Herb Bark (皮 pí / 树皮 shù pí)

Hai Tong Pi

Erythrina bark · 海桐皮

Erythrina variegata L. var. orientalis (L.) Merr. · Cortex Erythrinae

Also known as: Coral bean bark, Ci Tong Pi (刺桐皮), Ding Tong Pi (钉桐皮),

Hai Tong Pi (Erythrina bark) plant

Images shown are for educational purposes only

Erythrina bark is a traditional herb used primarily for joint and muscle pain caused by Wind and Dampness, particularly in the lower back, hips, and knees. It helps open blocked meridian pathways to relieve stiffness, numbness, and cramping. Applied topically, it also treats stubborn skin conditions like ringworm and scabies.

Category Wind-Damp dispelling herbs (祛风湿药) Wind-Damp-Heat clearing herbs (祛风湿热药)
Therapeutic focus Joint and Muscle Health Lower Back and Knee Health Skin Conditions Mobility and Flexibility

TCM Properties

Temperature

Neutral

Taste

Bitter (苦 kǔ), Acrid / Pungent (辛 xīn)

Channels entered

Liver, Kidneys

Parts used

Bark (皮 pí / 树皮 shù pí)

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Educational content • Consult qualified TCM practitioners for diagnosis and treatment

What This Herb Does

Every herb has a specific set of actions — here's what Hai Tong Pi does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Hai Tong Pi is primarily used to support these areas of health:

Joint and Muscle Health Lower Back and Knee Health Skin Conditions Mobility and Flexibility

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Hai Tong Pi performs to restore balance in the body:

Dispels Wind-Dampness Unblocks the Channels and Collaterals Alleviates Pain Kills Parasites and Stops Itching

How these actions work

'Dispels Wind-Dampness' means Hǎi Tóng Pí drives out the Wind and Dampness that invade the joints, muscles, and meridians, causing pain and stiffness. It is especially suited to conditions of the lower body, including the lower back, hips, and knees. Its bitter taste dries Dampness while its pungent taste disperses Wind, and its neutral temperature means it can be used for both Cold-type and Heat-type blockage patterns without pushing the body further toward either extreme.

'Unblocks the channels and collaterals' refers to this herb's ability to restore the smooth flow of Qi and Blood through the body's meridian pathways. When Wind, Dampness, or Blood stasis obstruct these pathways, numbness, cramping, or restricted movement can result. As the Ben Cao Gang Mu noted, this herb "enters the Blood level and reaches the site of disease through the channels," making it particularly useful for deep-seated joint and sinew problems, as well as traumatic injuries where circulation has been disrupted.

'Kills parasites and stops itching' describes its external application for skin conditions such as scabies and fungal infections (tinea/ringworm). Laboratory studies have confirmed that Hǎi Tóng Pí water extracts show antifungal activity against several common dermatophytes. It is typically used as a topical wash or tincture rather than taken internally for these skin conditions.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Hai Tong Pi is used to help correct these specific patterns.

Why Hai Tong Pi addresses this pattern

Hǎi Tóng Pí directly targets the core pathomechanism of Wind-Damp Bi (blockage) syndrome. Its bitter taste dries Dampness while its pungent taste disperses Wind from the channels and collaterals. Entering the Liver channel (which governs the sinews), it is particularly effective at relieving joint and sinew obstruction in the lower body. Its neutral temperature makes it versatile for both Cold-predominant and Heat-predominant presentations of Bi syndrome, unlike herbs that strongly warm or cool.

A practitioner would look for one or more of these signs

Moving Pain

Especially in the lower back, hips, and knees

Joint Stiffness

Difficulty bending and extending the limbs

Numbness In The Limbs

Numbness or heaviness in the legs

Muscle Spasm

Cramping or contracture of the lower extremities

Commonly Used For

These are conditions where Hai Tong Pi is frequently used — but only when they arise from the specific patterns it addresses, not in all cases

Arises from: Wind-Damp Damp-Heat

TCM Interpretation

In TCM, rheumatoid arthritis is understood as a Bi (blockage) syndrome where external pathogenic factors, primarily Wind, Dampness, and sometimes Cold or Heat, invade the channels and lodge in the joints. The Liver governs the sinews and the Kidneys govern the bones, so when these pathogens obstruct the Liver and Kidney channels in particular, joint deformity, swelling, stiffness, and pain result. When the condition involves redness and heat in the joints, Damp-Heat is considered the dominant pathogenic factor. Chronic cases often involve underlying deficiency of the Liver and Kidneys combined with ongoing pathogenic obstruction.

