title: Cinnamon extract and polyphenols affect the expression of tristetraprolin, insulin receptor, and glucose transporter 4 in mouse 3T3-L1 adipocytes.
abstract: Cinnamon improves glucose and lipid profiles of people with type 2 diabetes. Water-soluble cinnamon extract (CE) and HPLC-purified cinnamon polyphenols (CP) with doubly linked procyanidin type-A polymers display insulin-like activity. The objective of this study was to investigate the effects of cinnamon on the protein and mRNA levels of insulin receptor (IR), glucose transporter 4 (GLUT4), and tristetraprolin (TTP/ZFP36) in mouse 3T3-L1 adipocytes. Immunoblotting showed that CP increased IRbeta levels and that both CE and CP increased GLUT4 and TTP levels in the adipocytes. Quantitative real-time PCR indicated that CE (100mug/ml) rapidly increased TTP mRNA levels by approximately 6-fold in the adipocytes. CE at higher concentrations decreased IRbeta protein and IR mRNA levels, and its effect on GLUT4 mRNA levels exhibited a biphasic pattern in the adipocytes. These results suggest that cinnamon exhibits the potential to increase the amount of proteins involved in insulin signaling, glucose transport, and anti-inflammatory/anti-angiogenesis response.
authors.affiliation: Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, US Department of Agriculture, Beltsville, MD 20705-2350, USA. heping.cao@ars.usda.gov
authors.forename: Heping
authors.initials: H
authors.lastname: Cao
authors.forename: Marilyn M
authors.initials: MM
authors.lastname: Polansky
authors.forename: Richard A
authors.initials: RA
authors.lastname: Anderson
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002935:Cinnamomum zeylanicum / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000008:administration & dosage; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D051275:Glucose Transporter Type 4 / Q000378:metabolism*; D051379:Mice; D010636:Phenols / Q000008:administration & dosage; D010936:Plant Extracts / Q000008:administration & dosage*; D059808:Polyphenols; D011972:Receptor, Insulin / Q000378:metabolism*; D051816:Tristetraprolin / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D051275:Glucose Transporter Type 4; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D051816:Tristetraprolin; C497553:Zfp36 protein, mouse; D011972:Receptor, Insulin