Herb Bark (皮 pí / 树皮 shù pí)

Qin Pi

Ash bark · 秦皮

Fraxinus rhynchophylla Hance · Cortex Fraxini

Also known as: Cen Pi (岑皮), Chen Pi (梣皮)

Qin Pi (Ash bark) plant

Images shown are for educational purposes only

Ash bark is a cold, bitter herb traditionally used to address intestinal conditions involving inflammation and diarrhea, particularly when accompanied by mucus or blood in the stool. It is also well-known in Chinese medicine for soothing red, swollen, or painful eyes caused by excessive heat in the Liver. Its astringent quality helps firm up loose bowels and reduce abnormal vaginal discharge.

Category Heat-clearing herbs Herbs that clear Heat and dry Dampness (清热燥湿药)
Therapeutic focus Digestive Health Eye Health and Vision Women's Health Immune Support

TCM Properties

Temperature

Cold

Taste

Bitter (苦 kǔ), Astringent (涩 sè)

Channels entered

Liver, Gallbladder, Large Intestine

Parts used

Bark (皮 pí / 树皮 shù pí)

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What This Herb Does

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

Therapeutic focus

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

Digestive Health Eye Health and Vision Women's Health Immune Support

TCM Actions

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

Clears Heat and dries Dampness Astringes the Intestines and Stops Diarrhea Astringes to Stop Vaginal Discharge Clears Liver Heat and Brightens the Eyes

How these actions work

'Clears Heat and dries Dampness' means Qín Pí uses its cold, bitter nature to eliminate a combination of excess heat and accumulated moisture in the body, particularly in the digestive tract. In practice, this applies to conditions where the intestines are inflamed from damp-heat, such as dysentery with urgent, painful bowel movements and mucus or blood in the stool. It is especially valued as a key herb for damp-heat dysentery.

'Astringes the intestines and stops dysentery' refers to the herb's astringent taste, which gives it a firming, tightening quality that helps control diarrhea and dysentery. Unlike purely bitter-cold herbs that only drain heat, Qín Pí simultaneously clears the pathogenic heat and tightens the bowels to reduce excessive discharge. This dual action makes it uniquely suited for prolonged or stubborn cases of hot dysentery.

'Stops leukorrhea' extends the same astringent and heat-clearing mechanism to abnormal vaginal discharge caused by damp-heat flowing downward. When the discharge is yellow, foul-smelling, and accompanied by signs of heat, Qín Pí's cold and astringent properties help both clear the underlying heat and reduce the discharge itself.

'Clears Liver Heat and brightens the eyes' means Qín Pí enters the Liver channel and can drain excess heat that has accumulated there, since the Liver "opens to the eyes" in TCM theory. This makes it useful for red, swollen, painful eyes, excessive tearing, and corneal opacities (what classical texts call "screen and membrane over the eyes"). It can be taken internally or used as an external eye wash, and has been a go-to eye remedy since the earliest herbal texts.

Patterns Addressed

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

Why Qin Pi addresses this pattern

In Large Intestine Damp-Heat, pathogenic heat and moisture accumulate in the large intestine, disrupting its function of transporting and descending waste. This produces dysentery with urgent straining (tenesmus), abdominal pain, and bloody mucoid stools. Qín Pí directly addresses this pattern through its cold nature and bitter taste, which clear heat and dry dampness in the large intestine (one of its primary channel entries). Crucially, its astringent quality simultaneously firms the bowel wall to reduce the uncontrolled discharge of pus and blood, offering something that purely draining herbs like Huáng Lián cannot. Classical sources describe this as having the advantage of being "astringent without trapping the pathogen" (涩而不敛邪).

A practitioner would look for one or more of these signs

Dysentery

Bloody mucoid stools with tenesmus

Diarrhea

Damp-heat diarrhea with urgency

Abdominal Pain

Abdominal cramping with burning sensation

Commonly Used For

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

Arises from: Large Intestine Dryness

TCM Interpretation

In TCM, dysentery is understood as the result of toxic damp-heat invading the large intestine, often through contaminated food or drink. The heat and dampness damage the intestinal lining and disrupt the normal downward movement of waste, causing the characteristic combination of urgent straining (tenesmus), abdominal pain, and bloody mucoid stools. When heat toxin penetrates deep into the blood level of the intestines, bloody discharge predominates. The Liver and Gallbladder channels may also be involved, as the Liver governs the smooth flow of Qi throughout the body, including the digestive tract.

