Xanthium (cockleburs)

Xanthium (Cockleburs): A Comprehensive Reference

1. Identity: Botanical Names, Natural Source, and Common Forms

Taxonomy and Nomenclature

Xanthium strumarium L. (cocklebur) is a widely distributed herb belonging to the Asteraceae (Compositae) family. Within botanical and pharmacological literature, two species names appear most frequently and are often used interchangeably: Xanthium strumarium L. and Xanthium sibiricum Patr. ex Widder. Recognized synonyms for X. strumarium include X. sibiricum Widder, X. strumarium subsp. sibiricum (Widder) Greuter, and X. chinense Mill. Common English names include common cocklebur, rough cocklebur, clotbur, and burweed.

In Traditional Chinese Medicine (TCM), the dried, processed fruit of the plant is designated Xanthii Fructus (abbreviated XF) and carries the Chinese name Cang-Er-Zi (苍耳子). Xanthii Fructus, or "cangerzi" in Chinese, is widely studied as a traditional Chinese medicinal agent. It is the dried fruit of the composite plant Xanthium sibiricum Patr.

Natural Source and Geographic Distribution

Xanthium strumarium L. is a medicinal plant commonly found as a weed, widely distributed in North America, Brazil, China, Malaysia, and the hotter parts of India. Popularly called "rough cocklebur," "common cocklebur," or "clotbur," it can be found all over the world but is most prevalent in the temperate zone. Within India, it is commonly found as a weed in roadsides, banks of canals, and hedges throughout the warmer parts of the country.

Plant Parts Used and Common Preparations

More than 170 chemical constituents have been isolated and identified from X. strumarium. In particular, the fruit is the predominant medicinal part of X. strumarium and is one of the most commonly used herbal medicines to treat rhinitis and headache for thousands of years. Traditional medicine particularly uses the leaves, roots, and fruits of X. strumarium.

The fruit ripens in autumn, is harvested and dried, and impurities such as stems and leaves are removed. Before clinical use, the fruits of X. strumarium are often processed by stir-baking to a yellowish color, which aims to reduce toxicity and enhance efficacy. In order to meet clinical needs better, various forms of formulas are developed, such as pills, tablets, granules, oral liquid, and powders. In TCM, the fruit is also incorporated into compound herbal decoctions. In traditional preparations, it is typically used in combination with other botanicals to enhance its therapeutic effects and balance its properties; one of the most famous formulas featuring it is Cang Er Zi San, a blend that also includes magnolia flower (Xin Yi Hua), angelica root (Bai Zhi), and mint (Bo He).

2. Traditional and Historical Use

Traditional Chinese Medicine

The first record of the pharmacological effects of this plant can be traced back to ShenNong BenCaoJing, the earliest monograph of TCM during the Eastern Han dynasty. In this monograph, it was used for the treatment of anemofrigid headache and rheumatic arthralgia. Xanthii Fructus was first described in Shennong's Classic of Materia Medica (during the Qin and Han Dynasties) and was later recorded in the Compendium of Materia Medica (Ming Dynasty).

In Sheng Nong's Herbal Classic, a book published approximately 2,000 years ago, Xanthii Fructus was first documented for its ability to smooth nasal orifices and eliminate wind-dampness, and its toxicity was also noted. In Mingyi Bielu, another known TCM monograph, X. strumarium was recorded as an effective herbal medicine with the function of curing gonyalgia. In Yaoxinglun, the plant was described as an agent for treating hepatic heat and eye diseases. The monograph Xinxiu Bencao described X. strumarium with improving eyesight, antiepileptic, and antirheumatic properties. The plant was also listed in classical monographs including Bencao Shiyi, Bencao Mengquan, Depei Bencao, Caomu Bianfang, and Tianbao Bencao.

Xanthii Fructus is used in TCM to treat rhinitis, headache due to a cold, limb cramps and numbness, ulcers, and itching. In TCM, the plant is considered an important herb for "dispelling wind" and "opening the nasal passages." This herb has a warm nature and exhibits pungent and bitter flavor properties in classical TCM classification. Its therapeutic actions encompass dispelling wind-cold, clearing nasal obstruction, expelling wind, and eliminating dampness, establishing its primary use in the management of nasal disorders.

