Effect of saiboku-to, an antiasthmatic herbal medicine, on nitric oxide generation from cultured canine airway epithelial cells.
The effect of Saiboku-to (TJ-96), an antiasthmatic Kampo medicine, on the generation of nitric oxide (NO) from cultured canine tracheal epithelium was investigated using a highly specific amperometric sensor for this molecule in vitro. Immersion of the NO-selective electrode in the medium containing tracheal epithelial cells detected the baseline current of 16.8-57.0 pA, which corresponded to an NO concentration ([NO]) of 39.7 +/- 8.1 nM. Addition of TJ-96 increased [NO] in a concentration-dependent manner, the maximal increase from the baseline level and the concentration of TJ-96 required to produce a half-maximal effect (EC50) being 127.5 +/- 20.1 nM (P < 0.001) and 86 +/- 9 micrograms/ml, respectively. Pretreatment of cells with NG-nitro-L-arginine methylester (L-NAME) greatly inhibited the TJ-96-induced increase in [NO], whereas NG-nitro-D-arginine methylester (D-NAME) had no effect, and this inhibition was reversed by L-arginine but not by D-arginine. Cytochemical staining of the epithelial cells showed marked reactivity of NADPH diaphorase activity. These results suggest that NO is spontaneously released by the airway epithelium and that TJ-96 stimulates the epithelial NO generation.
Tamaoki
J
J
First Department of Medicine, Tokyo Women's Medical College, Japan.
Kondo
M
M
Chiyotani
A
A
Takemura
H
H
Konno
K
K
D000818:Animals; D002478:Cells, Cultured; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D005260:Female; D008297:Male; D008516:Medicine, Chinese Traditional; D009569:Nitric Oxide / Q000378:metabolism*; D008517:Phytotherapy; D014132:Trachea / Q000187:drug effects*
D009569:Nitric Oxide