Combination effects of Shosaikoto (Chinese traditional medicine) and prednisolone on the anti-inflammatory action.

Effects of combined use of Shosaikoto (one of the famous crude Chinese medicines) and prednisolone were examined in anti-inflammatory effects, using the carrageenan edema and the cotton pellet methods. Shosaikoto and prednisolone were orally given to rats or mice at the dose of 1.1 g/kg (corresponding to 10 times the usual human dose) for the former and 1.0, 4.0 and 16.0 mg/kg for the latter. Shosaikoto showed the mild anti-inflammatory action and significantly increased the anti-inflammatory effect of prednisolone in both experimental models. In cotton pellet method, combined use of Shosaikoto inhibited the decrease of adrenal weight induced by prednisolone. To clarify the mechanism of combined effects of prednisolone and Shosaikoto, the effects of Shosaikoto on the blood prednisolone level and on the secretion of endogenous glucocorticoid (corticosterone) were investigated by high performance liquid chromatography. The blood prednisolone level 20 min after the combined administration of Shosaikoto with prednisolone, 16 mg/kg, was about 2 times comparing with that of single administration of prednisolone. The half life period of blood prednisolone after the single administration of prednisolone was about 2 times comparing with that of the combined administration of Shosaikoto with prednisolone. On the other hand, the single administration of Shosaikoto increased the blood corticosterone level 1 h after the administration with significant manner. The increasing activity of Shosaikoto on the anti-inflammatory effect of prednisolone may be explained by its plural actions.