Croton Seeds (Croton tiglium L.): A Comprehensive Reference
1. Identity and Botanical Classification
Scientific Name and Taxonomy
Croton tiglium Linn., commonly known as Jamalgota or Purging Croton, is a well-recognized medicinal shrub belonging to the family Euphorbiaceae. It is an ancient medicinal plant that has been used for a long time and is widely distributed in tropical and subtropical regions. Synonyms recorded in the older botanical literature include Tiglium officinale Klotzsch and several Oxydectes species assigned by Kuntze. The specific epithet tiglium is of obscure origin; it may come from the traditional name given by pharmacists to the seeds of the croton plant, or it may derive from the Greek tiglos, meaning diarrhea, or alternatively refer to one of the Maluku islands in Indonesia, ostensibly a home habitat of the species.
Common Names Across Cultures
Croton tiglium is one of the 50 fundamental herbs used in traditional Chinese medicine, where it has the name bā dòu (巴豆). The seeds are known as Jamālgoṭa in Hindi, Marathi, and Urdu. The plant is known as japaala or jayapala in Sinhala and is used in the Sinhala traditional medical system of Sri Lanka and in Sanskrit. In Ayurvedic literature it is referred to as Kumbhinī, and in Thai it is called salod. In English it is most commonly called "purging croton" or the "croton oil plant." In French-language sources it appears as croton cathartique.
Plant Morphology
Croton tiglium is a small evergreen tree up to 5–7 m high. The plant bears small, unisexual flowers arranged in terminal racemes or panicles. Male flowers are numerous and possess five white petals with many stamens, while female flowers are fewer, lacking petals, and have a superior, three-lobed ovary. The fruit is a three-seeded capsule, approximately 8–10 mm in diameter, which dehisces upon maturation to release smooth, oval, brownish-gray seeds. Each seed contains an oily endosperm that constitutes the source of croton oil, one of the most pharmacologically active and toxic plant oils known.
Geographic Distribution
The plant is distributed in tropical countries, including Thailand, India, Sri Lanka, China, and Malaysia. Croton tiglium originates from tropical Asia and China and has been introduced into many parts of the world, including several countries of tropical Africa, such as Ghana, Nigeria, Cameroon, and Sudan, though an exact distribution in Africa is not known.
Medicinal Parts and Common Preparations
The seeds of C. tiglium, named "Badou" in China, were considered as the medicinal part of this plant according to the Chinese Pharmacopoeia Commission. Preparations encountered in the literature and in traditional practice include:
- Fixed (expressed) oil (croton oil): Seeds contain 30–45% of a fixed oil named croton oil and about 20% protein.
- Essential oil (CTEO): Supercritical CO₂ fluid extraction technology has been used to extract the croton tiglium essential oil.
- Whole seed powder or defatted seed powder: Used in traditional compounding after detoxification.
- Beeswax-coated pill (Badou pill): The Badou pill, which is made of Crotonis Fructus covered with beeswax, is clinically used in the treatment of mycobacterium tuberculosis, bone lumbar tuberculosis, and pulmonary tuberculosis.
- Phenol-croton oil chemical peel solutions: Used in modern aesthetic dermatology; described in detail in the dermatological evidence section below.
2. Traditional and Historical Use
Traditional Chinese Medicine (TCM)
The Chinese had written records dating from the second century B.C. for using croton seeds to treat gastrointestinal disorders, intestinal inflammation, rheumatism, headache, peptic ulcer, and visceral pain. It has been used as a traditional medicine for many applications such as constipation, as a purgative, and for treating dyspepsia and dysentery. In Chinese formulary tradition, the seeds were combined with other herbs in compound prescriptions. In Chinese medicine, croton seeds have been used in combination with other herbs to clear phlegm and address respiratory concerns.
Ayurveda
In Ayurvedic texts, the plant is known as Kumbhinī and is used for the treatment of constipation after Śodhana (detoxification process) of the seeds with Godugdha (cow milk). The seeds of Jayapala (Croton tiglium L.) are classified under Upavisha in classical Ayurvedic texts — a category of sub-poisons — known for their purgative action and used in the management of several disorders; the Ayurvedic Pharmacopoeia of India recommends Shodhana prior to internal administration.
