title: Grape seed proanthocyanidins extracts promote apolipoprotein A-I mRNA expression in HepG2 cells under experimental sugar and high-sugar conditions.
abstract: OBJECTIVE
  In this study, we investigated the effect of grape seed proanthocyanidins extracts (GSPE), which have been proved to have anti-oxidative and anti-aging functions, on the expression of apoA-L at mRNA level of HepG2 cells in vitro under the experimental conditions of high-sugar and sugar.
  
  
  METHODS
  Cell viability was measured by sulforhodamine B (SRB). The apoA-I mRNA expression was assayed by real-time fluorescence quantitative polymerase chain reaction. Firstly, HepG2 cells were incubated in 10% inactivated newborn calf serum in Dulbecco's Modified Eagle Medium (DMEM). Next, cells were incubated with high-sugar and sugar serum-free medium, and added different concentration of GSPE (2.5, 5 and 10 microg/ml) for more than 24 hours, and thereafter, investigated whether GSPE can promote more apoA-I expression in HepG2 cells under the experimental conditions of high-sugar and sugar.
  
  
  RESULTS
  In this experiment, HepG2 cells were incubated with high-sugar and sugar serum-free medium, and HepG2 cells incubated with high-sugar medium produced less apoA-I at mRNA level. The difference was significant (p < 0.05). When HepG2 cells were incubated with GSPE at concentration of 20 microg/ml or above for about 4 hours, cell viability measured by SRB was lower than 50%. However, cell viability of HepG2 cells incubated with GSPE at concentration of 10 microg/ml or below was higher than 70%. Therefore, we chose the HepG2 cells incubated with GSPE concentration of 2.5, 5, 10 microg/ml to observe the effect of GSPE on the mRNA expression of apoA-I. After incubated with GSPE, the apoA-I expression of HepG2 cells were significantly elevated at mRNA level compared to that of high sugar control (p < 0.05). Moreover, this action of GSPE showed dose dependent, and the dose of 2.5 microg/ml was optimal.
  
  
  CONCLUSIONS
  GSPE (concentration of higher than 20 microg/ml) could inhibit HepG2 cell survival, and in HepG2 cells, endogenous apoA-I was significantly suppressed following 24h of exposure to high concentrations of glucose. Meanwhile GSPE could promote expression of apoA-L dose dependently at mRNA level when its concentration was lower than 10 microg/ml.
authors.affiliation: Department of Intensive Care Unit, Oilu Hospital of Shandong University, Jinan 250012, China.
authors.forename: O
authors.initials: O
authors.lastname: Zhai
authors.forename: N
authors.initials: N
authors.lastname: Zhong
authors.forename: H Q
authors.initials: HQ
authors.lastname: Gao
authors.forename: B Y
authors.initials: BY
authors.lastname: Li
authors.forename: B
authors.initials: B
authors.lastname: Jiang
mesh_terms: D000199:Actins / Q000096:biosynthesis / Q000235:genetics; D016632:Apolipoprotein A-I / Q000096:biosynthesis* / Q000235:genetics; D002241:Carbohydrates / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004587:Electrophoresis, Agar Gel; D015870:Gene Expression / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology; D044945:Proanthocyanidins / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012639:Seeds / Q000737:chemistry; D027843:Vitis / Q000737:chemistry*
chemical_list: D000199:Actins; D016632:Apolipoprotein A-I; D002241:Carbohydrates; D010936:Plant Extracts; D044945:Proanthocyanidins; D012333:RNA, Messenger