title: Inhibitory effect of baicalin on allergic response in ovalbumin-induced allergic rhinitis guinea pigs and lipopolysaccharide-stimulated human mast cells.
abstract: OBJECTIVE
  Baicalin, a flavonoid compound purified from the dry roots of Scutellaria baicalensis Georgi, has generally been used for the treatment of various allergic diseases. However, there is little information about the anti-inflammatory effects of baicalin for allergic rhinitis. This study aims to investigate the anti-allergic effect of baicalin on allergic response in ovalbumin (OVA)-induced allergic rhinitis guinea pigs and lipopolysaccharide (LPS)-stimulated human mast cells.
  
  
  METHODS
  Using in vivo models, we evaluated the effect of baicalin on allergic rhinitis symptoms via recording the number of nasal rubs and sneezes. The levels of histamine, OVA-specific immunoglobulin E(IgE), eosinophil cationic protein (ECP) and inflammatory cytokines were measured using enzyme-linked immunosorbent assay (ELISA). The histological changes of nasal mucosa were observed by light microscope after HE staining. In vitro, the release of histamine and β-hexosaminidase of compound 48/80-induced human mast cells were measured by ELISA and PNP-NAG colorimetry, respectively. The productions of inflammatory cytokines of LPS-stimulated human mast cells were determined using ELISA. Western blot was used to test the protein expression of JAK2, p-JAK2, STAT5, p-STAT5, IKKβ, p-IKKβ, IκBα, p-IκBα and NF-κB (p65) of LPS-stimulated human mast cells.
  
  
  RESULTS
  The oral administration of baicalin at doses of 50 and 200 mg/kg improved allergic rhinitis symptoms and the histological changes of nasal mucosa and decreased the serum levels of histamine, ECP, interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α and OVA-specific IgE in OVA-induced allergic rhinitis guinea pigs. In vitro, baicalin suppressed the release of histamine and β-hexosaminidase in compound 48/80-induced human mast cells. In addition, baicalin also inhibited the productions of inflammatory cytokines such as IL-1β, IL-6, IL-8 and TNF-α and suppressed the phosphorylation of JAK2, STAT5, IKKβ, IκBα and the nuclear translocation of NF-κB (p65) subunit in LPS-stimulated human mast cells.
  
  
  CONCLUSIONS
  These results suggest that baicalin can effectively prevent allergic response in OVA-induced allergic rhinitis guinea pigs and inhibit inflammatory response via blocking JAK2-STAT5 and NF-κB signaling pathways in LPS-stimulated human mast cells. Considered together,the results show that baicalin may be a useful drug in the treatment of allergic rhinitis.
authors.affiliation: Department of Pharmacology, Chongqing Medical University, Chongqing, 400016, China.|Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing, 400016, China.
authors.forename: Yun-Jiang
authors.initials: YJ
authors.lastname: Zhou
authors.affiliation: Department of Pharmacology, Chongqing Medical University, Chongqing, 400016, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Pharmacology, Chongqing Medical University, Chongqing, 400016, China.
authors.forename: He-Huan
authors.initials: HH
authors.lastname: Sui
authors.affiliation: Department of Pharmacology, Chongqing Medical University, Chongqing, 400016, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Jingzhou Institute of Technology, Jingzhou, 434020, Hubei, China.
authors.forename: Chun-Ling
authors.initials: CL
authors.lastname: Zhou
authors.affiliation: Department of Pharmacology, Chongqing Medical University, Chongqing, 400016, China. huangjiajuncqmu@163.com.|Chongqing Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing, 400016, China. huangjiajuncqmu@163.com.
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Huang
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000097:blood; D005419:Flavonoids / Q000494:pharmacology / Q000627:therapeutic use*; D006168:Guinea Pigs; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D053614:Janus Kinase 2 / Q000378:metabolism; D008070:Lipopolysaccharides; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D009297:Nasal Mucosa / Q000187:drug effects / Q000276:immunology; D010047:Ovalbumin; D065631:Rhinitis, Allergic / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D050799:STAT5 Transcription Factor / Q000378:metabolism
chemical_list: D018926:Anti-Allergic Agents; D016207:Cytokines; D005419:Flavonoids; D008070:Lipopolysaccharides; D016328:NF-kappa B; D050799:STAT5 Transcription Factor; C038044:baicalin; D007073:Immunoglobulin E; D010047:Ovalbumin; D053614:Janus Kinase 2
keywords: Allergic rhinitis; Baicalin; Human mast cells; Lipopolysaccharide; Ovalbumin