Sri Lankan and Southeast Asian Traditions
The plant is known as japaala or jayapala in Sinhala and is used in the traditional medical system of Sri Lanka. In Thai medicine, Croton tiglium has been traditionally used as a potent purgative to treat colic, asthma, cough, phlegm, lymphatic disorders, blood disorders, and parasitic infections. The seeds are used in traditional medicine in various countries both as single and polyherbal recipes for purposes such as purgative action, flatulence, lymphatic drainage, dyspepsia, and dysentery.
In Malaya, a single kernel was historically eaten as a purgative; when purging had gone far enough, coconut milk was drunk to stop it.
European Pharmacopoeial Use
Trade of seeds and seed oil from Asia to Europe started in the 16th century and continued to be important until the beginning of the 20th century. Croton oil derives from the seeds of the Croton tiglium plant, and its medical applications have been well studied even from the 19th century. The oil appeared in the United States Pharmacopoeia under the monograph Oleum Tiglii (Croton Oil) and was classified as a drastic cathartic — a designation reflecting extreme potency and risk, which contributed to its eventual displacement from mainstream Western pharmacopoeias.
Homeopathy
Croton tiglium is represented in the homeopathic materia medica under the name Croton tiglium (abbreviated Croto-t.), prepared at extreme dilutions for conditions including skin irritation and digestive complaints. Homeopathic preparations use highly diluted forms of the plant far below any pharmacologically active concentration.
3. Key Constituents and Active Compounds
Fixed Oil (Croton Oil)
Seeds contain 34–57% croton oil. The oil also contains a group of proteins called "crotin," about 3.5% croton resin ("crotonol"), a glucoside called crotonoside (isoguanosine), and a non-volatile unsaturated fatty acid responsible for the purgative properties.
Fatty Acid Composition
The oil comprises the fatty acids oleic acid (37%), linoleic acid (19%), myristic acid (7.5%), arachidic acid (1.5%), palmitic acid (1%), formic acid (1%), acetic acid (0.5%), stearic acid (0.5%), and smaller amounts of butyric acid, lauric acid, tiglic acid, and valeric acid. It should be noted that exact proportions vary by extraction method and geographic origin; a separate analysis found linoleic acid (50.51%) and oleic acid (20.93%) as the higher fatty acids obtained from one Indonesian sample.
Tigliane Diterpenoids and Phorbol Esters
Tigliane diterpenoids have been identified as the characteristic compounds of C. tiglium. Key chemical constituents of the seeds include phorbol esters such as phorbol-12-myristate-13-acetate (PMA), along with alkaloids, fatty acids, and amino acids. Phorbol is a natural, plant-derived organic compound of the tigliane family of diterpenes; it was first isolated in 1934 as a hydrolysis product of croton oil derived from the seeds of Croton tiglium.
Approximately 150 constituents have been successfully isolated and identified from this plant, including terpenoids, fatty oils, alkaloids, and plant proteins. A 2017 study isolated seven discrete compounds from the seeds, including 12-O-(α-methyl)butyrylphorbol-13-decanoate and 12-O-tiglylphorbol-13-decanoate, along with a new compound bis(2,3-dihydroxypropyl) nonanedioate.
Toxic Proteins (Crotins)
Crotin inhibits protein synthesis, induces haemolysis, and causes local cell necrosis. Crotin is structurally analogous to ricin from castor bean, belonging to the group of plant toxalbumins. Crotonoside, a glycoside that is less poisonous than other constituents, is also present; the oil contains a powerful vesicating resin composed of crotonoleic acid, methyl crotonic acid, and several other fatty acids.
Essential Oil Volatile Constituents
GC-MS analysis of C. tiglium essential oil has identified monoterpenes and sesquiterpenes such as α-pinene, β-caryophyllene, and limonene, contributing to its aromatic and possibly antimicrobial profile.
