Rhamnus nakaharai

    Researchedby:
    Kamal Patel
    Last Updated: October 13, 2024

    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.



    1.

    Sources and composition

    1.1

    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]

    1.2

    Composition

    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]

    image

    2.

    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]

    3.

    Inflammation and Immunology

    3.1

    Mechanisms

    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]

    4.

    Intestinal Interactions

    4.1

    Mechanisms

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