title: Aloin Inhibits Interleukin (IL)-1β-Stimulated IL-8 Production in KB Cells.
abstract: Interleukin (IL)-1β, which is elevated in oral diseases including gingivitis, stimulates epithelial cells to produce IL-8 and perpetuate inflammatory responses. This study investigates stimulatory effects of salivary IL-1β in IL-8 production and determines if aloin inhibits IL-1β-stimulated IL-8 production in epithelial cells.
  
  
  
  Saliva was collected from volunteers to determine IL-1β and IL-8 levels. Samples from volunteers were divided into two groups: those with low and those with high IL-1β levels. KB cells were stimulated with IL-1β or saliva with or without IL-1 receptor agonist or specific mitogen-activated protein kinase (MAPK) inhibitors. IL-8 production was measured by enzyme-linked immunosorbent assay (ELISA). MAPK protein expression involved in IL-1β-induced IL-8 secretion was detected by Western blot. KB cells were pretreated with aloin, and its effect on IL-1β-induced IL-8 production was examined by ELISA and Western blot analysis.
  
  
  
  Saliva with high IL-1β strongly stimulated IL-8 production in KB cells, and IL-1 receptor agonist significantly inhibited IL-8 production. Low IL-1β-containing saliva did not increase IL-8 production. IL-1β treatment of KB cells induced activation of MAPK signaling molecules as well as nuclear factor-kappa B. IL-1β-induced IL-8 production was decreased by p38 and extracellular signal-regulated kinase (ERK) inhibitor treatment. Aloin pretreatment inhibited IL-1β-induced IL-8 production in a dose-dependent manner and inhibited activation of the p38 and ERK signaling pathway. Finally, aloin pretreatment also inhibited saliva-induced IL-8 production.
  
  
  
  Results indicated that IL-1β in saliva stimulates epithelial cells to produce IL-8 and that aloin effectively inhibits salivary IL-1β-induced IL-8 production by mitigating the p38 and ERK pathway. Therefore, aloin may be a good candidate for modulating oral inflammatory diseases.
authors.affiliation: Department of Oral Microbiology, Pusan National University, Yangsan, Korea.
authors.forename: Hee Sam
authors.initials: HS
authors.lastname: Na
authors.affiliation: Department of Oral Microbiology, Pusan National University, Yangsan, Korea.
authors.forename: Yu Ri
authors.initials: YR
authors.lastname: Song
authors.affiliation: Department of Oral Microbiology, Pusan National University, Yangsan, Korea.
authors.forename: Seyeon
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Oral Medicine, Pusan National University.
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Heo
authors.affiliation: Department of Biochemistry, Pusan National University.
authors.forename: Hae-Young
authors.initials: HY
authors.lastname: Chung
authors.affiliation: Department of Oral Microbiology, Pusan National University, Yangsan, Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Chung
mesh_terms: D002478:Cells, Cultured; D004642:Emodin / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D053583:Interleukin-1beta / Q000502:physiology*; D015850:Interleukin-6 / Q000502:physiology; D016209:Interleukin-8 / Q000378:metabolism*; D007624:KB Cells / Q000378:metabolism; D009059:Mouth Diseases / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; D048051:p38 Mitogen-Activated Protein Kinases; D004642:Emodin; C006457:alloin
keywords: Aloe; KB cells; epithelial cells; interleukin-1beta; interleukin-8