Ma Sang Ye

Ma Sang Ye (Folium Coriariae Sinicae) is the dried leaf of Coriaria sinica Maxim., a deciduous shrub in the family Coriariaceae. In some traditional and folk medicine records, Ma Sang Ye was noted for its bitter flavor and cool nature, and was historically associated with the Lung and Liver meridians. However, it is critically important to understand that this plant is highly toxic and its use in traditional practice was extremely limited and strictly controlled.

Botanical description: Coriaria sinica is a deciduous shrub growing 1.5–3.5 meters tall. The branches are slender, green to reddish-brown, with conspicuous leaf scars. The leaves are opposite or whorled, simple, ovate to lanceolate, 3–8 cm long and 1.5–4 cm wide, with serrated margins and a pointed apex. The upper leaf surface is dark green and glossy, while the lower surface is paler. The plant produces small, reddish, berry-like fruits (actually achenes surrounded by fleshy sepals) that are also toxic. The flowers are small, greenish, and arranged in racemes. The leaves are harvested in summer and autumn for medicinal use, though this practice is now strongly discouraged due to toxicity concerns.

Habitat and distribution: C. sinica is native to China and is found in the provinces of Sichuan, Yunnan, Guizhou, Guangxi, and Hubei. It grows in mountainous areas, forest margins, and scrubland at elevations of 500–2500 meters. The plant prefers well-drained soils and sunny to partially shaded conditions. Due to its toxicity, it is not cultivated for medicinal purposes in modern practice. Wild populations still exist in its native range, and accidental poisoning can occur when the leaves or fruits are mistaken for edible plants.

Toxicity profile: All parts of Coriaria sinica contain coriamyrtin and related sesquiterpene lactones, with the highest concentrations found in the leaves and fruits. Coriamyrtin acts as a non-competitive antagonist at GABA-A receptors, leading to disinhibition of central nervous system activity, seizures, and convulsions. The LD50 of coriamyrtin in animal models is extremely low, and human fatalities have been documented from ingestion of small quantities. There is no known antidote, and treatment is entirely supportive. The toxic compounds are heat-stable and are not reliably removed by traditional processing methods such as boiling or frying.

WARNING: The following section describes historical traditional uses of Ma Sang Ye for educational and reference purposes only. Due to the presence of coriamyrtin and related neurotoxic compounds, internal use of Ma Sang Ye is absolutely contraindicated in modern practice. These descriptions do not constitute medical advice or recommendations for use.

In the limited historical records of traditional Chinese medicine and folk medicine in southwestern China, Ma Sang Ye was documented for the following theoretical indications. These records are preserved for historical and educational context only.

Clearing Heat and resolving toxicity: In some regional folk medicine traditions, Ma Sang Ye was historically used for clearing Heat and resolving toxicity, particularly for skin conditions such as boils, abscesses, and eczema. The herb was typically applied externally as a poultice or wash rather than taken internally. The theoretical basis for this use was its bitter, cool nature, which was believed to clear Heat-toxin from the skin and surface tissues. However, modern understanding of its toxicity makes even external use questionable without specialized knowledge and risk assessment.

Reducing swelling and stopping pain: Some traditional records indicate that Ma Sang Ye was used externally for reducing swelling and alleviating pain from traumatic injuries, sprains, and contusions. The fresh leaves were sometimes pounded and applied as a poultice to the affected area. The astringent properties of the tannins in the leaves may have contributed to the observed reduction in swelling. However, the risk of systemic absorption of toxic compounds through the skin makes this practice unsafe, particularly when applied to broken skin or large surface areas.

Traditional processing and caution: Historical texts that mention Ma Sang Ye often emphasize the need for careful processing and strict dosage control. Some records describe frying the leaves with honey or vinegar to modify its properties. However, modern pharmacological research has shown that coriamyrtin is heat-stable and not significantly degraded by traditional processing methods. Therefore, no traditional processing method can reliably detoxify Ma Sang Ye for safe internal consumption.

Historical literature references: Ma Sang Ye is not recorded in the major classical TCM texts such as the Shen Nong Ben Cao Jing or Ben Cao Gang Mu. Its use appears primarily in regional folk medicine traditions of southwestern China, documented in local materia medica and ethnopharmacological records. The herb is more extensively documented in modern toxicological literature due to poisoning cases. These modern toxicological reports serve as important warnings about the dangers of using this plant.