Why Qin Pi Helps

Qín Pí is uniquely suited for dysentery because it combines two actions that most single herbs cannot: it clears heat and dries dampness (addressing the root cause) while simultaneously astringing the intestines (controlling the symptoms). Its cold nature directly counters the heat toxin in the bowel, and its bitter taste dries the accumulated dampness. The astringent quality firms the intestinal wall to stop the leakage of pus and blood without trapping the pathogen inside. This is why it appears in the classical formula Bái Tóu Wēng Tāng from the Shāng Hán Lùn, where it complements the powerful heat-clearing action of Bái Tóu Wēng, Huáng Lián, and Huáng Bǎi by adding its unique astringent quality to consolidate the bowels.

Also commonly used for

Diarrhea

Acute and chronic damp-heat diarrhea

Leukorrhea

Yellow vaginal discharge from damp-heat

Chronic Bronchitis

Cough and wheezing from Lung heat

Ulcerative Colitis

Inflammatory bowel conditions with damp-heat presentation

Psoriasis

Used externally as a wash for skin lesions

Styes

Paired with Dà Huáng for eye sty with constipation

Herb Properties

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

Temperature

Cold

Taste

Bitter (苦 kǔ), Astringent (涩 sè)

Channels Entered

Liver Gallbladder Large Intestine

Parts Used

Bark (皮 pí / 树皮 shù pí)

Dosage & Preparation

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

Standard dosage

6-12g

Maximum dosage

Up to 15-20g in severe acute damp-heat dysentery, under practitioner supervision. The standard upper limit is 12g for routine use.

Dosage notes

Use the lower range (6-9g) for clearing Liver heat and treating eye conditions, as the Liver-clearing effect does not require high doses. Use the upper range (9-12g) for damp-heat dysentery and leukorrhea, where the astringent and heat-clearing actions need to be stronger. For external eye washes, a small amount (3-6g) can be decocted in water and used to bathe the eyes after cooling and straining. Classical formulas often use around 9g (three liang in the Bai Tou Weng Tang of the Shang Han Lun, where liang is calculated at Han dynasty weight).

Preparation

No special decoction handling required. Qin Pi is simply decocted with other herbs in the standard manner. For external eye-wash use, the decoction should be carefully strained through fine cloth to remove any particulate matter before application.

Processing Methods

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

Processing method

The raw bark is cleaned, soaked until moistened through, then sliced into pieces or segments and dried in the sun. No additional processing agents are used.

How it changes properties

This is the standard preparation form rather than a true processing transformation. It does not significantly alter the herb's cold temperature, bitter-astringent taste, or primary actions. The cutting simply makes it suitable for decoction.

When to use this form

This is the default clinical form of Qín Pí used for all standard indications. There are no widely established honey-fried, wine-processed, or charcoal-processed forms in routine clinical use.

Common Herb Pairs

These ingredients are traditionally combined with Qin Pi for enhanced therapeutic effect

Bai Tou Weng
Bai Tou Weng 1:1.5 (Bái Tóu Wēng 15g : Qín Pí 12g)

Bái Tóu Wēng powerfully clears heat-toxin and cools the blood in the intestines, while Qín Pí adds astringent action to consolidate the bowels and prevent further loss of blood and fluids. Together they address both the root cause (heat toxin) and the symptom (bloody diarrhea) of hot dysentery.

When to use: Heat-toxin dysentery with bloody mucoid stools, tenesmus, and abdominal pain. This is the core pairing in Bái Tóu Wēng Tāng.

Huang Lian
Huang Lian 1:1 (Qín Pí 6-12g : Huáng Lián 6-12g)

Both herbs are bitter and cold, but Huáng Lián is stronger at clearing heat and drying dampness in the intestines, while Qín Pí adds its unique astringent quality. Together they provide powerful damp-heat clearing with intestinal firming, making the combination more effective for persistent dysentery than either herb alone.

When to use: Damp-heat dysentery or damp-heat diarrhea with urgent straining. Also used together as an eye wash or internal formula for acute red, painful eyes.