Additional Nitrogen-Containing Compounds
The pyrazine compound 2-(furan-2-yl)-5-(2,3,4-trihydroxybutyl)-1,4-diazine, named Crotonine, was identified from an ethanol extract. Traces of saponins and tannins have also been detected, which may assist in stabilizing emulsified formulations used for topical applications.
Overall Seed Proximate Composition
The chemical composition of the seeds includes oil (30.00–56.00%), carbohydrates (16.15%), proteins (16.00%), fibers (8.25%), and ash (3.60%).
4. Mechanisms of Action
Protein Kinase C (PKC) Activation
Phorbol esters have the ability to mimic diacylglycerols and activate protein kinase C (PKC), modulating downstream cell signaling pathways including the mitogen-activated protein kinase (MAPK) pathways. Phorbol esters are additionally thought to bind to chimaerins, the Ras activator RasGRP, and the vesicle-priming protein Munc-13; some phorbol esters also induce nuclear factor-kappa B (NF-κB).
Tumor Promotion and Dual Carcinogenic Complexity
Phorbol-12-myristate-13-acetate (PMA) was first observed to be a tumor promoter in mouse skin; subsequent studies showed that the carcinogenic effect was correlated to pro-inflammatory activity and to PKC activation, producing a diversity of biological effects. Most studies consistently indicate that C. tiglium seeds and PMA are not carcinogenic per se but act as tumor promoters; cancer caused by PMA requires continuous exposure to carcinogens for a long period of time and at certain concentrations. Numerous studies have also reported that not only PMA but also many other phorbol derivatives exhibit anticancer activity; it is probable that these compounds display dual actions — promoters of tumor on the one hand and antagonists of carcinogenesis on the other.
Gap Junctional Intercellular Communication (GJIC) Inhibition
Accompanied by phosphorylation of connexin43 (Cx43) and extracellular signal-regulated kinases 1/2 (ERK1/2), tiglium seed extract inhibited gap junctional intercellular communication (GJIC); these effects were blocked by a protein kinase C (PKC) inhibitor or MAPK inhibitors, suggesting that the seed-induced GJIC inhibition was regulated by phosphorylation of Cx43 via PKC and MAPK signaling pathways.
Purgative / Gastrointestinal Mechanism
The purgative action is attributed primarily to phorbol esters and the non-volatile unsaturated fatty acid fraction of croton oil. These agents act as powerful irritants to the intestinal mucosa, accelerating intestinal propulsion. A preclinical study evaluated the antinociceptive effect of seed extract through the writhing test in mice, investigated its effects on spontaneous smooth muscle contractions of isolated rabbit jejunum, and examined the in-vitro results through the in-vivo small intestine propulsion model. The direct effect of croton oil on guinea pig colonic smooth muscle cells has been studied, showing that it regulates gastrointestinal transit and affects the inflammatory and immunological milieu.
Apoptosis Induction
Anti-cancer effects of croton tiglium essential oil on A549 lung cancer cells have been proposed to operate partly through decreasing expression of proliferation factors, inhibiting invasion and migration factors, and enhancing expression of pro-apoptotic factors.
Keratolytic / Peeling Action (Topical)
In phenol-croton oil peels, phenol leads to the coagulation of the epidermis and carries croton's pro-inflammatory molecules to the dermis, leading to skin rejuvenation. Croton oil boosts phenol's activity by coagulating the keratin. Multiple histologic studies have shown the deposition of a substantial layer of collagen in the dermis that is aligned in an orderly manner and is believed to be the mechanism for the effacement of wrinkles; this layer remains constant for years, even decades.
5. Scientific Evidence by Area of Use
5.1 Gastrointestinal System — Purgative and Laxative Effects
Traditional basis: Croton seeds have a long history of use in traditional medicine systems, especially in Ayurveda and TCM, primarily for their potent purgative (laxative) properties; historically, these seeds have been employed to treat severe constipation.
