Phytanic acid, but not pristanic acid, mediates the positive effects of phytol derivatives on brown adipocyte differentiation.

The phytol derivatives phytanic acid and pristanic acid may activate nuclear hormone receptors and influence gene expression and cell differentiation. Phytanic acid induces brown adipocyte differentiation. It was determined that brown fat and brown adipocytes are sites of high gene expression of phytanoyl-CoA hydroxylase, the enzyme required for initiation of peroxisomal alpha-oxidation of phytanic acid. However, the effects of phytanic acid were not mediated by its alpha-oxidation product pristanic acid, which did not promote brown adipocyte differentiation or stimulate transcription of the uncoupling protein-1 gene. Moreover, acute cold exposure of mice caused a dramatic mobilization of the phytanic acid stores in brown adipose tissue thus suggesting that a high local exposure to phytanic acid in brown fat may contribute to signalling adaptive changes in the tissue in response to thermogenic activation.