Metabolites of oregano (Origanum vulgare) seed and their anti-obesity effects on 3T3-L1 adipocytes through down-regulated adipogenesis.

Metabolites of the 80% ethanol extract (OSE) and ethyl acetate fraction (OSEA) of oregano seed were analyzed by GC-MS, and anti-obesity effects of OSE and OSEA were evaluated in 3T3-L1 adipocyte. OSE possessed high content of glucose, fructofuranose, and sucrose while OSEA had high content of phenolic chemicals. OSEA contained higher levels of gallic acid, syringic acid, protocatechuic acid, and catechin than OSE. OSEA inhibited lipid droplet accumulation with concentration dependent manner in 3T3-L1 preadipocytes during differentiation. OSEA showed more inhibition ability than OSE by 13.7-fold at the level of 125 μg/mL. Additionally, relative mRNA and protein expression levels of pparγ, c/ebpα, fas, and srebp-1c which are related to adipogenesis were significantly lower in OSEA treatment group than in OSE treatment group (p < 0.05). Therefore, OSEA could be used as anti-obesity functional ingredient. © The Korean Society of Food Science and Technology 2022.