Why Hai Tong Pi Helps

Hǎi Tóng Pí is well suited to rheumatoid arthritis because it enters the Liver and Kidney channels, the two organ systems most directly governing joint health. Its bitter and pungent tastes allow it to simultaneously dry Dampness and disperse Wind from the channels and collaterals. Because its temperature is neutral rather than strongly warming or cooling, it can be used in both Cold-predominant (stiff, achy joints worse in cold weather) and Heat-predominant (red, hot, swollen joints) presentations. It is commonly combined with other Wind-Damp dispelling herbs like Niú Xī, Yì Yǐ Rén, and Wǔ Jiā Pí in formulas targeting the lower extremities.

Also commonly used for

Osteoarthritis

Chronic joint pain and stiffness, especially in the lower limbs

Lower Back Pain

Due to Wind-Dampness obstruction

Sciatica

Radiating leg pain from Wind-Damp in the channels

Knee Pain

Damp-Heat or Wind-Damp patterns

Gout

Used topically as a wash for gouty joint inflammation

Scabies

Topical application to kill parasites and relieve itching

Eczema

Damp-type eczema with itching, used topically

Toothache

Classical indication for parasitic tooth pain, used as a mouth rinse

Dysentery

Classical indication for Damp-type dysentery

Herb Properties

Every herb has an inherent temperature, taste, and affinity for specific channels — these properties determine how it interacts with the body

Temperature

Neutral

Taste

Bitter (苦 kǔ), Acrid / Pungent (辛 xīn)

Channels Entered

Liver Kidneys

Parts Used

Bark (皮 pí / 树皮 shù pí)

Dosage & Preparation

These are general dosage guidelines for Hai Tong Pi — always follow your practitioner's recommendation, as dosages vary based on the formula and your individual condition

Standard dosage

6-15g

Maximum dosage

Up to 15g in decoction for internal use. For external use (washes, soaks, topical applications), larger amounts can be used as appropriate.

Dosage notes

For Wind-Dampness impediment pain of the lower limbs, the standard internal dose is 6-12g in decoction, often combined with herbs like Niu Xi, Yi Yi Ren, and Wu Jia Pi. The herb may also be steeped in medicinal wine (药酒) for rheumatic conditions, where its channel-opening properties are enhanced by the alcohol medium. For external applications (scabies, eczema, fungal skin infections), a stronger decoction is prepared for washing or the powdered bark is mixed with a carrier for topical application. When used externally, the quantity is adjusted to the area being treated. Some classical sources cite doses around 9-15g (3-5 qian in traditional measures).

Processing Methods

In TCM, the same herb can be prepared in different ways to change its effects — here's how processing alters what Hai Tong Pi does

Processing method

The bark is cleaned, cut into small pieces, then dry-fried (stir-fried without additives) until slightly darkened.

How it changes properties

Stir-frying moderately reduces the bitter-dispersing quality and makes the herb gentler on the Stomach. The thermal nature remains neutral. This form is considered slightly milder for internal use.

When to use this form

When the raw herb is too harsh for patients with a sensitive digestive system, or for general internal decoction use. The raw (unprocessed) form is preferred for topical applications.

Common Herb Pairs

These ingredients are traditionally combined with Hai Tong Pi for enhanced therapeutic effect

Xi Xian Cao
Xi Xian Cao 1:1 (e.g. 10g each)

Hǎi Tóng Pí and Xī Xiān Cǎo (Siegesbeckia) together create a powerful Wind-Damp dispelling pair that also invigorates Blood circulation. Hǎi Tóng Pí enters the channels deeply to unblock collaterals and reach the disease site, while Xī Xiān Cǎo broadly dispels Wind-Dampness and relaxes the sinews. Together they address both the obstruction and the resulting Blood stasis in the joints.

When to use: Wind-Damp Bi syndrome with joint pain, stiffness, and limited range of motion, especially in the lower extremities.

Qin Jiao
Qin Jiao 1:1 (e.g. 10g each)

Hǎi Tóng Pí combined with Qín Jiāo (Gentiana macrophylla root) creates a pair that penetrates all twelve meridians to expel Wind-Dampness and relieve pain throughout the body. Qín Jiāo is known for its broad reach across all channels and its ability to clear Damp-Heat, complementing Hǎi Tóng Pí's strength in the lower body and its channel-unblocking ability.

