Pi Pa Ye
StarEriobotrya japonica
Traditionally used for
- Cough & breathing
- Digestion
Cautions & contraindications
- Diabetes
☯ TCM Properties
Transforms Phlegm, clears Lung Heat, descends Lung Qi and stops coughing; Harmonizes the Stomach, clears Stomach Heat and descends Stomach Qi
Traditional Chinese Uses
Pi Pa Ye (loquat leaf) is a cooling, bitter herb primarily used to descend rebellious Lung and Stomach Qi. For the Lungs, it clears heat, transforms phlegm, and relieves cough — particularly dry or heat-type coughs. For the Stomach, it settles upward-moving Qi to calm nausea, vomiting, and hiccup. Its descending and moistening properties make it especially helpful in hot, dry conditions.
Western Herbalism Properties
Pharmacological Effects
- Antiinflammatory: Ethanolic extract inhibited carrageenin paw edema in rats.
- Antidiabetic: Oral eriobotryanoside C (200 mg/kg) showed antidiabetic activity in mice.
Source: Zhu YP. Chinese Materia Medica: Chemistry, Pharmacology and Applications. Harwood Academic, 1998, p. 508.
Relationships
Full-screen graph →Click a node for details · double-click to expand it · Ctrl/⌘ + scroll or two fingers to zoom and pan.
Gallery
Botanical Description
Eriobotrya japonica is an evergreen tree or large shrub reaching 5-10 m tall. Leaves are large, elliptic to oblong-lanceolate, 15-30 cm long, dark glossy green and leathery above, with a densely woolly (rusty) underside and prominent veins. Small, fragrant, white flowers are borne in erect panicles in autumn. Fruits (loquats) are oval to pear-shaped, 3-5 cm long, yellow-orange, with sweet or slightly acidic flesh surrounding 1-5 large, dark seeds. In TCM, the dried leaf with the hairs brushed off (Pi Pa Ye) is used.
Hillsides, forest margins, and cultivated gardens; native to the mountains of central China, widely cultivated throughout subtropical and mild temperate regions worldwide for its fruit.
Eriobotrya japonica is widely cultivated throughout subtropical regions and has naturalized in many areas. While native to China, it is not threatened. No conservation concerns.
Active Constituents
Ursolic acid
Pentacyclic triterpene acid (ursane type)Concentration: The predominant triterpene acid of the leaf; seven triterpene acids are routinely quantified together by HPLC as the basis of leaf quality control
Anti-inflammatory, antioxidant and insulin-sensitising in preclinical models, and the constituent most often credited with the leaf's activity in bronchitis, skin disorders and metabolic disease. This is a leaf constituent — the triterpene profile of the leaf differs from that of the fruit and flower.
Oleanolic acid
Pentacyclic triterpene acid (oleanane type)Concentration: Second major triterpene acid of the leaf, isomeric with ursolic acid and co-assayed with it
Shares the anti-inflammatory and hepatoprotective activity of ursolic acid. Total leaf triterpene acid content varies substantially with season and provenance, so the delivered dose from a decoction is not fixed.
Corosolic acid (2-alpha-hydroxyursolic acid)
Pentacyclic triterpene acidConcentration: Minor triterpene acid of the leaf, among the seven quantified in pharmacognostic assays
The best-studied hypoglycaemic triterpene of the leaf, promoting glucose uptake in cell and rodent models. It is the constituent behind the leaf's Kampo and folk use in diabetes and the reason a hypoglycaemic drug interaction has to be considered.
Amygdalin
Cyanogenic glycosideConcentration: Present in the leaf, but at far lower levels than in the seed; quantified figures in the literature are for seed (mean 5900 mg/kg amygdalin, 410 mg/kg total cyanide) and flower (1.23-1.56 mg/g), not for leaf
Hydrolysed by beta-glucosidase to prunasin, mandelonitrile and ultimately hydrogen cyanide, which is the origin of the cyanide concern attached to this plant. It also contributes to the mild antitussive effect claimed for the drug. The safety-relevant point for practitioners is that the plant part matters: the exceedances of the acute reference dose for cyanide reported in the literature were in powdered loquat seed, and the leaf infusion carries a low cyanide risk by comparison. Do not carry seed figures across to the leaf.
Nerolidol sesquiterpene glycosides
Sesquiterpene glycosideConcentration: A characteristic leaf constituent group; four were isolated and structurally elucidated from loquat leaf, one of them new
Improved palmitic-acid-induced insulin resistance and reduced lipid accumulation in HepG2 hepatocytes through AMPK signalling. Cell-model evidence only.
