Bark Compound Targets Mechanism Responsible for Metabolic Dysfunction

Hyperlipidemia, a condition whereby blood lipids – particularly cholesterol  — are elevated, is closely linked to metabolic diseases such as atherosclerosis and type II diabetes.  The body’s production of blood lipids is regulated by a family of transcription factors known as sterol regulatory element-binding proteins (SREBPs).  Bao-Liang Song, from the Shanghai Institutes for Biological Sciences (China), and colleagues employed  a chemical screening process to identify compounds with potential to directly blocking the action of SREBP. The team observed betulin, a compound found in abundance in birch bark, reduced the activity of genes that are normally activated by SREBP, and lowered lipid levels within cells.  They then treated mice, fed a high-fat Western diet, with either betulin, a cholesterol-lowering statin, or placebo, for a six-week period.  Compared to placebo, both betulin and the statin reduced weight on the high-fat diet.  Betulin, however, also lowered lipid levels in blood, liver, and fat tissue. As well, betulin made the animals more sensitive to insulin, and reduced the number of atherosclerotic plaques formed. Explaining that: “Our study demonstrates that inhibition SREBP pathway can be employed as a therapeutic strategy to treat metabolic diseases including type II diabetes and atherosclerosis,” the researchers conclude that: “ Betulin, which is abundant in birch bark, could be a leading compound for development of drugs for hyperlipidemia.”