Currently, the fruits of X. strumarium have become an important traditional Chinese medicine commonly used in clinical practice for the treatment of nasal diseases (including acute and chronic rhinitis, allergic rhinitis, nasosinusitis, and nasal obstruction), itching diseases, and painful diseases. The fruits of X. strumarium remain a common TCM drug listed in the Chinese Pharmacopoeia, and atractyloside and chlorogenic acid are used as the quality indicator agents for evaluating the quality of the fruits.

Traditional Use in India and Other Regions

Extracts of the whole plant, especially leaves, roots, fruits, and seeds, have been applied in traditional medicine for the treatment of leucoderma, poisonous insect bites, epilepsy, salivation, long-standing cases of malaria, rheumatism, tuberculosis, allergic rhinitis, sinusitis, urticaria, rheumatoid arthritis, constipation, diarrhea, leprosy, lumbago, pruritus, and bacterial and fungal infections. Smallpox, cancer, leukoderma, epilepsy, excessive salivation, malaria, rheumatism, tuberculosis, and bacterial and fungal infections have all been traditionally treated with various parts of this plant. The plant also holds an important place in Unani medicine, where it has been used as a folk medicinal herb.

Xanthium sibiricum (Asteraceae), an annual herbaceous plant, has been used in traditional Chinese medicine for treating inflammatory diseases such as appendicitis, chronic bronchitis, rheumatism, and rhinitis.

3. Key Constituents and Active Compounds

Major Phytochemical Classes

The plant contains a wide spectrum of bioactive compounds, including sesquiterpene lactones, flavonoids, phenolic acids, and alkaloids, which contribute to its reported antibacterial, antifungal, antiviral, anti-inflammatory, hypoglycemic, antitussive, and anticancer effects. Constituents such as sesquiterpene lactones (xanthatin, xanthinosin, xanthanol, and isoxanthanol), glycosides, phenols, polysterols, fatty acids, carboxyatractyloside, caffeoylquinic acids, hydroquinone, and thiazinedione found in various parts of the plant explain the majority of its pharmacological effects.

Sesquiterpene Lactones (Xanthanolides)

Important compounds isolated from X. strumarium are the xantholides and xanthane epoxide derivatives (sesquiterpene lactones), including xanthumin, xanthinin, xanthatin, xanthinosin, xanthanol, isoxanthanol, 1α,5α-epoxyxanthatin, 1β,5β-epoxyxanthatin, 4-epixanthanol, 4-epi-isoxanthanol, 11α,13-dihydroxanthatin, 4β,5β-epoxyxanthatin-1α,4α-endoperoxide, 1β,4β,4α,5α-diepoxyxanth-11(13)-en-12-oic acid, tomentosin, 8-epi-xanthatin, and 8-epi-xanthatin-1β,5β-epoxide.

Xanthatin is the most extensively studied sesquiterpene lactone in the genus. Xanthatin is a naturally occurring bicyclic sesquiterpene lactone predominantly isolated from Xanthium species within the Compositae. Xanthium strumarium is a widely distributed plant whose aerial parts, especially the leaves, are rich in xanthatin. As one of the main active components in X. sibiricum, xanthatin has significant pharmacological effects in anti-tumor, anti-inflammatory, anti-bacterial, anti-fungal, and anti-viral aspects.

Diterpene Glycosides (Atractyloside and Carboxyatractyloside)

The dried ripe fruits of Xanthium sibiricum contain carboxyatractyloside and atractyloside as important constituents; these diterpenoid glycosides are responsible for the toxicity of the fruits. The toxic principle in X. strumarium poison was isolated and identified as carboxyatractyloside (CAT), a highly selective inhibitor of oxidative phosphorylation. The fruit also contains a glycoside called xanthostrumarine (carboxyatractyloside), and consists of approximately 30% drying oil, containing oleic and linoleic acids and phosphatides.

