San Cha Ku

Star

Melicope pteleifolia (Champ. ex Benth.) T.G. Hartley

Not yet clinically reviewed

Genus: Melicope Species: pteleifolia Pinyin: San Cha Ku
Thin Evodia Twig and Leaf三叉苦

Traditionally used for

  • Colds & fever
  • Urinary & fluids
  • Skin
  • Liver & jaundice
Moderate evidence · 4 studies

☯ TCM Properties

Category: clearing heat
Temperature: cold
Taste: bitter
Meridians: liver, lung, stomach
Functions:

Clears Heat and Resolves Toxicity; Dispels Wind-Dampness; Reduces Swelling and Alleviates Pain; Dries Dampness and Stops Itching; Moves Qi and Alleviates Pain

Traditional Chinese Uses

San Cha Ku (evodia lepta, three-fork bitter) is a bitter, cold herb used in Chinese medicine to clear Heat toxin and dry Dampness. It addresses inflammatory and infectious conditions with Heat toxin accumulation, including jaundice from Damp-Heat, urinary tract infections, inflammatory skin conditions, and malaria-type fever patterns. Its bitter, draining nature also directs pathological Heat downward and out through the urine. As a member of the rutaceae family, it shares properties with other bitter citrus-family herbs.

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Botanical Description

Melicope pteleifolia (syn. Euodia lepta) is an evergreen shrub or small tree of the Rutaceae family reaching 2 to 8 m in height, with smooth greyish-green bark and a strongly aromatic crushed-leaf scent characteristic of the family. Leaves are opposite, trifoliolate on a slender petiole; the leaflets are elliptic to elliptic-lanceolate, 6 to 15 cm long, entire-margined, glossy dark green above, paler beneath, and dotted with translucent oil glands visible against light. Small four-merous greenish-white to pale yellow flowers are borne in many-flowered axillary panicles; the species is functionally dioecious. The fruit is a cluster of one to four small follicles, each 3 to 5 mm across, dehiscing to release a single shining black seed. It grows in lowland and lower montane forests and thickets across southern China and Southeast Asia.

Active Constituents

3,5-di-C-beta-D-glucopyranosyl phloroacetophenone

Di-C-glycosidic phloroacetophenone

Concentration: reported as the major constituent of the leaves

Identified in vivo as the compound responsible for the antipyretic activity that underlies the traditional use of the leaves against fever and colds. It also inhibits TNF-alpha-induced prostaglandin E2 release in cell assays.

Phloroacetophenone derivatives (including spiroketal-hexofuranoside acetophenones)

Acylphloroglucinol (phloroacetophenone)

The dominant structural class in the leaf. Every one of the thirteen compounds isolated in one dedicated study shared a phloroacetophenone skeleton, and several inhibited TNF-alpha-induced prostaglandin E2, which is consistent with the herb's use for heat and inflammation.

Tamarixetin 3-robinobioside

Flavonol glycoside

The strongest neuraminidase inhibitor found in the leaves, with IC50 values of about 25 microM against H1N1, 23 microM against H9N2, 27 microM against wild-type H1N1 and 40 microM against an oseltamivir-resistant H274Y strain. It also moderately reduced H1N1-induced cytopathic effect in MDCK cells.

Kaempferol 3-robinobioside

Flavonol glycoside

Inhibits viral neuraminidase and moderately reduces H1N1-induced cytopathic effect in cell culture.

Melicoptelines A to E

Caryophyllaceae-type cyclopeptide alkaloid

Five cyclopeptide alkaloids unique to this species, three of which carry an unusual 3a-hydroxypyrroloindole ring formed from tryptophan. All five protected MDCK cells against influenza A; the most active had an EC50 of about 2.6 microM against H1N1, stronger than ribavirin in the same assay.

Leptols A and B

Meroterpenoid and coumarin hybrid

Two hybrid metabolites from the leaves reported to have anti-inflammatory activity in BV2 microglial cells.

Evodialones A and B

Polyprenylated acylcyclopentanone

Racemic polyprenylated acylcyclopentanones with an unusual carbon skeleton, isolated from this species under its former name Evodia lepta.

Benzopyrans

Benzopyran (chromene)

A minor class isolated alongside the acetophenones in the leaves, evaluated in the same neuraminidase inhibition screens.