Preclinical and experimental evidence: Studies in animal models have consistently confirmed purgative activity. A Thai study published in PMC (2025) demonstrated that untreated (raw) C. tiglium seeds, at a dose of 100 mg/kg, caused a significant purgative effect in rats, while the detoxification process reduced this effect. A separate study evaluated antinociceptive effects through the acetic acid-induced writhing test in mice and effects on spontaneous smooth muscle contractions of isolated rabbit jejunum; six compounds were tentatively identified as phorbol esters as the active agents.
Clinical evidence: There is minimal scientific research supporting the safe or effective use of croton seeds for routine gastrointestinal support; their use is generally limited to historical texts and some traditional applications under careful supervision. Most modern health authorities and herbalists advise against their use due to the risk of severe adverse reactions. While croton seeds have a well-documented traditional use as a powerful laxative, their safety profile is poor, and there is little to no scientific validation for their use in supporting general gastrointestinal health.
Evidence strength: Preclinical (animal) only for mechanistic confirmation; no controlled human clinical trials establishing safe or effective dosing for internal purgative use.
5.2 Dermatological Use — Chemical Peeling
Background: Since the 1960s, croton oil has been utilized in combination with phenol in a homemade dermatologic formula for deep chemical peeling procedures, an approach initially developed by Baker and Gordon and later refined by Hetter.
Mechanism and formulation: Hetter demonstrated that the active ingredient, croton oil, could vary from 0.2% to 1.6% concentration, allowing for variable concentrations of the peel depending on the patient's skin thickness or phototype. By using higher concentrations of croton oil, the concentrations of phenol can be lowered, therefore reducing the systemic toxicity of phenol.
Clinical indications studied: Phenol/croton oil peels reach the mid-reticular dermis and can treat atrophic/pox-like acne scars, severe dyschromias and deep rhytids, solar lentigines, seborrheic keratosis, Bowen disease, and angiosarcomas; they have also been used as sclerosing agents, for chemical matrixectomy, the treatment of stable vitiligo, and alopecia areata.
Clinical evidence: A retrospective case series (PubMed, 2024) enrolled 64 patients treated with phenol/croton oil peel between 2014 and 2023; 21 underwent resurfacing of the oral area (upper/lower lips), 15 underwent resurfacing of lower eyelid wrinkles, and 22 patients underwent full-face resurfacing. The main complications — scarring and hypopigmentation — were operator-dependent and largely preventable by controlling the depth of peel; in a reported series of 75 peels, patient response was overwhelmingly positive, with delayed healing and thickening occurring in small areas of the neck and temporal region in only 2 instances.
Concentration-related adverse effects: Croton oil used as a peeling agent in phenol at concentrations of 2% and over is almost always associated with depigmentation of the skin and delays in healing in areas other than the thick skin of the lower nose and around the mouth.
Evidence strength: Moderate for specific dermatological peeling indications, based on multiple clinical case series and retrospective studies. No large randomized controlled trials exist. Outcomes are generally positive but operator expertise is a critical variable.
5.3 Anticancer Activity
In vitro evidence: Phorbol esters from C. tiglium demonstrate significant anticancer properties, effectively inhibiting the growth of cancer cells including liver cancer, leukemia, lung cancer, prostate cancer, breast cancer, and gastric cancer. The inhibitory concentrations (IC₅₀) of these compounds are typically within the micromolar range.
A 2020 study published in PLOS ONE and indexed in PubMed Central examined the essential oil extracted from C. tiglium seeds against the A549 human lung cancer cell line in vitro. The proposed anti-cancer effect on A549 cells operated partly through decreasing expression of proliferation factors, inhibiting invasion and migration factors, and enhancing expression of pro-apoptotic factors; natural resources capable of inducing tumor cell cycle arrest and apoptosis are expected to be candidates for anticancer drugs, and the evidence suggested that CTEO may be a promising supplement for investigation as a chemopreventive or chemotherapeutic agent in human lung cancers, and may be considered for further clinical studies.