In the n-butanol fraction of the fruit extract, atractyloside and carboxyatractyloside and their desulphated derivatives are the major compounds responsible for the plant's toxicity. Carboxyatractyloside was found in cotyledons and seeds but not in adult leaves and burrs.

Phenolic Acids and Caffeoylquinic Acids

The chemical composition of X. strumarium includes phenolic compounds like chlorogenic and ferulic acids, thiazinediones, xanthanolide sesquiterpene lactones (8-epi-xanthatin and 8-epi-xanthatin epoxide), beta-sitosterol, strumasterol (C-24 epimer of stigmasterol), monoterpene and sesquiterpene hydrocarbons, caffeic acid, 1,3,5-tri-O-caffeoyl quinic acid, and 1,5-di-O-caffeoyl quinic acid. Using HPLC assays combined with reference standards, ten caffeoylquinic acids have been identified as predominant constituents of the fruits.

Additional Constituents

The plant is also known to be a rich source of iodine, and the leaves contain volatile oil components (terpenes) including δ-limonene and δ-carveol, which have potent antifungal activity. Xanthii Fructus contains water-soluble glycosides, sesquiterpene lactones, and phenolic acids.

4. Established Mechanisms of Action

Anti-inflammatory Pathways

To explore the anti-inflammatory mechanism of methanol extracts of X. strumarium, researchers used LPS-stimulated murine macrophage-like RAW264.7 cells and human monocyte-like U937 cells. Methanol extracts of X. strumarium significantly suppressed the up-regulation of both activator protein (AP)-1-mediated luciferase activity and the production of LPS-induced proinflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α.

The bioactive constituents of Xanthium strumarium L., particularly n-butanol-soluble compounds, modulate the LAT/PLCγ1/PKC signaling cascade. This molecular mechanism suppresses mast cell degranulation, reduces inflammatory mediator release, and enhances nasal vascular tone through dual pathways: α-adrenergic receptor-mediated vasoconstriction and nasal mucosal contraction. Collectively, these physiological responses alleviate rhinitis symptoms, including turbinate hypertrophy and nasal congestion.

Anticancer Mechanisms of Xanthatin

In cell-based studies, xanthatin demonstrated obvious dose- and time-dependent cytotoxicity against the human non-small-cell lung cancer (NSCLC) cell line A549. Flow cytometry analysis showed xanthatin induced cell cycle arrest at the G2/M phase, and xanthatin also had pro-apoptotic effects on A549 cells. Mechanistic data revealed that xanthatin downregulated Chk1, Chk2, and phosphorylation of CDC2, contributing to cell cycle arrest. Xanthatin also increased total p53 protein levels, decreased Bcl-2/Bax ratio, and decreased expression of procaspase-9 and procaspase-3, triggering the intrinsic apoptosis pathway. Furthermore, xanthatin blocked phosphorylation of NF-κB (p65) and IκBα, and inhibited TNFα-induced NF-κB (p65) translocation.

The anticancer mechanism of xanthatin involves multiple pathways, including activation of the p53 pathway, inhibition of the NF-κB pathway, and modulation of PI3K/Akt/mTOR signaling pathways to inhibit tumor cell occurrence and growth. Mammalian thioredoxin reductase (TrxR) enzymes represent a promising target for xanthatin. Xanthatin (XT) inhibits both purified TrxR and the enzyme in cells; mechanism studies reveal that XT targets the selenocysteine (Sec) residue of TrxR and inhibits enzyme activity irreversibly. Inhibition of TrxR by XT promotes oxidative stress-mediated apoptosis of HeLa cells.

Toxicological Mechanism of Carboxyatractyloside

The three major hepatotoxicity constituents in water extracts of Xanthium strumarium fruits — atractyloside, carboxyatractyloside, and 4'-desulphate-atractyloside — have shown significant cytotoxic effects in liver cell lines. The toxicological effects of X. strumarium fruits may result from inhibiting mitochondrial function by altering energy metabolism and inducing hepatocyte injury by influencing fatty acid metabolism.