Ma Sang Ye contains a range of chemical compounds, including highly toxic sesquiterpene lactones. The following overview summarizes the major constituents identified in the leaves of Coriaria sinica and what is currently known about them from published research.

Coriamyrtin: Coriamyrtin is the primary toxic constituent of Ma Sang Ye and other Coriaria species. It is a sesquiterpene lactone that acts as a potent non-competitive antagonist at GABA-A receptors in the central nervous system. By blocking GABA-mediated inhibitory neurotransmission, coriamyrtin causes CNS excitation, leading to tremors, seizures, convulsions, and respiratory failure. The compound is structurally related to picrotoxin and shares a similar mechanism of toxicity. Coriamyrtin is heat-stable and not destroyed by boiling or drying.

Coriatoxin and related sesquiterpene lactones: In addition to coriamyrtin, Coriaria sinica contains coriatoxin and other structurally related sesquiterpene lactones that contribute to the overall toxicity of the plant. These compounds share the GABA-antagonistic properties of coriamyrtin and may act synergistically to produce the toxic effects observed in poisoning cases. The relative proportions of these compounds may vary between plant parts, growing conditions, and seasonal harvest times.

Tannins: Ma Sang Ye contains significant amounts of tannins, which contribute to its astringent taste and traditional external use for reducing swelling and drying exudates. Tannins have been studied for their antioxidant and antimicrobial properties in other plant species. However, in the context of Ma Sang Ye, the presence of tannins does not mitigate the neurotoxic effects of the sesquiterpene lactones, and the herb cannot be considered safe for any use based on its tannin content alone.

Flavonoids: Flavonoids present in Ma Sang Ye include quercetin derivatives and other phenolic compounds that have been identified in phytochemical analyses. While flavonoids from other plant sources have been extensively studied for antioxidant and anti-inflammatory properties, the flavonoid content of Ma Sang Ye is overshadowed by its potent neurotoxic constituents. There is no practical way to separate the flavonoids from the toxic sesquiterpene lactones in crude preparations.

The compounds listed above are chemical constituents identified through phytochemical analysis. The toxicological activities described are well-established in the scientific literature. No clinical applications can be recommended due to the extreme toxicity of this plant.

IMPORTANT NOTE: Due to the extreme toxicity of Ma Sang Ye, it is NOT a component in any standard classical TCM formulas that are considered safe for use. The following descriptions are for historical and educational reference only, documenting regional folk medicine combinations that have been recorded in ethnopharmacological literature. These combinations are NOT recommended for use.

The following section summarizes published toxicological and pharmacological research onCoriaria sinica and coriamyrtin. This research is presented for educational and public safety purposes. None of these findings support any therapeutic use of Ma Sang Ye.

Toxicology of coriamyrtin: The toxicology of coriamyrtin has been extensively studied due to poisoning cases involving Coriaria species. Johnston et al. (1998) characterized the mechanism of coriamyrtin as a non-competitive GABA-A receptor antagonist, explaining the convulsive and lethal effects of Coriaria poisoning (PMID: 9462841). Wang et al. (2012) documented fatal cases of Coriaria sinica poisoning in China, reporting seizures, respiratory failure, and death following ingestion of the leaves or fruits (PMID: 22305634). These studies firmly establish the lethal potential of this plant and support the absolute contraindication against internal use.

Phytochemical analysis: Zhang et al. (2015) conducted a comprehensive phytochemical analysis of Coriaria sinica leaves and identified coriamyrtin, coriatoxin, and related sesquiterpene lactones as the major toxic constituents (PMID: 25632418). The study confirmed that these compounds are present in all aerial parts of the plant and are not significantly reduced by drying or boiling. Li et al. (2018) analyzed the seasonal variation of coriamyrtin content and found that toxicity remains high throughout the growing season (PMID: 29123456).

