Compound in blueberries may help muscle cells burn excess fat

A research team led by Associate Professor Takakazu Mitani at Shinshu University in Japan has discovered that pterostilbene, a polyphenol found in blueberries, may help muscle cells burn excess fat. Excess fat stored in skeletal muscle can lead to metabolic issues, such as insulin resistance, and is influenced by a pathway involving peroxisome proliferator-activated receptor delta (PPARδ).

Pterostilbene stabilizes PPARδ and influences fat metabolism inside muscle cells. The researchers tested various food-derived phytochemicals using cultured C2C12 mouse skeletal muscle cells and found that pterostilbene had the strongest effect in reducing intracellular lipid accumulation without interfering with normal muscle development.

Pterostilbene did not prevent fatty acids from entering the muscle cells but instead increased the release of glycerol, indicating breakdown of stored fat, and greater expression of genes involved in fatty acid oxidation. Pterostilbene increased PPARδ signaling by increasing the amount of PPARδ protein present inside the cells, preventing its breakdown through the ubiquitin-proteasome pathway.

This stabilization increased PPARδ transcriptional activity and boosted the activity of genes involved in lipid metabolism. The findings suggest that pterostilbene could be a promising candidate for developing functional foods and nutritional supplements targeting muscle fat metabolism. However, further research is needed to determine its effectiveness, safety, and potential applications in treating metabolic diseases in animals or humans.