5. Scientific Evidence by Area of Use

5.1 Allergic Rhinitis and Sinusitis

Traditional basis: The dried ripe fruits of Xanthium sibiricum are used in traditional Chinese medicine for the treatment of nasal congestion, nasal discharge, allergic rhinitis, sinusitis, and wind-cold headaches.

Preclinical (animal) evidence: A published rodent study specifically investigated the effects of caffeoylxanthiazonoside (CXT), a compound isolated from the fruits of X. strumarium, on allergic rhinitis in rats. Anti-allergic activity of CXT was evaluated by passive cutaneous anaphylaxis test; acetic acid-induced writhing tests were used to evaluate analgesic effects; acetic acid-induced vascular permeability tests were used to evaluate anti-inflammatory effect. The allergic rhinitis model in rats was established to evaluate effects on sneezing and nasal scratching frequencies, IgE level in serum, and histopathological examinations. Results demonstrated that CXT had favorable anti-allergic, anti-inflammatory, and analgesic effects.

A parallel study examined caffeoylquinic acids from X. strumarium fruits. That study revealed that the caffeoylquinic acids showed obvious anti-allergic and anti-inflammatory properties, and treatment was beneficial for ameliorating the nasal symptoms, decreasing pro-inflammatory cytokines, and inhibiting the release of histamine. The study investigated therapeutic effects of caffeoylquinic acids from fruits of X. strumarium on allergic rhinitis in animals; toxicity tests indicated that the caffeoylquinic acids have no obvious toxicity at tested doses.

Using an integrated approach combining phytochemistry, network pharmacology, and metabolomics, a further study evaluated an ovalbumin (OVA)-induced rat model of allergic rhinitis. The X. strumarium extract significantly increased serum concentrations of IL-2 and reduced the levels of serum IL-4, while also ameliorating inflammation in the nasal sub-mucosal area. A total of 119 compounds were isolated from XS, and 59 were identified as active ingredients through ADME-TOX screening. Network pharmacology analysis implied that the active ingredients could regulate the inflammatory response via "multi-component, multi-target" patterns.

Network pharmacology (mechanistic modeling): Xanthii Fructus has been used for treatment of allergic rhinitis (AR), but its pharmacological mechanism of action has remained unclear; a network pharmacology approach was applied to explore the potential mechanism of XF in treatment of AR.

Evidence strength: Most of the evidence for beneficial effects comes from laboratory (in vitro) or animal studies. While promising, these results cannot be considered definitive proof for treatment in humans. Clinical studies are limited. Human clinical trial data from high-quality randomized controlled trials are not yet available in the indexed peer-reviewed literature; the evidence base for allergic rhinitis is predominantly preclinical.

5.2 Anti-Inflammatory and Analgesic Effects

The bioactive compounds in Xanthium strumarium exhibit diverse pharmacological properties, including anti-allergic rhinitis, antitumor, anti-inflammatory, analgesic, antibacterial, antifungal, antioxidant, insecticidal, antiparasitic, anti-diabetic, and antiviral effects. Evidence for anti-inflammatory activity derives predominantly from in vitro cell-line studies and murine models. Xanthium strumarium L. is a traditional Chinese medicine prescribed to treat arthritis, bronchitis, and rhinitis, although the mechanism by which it ameliorates various inflammatory diseases is not yet fully understood.

In cell culture experiments using LPS-stimulated macrophages, methanol extracts of X. sibiricum roots were investigated for anti-inflammatory activity. The study aimed to investigate the anti-inflammatory effect of methanol extracts of X. sibiricum roots (MXS) and to further determine the underlying mechanism in order to assess its medicinal value. Anti-inflammatory activity in LPS-stimulated RAW 264.7 macrophages was assessed by measuring the production of nitric oxide (NO) using the Griess reagent system. No large-scale human trials specifically evaluating isolated anti-inflammatory endpoints were identified in the indexed literature.

