Genipin, a metabolite of geniposide from Gardenia jasminoides, inhibits adipogenesis and improves lipid metabolism in adipocytes

Abstract

Genipin is an aglycone metabolite of geniposide which is derived from gardenia (Gardenia jasminoides) fruit. Geniposide is deglycosylated to genipin by β-glucosidase in animal intestine and liver. Gardenia fruit is well-known for its food coloring usage and also various health benefits such as anti-inflammatory and hypolipidemic activities as well, which give promising potential to control metabolic disorders and obesity. However, the effects of gardenia fruit and its active components involved in the development obesity have been poorly investigated. Thus, the present study was carried out to identify the effects of genipin, originated from gardenia fruit, on the obesity in the aspects of adipogenesis and lipid metabolism. The data showed that genipin, but not geniposide, inhibits adipogenesis and improves lipid metabolism significantly at 100 μM in 3T3-L1 cells, associated with the down-regulation of adipogenesis-related proteins (peroxisome proliferator-activated receptor gamma

PPARγ, CCAAT/enhancer-binding protein alpha

C/EBPα, and fatty acid synthase

FAS) expression. However, genipin did not show the suppressive effect on the phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase (ERK). Moreover, glycerol release levels which is an indication of lipid metabolism, specifically lipolysis, was also decreased. Taken together, the results elucidate that genipin inhibits adipogenesis in 3T3-L1 preadipocytes and improves lipid metabolism in 3T3-L1 adipocytes. These results suggest that genipin might play a role as a potential chemopreventive compound for the control of body weight/fat.