Mu Dan Pi
Mu Dan Pi 3:2 (Qín Pí 9g : Mǔ Dān Pí 6g)

Mǔ Dān Pí cools Blood and clears heat from the blood level, while Qín Pí clears damp-heat and astringes discharge. Together they address damp-heat vaginal discharge complicated by blood-level heat, covering both the dampness and blood aspects of the pathology.

When to use: Damp-heat leukorrhea with blood-tinged discharge, or heavy menstrual bleeding from heat. A classical combination from the Ben Cao Hui Yan.

Huang Qi
Huang Qi 1:1 (Qín Pí 12g : Huáng Bǎi 12g)

Both herbs clear heat from the lower body (Lower Jiāo), but Huáng Bǎi is stronger at draining Kidney Fire and drying dampness, while Qín Pí adds Liver channel clearing and astringent action. Together they provide comprehensive lower-body heat clearing with bowel consolidation.

When to use: Hot dysentery with tenesmus, or damp-heat leukorrhea. Both appear together in Bái Tóu Wēng Tāng.

Key Formulas

These well-known formulas feature Qin Pi in a prominent role

Bai Tou Weng Tang 白头翁汤 Assistant

This is the definitive formula featuring Qín Pí, from the Shāng Hán Lùn. It treats heat-toxin dysentery with bloody stools, and Qín Pí serves as Assistant, contributing its unique astringent quality to consolidate the bowels while the other three herbs (Bái Tóu Wēng, Huáng Lián, Huáng Bǎi) clear heat-toxin. This formula perfectly showcases both of Qín Pí's core actions: clearing damp-heat and astringing the intestines.

Comparable Ingredients

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

Huang Lian
Qin Pi vs Huang Lian

Both Qín Pí and Huáng Lián are bitter and cold, and both treat hot dysentery and red, painful eyes. However, Huáng Lián has much stronger heat-clearing power, can also drain Heart Fire and stop vomiting, and has a broader range of clinical applications. Qín Pí's distinguishing advantage is its astringent quality, which directly firms the bowels and stops discharge, making it the better choice when damp-heat leukorrhea is present or when the dysentery has a lingering, draining quality that needs tightening.

Ku Shen
Qin Pi vs Ku Shen

Both Qín Pí and Kǔ Shēn clear heat and dry dampness, and both treat dysentery and leukorrhea. However, Kǔ Shēn is stronger at killing parasites and treating skin conditions (eczema, itching), and also promotes urination. Qín Pí is more specifically focused on the intestines and eyes, and its astringent quality makes it better for consolidating the bowels in prolonged dysentery.

Huang Qi
Qin Pi vs Huang Qi

Both clear heat from the lower body and treat damp-heat dysentery and leukorrhea. Huáng Bǎi is more strongly associated with draining Kidney Fire and treating bone-steaming tidal fever from Yin Deficiency, actions that Qín Pí does not share. Qín Pí is preferred when the eyes are also affected by Liver Heat, and when an astringent action is needed to consolidate the bowels.

Identity & Adulterants

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

Qin Pi can be confused with bark from other Fraxinus species not listed in the Pharmacopoeia, such as F. mandshurica (水曲柳) or F. bungeana (小叶白蜡树), which have different chemical profiles and may lack adequate esculin content. The bark of Chun Pi (椿皮, Ailanthus bark from Ailanthus altissima) is sometimes substituted, as both are tree barks used for damp-heat dysentery and leukorrhea, but they come from entirely different plant families and have different properties. Authentication can be confirmed by the water-soak fluorescence test: genuine Qin Pi produces a bright blue-green fluorescence under daylight or UV light (365 nm) when soaked in water, due to its esculin and esculetin content. Material that fails to produce this fluorescence should be rejected.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Qin Pi

Non-toxic

Qin Pi is classified as non-toxic (无毒) in classical literature and the Chinese Pharmacopoeia. No reports of serious adverse reactions at standard dosage (6-12g) have been documented. Its primary active compounds are coumarins (esculin and esculetin), which have a structural similarity to dicoumarol and possess mild anticoagulant properties, but at standard oral doses this effect is clinically insignificant. Mild gastrointestinal discomfort (nausea, cramping) may occur with excessive dosage, particularly in those with weak digestion. The coumarin compound esculin has very low oral bioavailability (approximately 0.6%), further limiting systemic toxicity risk.