5.3 Anticancer Activity

In vitro evidence: Recent studies demonstrated that xanthatin had significant antitumor activity in a variety of cell culture systems implicated in colon, breast, lung, cervix, and skin cancers. However, the molecular mechanisms underlying these effects remain poorly understood.

Studies examined the inhibitory effect of xanthatin (1–40 μM) against lung cancer cells (cell lines A549, H1975, H1299, H1650, and HCC827), finding that xanthatin could downregulate STAT3, GSK3β, and β-catenin; xanthatin could also trigger Chk1-mediated DNA damage and destabilize Cdc25C via lysosomal degradation. Ahn et al. (1995) isolated three cytotoxic compounds from the leaves of X. strumarium; among them, xanthatin and 8-epi-xanthatin possessed obvious anti-tumor activity on A549 cells with IC50 values of 1.3 and 1.1 μg/mL, respectively.

Xanthatin, 4-epixanthanol, 4-epi-isoxanthanol, and 2-hydroxyxanthinosin isolated from the chloroform extract of the leaves have been reported to show growth-inhibitory effect on A431 (skin cancer), HeLa (cervix cancer), and MCF-7 (breast cancer) cells. Xanthatin and xanthinosin isolated from X. strumarium were shown to have moderate to high cytotoxic activity on WiDr ATCC, MB-231 ATCC, and NCI-417 cells. Furthermore, 8-epi-xanthatin and 8-epi-xanthatinepoxide from X. strumarium significantly reduced the in vitro proliferation of A549 (non-small cell lung cancer), SK-OV-3 (ovary cancer), SK-MEL-2 (melanoma), XF498 (central nervous system cancer), and HCT-15 (colon cancer) cell lines.

Breast cancer stem cells (in vitro): Experimental evidence strongly suggests that (–)-xanthatin, a xanthanolide sesquiterpene lactone, exhibits anti-proliferative effects on human breast cancer cells (in vitro) as well as anti-tumor effects in experimental animals (in vivo). It has not yet been established whether (–)-xanthatin abrogates the formation of breast cancer stem cells (CSCs). A study using chemically synthesized pure (–)-xanthatin and a mammosphere culture system demonstrated for the first time that (–)-xanthatin exhibited the ability to kill mammospheres, similar to salinomycin, an established selective killer of CSCs.

Evidence strength: All anticancer evidence is preclinical — derived from cell lines and animal models. No human clinical trials evaluating X. strumarium or xanthatin as a cancer therapeutic are reported in the indexed literature. Further studies are needed to establish that (–)-xanthatin in X. strumarium is effective as a killer of breast cancer in human settings.

5.4 Antimicrobial Activity

Antimicrobial activity of X. strumarium leaf extracts was evaluated against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, and Clostridium perfringens. S. aureus and C. perfringens were more sensitive to non-polar than to polar fractions; all extracts had strong antimicrobial activity against the evaluated microorganisms.

The antimicrobial potential of an alcoholic extract and various fractions of Xanthium strumarium was investigated against different strains of bacteria and fungi. The chloroform fraction was found to be the most active among fractions, showing good activity against Escherichia coli, Shigella flexneri, Bacillus subtilis, and Staphylococcus aureus. Most of the activity detected was against gram-positive (S. aureus) bacteria. The chloroform fraction exhibited significant antibacterial activity (19 mm zone of inhibition) against the gram-negative bacterium Shigella flexneri.

The leaves contain volatile oil components including δ-limonene and δ-carveol, which have potent antifungal activity. Xanthumin, tomentosin, 8-epi-xanthatin, and 8-epi-xanthatin-1β,5β-epoxide isolated from an acetone extract of the aerial parts show antimalarial activity against chloroquine-resistant Plasmodium falciparum strain K1.

Evidence strength: Antimicrobial evidence is exclusively preclinical (in vitro). No human trials investigating X. strumarium for infectious disease treatment have been identified.

