The experimental results showed that volatile oil of Origanum vulgare L. (VO) significantly inhibited skindelayed type hypersensitivity (DTH) of mice induced by Dinitrochlorobenzene (DNCB) and sheep red blood cell(SRBC), and also inhibited the production of hemolysin in serum and SRBC hemolysis mediated by spleen cells atthe same dose of 100 mg·kg-1×7 d ip. The results also indicated it could cause thymus and spleen atrophyin mice at the dose. When the dose of VO was reduced to 50 mg·kg-1·d-1×7 d ip, it significantly increasedthe level of hemolysin in the serum of the mice and SRBC hemolysis mediated by spleen cells. VO couldremarkably inhibited DTH in mice induced by DNCB and SRBC at the dose. It suggested that VO could inhibit specificCell-mediated immunity and had different effects on specific humoral immunity with different doses.