Chlorogenic acid and related caffeoylquinic acids
Hydroxycinnamic acid ester (phenylpropanoid)Concentration: Major phenolic fraction of the leaf aqueous extract
Antioxidant and alpha-glucosidase-inhibiting; the phenolic fraction accounts for much of the leaf water extract's antidiabetic activity in rodent models.
Flavonol glycosides (quercetin and kaempferol glycosides)
Flavonoid glycosideConcentration: Numerous individual glycosides reported; the leaf's total flavonoid content varies with cultivar and harvest
Antioxidant and anti-inflammatory. Part of the structurally diverse flavonoid and phenolic set catalogued for the leaf and linked to its antidiabetic potential.
Megastigmane glycosides
Norisoprenoid (megastigmane) glycosideConcentration: A minor but characteristic leaf constituent class among the 164 compounds catalogued from Eriobotrya japonica leaf
Reported with antioxidant and mild anti-inflammatory activity. Chemotaxonomically useful for confirming leaf identity.
⚠ Drug Interactions
Raw unbrushed loquat leaf (trichomes retained) supplied in place of processed Pi Pa Ye
The underside of the loquat leaf carries dense trichomes. Retained in a decoction or powder they cause intense mechanical irritation of the throat and respiratory tract, provoking severe coughing and laryngeal oedema — the opposite of the effect the herb is prescribed for. Brushing off the hairs is therefore a mandatory processing step, not a cosmetic one, and is recorded as such in the classical prescriptions. Poorly processed or coarsely cut material can retain them.
Clinical note: Inspect the cut herb: the abaxial surface should be free of rust-coloured felted hairs. Decoct in a cloth bag or strain through fine mesh if there is any doubt. Honey-roasted Pi Pa Ye is the usual choice for cough and raw Pi Pa Ye for vomiting; both must be de-haired first.
Insulin, sulfonylureas, metformin and other glucose-lowering drugs
Loquat leaf aqueous extract lowered blood glucose and improved lipid profile in diabetic rodent models, and its triterpene acids (notably corosolic acid) and phenolics have documented glucose-lowering activity in cell and animal systems. The evidence is preclinical: a PubMed search for randomised or controlled clinical trials of Eriobotrya japonica returns no results, so there is no human pharmacokinetic or pharmacodynamic study to size the effect. The direction of effect is nonetheless consistent and the leaf is used for diabetes in Kampo and folk practice.
Clinical note: In a patient on glucose-lowering therapy who starts Pi Pa Ye at therapeutic doses, ask for home glucose monitoring for the first two weeks and warn about hypoglycaemia symptoms. The risk is greatest with insulin and sulfonylureas.
Other cyanogenic herbs (Prunus armeniaca seed, Ku Xing Ren; Prunus persica seed, Tao Ren)
Pi Pa Ye and the bitter apricot and peach kernels are all amygdalin-bearing Rosaceae drugs and are routinely combined in Lung formulas, so their cyanogenic glycosides add. The load from loquat leaf is small — the documented cyanide exceedances involve loquat seed and apricot kernel, not loquat leaf — but the kernels are the dominant contributor and the leaf adds to them rather than offsetting them.
Clinical note: The practical control is the apricot or peach kernel dose, which should be kept within pharmacopoeial limits and processed as directed; the leaf does not need separate restriction. Do not substitute loquat seed or kernel for loquat leaf under the name Pi Pa Ye.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 6–10 g | daily | — | adult | 中国药典 2020年版 一部 【枇杷叶】【用法与用量】6～10g。 — Chinese Pharmacopoeia 2020, Vol. I. Wrap in cloth (bao jian) to remove hairs; honey-fried for cough, raw for stomach heat. |
Evidence Tier
Moderate evidence · 4 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
4
1 verified · 3 unverified
Show 4 studies
- Loquat (Eriobotrya japonica (Thunb) Lindl.): Evaluation of nutritional value, polyphenol composition, antidiabetic effect, and toxicity of leaf aqueous extract
- Acute and Subacute Oral Toxicity Evaluation of Eriobotrya japonica Leaf Triterpene Acids in ICR Mice
- Four sesquiterpene glycosides from loquat (Eriobotrya japonica) leaf ameliorates palmitic acid-induced insulin resistance and lipid accumulation in HepG2 Cells via AMPK signaling pathway
- Long term administration of loquat leaves and their major component, ursolic acid, attenuated endogenous amyloid-β burden and memory impairment
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Loquat (Eriobotrya japonica (Thunb) Lindl.): Evaluation of nutritional value, polyphenol composition, antidiabetic effect, and toxicity of leaf aqueous extract
Characterised the nutritional and polyphenol composition of Moroccan loquat leaf and tested the aqueous leaf extract for antidiabetic and antihyperlipidaemic activity and oral toxicity in rodents. The extract lowered glucose and improved lipids without acute oral toxicity at the doses tested. This is the plant part in question — the leaf — but the evidence is animal, not human.
