Hop water extract inhibits double-stranded RNA-induced thymic stromal lymphopoietin release from human nasal epithelial cells

• Published in: American journal of rhinology & allergy Vol. 26; no. 6; pp. 433 - 438
• Main Authors: Fuchimoto, Jun, Kojima, Takashi, Kobayashi, Naoyuki, Ohkuni, Tsuyoshi, Ogasawara, Noriko, Masaki, Tomoyuki, Obata, Kazufumi, Nomura, Kazuaki, Kondoh, Atsushi, Shigyo, Tatsuro, Himi, Tetsuo, Sawada, Norimasa
• Format: Journal Article
• Language: English
• Published: United States 01-11-2012
• Subjects: Cell Survival - drug effects; Cells, Cultured; Cytokines - secretion; Dexamethasone - pharmacology; Humans; Humulus; Interleukin-1beta - pharmacology; Nasal Mucosa - cytology; Nasal Mucosa - drug effects; Nasal Mucosa - secretion; NF-kappa B - metabolism; Plant Extracts - pharmacology; Protein Kinase C - metabolism; RNA, Double-Stranded - pharmacology; Tetradecanoylphorbol Acetate - pharmacology
• ISSN: 1945-8924; 1945-8932
• DOI: 10.2500/ajra.2012.26.3814

Thymic stromal lymphopoietin (TSLP) acts as a master switch for allergic inflammation and plays a key role in allergic diseases, including allergic rhinitis. Double-stranded RNA (dsRNA) recognized by Toll-like receptor 3 (TLR3) strongly activates TSLP release from human nasal epithelial cells (HNECs). Hop (Humulus lupulus L.) extracts have been shown to have potent pharmacologic effects on inflammation.
To investigate whether a hop water extract (HWE) prevents TSLP release from HNECs, human telomerase reverse transcriptase (hTERT)-transfected HNECs, used as a model of normal HNECs, were pretreated with HWE before treatment with the TLR3 ligand Polyinosine-polycytidylic acid (poly[I:C]).
In the hTERT-transfected HNECs, treatment with HWE significantly reduced poly(I:C)-induced production and release of TSLP in a dose-dependent manner, as well as dexamethasone. Treatment with the protein kinase C (PKC) inhibitor GF109203X and NF-κB inhibitor IMD-0354 also reduced poly(I:C)-induced TSLP release from hTERT-transfected HNECs. Treatment with HWE efficiently prevented up-regulation of PKC activity by 12-O-tetradecanoyl phorbol-13-acetate but not NF-κB activity induced by IL-1β in hTERT-transfected HNECs.
Our results clearly indicated that HWE inhibited dsRNA-induced production and release of TSLP via a PKC signal pathway in HNECs and it may have potent preventive effects against allergic rhinitis.