Eriocalyxin B Inhibits Adipogenesis in 3T3-L1 Adipocytes by Cell Cycle Arrest

Eriocalyxin B, an ent-Kaurene diterpenoid extracted from a traditional Chinese herb Isodon eriocalyx, has been shown to possess multifunctional activities such as anti-cancer and anti-inflammatory. However, the function and mechanism of the compound in adipocyte differentiation is still unknown. Here we reported that eriocalyxin B blunted adipogenesis remarkably by inhibiting the accumulation of lipid droplets, triglycerides and the expressions of adipogenesis-related factors, including C/EBP beta, C/EBP alpha, PPAR gamma, and FABP4. Moreover, we showed that the inhibition might be the consequence of cell cycle being arrested at the G2/M phase during the mitotic clonal expansion of adipocyte differentiation, most likely by suppressing mRNAs and proteins of CDK1, CDK2, Cyclin A and Cyclin B1. Overall, we conclude that eriocalyxin B is capable of inhibiting adipocyte differentiation at the early stage through downregulating the proteins involved in cell cycle progression.