundant active ingredient in the aerial parts, which exhibits various pharmacological activities as shown by in vitro studies.

8. Reproductive and Hormonal Effects

Evidence rating: Animal studies; relevance to humans uncertain.

An animal study found that an S. acmella ethanolic flower extract rich in alkylamides affected male sexual functioning by increasing levels of testosterone, follicle-stimulating hormone, and luteinizing hormone, with the effect being significant and lasting at high doses. The hydroethanolic extract of the flowers has also been administered to female rats in safe doses and shown to impact the reproductive cycle without influencing fertility or other aspects of health; this finding has implications as a contraceptive. These findings are preliminary and derived exclusively from animal models; their applicability to humans is unknown.

9. Insecticidal Activity

Evidence rating: In vitro and laboratory studies; not a primary supplement application.

Spilanthol is among the most active alkamides isolated from aerial parts of A. oleracea to demonstrate insecticidal and acaricidal activity. Spilanthol was shown to be toxic against adults of P. americana. It is one of the most potent compounds when compared with conventional insecticides such as carbaryl, lindane, and bioresmethrin, with a potency found to be 1.3, 3.8, and 2.6 times, respectively.

Body Systems and Health Areas of Association

Acmella oleracea, commonly known as the "toothache plant" or "jambu," is a significant medicinal plant that has been traditionally used in Brazil and other tropical and subtropical regions for relieving dental pain, as an anti-inflammatory agent, and as a culinary spice. Due to its versatile utility, this plant has been extensively studied in modern medicine and pharmacy for its diverse pharmacological properties, including anesthetic, analgesic, anti-inflammatory, antioxidant, and antimicrobial activities.

Oral and Dental Health: The primary and most evidence-supported area of use. Involves topical analgesia, numbing of oral mucosa, and potential antimicrobial action against oral bacteria.
Musculoskeletal and Pain Systems: Analgesic and anti-inflammatory activity studied in preclinical models of acute and chronic pain.
Gastrointestinal System: Gastroprotective effects in preclinical models via the polysaccharide rhamnogalacturonan.
Immune System: Immunomodulatory properties studied in vitro via cannabinoid receptor interactions and NF-κB pathway modulation.
Skin / Integumentary System: Anti-aging, anti-inflammatory, and antimicrobial effects studied in cosmetic applications.
Endocrine / Reproductive System: Animal data on hormonal effects (testosterone, FSH, LH) and reproductive cycle modulation; no human data.
Renal System: Diuretic effects documented in animal studies.

Dosage Forms and Dosages Reported in Studies

No universally standardized or regulatory-approved dosing recommendation exists for Acmella oleracea as a dietary supplement. The following dosing information is drawn directly from specific published studies and traditional documentation:

Topical dental ointment: Researchers applied Acmella oleracea ointment to dried buccal mucosa in a human study, with two concentrations of ointment evaluated for topical anesthetic effectiveness. Specific concentration percentages were not disclosed in the available abstract but were compared directly to benzocaine 20%.
Jambu extract in combined topical formulation: In a randomized crossover clinical trial with 40 healthy volunteers, one formulation included jambu extract at 20%.
Mucoadhesive films: Three mucoadhesive films were developed using 10% or 20% of crude jambu extract, and 10% of crude jambu extract treated with activated carbon.
Traditional internal use: Traditional dosages among indigenous and folk practitioners generally involve 1–2 grams of dried herb steeped in tea, administered 1–3 times daily for internal use.
Spilanthol concentration in flowers: HPLC analysis revealed spilanthol content at 18.44 mg/g in flower extracts.

Comprehensive human clinical trials are still limited. More research is needed to confirm the efficacy and safety of Acmella oleracea in nutritional products and to fully understand its mechanisms of action.

Safety Considerations and Interactions

General Safety Profile

Research indicates that A. oleracea contains a variety of phytochemicals exhibiting diverse pharmacological activities. The results highlight the significant medicinal potential while also identifying areas for further research, particularly regarding its toxicological impacts on humans and animals. No comprehensive clinical human trials have been done on Acmella, but it is generally considered safe at food and traditional use levels.

