title: Luteolin inhibits lipopolysaccharide actions on human gingival fibroblasts.
abstract: Periodontal disease comprises a group of infections that lead to inflammation of the gingiva, periodontal tissue destruction, and in severe cases is accompanied by alveolar bone loss with tooth exfoliation. Actinobacillus actinomycetemcomitans is a Gram-negative microorganism, which possesses and produces lipopolysaccharide (LPS) molecules that play a key role in disease development. Human gingival fibroblasts are the major constituents of gingival connective tissue and may interact directly with bacteria and bacterial products including LPS. Flavonoids possess antioxidant and anti-inflammatory properties that reduce inflammatory molecule expression in macrophages and monocytes. In this study, we evaluated the ability of diverse flavonoids to regulate nitric oxide production of LPS-stimulated human gingival fibroblasts, and studied the effect of luteolin on diminish phosphorylation in mitogen-activated protein kinase (MAPK) family members as well as in protein kinase B (Akt), nuclear factor kappa B (NF-kappaB) activation, inducible nitric oxide synthase (NOS) expression, and nitric oxide (NO) synthesis. We also found that pretreatment with three flavonoids, including quercetin, genistein, and luteolin, blocked nitric oxide synthesis in a dose-dependent fashion. Luteolin exerted the strongest blocking action on expression of this inflammatory mediator. Luteolin pretreatment attenuated LPS-induced extracellular signal-regulated kinase, p38, and Akt phosphorylation. LPS treatment of human gingival fibroblasts resulted in NF-kappaB translocation. Cell pretreatment with luteolin abolished LPS effects on NF-kappaB translocation. In addition, luteolin treatment blocked LPS-induced cellular proliferation inhibition without affecting genetic material integrity. We concluded that luteolin interferes with LPS signaling pathways, reducing activation of several mitogen-activated protein kinase family members, and inhibits inflammatory mediator expression.
authors.affiliation: Laboratorio de Bioquímica de la División de Estudios de Posgrado de la Facultad de Odontología, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 México, D.F., México. gloria@fo.odonto.unam.mx
authors.forename: Gloria
authors.initials: G
authors.lastname: Gutiérrez-Venegas
authors.forename: Perla
authors.initials: P
authors.lastname: Kawasaki-Cárdenas
authors.forename: Santa Rita
authors.initials: SR
authors.lastname: Arroyo-Cruz
authors.forename: Silvia
authors.initials: S
authors.lastname: Maldonado-Frías
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002867:Chromones / Q000494:pharmacology; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology; D005881:Gingiva / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D047311:Luteolin / Q000494:pharmacology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D011134:Polysaccharides / Q000494:pharmacology*; D021381:Protein Transport / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D002867:Chromones; D004791:Enzyme Inhibitors; D005419:Flavonoids; D009025:Morpholines; D016328:NF-kappa B; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011134:Polysaccharides; D009569:Nitric Oxide; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D019001:Nitric Oxide Synthase; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D047311:Luteolin