Abstract: Objective To investigate the mechanism of myricetin combined with PLIN1 silencing on lipolysis of 3T3-L1 adipocytes. Methods 3T3-L1 adipocytes were routinely induced to differentiate by the hormonal cocktail. According to the optimal concentration of Myric combined with the high efficient transfection vector of sh-PLIN1, the intervention experiment was divided into four groups: control group, transfection group (sh-RNA), Myricetin group (Myric) and combination group (Myric+sh-RNA). The Oil Red O staining was used to observe the morphology of lipid droplets. The protein expression levels of ERK, p-ERK, MEK, p-MEK and p-HSL were detected by Western blot. Enzyme linked immunosorbent assay (ELISA) was used to measure the content of the cyclic adenosine monophosphate (cAMP), protein kinase A (PKA) and p-PKC. Results Compared to Myric group and sh-RNA group, size of lipid droplets decreased obviously in Myric+sh-RNA group. Compared to sh-RNA group and control group，the relative value of p-PKC, p-ERK/ERK, p-MEK/MEK and p-HSL increased significantly in Myric+sh-RNA group and Myric group (P<0.05), meanwhile, the content of cAMP and PKA decreased significantly (P<0.05). Conclusions Myric may promote lipolysis through the activation of PKC-MEK/ERK signaling pathway, and further increase expression level of p-HSL in this pathway. Meanwhile, Myric may also inhibit the activity of related factors in cAMP/PKA signaling pathway.

Key words: Myricetin, Perilipin 1 gene silencing, 3T3-L1 adipocytes, signal pathways of lipolysis