5.5 Hypoglycemic Effects

Modern pharmacological research has shown that Xanthii Fructus exerts hypoglycemic, anti-inflammatory, and other effects. Pharmacological activities reviewed for X. strumarium include hypoglycaemic, antimitotic, antioxidant, and antitrypanosomal activities. Evidence for hypoglycemic activity derives from animal and cell-based experiments. No controlled clinical trials in human diabetic populations have been identified in the indexed literature.

5.6 Antioxidant Activity

One PMC-published study defined the beneficial properties of various extracts of X. strumarium. Evaluations were conducted on total phenolic and flavonoid contents of the extracts. HPLC-DAD was used to determine phenolic profiles. DPPH, ABTS, and FRAP assays were used to evaluate free radical scavenging properties. These are standard in vitro antioxidant assays; their translation to in vivo human antioxidant benefit has not been formally tested in clinical trials.

6. Body Systems and Health Areas Associated with Xanthium

• Respiratory / ENT system: Xanthii Fructus is used in clinical practice for the treatment of nasal diseases including acute and chronic rhinitis, allergic rhinitis, nasosinusitis, and nasal obstruction.
• Musculoskeletal / inflammatory system: X. strumarium has been extensively applied to treat rheumatism and arthritis.
• Dermatological system: The plant has been used in traditional medicine for the treatment of leucoderma, urticaria, leprosy, and pruritus.
• Oncology (preclinical): Compounds from X. strumarium have been extensively investigated in lung cancer, breast cancer, cervical cancer, colon cancer, liver cancer, meningioma, and leukemia.
• Metabolic / endocrine system: Xanthii Fructus exerts hypoglycemic effects in pharmacological research.
• Antimicrobial / antiparasitic: Compounds from the plant show antimalarial activity against chloroquine-resistant Plasmodium falciparum.
• Nervous system: CNS depressant activity has been documented among the pharmacological activities reviewed for the plant.
• Urinary system: Diuretic effects have been documented among the reviewed pharmacological activities.

7. Dosage Forms and Reported Dosages

According to the Pharmacopoeia of the People's Republic of China (Edition 2000), the daily dosage of Xanthii Fructus for an adult is 3–9 g. Suitable quantities are used for external application.

Before clinical use, the fruits of X. strumarium are often processed by stir-baking to a yellowish color, which aims to reduce toxicity and enhance efficacy. According to TCM theory, stir-baking (a processing method) can reduce the toxicity and enhance the efficacy of Xanthii Fructus.

In toxicological studies conducted in rats: the urine and serum metabolites were measured after treatment of rats with Xanthium strumarium fruit (XSF) at doses of 7.5, 15.0, and 30.0 g/kg/day for 5 days. Treatment of rats with the fruits of the plant at a dose of 30.0 g/kg resulted in hepatotoxicity, as indicated by changes in serum biochemical profiles and confirmed by histopathological liver examination.

Regarding carboxyatractyloside content: content of carboxyatractyloside (CAL) decreased dramatically after the processing procedure, while atractyloside (AL) content increased after processing. CAL was reported to be approximately 1.16–2.25 mg/g in raw Xanthii Fructus (XF) and 0–0.21 mg/g in processed Xanthii Fructus (PXF).

In rat toxicology studies, the calculated LD50 of carboxyatractyloside (CAT) given intraperitoneally was 13.5 mg/kg of body weight. The LD50 of atractyloside (AL) is 15 mg/kg in dog (intravenous), 434 mg/kg in mouse (intraperitoneal), and 143 mg/kg in rat (intraperitoneal).

In cell-based anticancer experiments, xanthatin was tested at concentrations of 1–40 μM against lung cancer cell lines. Xanthatin and 8-epi-xanthatin possessed anti-tumor activity on A549 cells with IC50 values of 1.3 and 1.1 μg/mL, respectively.

Various forms of formulas are developed for clinical application, including pills, tablets, granules, oral liquid, and powders. In the Chinese pharmacopoeia, more than ten Chinese proprietary drugs contain Xanthii Fructus or stir-baked Xanthii Fructus.