Contraindications

Situations where Qin Pi should not be used or requires extra caution

Avoid

Spleen and Stomach deficiency-cold (脾胃虚寒). Qin Pi is bitter, astringent, and cold in nature. Using it in people with cold, weak digestion can worsen symptoms like loose stools, poor appetite, and abdominal pain from cold. The Ben Jing Feng Yuan specifically states it is prohibited for those with a weak stomach and poor appetite.

Caution

Diarrhea or dysentery caused by Spleen deficiency rather than damp-heat. Because Qin Pi's cold nature can further injure Spleen Yang, it should only be used for diarrhea with clear signs of heat (burning sensation, urgency, foul odor, yellow tongue coating), not for watery stools from cold deficiency.

Caution

Vaginal discharge (leukorrhea) from Spleen deficiency without damp-heat signs. Qin Pi is appropriate for yellow, foul-smelling discharge from damp-heat, but not for clear, thin, odorless discharge from Yang deficiency.

Avoid

Known allergy or hypersensitivity to Fraxinus bark or its coumarin constituents (esculin, esculetin).

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Classical sources list Qin Pi in formulas that are explicitly noted as contraindicated during pregnancy (e.g., a formula for styes combining Qin Pi with Da Huang carries the note "pregnant women should not take this"). While Qin Pi itself is not traditionally classified as a strong pregnancy-prohibited herb, its cold and bitter nature can potentially harm fetal development by injuring Spleen Yang, and its coumarin constituents have mild anticoagulant properties. It should be avoided during pregnancy unless specifically prescribed by an experienced practitioner.

Breastfeeding

No specific classical or modern contraindications for use during breastfeeding have been documented. However, the coumarin compounds in Qin Pi (esculin, esculetin) may transfer into breast milk, and its cold, bitter nature could theoretically affect the infant's digestion. Use during breastfeeding should only occur under practitioner supervision, at the lowest effective dose, and for short durations.

Children

Qin Pi has a long history of pediatric use in classical literature, particularly for childhood convulsions (小儿惊痫) with fever and for bathing feverish children. The Ming Yi Bie Lu specifically mentions treating childhood epilepsy and fever. Dosage should be reduced proportionally by body weight, typically one-third to one-half of the adult dose for children over 3 years old. Because of its cold and bitter nature, it should be used with particular caution in children with weak digestion, and treatment duration should be kept short.

Drug Interactions

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

Anticoagulant and antiplatelet medications (warfarin, heparin, aspirin, clopidogrel): The coumarin compounds in Qin Pi (esculin and esculetin) are structurally related to dicoumarol and possess mild anticoagulant activity. Although the effect at standard oral doses is likely minimal due to low oral bioavailability, concurrent use with blood-thinning medications warrants caution and monitoring.

Vitamin B1 (thiamine): Some sources indicate that Qin Pi's tannin content may interfere with vitamin B1 absorption. Patients taking thiamine supplements should separate administration times.

CYP450 enzyme substrates: Esculetin has been shown in laboratory studies to modulate certain cytochrome P450 enzymes. While clinical significance at standard herbal doses is unclear, caution is advisable when combining with drugs that have a narrow therapeutic index and are metabolized by CYP450 pathways.

Dietary Advice

Foods and dietary considerations when taking Qin Pi

Because Qin Pi is cold and bitter, it works best when the diet avoids excessively cold or raw foods that could further burden the Spleen. Warm, easily digestible foods are preferable during treatment. When used for damp-heat dysentery, avoid greasy, fried, and spicy foods that may aggravate the condition. Avoid vinegar and sour foods in excess, as these may counteract its astringent action on the intestines.

Botanical Description

Physical characteristics and morphology of the Qin Pi source plant

Qin Pi comes from several species of ash tree (Fraxinus) in the olive family (Oleaceae). The primary source species, Fraxinus rhynchophylla Hance (苦枥白蜡树, "bitter oak white wax tree"), is a large deciduous tree growing up to 25 meters tall. It has grey-brown bark that is smooth in younger trees and develops rough, scaly fissures with age. The leaves are large compound (pinnate) leaves with 4 to 8 pairs of lance-shaped, toothed leaflets. Flowers are small, greenish, borne in clusters, and wind-pollinated, appearing around May to June. The tree produces single-seeded winged fruits (samaras). It grows naturally on mountain slopes, along rivers, and at forest edges at elevations of 800 to 1600 meters.

