3-hydroxybutyrate (BHBA)

3-hydroxybutyrate (BHBA) (CAS No.: 300-85-6) is an endogenous ketone body generated during fatty acid β-oxidation and serves as a key metabolic intermediate and signaling molecule, particularly elevated under conditions of impaired glucose utilization such as type I diabetes, fasting, or caloric restriction. As a small-molecule metabolite, BHBA is widely studied in metabolic disease research and epigenetic regulation due to its dual role in cellular energetics and signaling. Mechanistically, BHBA modulates membrane lipid composition and biophysical properties, altering membrane fluidity and stability, which in turn influences receptor function, signal transduction pathways, and cellular energy homeostasis. In addition, BHBA acts as an endogenous inhibitor of class I histone deacetylases, leading to increased histone acetylation and transcriptional reprogramming, while showing selectivity by not inhibiting class IIb HDACs such as HDAC6. These activities link metabolic state to chromatin regulation and gene expression. In vitro studies typically employ BHBA at millimolar to low millimolar concentrations to recapitulate physiological or pathophysiological ketosis, although effective levels vary depending on cell type and experimental design. BHBA is broadly applied in cell-based assays and animal models to investigate diabetes pathogenesis, metabolic reprogramming, ketone body signaling, and epigenetic modulation, as well as in drug discovery efforts targeting metabolic and chromatin-associated pathways.