Rhamnus nakaharai

Last Updated: November 18, 2022

Rhamnus nakaharai is a herb that has been used as folk medicine in Taiwan for intestinal distress (mostly constipation) and asthma, it is a good source of quercetin glycosides but not much research exists on the herb per se.


Rhamnus nakaharai is most often used for

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Sources and composition


Sources and History

Rhamnus Nakaharia (from the family Rhamnaceae) is a folk medicine originating in Taiwan that has been used to treat constipation, inflammation, malignant tumors, and asthma.[1]



Rhamnus Nakaharai (RN) is a Taiwanese herbal medicine that contains:

  • The napthalenic compound 6-methoxysorigenin and various glycosides and acylates of the parent compound, such as alpha-sorinin[1] although 6-methoxyorigenin appears to be isolated from the wood component of the herb[1]
  • Isotorachyrsone and derivatives.[2][3]
  • Quercetin glycosides, specifically 3-O-Methylquercetin.[2][4]



Interactions with Oxidation

The compound 6-methoxyorigenin appears to have anti-oxidative effects in vitro,[1] as well as the related compound Isotorachrysone, which share structural similarities.[3] 6-methoxygenin outperformed Trolox (a research standard) on Metal-chelating and protecting from lipid peroxidation, and was slightly outperformed on a DPPH test.[1] The IC50 of the metal chelating ability of 6-methoxyorigenin (615.90+/-5.79) was lesser than that of EDTA (127.92+/-6.27).[1]


Inflammation and Immunology



3-O-Methylquercetin has been found to suppress the inflammatory (Nitric Oxide mediated) response from LPS (research pro-inflammatory agent) in macrophages in vitro.[4] 3-O-Methylquercetin was found to inhibit Nitric Oxide release, protein expression of iNOS (induced by inflammation) and mRNA translation of iNOS with IC50 values of 4.23uM, 4.36uM, and 6.53uM respectively.[4]


Intestinal Interactions



3-O-Methylquercetin appears to be a selective PDE3 inhibitor with an IC50 of 1.6mM via competitive inhibition.[5]

2.^Lin CN, Lu CM, Lin HC, Ko FN, Teng CMNovel antiplatelet naphthalene from Rhamnus nakaharaiJ Nat Prod.(1995 Dec)
3.^Hsiao G, Ko FN, Lin CN, Teng CMAntioxidant properties of isotorachrysone isolated from Rhamnus nakaharaiBiochim Biophys Acta.(1996 Nov 14)
4.^Jiang JS, Shih CM, Wang SH, Chen TT, Lin CN, Ko WCMechanisms of suppression of nitric oxide production by 3-O-methylquercetin in RAW 264.7 cellsJ Ethnopharmacol.(2006 Jan 16)
5.^Ko WC, Chen MC, Wang SH, Lai YH, Chen JH, Lin CN3-O-methylquercetin more selectively inhibits phosphodiesterase subtype 3Planta Med.(2003 Apr)