title: Effect of Cudrania tricuspidata and Kaempferol in Endoplasmic Reticulum Stress-Induced Inflammation and Hepatic Insulin Resistance in HepG2 Cells.
abstract: In this study, we quantitated kaempferol in water extract from Cudrania tricuspidata leaves (CTL) and investigated its effects on endoplasmic reticulum (ER) stress-induced inflammation and insulin resistance in HepG2 cells. The concentration of kaempferol in the CTL was 5.07 ± 0.08 mg/g. The HepG2 cells were treated with 300 µg/mL of CTL, 500 µg/mL of CTL, 1.5 µg/mL of kaempferol or 2.5 µg/mL of kaempferol, followed immediately by stimulation with 100 nM of thapsigargin for ER stress induction for 24 h. There was a marked increase in the activation of the ER stress and inflammation response in the thapsigargin-stimulated control group. The CTL treatment interrupted the ER stress response and ER stress-induced inflammation. Kaempferol partially inhibited the ER stress response and inflammation. There was a significant increase in serine phosphorylation of insulin receptor substrate (IRS)-1 and the expression of C/EBPα and gluconeogenic genes in the thapsigargin-stimulated control group compared to the normal control. Both CTL and kaempferol suppressed serine phosphorylation of IRS-1, and the treatments did not interrupt the C/EBPα/gluconeogenic gene pathway. These results suggest that kaempferol might be the active compound of CTL and that it might protect against ER stress-induced inflammation and hyperglycemia.
authors.affiliation: Department of Medical Nutrition, Kyung Hee University, Yongin 17104, Korea. eorkfgod@naver.com.
authors.forename: Ok-Kyung
authors.initials: OK
authors.lastname: Kim
authors.affiliation: Division of Food and Nutritional Science, Chonnam National University, Gwangju 61186, Korea. wjjun@chonnam.ac.kr.
authors.forename: Woojin
authors.initials: W
authors.lastname: Jun
authors.affiliation: Department of Medical Nutrition, Kyung Hee University, Yongin 17104, Korea. jlee2007@khu.ac.kr.
authors.forename: Jeongmin
authors.initials: J
authors.lastname: Lee
mesh_terms: D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000378:metabolism; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy*; D055504:Insulin Receptor Substrate Proteins / Q000378:metabolism; D007333:Insulin Resistance; D044949:Kaempferols / Q000494:pharmacology*; D029586:Moraceae / Q000737:chemistry*; D010766:Phosphorylation / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D019284:Thapsigargin; D014867:Water / Q000494:pharmacology
chemical_list: D022763:CCAAT-Enhancer-Binding Protein-alpha; D055504:Insulin Receptor Substrate Proteins; D044949:Kaempferols; D010936:Plant Extracts; D014867:Water; D012694:Serine; D019284:Thapsigargin; C006552:kaempferol
keywords: Cudrania tricuspidata; ER stress; inflammation; insulin resistance; obesity