DL-norvaline inhibited adipogenesis in 3T3-L1 preadipocytes and ameliorated sphingolipid and glycerophospholipid metabolism in obese mice through the PPAR signaling pathway based on lipidomics and transcriptomics

Macronutrients participate in vital biological processes and are critical in regulating organismal health. DL-norvaline, a nonproteinogenic amino acid, is an important pharmaceutical intermediate and a functional food ingredient for obesity control. This study aimed to explore the ameliorative effect and underlying mechanisms of DL-norvaline on lipid metabolism in high-fat diet-induced obese mice. The results showed that DL-norvaline inhibited adipogenesis and lipid accumulation in 3T3-L1 adipocytes, ameliorated tissue weight, food efficiency ratio and serum biochemical markers in obese mice. The combined transcriptomics and lipidomics analysis showed that lipid metabolism of adipose tissue such as sphingolipid and glycerophospholipid metabolism was ameliorated in obese mice after DL-norvaline treatment, particularly ceramides, via regulating peroxisome proliferators-activated receptor signaling pathway. This study offered a complementary perspective for exploring the effects of amino acids on lipid metabolism and speculated the possible mechanisms of ameliorating lipid-metabolism disorders by DL-norvaline in obese mice.