Acute and Subacute Oral Toxicity Evaluation of Eriobotrya japonica Leaf Triterpene Acids in ICR Mice
Single doses of 0.30 to 3.00 g/kg and 28 daily doses of 150, 300 and 600 mg/kg of loquat leaf triterpene acids in ICR mice. No mortality at any dose, so the acute oral LD50 exceeds 3.00 g/kg; only transient piloerection at the top acute dose, and no organ toxicity, haematological or histopathological change on repeat dosing. Body weight fell at 600 mg/kg, consistent with the fraction's known anti-obesity effect. It supports a wide margin for the triterpene fraction specifically, which is not the same as a safety statement for whole-leaf decoction.
Four sesquiterpene glycosides from loquat (Eriobotrya japonica) leaf ameliorates palmitic acid-induced insulin resistance and lipid accumulation in HepG2 Cells via AMPK signaling pathway
Isolated four nerolidol sesquiterpene glycosides from loquat leaf, one of them new, and showed that they reduced palmitic-acid-induced insulin resistance and lipid accumulation in HepG2 hepatocytes via AMPK signalling. A single preclinical cell study; it identifies constituents and a plausible mechanism, not a clinical effect.
Long term administration of loquat leaves and their major component, ursolic acid, attenuated endogenous amyloid-β burden and memory impairment
Long-term dietary loquat leaf, and ursolic acid alone, reduced endogenous amyloid-beta burden and memory impairment in a mouse model. Relevant here only as evidence that ursolic acid is the leaf's dominant bioactive triterpene and is systemically absorbed; it has no bearing on the Lung and Stomach indications the drug is prescribed for.
⚠ Safety & Contraindications
- Diabetes
Contraindications
Its use is prohibited in patients with vomiting due to stomach cold or coughs due to wind-cold.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 282–289.
Historical Texts
Ming Yi Bie Lu (Miscellaneous Records of Famous Physicians)
attributed to Tao Hongjing, c. 500 CEDian Nan Ben Cao (Materia Medica of Southern Yunnan), Lan Mao
Ming dynasty, 15th centuryBen Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1596Yi Zong Jin Jian (Golden Mirror of the Medical Tradition), imperial compilation
Qing dynasty, 1742References
- Zhu, Xu; Wang, Lin; Zhao, Tie; Jiang, Qinghua. Traditional uses, phytochemistry, pharmacology, and toxicity of Eriobotrya japonica leaves: A summary . Journal of Ethnopharmacology (2022) [DOI]
- Kim, Min Hee; Yeon, Sang Won; Ryu, Se Hwan; Lee, Hak Hyun; Turk, Ayman; Jeong, So Yeong; Kim, Young Jun; Lee, Ki Yong; Hwang, Bang Yeon; Lee, Mi Kyeong. Structural Diversity and Anti-Diabetic Potential of Flavonoids and Phenolic Compounds in Eriobotrya japonica Leaves . Molecules (2025) [DOI]
- Tan, Hui; Sonam, Tamrakar; Shimizu, Kuniyoshi. The Potential of Triterpenoids from Loquat Leaves (Eriobotrya japonica) for Prevention and Treatment of Skin Disorder . International Journal of Molecular Sciences (2017) [DOI]
- Li, E N; Luo, J G; Kong, L Y. Qualitative and quantitative determination of seven triterpene acids in Eriobotrya japonica Lindl. by high-performance liquid chromatography with photodiode array detection and mass spectrometry . Phytochemical Analysis (2009) [DOI]
- Tanaka, Tomoya; Kimura, Keisuke; Kan, Kimiko; Katori, Yoshiko; Michishita, Kumi; Nakano, Hisako; Sasamoto, Takeo. Quantification of amygdalin, prunasin, total cyanide and free cyanide in powdered loquat seeds . Food Additives & Contaminants: Part A (2020) [DOI]
- Zhang, Weiye; Zhang, Zhubin; Bian, Ziwen; Zuo, Qi; Quan, Xue; Gong, Jiahao; Ju, Bingling; Feng, Liang; Jia, Xiaobin; Yang, Bing. Processing-induced detoxification of toxic Traditional Chinese Medicines: a systematic review of attenuation mechanisms at physical, chemical, and in vivo levels . Chinese Medicine (2026) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
📝 Notes
Public notes from the community and your own private notes on Pi Pa Ye.
No notes yet.