8. Safety Considerations and Interactions

Organ Toxicity: Liver, Kidney, and Gastrointestinal Tract

Toxicological studies have shown that Xanthii Fructus poisoning can cause substantial damage to organs, particularly the liver, kidney, and gastrointestinal tract, with the liver being the primary target. Because of the coexistence of its efficacy and toxicity, Xanthii Fructus often leads to a series of safety problems in clinical application.

Hepatotoxicity is one of the major concerns with herbal medicines in general, because of the important role of the liver in drug metabolism and toxicity. Hepatic injury is a fundamental pathological process in most hepatic diseases, and long-standing hepatic injury leads to hepatic fibrosis, liver cirrhosis, and even hepatocellular carcinoma. Xanthium strumarium L., commonly known as cocklebur, is recorded in the FDA Poisonous Plant Database.

The Principal Toxic Compound: Carboxyatractyloside

The whole plant, especially the seeds, contains toxic compounds known as carboxyatractylosides, which cause poisoning in humans and animals. The toxicological effects of X. strumarium fruits may result from inhibiting mitochondrial function by altering energy metabolism and inducing hepatocyte injury by influencing fatty acid metabolism. Carboxyatractyloside recovered from the aqueous extract of X. strumarium and authentic carboxyatractyloside, when fed to pigs, caused signs and lesions typical of cocklebur intoxication.

Xanthostrumarine (carboxyatractyloside) occurs in high concentrations in germinating seeds and very young seedlings, causing death in animals that feed on them, such as cattle, sheep, pigs, and rats, but not in chickens. Cocklebur (Xanthium strumarium) fed to feeder pigs was associated with acute to subacute hepatotoxicosis. Cotyledonary seedlings fed at 0.75% to 3% of body weight or ground bur fed at 20% to 30% of the ration caused acute depression, convulsions, and death.

Human Poisoning Cases

In a reported case in Turkey, nine people of different ages were poisoned because they ate the seeds of the cocklebur plant, and three of them (one aged 5 and two aged 9 years old) were reported to die despite treatment. A 25-year-old woman in Iran was admitted to the hospital with symptoms of intoxication three days after consuming a mixture of cocklebur leaves, stems, and seeds prepared as a hot-water infusion; the patient recovered after symptomatic treatment. Consumption of fruits (burrs) and cotyledonary-stage leaves (two-leaf stage) has been documented to lead to hepatic necrosis and myocardial injury in humans.

The coagulation disorder, hypoglycemia, and liver failure observed in cocklebur poisoning indicate that prognosis can be poor. There is no specific antidote; treatment is performed symptomatically. To reduce absorption, stomach lavage and activated charcoal administration are considered appropriate initial interventions.

Processing and Toxicity Reduction

A comparative study showed that stir-baking significantly reduced the cytotoxicity and enhanced the bioactivity of Xanthii Fructus. The anti-inflammatory effects of stir-baked Xanthii Fructus were more potent than those of raw Xanthii Fructus in macrophage assays. Fruits treated at higher temperatures showed a lower content of carboxyatractyloside and an increased content of atractyloside, which is 50 times less toxic than carboxyatractyloside. This indicates that the roasting process can reduce toxicity effectively.

For the safe use of Cang'erzi, the effect of processing should be monitored and analysis of carboxyatractyloside and atractyloside should be obligatory in quality control.

Differentiation of Plant Part Safety

Carboxyatractyloside was found in cotyledons and seeds but not in adult leaves and burrs. Thus, only Xanthium strumarium leaves in the adult stage may be used for medicinal purposes, according to one study.

Limitations of the Current Evidence Base

Research still needs quantitation of individual constituents and assessment of their pharmacological activities in humans. Clinical studies are limited. The effects of dosage, long-term use, interactions, and safety — especially for vulnerable populations including children, pregnant women, and people with liver/kidney issues — remain under-studied. Safety-related thinking has focused on how to promote clinical rational application via strict processing, reasonable compatibility, medication information, contraindication observance, and strict control of dose and course of treatment, in order to promote safe and reasonable application of Xanthii Fructus.

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