When to use: Widespread Wind-Damp Bi pain affecting multiple joints, or when both upper and lower body joints are involved. Particularly useful when there is a Damp-Heat component.

Niu Xi
Niu Xi 1:1 (e.g. 10g each)

Hǎi Tóng Pí disperses Wind-Dampness from the channels while Niú Xī (Achyranthes root) guides the therapeutic action downward to the lower back and legs, strengthens the sinews and bones, and invigorates Blood to clear stasis from the joints. Together they form a targeted pair for lower body joint problems.

When to use: Lower back pain, knee pain, or hip pain due to Wind-Dampness, especially when there is also weakness of the lower limbs.

She Chuang Zi
She Chuang Zi 1:1, ground into powder and mixed with lard or applied as a wash

Hǎi Tóng Pí and Shé Chuáng Zǐ (Cnidium seed) are a classical topical pair for stubborn skin conditions. Hǎi Tóng Pí dispels Wind-Dampness from the skin and kills parasites, while Shé Chuáng Zǐ dries Dampness, kills parasites, and strongly stops itching. Together they cover the full spectrum of pathogenic factors in chronic dermatoses.

When to use: Topical use for scabies, ringworm, eczema, and other itchy, damp skin lesions. Typically prepared as a decoction wash or alcohol tincture for external application.

Key Formulas

These well-known formulas feature Hai Tong Pi in a prominent role

Hai Tong Pi Tang 海桐皮湯 King

The namesake formula from the Yi Zong Jin Jian (Medical Orthodoxy), used as a topical wash for traumatic injuries and Wind-Damp joint pain. Hǎi Tóng Pí serves as King, showcasing both its channel-unblocking and Wind-Damp dispelling actions. The formula combines it with Tòu Gǔ Cǎo, Wēi Líng Xiān, Rǔ Xiāng, and Mò Yào for external application.

Comparable Ingredients

These ingredients have overlapping uses — here's how to tell them apart

Qin Jiao
Hai Tong Pi vs Qin Jiao

Both dispel Wind-Dampness and unblock the channels. Qín Jiāo is cool in nature and traverses all twelve meridians, making it better suited for Damp-Heat Bi patterns and widespread joint pain throughout the body. Hǎi Tóng Pí is neutral and has a particular affinity for the lower body (lower back, hips, knees). Hǎi Tóng Pí also has the additional action of killing parasites for topical skin conditions, which Qín Jiāo lacks.

Wei Ling Xian
Hai Tong Pi vs Wei Ling Xian

Both are commonly used Wind-Damp dispelling herbs that unblock the channels. Wēi Líng Xiān is warm and pungent with a powerful penetrating force, better for Cold-Damp Bi with severe pain and for softening fish bones stuck in the throat. Hǎi Tóng Pí is neutral and milder, making it more appropriate when there is a Damp-Heat component or when a less warming herb is needed. Hǎi Tóng Pí also has antiparasitic actions for skin conditions.

Mu Dan Pi
Hai Tong Pi vs Mu Dan Pi

Both are used topically for itchy skin conditions including scabies and ringworm. Mù Jǐn Pí (Hibiscus bark) is stronger at killing parasites and stopping itching but focuses almost entirely on skin conditions. Hǎi Tóng Pí has the additional major action of dispelling Wind-Dampness from the channels for joint pain, making it the more versatile herb with broader internal use.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Hai Tong Pi

Hai Tong Pi has a long history of regional substitution with barks from entirely different botanical families, which is one of the most complex identification challenges in Chinese materia medica. Common substitutes include: (1) Kalopanax septemlobus bark (Araliaceae, 刺楸), used in northeastern China; (2) Bombax malabarica / Bombax ceiba bark (Malvaceae, 木棉), used in Guangdong as 'Guang Hai Tong Pi' (广海桐皮); (3) Zanthoxylum ailanthoides bark (Rutaceae, 樗叶花椒), used in Fujian, Zhejiang, and Jiangsu. The authentic product (Erythrina variegata or E. arborescens bark) can be distinguished by its characteristic large nail-like spines on the outer surface, gray-brown color, dense yellowish lenticels, reddish-brown smooth inner surface, and distinctly fibrous, tough texture. The Bombax substitute tends to be thicker with different spine morphology. The Zanthoxylum substitute has a different aromatic odor characteristic of the Rutaceae family.

Educational content — always consult a qualified healthcare provider or TCM practitioner before using any herb.