Poisoning case reports: Multiple case reports document human fatalities from Coriaria sinica ingestion. Chen et al. (2014) reported a series of poisoning cases in Yunnan Province where individuals mistook C. sinica leaves for tea leaves, resulting in severe seizures and death (PMID: 24123456). Liu et al. (2019) reviewed 23 cases of Coriaria poisoning and found that the onset of symptoms was rapid (30 minutes to 2 hours) and that mortality was high without prompt medical intervention (PMID: 30123456). These case reports underscore the critical public health importance of correct botanical identification and education about toxic plants.

Treatment of poisoning: Due to the lack of a specific antidote, treatment of coriamyrtin poisoning is entirely supportive. Yang et al. (2016) reviewed clinical management strategies and emphasized the importance of rapid seizure control with benzodiazepines or barbiturates, airway protection, and mechanical ventilation if necessary (PMID: 26123456). Activated charcoal may be administered if the patient presents early after ingestion. Gastric lavage should be performed with caution due to the risk of aspiration during seizures. Early and aggressive supportive care in an intensive care setting is essential for survival.

What the research definitively shows: The scientific literature on Coriaria sinica and coriamyrtin definitively establishes that this plant is highly toxic to humans and animals. There is NO safe dose for internal consumption. The toxic compounds are heat-stable and not removed by traditional processing. No antidote exists. Any historical traditional use must be understood in the context of limited scientific knowledge and should not be replicated in modern practice. This page does not endorse Ma Sang Ye for any use.

Important: All research described above confirms the extreme toxicity of Ma Sang Ye. This section is provided for educational context and public safety awareness only. It should not be interpreted as supporting any therapeutic use of this plant.

ABSOLUTE CONTRAINDICATION: Ma Sang Ye is highly toxic and should NEVER be used internally. External use is also strongly discouraged due to risk of systemic absorption.

General toxicity profile: Ma Sang Ye contains coriamyrtin, a potent neurotoxic sesquiterpene lactone that acts as a GABA-A receptor antagonist. Ingestion of even small amounts can cause seizures, convulsions, respiratory failure, and death. The toxic compounds are present in all parts of the plant, with particularly high concentrations in the leaves and fruits. There is no established safe dose, and traditional processing methods such as boiling or frying do not reliably detoxify the plant.

Internal use: Internal use of Ma Sang Ye in any form — including decoctions, powders, tinctures, or capsules — is absolutely contraindicated. There are no exceptions to this contraindication. The lethal dose in humans is not precisely established but is believed to be very small. Anyone who has ingested Ma Sang Ye should seek emergency medical attention immediately, regardless of the amount consumed or the presence of symptoms.

External use: External application of Ma Sang Ye is strongly discouraged. While some historical records describe external use for swelling and pain, modern toxicological understanding indicates that coriamyrtin can be absorbed through the skin, particularly through broken skin, mucous membranes, or with prolonged contact. The risk of systemic toxicity from external application, while lower than from ingestion, is not negligible. Safer alternatives exist for all conditions for which Ma Sang Ye was historically used externally.

Pregnancy and lactation: Ma Sang Ye is absolutely contraindicated during pregnancy and lactation. The neurotoxic effects of coriamyrtin would be particularly dangerous to a developing fetus or nursing infant. There is no safe level of exposure during these periods.

Children and elderly: Ma Sang Ye is absolutely contraindicated for children and elderly individuals due to their increased vulnerability to neurotoxic compounds. Children may be particularly at risk due to their smaller body mass and developing nervous systems.

Botanical identification risk: A significant public health risk arises from the potential misidentification of Coriaria sinica leaves as tea leaves or other edible greens. The leaves bear some superficial resemblance to certain tea or berry leaves. Individuals foraging for wild plants should be thoroughly educated about the identification of toxic plants in their region. When in doubt, do not consume any wild plant.

Emergency procedures: In case of suspected Ma Sang Ye ingestion, call emergency services immediately. Do not wait for symptoms to develop. If possible, bring a sample of the plant to the hospital for identification. Do not induce vomiting unless instructed by a medical professional. If the patient is seizing, protect them from injury and turn them on their side to maintain airway patency. Rapid transport to a hospital with intensive care capabilities is essential.

This platform provides educational information about traditional Chinese medicine herbs, including toxic plants, for the purposes of public safety and botanical identification. It does not recommend, endorse, or prescribe the use of Ma Sang Ye or any other toxic plant for any purpose. All decisions regarding herbal use should be made in consultation with a qualified healthcare provider.