title: The effects of catechin isolated from green tea GMB-4 on NADPH and nitric oxide levels in endothelial cells exposed to high glucose.
abstract: OBJECTIVE
  This study aimed to investigate whether a catechin isolated from GMB-4 green tea is able to increase the reducing equivalent system and nitric oxide (NO) level in endothelial cells exposed to high glucose (HG) level.
  
  
  METHODS
  Endothelial cells were obtained from human umbilical vascular tissues. At confluent, human endothelial cells were divided into five groups, which included control (untreated), endothelial cells exposed to HG (30 mM), endothelial cells exposed to HG in the presence of green tea catechin (HG + C) at the following three doses: 0.03; 0.3; and 3 mg/ml. Analysis of NADP(+), NADPH, and NO levels were performed colorimetrically.
  
  
  RESULTS
  This decrease in NADPH was significantly (P < 0.05) attenuated by both the 0.3 and 3 mg/ml treatments of catechin. HG level significantly decreased NO compared with untreated cells. This increase in NO was significantly attenuated by the 0.3 mg/ml dose of the catechin.
  
  
  CONCLUSIONS
  In conclusion, catechin isolated from GMB-4 green tea prohibits the decrease in NADPH and NO in endothelial cells induced by HG. Therefore this may provide a natural therapy for attenuating the endothelial dysfunction found in diabetes mellitus.
authors.affiliation: Department of Nurse, Surya Mitra Husada Health School, Kediri, East Java, Indonesia.
authors.forename: Yuly
authors.initials: Y
authors.lastname: Peristiowati
authors.affiliation: Department of Public Health, Surya Mitra Husada Health School, Kediri, East Java, Indonesia.
authors.forename: Indasah
authors.initials: I
authors.lastname: Indasah
authors.affiliation: Department of Physiology Molecular, Faculty of Medicine, University of Brawijaya, Malang, East Java, Indonesia.
authors.forename: Retty
authors.initials: R
authors.lastname: Ratnawati
keywords: Endothelial dysfunction; green tea; high glucose level; oxidative status