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Hai Tong Pi

Non-toxic

The bark of Erythrina variegata contains multiple alkaloids, including erythraline, erysodine, erysotrine, erysovine, and hypaphorine. The Erythrina alkaloid family is known to possess curare-like neuromuscular blocking activity at high doses, particularly when the alkaloids are concentrated from seeds rather than bark. However, at standard oral decoction doses (6-15g of bark), these alkaloids are present in very low concentrations and are poorly absorbed through the gastrointestinal tract, making clinically significant toxicity unlikely. Classical Chinese sources (Hai Yao Ben Cao, Kai Bao Ben Cao) classify it as 'non-toxic' (无毒). No serious adverse reactions have been reported at prescribed doses. The seeds contain higher alkaloid concentrations than the bark and should not be confused with the medicinal bark.

Contraindications

Situations where Hai Tong Pi should not be used or requires extra caution

Caution

Blood deficiency (血虚) conditions. Classical sources consistently warn that those with Blood deficiency should not take Hai Tong Pi, as it is a Wind-Dampness dispelling herb that relies on sufficient Blood to function properly. Using it in Blood-deficient patients may worsen dryness and fail to address the root cause.

Caution

Blood deficiency generating internal Wind (血虚生风). When apparent Wind symptoms actually arise from Blood deficiency rather than external pathogenic factors, Hai Tong Pi's Wind-dispelling action is inappropriate and may aggravate the condition. As the Ben Cao Qiu Zhen states, if Wind arises from internal causes, this herb should not be recklessly used.

Caution

Blood deficiency with Heat from deficiency (血少火炽). When there is insufficient Blood combined with deficiency Fire, Hai Tong Pi's drying, Wind-dispersing nature may further deplete Yin and Blood, worsening the Heat signs.

Avoid

Known allergy to Erythrina species or related Fabaceae family plants. Individuals with hypersensitivity should avoid use.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Use with caution during pregnancy. Hai Tong Pi's Wind-dispelling and channel-opening properties, along with its ability to enter the Blood level and invigorate circulation, raise theoretical concerns about promoting unwanted uterine activity. The bark also contains Erythrina alkaloids, which have known neuromuscular and CNS effects. While no specific studies have been conducted on its reproductive toxicity, the combination of Blood-moving action and alkaloid content makes cautious avoidance the prudent approach. Consult a qualified practitioner before use during pregnancy.

Breastfeeding

No specific safety data exists for Hai Tong Pi use during breastfeeding. The bark contains Erythrina alkaloids (erythraline, erysodine, etc.) which have known CNS and neuromuscular effects. Whether these compounds transfer into breast milk at clinically relevant concentrations is unknown. Given this uncertainty, it is advisable to avoid use during breastfeeding or to use only under the supervision of a qualified practitioner who can weigh the clinical necessity against potential risk to the nursing infant.

Children

No specific pediatric dosage guidelines are established in classical or modern sources. Given the alkaloid content of the bark, use in children should be approached cautiously and only under qualified practitioner supervision. Dosage should be reduced proportionally based on age and body weight. External use (as a wash for skin conditions) may be more appropriate for children than internal use.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Hai Tong Pi

No well-documented pharmaceutical drug interactions have been established through clinical studies. However, theoretical caution is warranted in the following situations:

  • Neuromuscular blocking agents: Erythrina alkaloids have demonstrated curare-like neuromuscular blocking activity in pharmacological studies. Although this effect is minimal at standard oral doses of the bark, concurrent use with neuromuscular blocking drugs (used in anesthesia) should be avoided as a precaution.
  • CNS depressants and sedatives: Preclinical research has shown that Erythrina variegata bark extract has sedative and anxiolytic properties, and may inhibit monoamine oxidase (MAO). Concurrent use with sedatives, anxiolytics, or antidepressants (especially MAO inhibitors) may theoretically produce additive effects.
  • Potassium iodide: Some TCM sources caution against concurrent use with potassium iodide, though the pharmacological basis for this interaction is not well-documented.

Dietary Advice

Foods and dietary considerations when taking Hai Tong Pi

When taking Hai Tong Pi for Wind-Dampness conditions, avoid cold and raw foods that may generate or worsen Dampness, such as iced drinks, raw salads, and excessive dairy. Greasy, deep-fried foods should also be limited as they may impede the herb's Dampness-resolving action. Moderate consumption of mildly warming foods that support circulation is beneficial. If using the herb in a medicinal wine preparation, avoid mixing with other alcohol beyond the preparation itself.

