Visit our Expo - Redox and Inflammation signaling 2012

Session IX. Novel compounds targeting inflammatory signaling pathways Poster IX, 3
Wogonin prevents immunosuppressive action but not anti-inflammatory effect induced
by glucocorticoid
Riyo Enomoto1, Chie Suzuki1, Chika Koshiba1, Takayuki Nishino1, Mikiko
Nakayama1, Hiroyuki Hirano2, Toshio Yokoi2 and Eibai Lee1.
1Department of Pharmacology and 2Department of Pharmaceutical Chemistry, Faculty
of Pharmaceutical Sciences, Kobe Gakuin University, Ikawadani-cho, Nishi-ku, Kobe
651-2180 Japan. E-mail : enomoto@pharm.kobegakuin.ac.jp
Glucocorticoid such as dexamethasone has anti-inflammatory and immunosuppressive action
as major pharmacological effects. The latter action caused by lymphocyte apoptosis is not
only therapeutic effect but also adverse reaction. Wogonin, a plant flavone, inhibited
dexamethasone-induced apoptotic changes such as DNA fragmentation, nuclear condensation,
phosphatidylserine exposure and caspase activation in rat thymocytes. Since wogonin
inhibited the dexamethasone-induced DNA fragmentation in the noncompetitive manner, a
target of this flavone is unlikely to the glucocorticoid receptor. This flavone also protected
apoptosis induced by other glucocorticoids. Since wogonin reduced one of major
pharmacological effects of dexamethasone, we examined whether this flavone diminishes the
anti-inflammatory action, another pharmacological effect. The anti-inflammatory action was
measured by the carrageenan-induced edema model. Although dexamethasone significantly
suppressed paw edema induced by carrageenan, wogonin had no effect on the antiinflammatory
action of dexamethasone. These results suggest that wogonin may be an useful
compound to reduce the immunosuppressive side effect of glucocorticoids.
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