2.3. Reagents and cell culture
HPLC grade solvents (acetonitrile and water) were purchased from Samchun
Pure Chemicals (Pyeongtaek, Korea). Chicken egg ovalbumin (OVA),
dinitrophenol (DNP)-specific monoclonal IgE, DNP-human serum albumin
(HSA), and Evans blue were purchased from Sigma-Aldrich (St. Louis, MO,
USA). Aluminum hydroxide (ImjectTM) were obtained from
Thermo Fisher Scientific (Rockford, IL, USA). All other chemicals were
obtained from Sigma-Aldrich unless otherwise noted. The human mast cell
line HMC-1 was grown in Iscove´s Modified Dulbecco´s Medium (IMDM)
supplemented with 10% fetal bovine serum (FBS) and 1%
penicillin/streptomycin (Invitrogen, Carlsbad, CA, USA) at 37°C under
humidified atmosphere containing 5% carbon dioxide
(CO2).
2.4. OVA-induced allergic
airway inflammation
BALB/c mice (6-8 week old) were used for experimental study after one
week of acclimation. OVA-induced allergic airway inflammation was
generated using previously described modifications (Casaro et al.,
2019). Briefly, mice were sensitized by intraperitoneal injection on
days 0 and 14 with 200 µL saline suspension containing 50 µg OVA
emulsified in 1.6 mg aluminum hydroxide. After one week, mice were
further challenged by intranasal inhalation of 1% OVA aerosol from days
21 to 24 for 30 min. Dimethyl sulfoxide (DMSO, 1%) in
phosphate-buffered saline (PBS) or sophoricoside (3 or 30 mg/kg) was
intraperitoneally administered an hour before OVA challenge from days 20
to 25. Mice were sacrificed 24 h after final treatment, and blood and
organs were collected for further experiments. All animal care and
studies were conducted under specific pathogen-free conditions in
accordance with the guidelines of the Institutional Animal Care and Use
Committee at Chung-Ang University (Approval number: 2019-00113).