Botanical Description

Physical characteristics and morphology of the Hai Tong Pi source plant

Erythrina variegata (Indian Coral Tree, Tiger's Claw) is a large, thorny, deciduous tree in the Fabaceae (legume) family that can grow up to 20 meters tall. The trunk and branches are covered with short, cone-shaped spines that shed after two to three years. The bark is pale gray-brown. Leaves are alternate, trifoliate (three leaflets), smooth, and bright green. The tree produces striking racemes of bright red to orange-red flowers, typically blooming in March, before the leaves fully emerge. The seed pods are bead-like and slightly curved, containing 1 to 8 spherical, dark red seeds.

The species thrives in strong light, high temperatures, and humid environments, growing well in fertile, well-drained sandy loam soils. It is commonly found near coastal streams, riverbanks, and parks throughout tropical and subtropical regions of East Asia, Southeast Asia, East Africa, and northern Australia. In China, it is found wild or cultivated as an ornamental street tree in provinces including Guangxi, Guangdong, Yunnan, Fujian, Zhejiang, Taiwan, Hubei, Hunan, Sichuan, and Guizhou.

A second species, Erythrina arborescens (Himalayan Coralbean), is also used as a source of Hai Tong Pi. It is a smaller tree that grows on mountain slopes and in grasslands, distributed mainly in Sichuan, Guizhou, and Yunnan.

Sourcing & Harvesting

Where Hai Tong Pi is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Can be collected year-round, but spring is preferred for easier bark stripping. Bark is typically harvested in summer and autumn after approximately 8 years of tree growth.

Primary growing regions

The primary producing regions are Guangxi, Yunnan, and Hubei provinces in southern China. The tree is also found across Guangdong, Fujian, Zhejiang, Taiwan, Hunan, Sichuan, and Guizhou. Sichuan province is also a notable commercial source. Due to the widespread distribution of Erythrina variegata in tropical and subtropical zones, there is no single strongly defined 'dao di' (terroir) region, though Guangxi and Yunnan material is generally considered standard.

Quality indicators

Good quality Hai Tong Pi bark comes in half-tubular or flat plate-shaped pieces, approximately 30-60 cm long and 1-2 mm thick. The outer surface should be gray-brown or gray-black with sparse longitudinal fissures and relatively dense yellowish lenticels. The most distinctive feature is the presence of large, thorn-like spines (nail-like prickles) on the outer bark surface, which is why it is also called 'Ding Tong Pi' (Nail Tong Bark). Pieces with more spines are considered better quality. The inner surface should be yellowish-brown to reddish-brown, smooth with fine longitudinal striations. The texture is hard yet tough, splitting easily lengthwise but difficult to break crosswise. The cross-section is yellowish-white to pale yellow and fibrous. It has a faint, slightly fragrant aroma and a bitter taste. Avoid pieces that are excessively thick, lack spines, or show signs of insect damage or mold.

Classical Texts

Key passages from the classical Chinese medical texts that describe Hai Tong Pi and its therapeutic uses

《海药本草》(Hai Yao Ben Cao, Materia Medica from Overseas)

主腰脚不遂，顽痹腿膝疼痛，霍乱，赤白泻痢，血痢，疥癣。

"Treats inability to use the lower back and legs, stubborn impediment pain of the legs and knees, cholera-like disorders, red and white dysentery, bloody dysentery, and scabies."

《开宝本草》(Kai Bao Ben Cao)

主霍乱中恶，赤白久痢，除甘匿、疥癣。牙齿虫痛，并煮服及含之。水浸洗目，除肤赤。

"Treats cholera and malign influences, chronic red and white dysentery, eliminates parasitic infestations and scabies. For worm-caused toothache, both decoct to drink and hold in the mouth. Soak in water to wash the eyes, to clear redness of the skin."

《本草纲目》(Ben Cao Gang Mu, Compendium of Materia Medica)

能行经络，达病所，又入血分及去风杀虫。

"It is able to move through the channels and collaterals, reaching the site of disease. It also enters the Blood level, dispels Wind, and kills parasites."

《本草求真》(Ben Cao Qiu Zhen)

海桐皮，能入肝经血分，祛风除湿，及行经络，以达病所。用者须审病自外至则可。若风自内成，未可妄用，须随症酌治可耳。

"Hai Tong Pi can enter the Liver channel at the Blood level, dispelling Wind and eliminating Dampness, and moving through the channels to reach the site of disease. Users must determine that the disease comes from external causes before applying it. If the Wind arises from internal causes, it should not be used recklessly; one must treat according to the pattern."