Reproductive and Teratogenic Concerns

This is the most substantiated safety concern in the peer-reviewed literature. In vivo studies suggest potential teratogenic effects with high doses of a hydroethanolic extract of A. oleracea. A study published in a peer-reviewed pharmacology journal using a zebrafish model found that teratogenic effects were observed in offspring, including tail deformation, cardiac and yolk edema, scoliosis, and growth retardation, which were more prominent in groups born from progenitors exposed to the highest concentrations (100 and 200 μg/L); but only yolk and cardiac edema had a statistically significant difference compared to the control group. Overall, data from that study show that the treatment caused no detrimental changes in progenitors regarding their gonads or fertility but caused some potentially teratogenic activity in embryos, which may be due to the action of spilanthol's metabolites M3, M6, M7, M8, M16, M28, and M31. These findings are from animal (zebrafish) models, and their direct applicability to human pregnancy cannot be determined from current data, but they represent a meaningful signal of concern.

Diuretic Interaction Potential

Care should be exercised if using diuretics, as Acmella can have a diuretic effect. Concurrent use with diuretic medications could theoretically potentiate diuretic effects; this interaction has not been formally studied in humans.

Hormonal / Endocrine Interaction Potential

An animal study found that an S. acmella ethanolic flower extract rich in alkylamides affected male sexual functioning by increasing levels of testosterone, follicle-stimulating hormone, and luteinizing hormone, with the effect being significant and lasting at high doses. Care should be exercised when taking drugs for prostate cancer, as Acmella can increase testosterone. These data derive from animal research only and have not been confirmed in human studies.

Allergenicity

Use of Acmella oleracea should be avoided by individuals who are allergic to members of the Asteraceae family. The Asteraceae (daisy/composite) family includes ragweed, chrysanthemums, marigolds, and related plants; those with established allergies to these plants should exercise caution.

Cytotoxicity (In Vitro Only)

In vitro, a hydroethanolic extract of S. acmella produced cytotoxic effects in tumor cell cytoskeletons. This finding is from cell culture experiments only and does not establish safety or toxicity in living human subjects at supplement doses.

Absence of Comprehensive Human Safety Data

Research highlights the significant medicinal potential of A. oleracea while also identifying areas for further research, particularly regarding its toxicological impacts on humans and animals. Barriers to bringing this extract to the pharmaceutical scene are related to efficiency: it takes a large number of flowers to acquire enough concentrated spilanthol. Therefore, it is timely and costly to produce relative to already existing antinociceptive and anti-inflammatory drugs. The overall body of human safety data for systemic oral supplementation remains insufficient to establish a defined safe dose range.

Regulatory and Commercial Status

There is active research into developing A. oleracea as a functional health food ingredient. In particular, spilanthol has seen a significant increase in patent registrations. Its applications are being widely explored in oral care products, personal care items, detergents, and the food and beverage industry. These attributes have led to its incorporation into diverse commercial formulations, including oral care products, dermo-cosmetics, and natural preservatives.

The plant and its extracts are not covered by major governmental health body monographs (NIH Office of Dietary Supplements, NCCIH, EMA Community Herbal Monographs, German Commission E, or WHO Monographs) as of the time of writing. There is no approved pharmacopeial monograph for Acmella oleracea in the United States Pharmacopeia or European Pharmacopoeia for dietary supplement use, and it does not appear in the NIH ODS botanical fact sheet registry. Its use is governed by general dietary supplement regulations rather than species-specific approved guidance.

Summary of Evidence Strength

Topical dental anesthesia: Preliminary positive human clinical data (small controlled studies); effect comparable to benzocaine 20% in limited trials. Further large RCTs needed.
Systemic anti-inflammatory/analgesic: Strong preclinical (in vitro and animal) mechanistic evidence; no substantive human clinical trial data for systemic internal use.
Gastroprotection: Preclinical only; mechanism identified for rhamnogalacturonan.
Immunomodulation: In vitro data only; no human clinical trials.
Antimicrobial/antifungal: In vitro data only.
Skin anti-aging (topical): Small human volunteer studies, often with combined formulations; promising but not definitive.
Hormonal/reproductive effects: Animal data only; uncertain human relevance.
Safety in pregnancy: Animal (zebrafish) data raises teratogenic concern at high doses; no human data to characterize risk.

References

Health Conditions

Health conditions that Fiesta flower may help support.

No conditions available.

Body Systems

Body systems that Fiesta flower may help support.

No body systems available.