Wogonin prevents immunosuppressive action but not anti-inflammatory effect induced by glucocorticoid.
Glucocorticoid, such as dexamethasone, has anti-inflammatory and immunosuppressive action as major pharmacological effects. The latter action caused by lymphocyte apoptosis is not only a therapeutic effect but also an adverse reaction. Wogonin, a plant flavone found in Scutellaria baicalensis Georgi, inhibited dexamethasone-induced apoptotic changes, such as DNA fragmentation, nuclear condensation, phosphatidylserine translocation, and caspase activation in rat thymocytes. Since wogonin inhibited dexamethasone-induced DNA fragmentation in a noncompetitive manner, a target of this flavone is unlikely to be an antagonist of glucocorticoid receptor. Wogonin did not only act as an inhibitor of caspases, but also protected apoptosis induced by other glucocorticoids. Since wogonin reduced one of the major pharmacological effects of dexamethasone, we examined whether this flavone diminishes the anti-inflammatory action, another pharmacological effect. The anti-inflammatory action of dexamethasone was evaluated by carrageenan-induced paw edema model. Although dexamethasone significantly suppressed paw edema induced by carrageenan, wogonin had no effect on the anti-inflammatory action of dexamethasone. These results suggest that wogonin may be a useful compound to reduce the immunosuppressive side effect of glucocorticoid.
Enomoto
Riyo
R
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan. elee@pharm.kobegakuin.ac.jp
Suzuki
Chie
C
Koshiba
Chika
C
Nishino
Takayuki
T
Nakayama
Mikiko
M
Hirano
Hiroyuki
H
Yokoi
Toshio
T
Lee
Eibai
E
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D003907:Dexamethasone / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D004365:Drugs, Chinese Herbal / Q000009:adverse effects / Q000494:pharmacology; D004487:Edema / Q000473:pathology / Q000517:prevention & control; D044950:Flavanones / Q000494:pharmacology*; D006854:Hydrocortisone / Q000009:adverse effects / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D008214:Lymphocytes / Q000187:drug effects; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects
D000893:Anti-Inflammatory Agents; D004365:Drugs, Chinese Herbal; D044950:Flavanones; D007166:Immunosuppressive Agents; D003907:Dexamethasone; C085514:wogonin; D006854:Hydrocortisone