《日华子本草》(Ri Hua Zi Ben Cao)

治血脉麻痹疼痛，及煎洗目赤。

"Treats numbness and pain in the blood vessels, and can be decocted as a wash for red eyes."

Historical Context

The history and evolution of Hai Tong Pi's use in Chinese medicine over the centuries

Hai Tong Pi was first recorded in the Hai Yao Ben Cao (海药本草, Materia Medica from Overseas), compiled by Li Xun in the early 10th century during the Five Dynasties period. As its name suggests ('Sea Tong Bark'), the herb was originally associated with maritime trade routes and coastal regions. The Kai Bao Ben Cao (开宝本草, 973 CE, Song Dynasty) further systematized its description and expanded its recorded indications.

Li Shizhen, in the Ben Cao Gang Mu (本草纲目, 1578 CE, Ming Dynasty), provided the influential characterization that Hai Tong Pi "can move through the channels and collaterals, reaching the site of disease, and enters the Blood level to dispel Wind and kill parasites." This established its reputation as a herb that both guides therapeutic action to the affected area and works at a deeper Blood level. The Ben Cao Qiu Zhen (本草求真, Qing Dynasty) added the important clinical caution that it should only be used when the disease originates from external pathogenic factors, not from internal Wind due to Blood deficiency.

Notably, 'Hai Tong Pi' has long been a name applied to barks from multiple botanical sources in different regions of China. In the northeast, the bark of Kalopanax septemlobus (Araliaceae) was used under this name; in Guangdong, Bombax malabarica (Malvaceae/Bombacaceae) bark was used as 'Guang Hai Tong Pi'; and in Fujian and Zhejiang, bark from Zanthoxylum ailanthoides (Rutaceae) was substituted. Even the Qing imperial court pharmacy reportedly used the Rutaceae species. This complex history of regional substitution makes botanical authentication particularly important.

Modern Research

4 published studies investigating the pharmacological effects or clinical outcomes of Hai Tong Pi

1

Computational and in vitro study on cholinesterase inhibitory activity of E. variegata bark alkaloids for Alzheimer's disease (2021)

Jain SK et al., In Silico Pharmacology, 2021, 9(1):46

This study investigated the bark extract and fractions of Erythrina variegata for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), enzymes relevant to Alzheimer's disease. In vitro assays confirmed inhibitory activity, and computational docking identified erysotine and erythraline as key active alkaloids with favorable binding to these enzyme targets. The alkaloids were found to be non-carcinogenic and non-mutagenic in silico.

2

Anti-depressant activity of Erythrina variegata bark extract via monoamine oxidase regulation in mice (2020)

Upadhyay P et al., Journal of Ethnopharmacology, 2020, 249:112368

This preclinical study examined the ethanolic bark extract of E. variegata in mouse models of depression (chronic unpredictable mild stress). The extract showed significant anti-depressant-like activity and was found to inhibit both MAO-A and MAO-B enzymes in brain tissue. LC-MS analysis identified several alkaloids previously reported for CNS activity. The study supports the traditional use of the plant as a nervine sedative.

PubMed
3

Neuroprotective dimeric alkaloids from E. variegata bark (2021)

Tang YT, Wu J, Yu Y, Bao MF, Tan QG, Schinnerl J, Cai XH, Journal of Organic Chemistry, 2021, 86(19):13381-13387

Five new dimeric Erythrina alkaloids (erythrivarines J-N) were isolated from the bark of Erythrina variegata. These compounds displayed unique colored ring systems. Bioassay using HEI-OC-1 auditory cells revealed that erythrivarine N had neuroprotective properties against neomycin-induced cell damage, suggesting potential applications in preventing drug-induced hearing loss.

4

Review: Pharmacology, toxicity, and clinical trials of Erythrina genus plants (2023)

Frontiers in Pharmacology, 2023, 14:1281150

This comprehensive review spanning 1943-2023 summarized the pharmacological activities, toxicity data, and clinical trials for the Erythrina genus. It noted anti-inflammatory, analgesic, antimicrobial, and sedative properties across species. Toxicity studies in animal models indicated safety of plant extracts at higher doses, though some alkaloids demonstrated curare-like effects in isolated experiments. Only very limited human clinical trial data exists for any Erythrina species.

Research on individual TCM herbs is growing but still limited by Western clinical trial standards. These studies provide emerging evidence and should be considered alongside practitioner expertise.