Cinnamon extract regulates glucose transporter and insulin-signaling gene expression in mouse adipocytes

Abstract 

Cinnamon extracts (CE) are reported to have beneficial effects on people with normal and impaired glucose tolerance, the metabolic syndrome, type 2 diabetes, and insulin resistance. However, clinical results are controversial. Molecular characterization of CE effects is limited. This study investigated the effects of CE on gene expression in cultured mouse adipocytes. Water-soluble CE was prepared from ground cinnamon (Cinnamomum burmannii). Quantitative real-time PCR was used to investigate CE effects on the expression of genes coding for adipokines, glucose transporter (GLUT) family, and insulin-signaling components in mouse 3T3-L1 adipocytes. CE (100μg/ml) increased GLUT1 mRNA levels 1.91±0.15, 4.39±0.78, and 6.98±2.18-fold of the control after 2-, 4-, and 16-h treatments, respectively. CE decreased the expression of further genes encoding insulin-signaling pathway proteins including GSK3B, IGF1R, IGF2R, and PIK3R1. This study indicates that CE regulates the expression of multiple genes in adipocytes and this regulation could contribute to the potential health benefits of CE.

Abbreviations: ADIPOQ, adiponectin, AKT1, thymoma viral proto-oncogene 1, CE, cinnamon extract, DMEM, Dulbecco's modified Eagle's medium, GLUT, glucose transporter, GSK3B, glycogen synthase kinase 3 beta, GYS1, glycogen synthase 1, IGF, insulin-like growth factor, IGFR, insulin-like growth factor receptor, INS, insulin, INSR, insulin receptor, IRS, insulin receptor substrate, LEP, leptin, LEPR, leptin receptor, PIK3CB, phosphatidylinositol 3-kinase, catalytic, beta, PIK3R1, phosphatidylinositol 3-kinase, regulatory subunit 1, RPL32, ribosomal protein L32, SHC1, Src homology 2 domain-containing transforming protein 1, SOS1, Son of sevenless 1, TTP, tristetraprolin, ZFP36, zinc finger protein 36

Keywords: Adipocytes, Cinnamon (Cinnamomum burmannii), Diabetes, Gene expression, Obesity