A separate phytochemical study found that compounds 2 (12-O-(α-methyl)butyrylphorbol-13-decanoate) and 3 (12-O-tiglylphorbol-13-decanoate) showed cytotoxic activities against human lung cancer cell line A549 with IC₅₀ values of 47.8 and 7.0 μmol/L, respectively, and against human hepatocarcinoma cell line HepG2 with IC₅₀ values of 71.4 and 44.0 μmol/L, respectively.
Mutagenicity and tumor promotion: Tiglium seed extract produced mutagenic responses in five Salmonella typhimurium strains in the Ames assay, whereas it did not alter the frequencies of chromosomal aberrations or micronuclei, indicating mutagenic potential but not clastogenicity. The presence of PMA poses a major drawback due to its toxicity and role as a tumor promoter.
Evidence strength: Preliminary; evidence is entirely in vitro and preclinical. No human clinical trials have evaluated croton seed extracts for cancer treatment. The dual role of phorbol esters as both potential anticancer agents and tumor promoters creates a complex safety picture that has not been resolved in human studies.
5.4 Antimicrobial Activity
C. tiglium seeds have been reported to have a wide range of biological and pharmacological activities, including antifungal and antibacterial properties. Ethanolic extract of Croton tiglium has shown antifungal activity for treating dermatophytes caused by Trichophyton mentagrophytes, T. rubrum, and Epidermophyton floccosum. These are in vitro findings from laboratory studies, and no controlled human clinical trials have validated antimicrobial efficacy in clinical infections.
Evidence strength: In vitro only; no clinical evidence in human infections.
5.5 Anti-inflammatory and Antinociceptive Activity
Phorbol esters from C. tiglium exhibit a range of pharmacological activities, including anti-inflammatory properties. Diterpenoids such as croton oil phorbol esters exhibit both therapeutic and toxic effects by modulating protein kinase C (PKC) pathways, influencing cell proliferation, inflammation, and differentiation. Controlled extraction, detoxification, and dosage optimization have revealed significant anti-inflammatory and analgesic effects in preclinical models. All anti-inflammatory evidence currently derives from in vitro and animal studies; no human clinical trials have been conducted.
Evidence strength: Preclinical (in vitro and animal); no human evidence.
5.6 Antiviral Activity (Including Anti-HIV)
C. tiglium seeds have also been reported to have anti-HIV activity in laboratory studies. TPA (phorbol-12-myristate-13-acetate) has been reported to inhibit the HIV-cytopathic effects on MT-4 cells. This remains an area of in vitro investigation only, with no human clinical evidence.
Evidence strength: In vitro only; no clinical evidence in human viral infections.
6. Body Systems and Health Areas of Association
- Gastrointestinal system: Primary historical indication; C. tiglium is widely used for defecation, treatment of gastrointestinal diseases, and induced labour.
- Musculoskeletal system: Used in China to treat gastrointestinal disorders, intestinal inflammation, and rheumatism.
- Dermatological system: Modern chemical peel applications as well as historical topical use as a counterirritant.
- Neurological/pain system: C. tiglium has been used to treat neurological diseases such as peripheral facial paralysis.
- Respiratory system: Used in Thai medicine for conditions including asthma, cough, and phlegm.
- Oncological research: Subject of ongoing in vitro anticancer investigations.
- Infectious disease (preclinical): Antifungal and antibacterial activity documented in laboratory models.
7. Dosage Forms and Dosages Reported in Studies
Given the extreme toxicity of raw croton seeds and oil, dosages mentioned below are those recorded in research literature and historical sources only, and reflect the narrow margin between therapeutic and lethal doses.
- Ayurvedic Shodhana (detoxified) seeds: Used for the treatment of constipation after Śodhana with Godugdha (cow milk). Detoxification quantitatively reduces toxic constituents: the content of phorbol ester equivalent to PMA in unpurified sample was 5.2 mg/100 g and in purified sample was 1.8 mg/100 g of dried seeds.
- Shodhana and phorbol ester reduction: Studies using HPTLC and HPLC fingerprinting show that Shodhana with cow's milk or ginger juice reduces phorbol ester content by up to 80–90%, while preserving beneficial fatty acids and minor diterpenoids.
