title: Antioxidant activities of aqueous leaf extracts of Toona sinensis on free radical-induced endothelial cell damage.
abstract: BACKGROUND
  In Taiwan, Toona sinensis (Toona sinensis) is well known as a traditional Chinese medicine, while the underlying pharmacological mechanisms of this drug are still a matter of debate.
  
  
  METHODS
  The purpose of this study was to evaluate the protective effects of non-cytotoxic concentrations of aqueous leaf extracts of Toona sinensis (TS extracts; 50-100 μg/mL) and gallic acid (5 μg/mL), a major component of these extracts, against AAPH-induced oxidative cell damage in human umbilical vein endothelial cells (ECs).
  
  
  RESULTS
  Exposure of ECs to AAPH (15 mM) decreased cell viability from 100% to 43%. However, ECs were pre-incubated with TS extracts prior to AAPH induction resulted in increased resistance to oxidative stress and cell viability in a dose-dependent manner. An increase in ECs-derived PGI(2) and IL-1 β in response to AAPH exposure was positively correlated with cytotoxicity and negatively with TS extracts concentrations. In addition, gallic acid also suppressed PGI(2) and IL-1 β production in AAPH-induced ECs. Notably, TS extracts/gallic acid treatment significantly inhibited ROS generation, MDA formation, SOD/catalase activity, and Bax/Bcl-2 dysregulation in AAPH-stimulated ECs. Pretreatment of ECs with TS extracts/gallic acid also suppressed AAPH-induced cell surface expression and secretion of VCAM-1, ICAM-1 and E-selectin, which was associated with abridged adhesion of U937 leukocytes to ECs. Moreover, TS extracts/gallic acid treatment significantly inhibited the AAPH-mediated up regulation of PAI-1 and down regulation of t-PA in ECs, which may decrease fibrinolytic activity.
  
  
  CONCLUSIONS
  Therefore, Toona sinensis may possess antioxidant properties that protect endothelial cells from oxidative stress. Our results also support the traditional use of Toona sinensis in the treatment of free radical-related diseases and atherosclerosis.
authors: Institute of Nutrition, China Medical University, Taichung, Taiwan.
authors: Hsin-Ling
authors: HL
authors: Yang
authors: Ssu-Ching
authors: SC
authors: Chen
authors: Kai-Yuan
authors: KY
authors: Lin
authors: Mei-Tsun
authors: MT
authors: Wang
authors: Yu-Chang
authors: YC
authors: Chen
authors: Hui-Chi
authors: HC
authors: Huang
authors: Hsin-Ju
authors: HJ
authors: Cho
authors: Lai
authors: L
authors: Wang
authors: K J Senthil
authors: KJ
authors: Kumar
authors: You-Cheng
authors: YC
authors: Hseu
mesh_terms: D000578:Amidines / Q000633:toxicity; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D018920:Coculture Techniques; D019610:Cytoprotection; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D019040:E-Selectin / Q000378:metabolism; D011464:Epoprostenol / Q000378:metabolism; D005609:Free Radicals / Q000378:metabolism*; D005707:Gallic Acid / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D029582:Meliaceae / Q000737:chemistry; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects*; D018515:Plant Leaves; D010946:Plants, Medicinal; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012997:Solvents / Q000737:chemistry*; D013482:Superoxide Dismutase / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000378:metabolism; D020298:U937 Cells; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism; D014867:Water / Q000737:chemistry*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D000578:Amidines; D000975:Antioxidants; C494826:BAX protein, human; D004365:Drugs, Chinese Herbal; D019040:E-Selectin; D005609:Free Radicals; D053583:Interleukin-1beta; D016877:Oxidants; D017395:Plasminogen Activator Inhibitor 1; D019253:Proto-Oncogene Proteins c-bcl-2; C546936:SELE protein, human; C051321:SERPINE1 protein, human; D012997:Solvents; D019010:Vascular Cell Adhesion Molecule-1; D051028:bcl-2-Associated X Protein; D014867:Water; D018799:Intercellular Adhesion Molecule-1; D008315:Malondialdehyde; D005707:Gallic Acid; C046728:2,2'-azobis(2-amidinopropane); D011464:Epoprostenol; D002374:Catalase; D013482:Superoxide Dismutase; D010959:Tissue Plasminogen Activator