Other officially recognized source species include F. chinensis Roxb. (白蜡树, the common Chinese ash, also used for cultivating wax insects), F. szaboana Lingelsh. (尖叶白蜡树), and F. stylosa Lingelsh. (宿柱白蜡树). The medicinal part is the dried branch bark or trunk bark, harvested after the tree trunk reaches at least 15 cm in diameter, typically after 5 to 8 years of growth.

Sourcing & Harvesting

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

Harvesting season

Spring and autumn. The bark is stripped from branches or trunks after 5-8 years of growth (trunk diameter at least 15 cm), then sun-dried.

Primary growing regions

The traditional daodi (道地) production area for Qin Pi is the Qinling Mountain region of Shaanxi province, which is the origin of the herb's name ("Qin" referring to the ancient Qin state in that area). Key production counties include Taibai, Fengxian, and Luonan in Shaanxi, as well as neighboring Tianshui and Longnan in Gansu province. Other major production regions include Liaoning, Jilin, Heilongjiang (northeast China), Hebei, Henan, Inner Mongolia, Shanxi, and Sichuan. Northeast China (particularly Liaoning and Jilin) produces significant commercial quantities. The Qinling Mountain material is traditionally considered the highest quality.

Quality indicators

Good quality branch bark (枝皮) comes in rolled tubes or trough shapes, 10-60 cm long and 1.5-3 mm thick. The outer surface should show a grey-white to grey-brown color with visible grey-white lenticel dots and fine diagonal wrinkles. The inner surface should be yellowish-white or light brown and smooth. The texture should be hard and brittle with a fibrous, yellowish-white cross-section. Good quality trunk bark (干皮) is thicker (3-6 mm), with a grey-brown outer surface showing cracked fissures and reddish-brown lenticels. The key quality test is soaking in water: authentic Qin Pi produces a distinctive blue-green (碧蓝色) fluorescence visible in daylight, caused by its esculin content. The taste should be distinctly bitter. Avoid material that lacks the characteristic fluorescence, is excessively dark, or tastes bland.

Classical Texts

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

Shen Nong Ben Cao Jing (《神农本草经》)

Chinese: 主风寒湿痹，洗洗寒气，除热，目中青翳白膜。

English: "It treats wind-cold-damp impediment, chilly sensations of the skin, eliminates heat, and clears greenish cataracts and white films of the eye."

Ming Yi Bie Lu (《名医别录》)

Chinese: 疗男子少精，妇人带下，小儿痫，身热，可作洗目汤。

English: "It treats scanty essence in men, vaginal discharge in women, and childhood convulsions with fever. It can be made into an eye-wash decoction."

Ben Cao Gang Mu (《本草纲目》, Li Shizhen)

Chinese: 秦皮，治目病，惊癎，取其平木也，治下痢崩带，取其收涩也。又能治男子少精，取其涩而补也。此药乃惊、癎、崩、痢所宜，而人止知其治目一节，几于废弃，良为可惋。

English: "Qin Pi treats eye diseases and fright-epilepsy by calming the Liver (Wood); it treats dysentery and abnormal discharge through its astringent action; and it treats scanty essence in men through its binding and supplementing quality. This herb is suitable for convulsions, epilepsy, flooding, and dysentery, yet people only know of its use for eye conditions, nearly abandoning it — truly a pity."

Ben Cao Hui Yan (《本草汇言》)

Chinese: 秦皮，味苦性涩而坚，能收敛走散之精气。故仲景用白头翁汤，以此治下焦虚热而利者，取苦以涩之之意也。

English: "Qin Pi is bitter in taste, astringent and firm in nature, able to collect and bind the leaking essence-Qi. Therefore Zhang Zhongjing used it in Bai Tou Weng Tang to treat diarrhea from deficiency-heat of the lower burner, employing bitterness to astringe."

