Birch tar had no effect E. coli stopped or at least slowed the growth of cultures S. aureus. To what extent depends on the species of birch and the concentration of tar, probably different species of birch and perhaps individual trees produce tar with different chemical compositions. The most effective bunch taken from silver birch (Drooping birch) tree gave a “relatively strong response”. Meanwhile, results from four other trees ranged from mild to moderate, and another showed no effect.
The results, along with some previous research, confirm – or, more precisely, explain in scientific terms – what indigenous peoples such as the Mi’kmaq, Saami and Yakut have known for at least several thousand years. why my maskwio works as an antiseptic.
“Our findings not only reinforce what previous studies have reported, but also reflect conventional knowledge,” Siemssen and colleagues wrote. Their findings also suggest that traditional knowledge may be much, much older than even Mi’kmaq oral history records (or at least may have been discovered more than once in our evolutionary past).
How it works, for chemistry nerds
But how does birch sap work against bacteria? One clue is that, like most other plant-based antimicrobials, birch resin slows the growth of gram-positive bacteria. S. aureus but not gram-negative E. coli; This is probably because Gram-negative bacteria like it E. coli It has an extra outer membrane that can keep antimicrobial compounds out.
These compounds are probably ring-shaped molecules called phenolic derivatives; they are found mainly in plant tissues and are a common ingredient in antiseptics and disinfectants (if you’ve ever used an antiseptic mouthwash or a pre-operative skin cleanser like Hibiclens, you’ve used the phenolic derivative chlorhexidine). Other chemicals may also play a role, including terpenes and terpenoids, which help protect plants from being eaten by insects or infected by fungi.
Siemssen and colleagues suggest that more detailed chemical studies could help clarify which combination and ratio of all these chemicals are most effective, something that could even be useful for modern medicine.
