title: Amelioration of insulin resistance by Rk1 + Rg5 complex under endoplasmic reticulum stress conditions.
abstract: BACKGROUND
  Diabetes mellitus is a metabolic syndrome exaggerated by stress conditions. Endoplasmic reticulum stress (ERS) impairs the insulin signaling pathway making the diabetic conditions worsen. Pharmacological agents are supplied externally to overcome this malfunction. Ginsenosides from Panax ginseng C.A Meyer possesses many pharmacological properties and are used for the treatment of diabetes.
  
  
  OBJECTIVE
  To investigate the effects of the Rk1 +Rg5 complex on the amelioration of insulin resistance in 3T3-L1 cells under endoplasmic reticulum stress conditions.
  
  
  METHODS
  Heat-processed ginseng extracts are found to contain many pharmacologically active ginsenosides. Among them Rk1 +Rg5 is found to be present in higher concentrations than the other minor ginsenosides. The Rk1 +Rg5 complex was tested for its effect in the 3T3-L1 insulin-resistant model and subjected to the MTT assay, glucose oxidase assay and gene expression studies using RT-PCR and real-time PCR under endoplasmic reticulum stress conditions.
  
  
  RESULTS
  Rk1 +Rg5 treatment is found to increase the glucose uptake into the cells when compared to that of a positive control (tunicamycin treatment group, TM). Further we have analyzed the role at gene expression level. The Rk1 +Rg5 complex was found to show an effect on the IGF 2R receptor, CHOP-10, and C/EBP gene at a particular treated concentration (50 μM). Moreover, stress condition (about 50% decreases) was overcome by the ginsenoside treatments at 50 μM.
  
  
  CONCLUSIONS
  The present results showed that under endoplasmic reticulum stress conditions Rk1 +Rg5 complex exhibits a potential protective role in insulin-resistant 3T3-L1 cells.
authors.affiliation: Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Suwon, Korea.
authors.forename: Shree Priya
authors.initials: SP
authors.lastname: Ponnuraj
authors.affiliation: Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Suwon, Korea.
authors.forename: Fayeza
authors.initials: F
authors.lastname: Siraj
authors.affiliation: Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Suwon, Korea.
authors.forename: Sera
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Suwon, Korea.
authors.forename: Hae Yong
authors.initials: HY
authors.lastname: Noh
authors.affiliation: Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Suwon, Korea.
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Min
authors.affiliation: Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Suwon, Korea.
authors.forename: Yeon-Ju
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Oriental Medicinal Materials and Processing, Kyung Hee University, Suwon, Korea.
authors.forename: Deok-Chun
authors.initials: DC
authors.lastname: Yang
keywords: 3T3-L1; dexamethasone; diabetes; ginsenosides; insulin; insulin resistance