“How lovely yellow is! It stands for thesun.”
- Vincent Van Gogh

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In this week’s leaf I am going to get personal. The person on the cover is yours truly, examining a #Phellodendronsapling in its native habitat, Sichuan, China.

This tree is a member of the #Rutaceae, a family that also includes citrus. Despite its name (Phello-dendron means cork tree) it is unrelated to the cork oak used to make bottle stoppers.

A distinctive feature of Phellodendron is the vibrant yellow colour of its inner bark (see picture insert). This is due to #berberine, a isoquinoline alkaloid. Also found in #Berberis (hence the name) and other species, berberine typically accumulates in bark or root tissue. Several of these other species are also medicinal plants.  

Phellodendron bark is one of 50 fundamental botanicals used in Chinese medicine. Besides its rich berberine content (often more than 5% of thedry bark), it contains several other #protoberberberine alkaloids. Alkaloids are thought to protect plants against bacteria and fungi, and are particularlyimportant in bark because that’s where sugar-rich products of photosynthesisflow.

The medicinal properties of berberine-rich botanicals derive in part from the antimicrobial activities that can rectify pathogenic imbalancesin the gut microbiome. However, the same botanicals are also used to treat disorders that have no microbial involvement.

We at @Green Mountain Biotech are particularly interested in Phellodendron, as its extract is highly and selectively active against skin pathogens but allows beneficial skin bacteria to flourish. This makes Phellodendron extract an attractive choice for treating acne and bacterial infections that are secondary to dermatitis.

A final note: There are other yellow phytochemicals unrelated toberberine, each with their own properties. Van Gogh would likely haveappreciated them all.

Reading list

Phellodendron, Wikipedia,  https://en.wikipedia.org/w/index.php?title=Phellodendron&oldid=1043910102

Neag, MA et al. (2018).Berberine: Botanical Occurrence, Traditional Uses, Extraction Methods, andRelevance in Cardiovascular, Metabolic, Hepatic, and Renal Disorders. Frontiersin pharmacology, 9, 557. https://doi.org/10.3389/fphar.2018.00557

Bomstein,Y. and Marder, J., 2019.Synergistic herbal compositions with prebioticproperties for treatment of acne. U.S. Patent Application 16/347,679. https://patents.google.com/patent/US20190269747A1/en