Historical Context

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

Qin Pi was first recorded in the Shen Nong Ben Cao Jing (Divine Farmer's Classic of Materia Medica), placing it among the oldest documented Chinese medicinal substances, with over 2,000 years of continuous use. Its original name was "Cen Pi" (岑皮) or "Chen Pi" (梣皮), and alternative names include "Qin Bai Pi" (秦白皮) and "La Shu Pi" (蜡树皮, "wax tree bark"). The name "Qin" is believed to reference the ancient Qin state region (modern Shaanxi) where the herb was originally sourced.

A distinctive identifying feature known since ancient times is that when the bark is soaked in water, it produces a striking blue-green (碧) fluorescence visible in sunlight. The Ben Cao Chong Yuan describes this: "soak the bark in water and the color turns a blue-green; when applied to paper and viewed, it also shows this blue-green color — this confirms its authenticity." This characteristic, caused by the coumarin compound esculin, was one of the earliest known natural fluorescence phenomena and remains used in pharmacognostic identification today.

Li Shizhen lamented in the Ben Cao Gang Mu that this herb had become nearly abandoned because practitioners only remembered its use for eye conditions, forgetting its broader applications for dysentery, convulsions, and vaginal discharge. Zhang Zhongjing's famous Bai Tou Weng Tang (Pulsatilla Decoction) from the Shang Han Lun, used for hot dysentery with blood, prominently includes Qin Pi as one of its four ingredients alongside Bai Tou Weng, Huang Lian, and Huang Bai. The white wax (白蜡) produced by insects raised on these ash trees also has a long history in Chinese medicine and industry, traditionally attributed to the influence of the Tang-dynasty physician Sun Simiao.

Modern Research

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

1

Pharmacological activities of esculin and esculetin: A review (2023)

Cai T, Cai B. Medicine. 2023;102(40):e35306.

This review systematically evaluated the pharmacological activities of esculin and esculetin, the two main coumarin compounds in Qin Pi (Cortex Fraxini). In laboratory and animal studies, both compounds demonstrated antioxidant, anti-inflammatory, antibacterial, anti-tumor, antidiabetic, and immunomodulatory effects. Their anti-inflammatory action works primarily by blocking the NF-kB and MAPK inflammatory signaling pathways. The authors concluded that both compounds are promising candidates for further clinical development.

DOI
2

Esculetin from Fraxinus rhynchophylla attenuates atopic skin inflammation (Animal study, 2018)

Jeong NH, Yang EJ, Jin M, et al. International Immunopharmacology. 2018;59:209-216.

In a mouse model of atopic dermatitis (eczema-like skin inflammation), oral administration of esculetin (a key active compound from Qin Pi bark) significantly reduced ear swelling, scratching, and inflammatory markers including IgE, IgG2a, and histamine levels. It also suppressed multiple inflammatory cytokines (TNF-alpha, IFN-gamma, IL-4, IL-13, IL-17) in skin tissue, suggesting potential for treating allergic skin conditions.

PubMed
3

Antioxidant and anti-inflammatory effects of esculin and esculetin (Review, 2024)

Published in Experimental and Therapeutic Medicine. 2024. PMC11046185.

This systematic review examined how esculin and esculetin exert their antioxidant effects by promoting endogenous antioxidant enzymes (SOD, glutathione peroxidase, glutathione reductase) through the Nrf2 signaling pathway. Their anti-inflammatory effects involve inhibition of the NF-kB and MAPK pathways, reducing levels of pro-inflammatory factors like TNF-alpha, IL-1 beta, and IL-6. The authors suggested both compounds show promise for treating conditions associated with oxidative stress and inflammation, such as ulcerative colitis and acute organ injury.

4

Comparative Studies of Fraxinus Species: Phytochemical Analysis and Anti-Lipase Enzyme Activity (2020)

Published in Plants (Basel). 2020;9(4):534.

This study compared five Korean Fraxinus species used as sources for Qin Pi, analyzing their microscopic features, chemical composition, and potential anti-obesity activity. The bark extracts showed lipase-inhibiting activity, with certain isolated compounds (ligstroside, calceolarioside B) showing over 55% lipase inhibition at 100 micromolar concentration, suggesting potential applications for managing fat absorption.

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.