title: Psidium guajava extract inhibits thymus and activation-regulated chemokine (TARC/CCL17) production in human keratinocytes by inducing heme oxygenase-1 and blocking NF-κB and STAT1 activation.
abstract: Psidium guajava (P. guajava) is a food and medicinal plant with antioxidant, anti-inflammatory, and anti-allergic activities that support its traditional uses. The aim of this study was to determine the effects of P. guajava ethyl acetate extract (PGEA) on atopic dermatitis and to investigate the possible mechanisms by which PGEA inhibits cytokine-induced Th2 chemokine expression in HaCaT human keratinocyte cells. We found that PGEA suppressed the IFN-γ/TNF-α-co-induced production of thymus and activation-regulated chemokine (TARC) protein and mRNA in HaCaT cells. Additionally, PGEA inhibited the TNF-α/IFN-γ-co-induced activation of NF-κB and STAT1 and increased the expression of heme oxygenase-1 (HO-1) protein and mRNA. HO-1 inhibitor enhanced the suppressive effects of PGEA on TNF-α/IFN-γ-co-induced TARC production and gene expression. Collectively, these data demonstrate that PGEA inhibits chemokine expression in keratinocytes by inducing HO-1 expression and it suggests a possible therapeutic application in atopic dermatitis and other inflammatory skin diseases.
authors.affiliation: Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon 305-764, Republic of Korea.
authors.forename: Eun Hee
authors.initials: EH
authors.lastname: Han
authors.forename: Yong Pil
authors.initials: YP
authors.lastname: Hwang
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Choi
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Yang
authors.forename: Jong Kwon
authors.initials: JK
authors.lastname: Seo
authors.forename: Young Chul
authors.initials: YC
authors.lastname: Chung
authors.forename: Hye Gwang
authors.initials: HG
authors.lastname: Jeong
mesh_terms: D018926:Anti-Allergic Agents / Q000494:pharmacology / Q000627:therapeutic use; D002460:Cell Line; D054414:Chemokine CCL17 / Q000276:immunology*; D003876:Dermatitis, Atopic / Q000188:drug therapy / Q000276:immunology; D004790:Enzyme Induction / Q000187:drug effects; D051547:Heme Oxygenase-1 / Q000378:metabolism*; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D016328:NF-kappa B / Q000378:metabolism*; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D031647:Psidium / Q000737:chemistry*; D050794:STAT1 Transcription Factor / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D018926:Anti-Allergic Agents; C106230:CCL17 protein, human; D054414:Chemokine CCL17; D016328:NF-kappa B; D010936:Plant Extracts; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D051547:Heme Oxygenase-1