title: Resveratrol, piperine and apigenin differ in their NADPH-oxidase inhibitory and reactive oxygen species-scavenging properties.
abstract: BACKGROUND
  Many plant-derived chemicals have been studied for their potential benefits in ailments including inflammation, cancer, neurodegeneration, and cardiovascular disease. The health benefits of phytochemicals are often attributed to the targeting of reactive oxygen species (ROS). However, it is not always clear whether these agents act directly as antioxidants to remove ROS, or whether they act indirectly by blocking ROS production by enzymes such as NADPH oxidase (NOX) enzymes, or by influencing the expression of cellular pro- and anti- oxidants.
  
  
  OBJECTIVE
  Here we evaluate the pro- and anti-oxidant and NOX-inhibiting qualities of four phytochemicals: celastrol, resveratrol, apigenin, and piperine.
  
  
  METHODS
  This work was done using the H661 cell line expressing little or no NOX, modified H661 cells expressing NOX1 and its subunits, and an EBV-transformed B-lymphoblastoid cell line expressing endogenous NOX2. ROS were measured using Amplex Red and nitroblue tetrazolium assays. In addition, direct ROS scavenging of hydrogen peroxide or superoxide generated were measured using Amplex Red and methyl cypridina luciferin analog (MCLA).
  
  
  RESULTS
  Of the four plant-derived compounds evaluated, only celastrol displayed NOX inhibitory activities, while celastrol and resveratrol both displayed ROS scavenging activity. Very little impact on ROS was observed with apigenin, or piperine.
  
  
  CONCLUSIONS
  The results of this study reveal the differences that exist between cell-free and intracellular pro-oxidant and antioxidant activities of several plant-derived compounds.
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: Scott
authors.initials: S
authors.lastname: Whitehouse
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: Pei-Lin
authors.initials: PL
authors.lastname: Chen
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Greenshields
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: Mat
authors.initials: M
authors.lastname: Nightingale
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2; Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: David W
authors.initials: DW
authors.lastname: Hoskin
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2. Electronic address: kbedard@dal.ca.
authors.forename: Karen
authors.initials: K
authors.lastname: Bedard
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D047310:Apigenin / Q000494:pharmacology*; D052117:Benzodioxoles / Q000494:pharmacology*; D002460:Cell Line; D006801:Humans; D006861:Hydrogen Peroxide; D009249:NADP / Q000037:antagonists & inhibitors; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors*; D010084:Oxidation-Reduction; D053978:Pentacyclic Triterpenes; D010880:Piperidines / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D053284:Polyunsaturated Alkamides / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D014315:Triterpenes / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D000975:Antioxidants; D052117:Benzodioxoles; D053978:Pentacyclic Triterpenes; D010880:Piperidines; D010936:Plant Extracts; D053284:Polyunsaturated Alkamides; D017382:Reactive Oxygen Species; D013267:Stilbenes; D014315:Triterpenes; D009249:NADP; D047310:Apigenin; D006861:Hydrogen Peroxide; D019255:NADPH Oxidases; C050414:celastrol; D000077185:Resveratrol; C008922:piperine
keywords: Antioxidant; Celastrol; NADPH oxidase (NOX); Reactive oxygen species; Resveratrol