title: Anti-inflammatory activity of Barleria lupulina: Identification of active compounds that activate the Nrf2 cell defense pathway, organize cortical actin, reduce stress fibers, and improve cell junctions in microvascular endothelial cells.
abstract: BACKGROUND
  Hot aqueous extracts of the plant Barleria lupulina (BL) are used for treating inflammatory conditions and diabetic vascular complications.
  
  
  OBJECTIVE
  The goal was to identify active compounds in hot aqueous extracts of BL (HAE-BL) that are consistent with a role in reducing inflammation and reducing the vascular pathology associated with diabetes. In particular, we examined activation of the Nrf2 cell defense pathway because our initial findings indicated that HAE-BL activates Nrf2, and because Nrf2 is known to suppress inflammation. Activation of Nrf2 by HAE-BL has not been described previously.
  
  
  METHODS
  Human endothelial cells, real-time PCR, western blotting, cytoskeletal analyses, and assay-guided fractionation with HPLC were used to identify specific compounds in HAE-BL that activate the Nrf2 cell defense pathway and reduce markers of inflammation in vitro.
  
  
  RESULTS
  HAE-BL potently activated the Nrf2 cell defense pathway in endothelial cells consistent with its traditional use and reported success in reducing inflammation. Assay guided fractionation with HPLC identified three alkyl catechols: 4-ethylcatechol, 4-vinylcatechol, and 4-methylcatechol, that are each potent Nrf2 activators. In addition to activating Nrf2, HAE-BL and akyl catechols each profoundly improved organization of the endothelial cell actin cytoskeleton, reduced actin stress fibers, organized cell-cell junctions, and induced expression of mRNA encoding claudin-5 that is important for formation of endothelial tight junctions and reducing vascular leak.
  
  
  CONCLUSIONS
  HAE-BL contains important alkyl catechols that potently activate the Nrf2 cell defense pathway, improve organization of the endothelial cell cytoskeleton, and organize tight cell junctions. All of these properties are consistent with a role in reducing inflammation and reducing vascular leak. Because activation of the Nrf2 cell defense pathway also prevents cancers, neuro-degeneration, age-related macular degeneration, and also reduces the severity of chronic obstructive pulmonary disorder and multiple sclerosis, HAE-BL warrants additional consideration for these other serious disorders.
authors.affiliation: Department of Pathology and Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Senger
authors.affiliation: Department of Pathology and Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA.
authors.forename: Mien V
authors.initials: MV
authors.lastname: Hoang
authors.affiliation: School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea.
authors.forename: Ki Hyun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Pharmaceutical Sciences, Daniel K Inouye College of Pharmacy, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, HI 96720, USA.
authors.forename: Chunshun
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Pharmaceutical Sciences, Daniel K Inouye College of Pharmacy, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, HI 96720, USA. Electronic address: scao@hawaii.edu.
authors.forename: Shugeng
authors.initials: S
authors.lastname: Cao
mesh_terms: D027901:Acanthaceae / Q000737:chemistry*; D000199:Actins / Q000378:metabolism*; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002396:Catechols / Q000302:isolation & purification / Q000494:pharmacology; D002478:Cells, Cultured; D062507:Claudin-5 / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D055806:Microvessels / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism*; D064209:Phytochemicals / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008517:Phytotherapy; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D015398:Signal Transduction; D022502:Stress Fibers / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019108:Tight Junctions / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D000199:Actins; D000893:Anti-Inflammatory Agents; C107466:CLDN5 protein, human; D002396:Catechols; D062507:Claudin-5; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D064209:Phytochemicals; D010936:Plant Extracts; C018599:4-methylcatechol; C527200:4-ethylcatechol
keywords: 4-Ethylcatechol; 4-Ethylcatechol (PubChem CID: 70761); 4-Methylcatechol; 4-Methylcatehcol (PubChem CID: 9958); 4-Vinylcatechol; 4-Vinylcatechol (PubChem CID: 151398); Actin cytoskeleton; Barleria lupulina; Caffeic acid (PubChem CID: 689043); Endothelial barrier function; Microvascular endothelial cells; Nrf2; Poliumoside (PubChem CID: 6442411); Shanzhiside methyl ester (PubChem CID: 13892722); Traditional medicine