Patrick Guilfoile: Birch bark bandages may be back in vogue
Birch bark has been used in traditional medicine to treat a variety of ailments including serving as bandages to treat skin wounds. Subsequently, a number of scientific studies have demonstrated the healing properties of birch bark extracts. These include reports of healing herpes skin sores, burned tissue, and skin grafts. Scientists from Germany recently filled in some of the molecular details of how birch bark aids the healing process.
In any laboratory experiment, an assay of some type is required, in order to measure the effect of a treatment. In this work, researchers used two primary assays. One involved testing human skin cells from foreskins (collected from hospital circumcisions) in Petri dishes. Scientists tested these skin cells with various concentrations of birch bark extract to see how they responded, and whether the response was consistent with enhanced wound healing.
The other assay involved using ear punches from slaughtered pigs, the tissue resembling the dots produced by a paper punch. The researchers created wounds by removing the top layers of skin from the center of the ear punch, then bathing the tissue in medium with or without birch bark extract.
In the first set of experiments, the scientists found that the birch bark extract triggered an inflammatory response. Although that may sound bad, it is a critical first step in healing a cut, burn, or sore. Inflammation causes movement of immune cells to the site of the damage. These cells then clear out damaged tissue and help prevent infection. Based on these experiments, it appears that birch bark extract triggers inflammation for only a short window of time, sufficient to start healing, but not so long that it causes additional damage.
In the second set of experiments, researchers demonstrated that birch bark extract aided in another key step of wound healing, the migration of skin cells to a cut or sore. Birch bark extract triggered the formation of foot-like structures used by the skin cells to move toward a wound. These skin cells ultimately bridge the gap between the two sides of damaged tissue, so their ability to migrate to a wound is a critical part of the healing process.
Physicians use many traditional remedies in modern medicine. They include digitalis to treat heart conditions, aspirin for headaches, and quinine for malaria. Since we now have a detailed understanding of how birch bark can aid in healing skin wounds, birch bark extract may someday become as common a medical treatment as the use of aspirin.
More information is available at:
Ebeling S and others. From a Traditional Medicinal Plant to a Rational Drug: Understanding the Clinically Proven Wound Healing Efficacy of Birch Bark Extract. PLoS ONE 9(1): e86147. doi:10.1371/journal.pone.0086147, January, 2014.
PATRICK GUILFOILE has a doctorate in bacteriology and is the associate vice president at Bemidji State University.