- Traditional Malay use: In Malaya, a single kernel was taken as a purgative, with coconut milk drunk to stop purging when needed.
- Animal toxicology — acute oral LD₅₀ (extract): Acute oral LD₅₀ of tiglium seed extract in rats was estimated to be greater than 2000 mg/kg; the no-observed-adverse-effect level (NOAEL) of the extract administered orally was determined to be 500 mg/kg/day in both male and female rats.
- Animal toxicology — purgative dose (raw seed powder, rats): Only raw (untreated) C. tiglium at the dose of 100 mg/kg caused a significant purgative effect in rats.
- Phenol-croton oil dermatological peel concentrations: Croton oil can vary from 0.2% to 1.6% concentration in Hetter peel formulas, depending on the patient's skin thickness or phototype.
8. Safety Considerations and Toxicological Profile
Extreme Acute Toxicity
Half a drop of croton oil can be toxic; 20 drops can be lethal. The fatal dose is cited as 4–5 crushed seeds or 20 drops of oil (approximately 1–2 ml); the fatal period has been reported as 6 hours to 3 days. For a man, approximately four seeds represent a lethal dose.
Signs and Symptoms of Poisoning
Ingestion causes a burning sensation of the oral cavity, vomiting, diarrhoea, abdominal pain, oliguria, proteinuria, dizziness, headache, delirium, and convulsion. Crotin inhibits protein synthesis, induces haemolysis, and causes local cell necrosis; eye contact may result in keratoconjunctivitis. Applied to the skin, the oil produces burning, redness, and vesication.
Reported Poisoning Events
A poisoning outbreak due to malicious addition of C. tiglium in food, affecting 26 cases with mainly gastrointestinal tract symptoms, has been reported in China.
Tumor-Promoting Properties of Phorbol Esters
The presence of PMA poses a major drawback due to its toxicity and role as a tumor promoter; various methods have been developed to reduce the toxicity of Croton tiglium seeds by lowering PMA levels, but comprehensive data on the reduction of carcinogenic promotion activity is still lacking.
Regulatory Status (Thailand)
C. tiglium seeds have been banned from use as an ingredient in Thai traditional medicine in Thailand since 1978, as they are classified as toxic plant material.
Detoxification (Shodhana) — Mechanism and Evidence
The toxicity of C. tiglium seeds may be due to the presence of phorbol esters and crotonic acid along with other constituents; these constituents are oil-soluble and may be removed by cow milk during the process of Śodhana; reduction in the level of these constituents after purification decreases the toxicity of the seeds. Detoxification can also enhance the relative concentration of certain antioxidants like tocopherols and phenolic acids, suggesting that detoxified C. tiglium extracts may retain therapeutic benefits with improved safety profiles.
Subchronic Toxicology (Animal Data)
Toxicological properties of tiglium seed extract were evaluated by toxicity assays to determine single-dose acute toxicity (125, 250, 500, 1000, or 2000 mg/kg), 14-day repeated-dose toxicity (125, 250, 500, 1000, or 2000 mg/kg), and 13-week repeated-dose toxicity (31.25, 62.5, 125, 250, and 500 mg/kg) in rats. The NOAEL was established at 500 mg/kg/day in this rodent model, though extrapolation to human safety has not been validated in clinical studies.
Dermatological Peel Complications
Complications from croton oil peels are the same as with any deep resurfacing technique; the main complications, scarring and hypopigmentation, are operator-dependent and are largely preventable by controlling the depth of peel. Insufficient levels of PMA in commercial croton oil preparations may compromise expected clinical efficacy of chemical peels, while uncontrolled concentrations could raise safety concerns.
Mutagenicity
As C. tiglium contains phorbol derivatives, its mutagenicity and tumor-promoting activity have been investigated; tiglium seed extract produced mutagenic responses in five Salmonella typhimurium strains in the Ames assay, whereas it did not alter the frequencies of chromosomal aberrations or micronuclei, indicating mutagenic potential but not clastogenicity.
References
Go back