⚠ Drug Interactions

Wu Zhu Yu (Tetradium ruticarpum, formerly Evodia rutaecarpa) through the shared genus name in older Latin nomenclature

Moderate Evidence: Theoretical

This herb still circulates in Chinese pharmaceutical literature under the Latin name Radix et Folium Evodiae Leptae, because Melicope pteleifolia was long placed in the genus Evodia. Wu Zhu Yu, a hot, acrid, mildly toxic drug used in small doses, was until recently Evodia rutaecarpa. The two are botanically distinct genera and pharmacologically opposite in TCM terms, and Wu Zhu Yu carries documented cytochrome P450 1A2 induction and inhibition effects that Melicope pteleifolia is not known to have. The hazard here is a nomenclature hazard rather than a documented market adulteration, and is recorded on that basis.

Clinical note: Order by the current binomial Melicope pteleifolia, not by Evodia. Melicope leaf material is the trifoliolate leaf of a shrub eaten as a vegetable and drunk as a cooling tea; Wu Zhu Yu is a small dried fruit dosed at a few grams.

Oseltamivir and other neuraminidase inhibitors

Minor Evidence: Theoretical

Leaf flavonol glycosides inhibit influenza neuraminidase in enzyme assays, including against an oseltamivir-resistant H274Y strain, and the leaf cyclopeptide alkaloids are protective in infected cell culture. This is enzyme and cell-culture work only; there is no pharmacokinetic study, no human data, and no reason to expect a competitive interaction at oral doses of the herb.

Clinical note: Do not present this herb as a substitute for antiviral therapy, and do not withhold oseltamivir on the strength of the in vitro data. No dose adjustment is indicated.

NSAIDs and paracetamol

Minor Evidence: Theoretical

The major leaf constituent has demonstrated antipyretic activity in animals, and several leaf constituents inhibit TNF-alpha-induced prostaglandin E2 in cells. Additive temperature lowering with a conventional antipyretic is plausible on that basis but has not been measured.

Clinical note: No action needed beyond the usual caution about masking fever as a sign. The herb has a long record of use as a food and cooling tea in southern China, Malaysia and Vietnam.

Evidence Tier

Moderate evidence · 4 studies

Recorded 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.

Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description

Clinical Studies

Constituents of the Edible Leaves of Melicope pteleifolia with Potential Analgesic Activity

Lee BW, Park JG, Ha TKQ, Pham HTT, An JP, Noh JR, Lee CH, Oh WK (2019) Journal of Natural Products animal

Thirteen compounds were isolated from the leaves, six of them new, and all shared a phloroacetophenone skeleton. Three inhibited TNF-alpha-induced prostaglandin E2, and in vivo work identified the major constituent 3,5-di-C-beta-D-glucopyranosyl phloroacetophenone as the compound responsible for the antipyretic activity that supports the herb's traditional use for fever.

Chemical constituents from Melicope pteleifolia leaves

Nguyen NH, Ha TK, Choi S, Eum S, Lee CH, Bach TT, Chinh VT, Oh WK (2016) Phytochemistry in vitro

Eight new compounds, including five spiroketal-hexofuranoside acetophenones, and sixteen known compounds were isolated from the leaves and screened for neuraminidase inhibition. Tamarixetin 3-robinobioside was the strongest inhibitor across H1N1, H9N2, wild-type H1N1 and an oseltamivir-resistant H274Y strain, with IC50 values of roughly 23 to 40 microM, and it and two kaempferol glycosides moderately reduced H1N1-induced cytopathic effect in MDCK cells.

Melicopteline A–E, Unusual Cyclopeptide Alkaloids with Antiviral Activity against Influenza A Virus from Melicope pteleifolia

Lee BW, Ha TKQ, Park EJ, Cho HM, Ryu B, Doan TP, Lee HJ, Oh WK (2021) The Journal of Organic Chemistry in vitro

Five previously unknown Caryophyllaceae-type cyclopeptide alkaloids were isolated from the leaves, three carrying an unusual tryptophan-derived 3a-hydroxypyrroloindole ring. All five protected MDCK cells against influenza A, with the most active showing an EC50 of 2.57 microM against H1N1, more potent than the ribavirin control.

Leptols A and B, one meroterpenoid and one coumarin hybrid from the leaves of Melicope pteleifolia and its anti-inflammation in BV2 cells

Wei HL, Sun JJ, Chen JQ, Wang T, Li J, Tu PF (2025) Journal of Asian Natural Products Research in vitro Verified: In vitro / animal

Reports two new hybrid metabolites from the leaves, a meroterpenoid and a coumarin hybrid named leptols A and B, and their anti-inflammatory activity in BV2 microglial cells.

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.

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