This record provides bibliographic details and links to the original research. An editorial study breakdown is not available.
What the researchers found
Phellinus linteus polysaccharides inhibited CYP1A1, CYP1A2, CYP2B1 and CYP2E1 activity in rat liver microsomes at 0.5-3 mg/ml. This is the only direct cytochrome P450 evidence for the mushroom, and it is an isolated-microsome result in a rat system, not a human drug-interaction study.
Why it matters
This is the single primary source underlying any meshima drug-interaction discussion. It establishes that P. linteus polysaccharides can inhibit some CYP isozymes in vitro, but the isozymes involved (1A1, 1A2, 2B1, 2E1) are not the ones that handle the bulk of commonly prescribed drugs, and rat CYP2B1 has no direct human equivalent.
The numbers in context
Polysaccharide concentrations tested: 0.5, 1 and 3 mg/ml. Isozymes inhibited: CYP1A1, CYP1A2, CYP2B1, CYP2E1. Broth grown with 5% mulberry extract was most potent against CYP1A1, 1A2 and 2B1; 10% mulberry extract broth was most potent against CYP2E1.
How the study worked
Rat liver microsomes were incubated with polysaccharide fractions isolated from cultured broth and mycelia of Phellinus linteus, and individual cytochrome P450 isozyme activities were measured.
Who was studied
Rat liver microsomes (in vitro).
What this study cannot tell us
In vitro rat liver microsome assay only. No whole-animal pharmacokinetics, no human data, and no measurement of CYP3A4 or CYP2C8 (the isozymes that metabolise most commonly prescribed medications). Concentrations used in the assay cannot be mapped to blood levels achieved by oral supplementation.
Read the original research
Inhibition of cytochrome P450 isozymes in rat liver microsomes by polysaccharides derived from Phellinus linteus.
Biotechnology letters, 25(2), 167-172
Citation
Shon, Yun Hee; Nam, Kyung Soo. (2003). Inhibition of cytochrome P450 isozymes in rat liver microsomes by polysaccharides derived from Phellinus linteus.. Biotechnology letters, 25(2), 167-172. https://doi.org/10.1023/a:1021935922722