Phenolic components rich ethyl acetate fraction of Orostachys japonicus inhibits lipid accumulation by regulating reactive oxygen species generation in adipogenesis.

In this study, Orostachys japonicus was extracted with ethyl alcohol and fractionated by a serial of organic solvents. The ethyl acetate fraction was found to be the most effective among the tested five fractions. High-performance liquid chromatography and mass spectrometry analysis of the ethyl acetate fraction presented epicatechin gallate, quercetin-3-O-glucoside, and kaempferol-3-O-rutinoside. Treatment with O. japonicus inhibited reactive oxygen species (ROS) generation and lipid accumulation during adipogenesis. The gene expression of enzymes involved in the antioxidant system increased in O. japonicus-treated cells. messeanger RNA (mRNA) and protein expression of the pro-oxidant enzymes such as nicotinamide adenine dinucleotide phosphate hydrogen oxidase4 and glucose-6-phosphate dehydrogenase suppressed in O. japonicus-treated cells. O. japonicus also inhibited the mRNA and protein levels of adipogenic transcription factors (including proliferator activated receptor-γ and CCAAT/enhancer-binding protein-α) and their target gene (adipocyte protein 2). These results suggest that O. japonicus inhibits adipogenesis by controlling pro-/anti-oxidant enzyme responses and adipogenic transcription factors. PRACTICAL APPLICATIONS: ROS generation is markedly related to the pathogenesis and development of metabolic disorders. Treatment with O. japonicus inhibited ROS generation and lipid accumulation during adipogenesis. This result indicates that O. japonicus inhibit adipogenesis by controlling pro-/anti-oxidant enzyme responses and adipogenic mediators.