Inhibitory effects of compounds isolated from the dried branches and leaves of murta ( Myrceugenia euosma ) on lipid accumulation in 3T3-L1 cells

As obesity is a global health concern the demand for anti-obesity drugs is high. In this study, we investigated the anti-obesity effect of the dried branches and leaves of murta ( Myrceugenia euosma Legrand, Myrtaceae). A methanol extract of the dried branches and leaves of murta inhibited adipogenesis in 3T3-L1 cells. Three known flavanones—cryptostrobin ( 1 ), pinocembrin ( 4 ), and 5,7-dihydroxy-6,8-dimethylflavanone ( 6 ), and three chalcones—2′,6′-dihydroxy-3′-methyl-4′-methoxychalcone ( 2 ), pinostrobin chalcone ( 3 ), and 2′,6′-dihydroxy-4′-methoxy-3′,5′-dimethylchalcone ( 5 ) were isolated from the active fraction. Structures of these compounds were identified using various spectral data. Each of these compounds also inhibited adipogenesis in 3T3-L1 cells. In particular, compound 3 was a more potent inhibitor of triglyceride accumulation than the positive control berberine. Gene expression studies revealed that treatment of 3T3-L1 cells with 3 lowers the expression levels of CCAAT/ enhancer-binding protein α and peroxisome proliferator activator γ 2 during adipogenesis without affecting cell viability. Treatment of 3T3-L1 cells with 3 reduced the expression levels of mRNAs encoding sterol regulatory element-binding protein 1c and several lipogenic enzymes, including fatty acid synthase and stearoyl CoA desaturase-1 . These results indicate that the methanol extract and compounds isolated from the dried branches and leaves of murta exert their anti-obesity effects through the inhibition of adipogenesis.