Introduction:
Dracocephalum kotschyi is a native medicinal plant in Iran. D. kotschyi extract has been shown to inhibit lectin-induced cellular immune response in vitro. The objective of this research was to examine immunomodulatory action of D. kotschyi extract in animal model.Methods: To investigate the effect of D. kotschyi hydroalcoholic extract on innate immune system, mice left hind footpad thickness were measured and the D. kotschyi extract were administered via i.p. injection to the animals. An hour later, the animals were received an injection of sheep red blood cell (SRBC) into the left footpad (s.c). Footpad thickness was measured at 1, 2, 4, 6, 8, 24 and 48 hours intervals following antigen challenge.For investigation of effect of test drugs on acquired immunity, SRBC was injected (s.c) on the back of the animals and left in the cage for five successive days. On sixth day, SRBC was injecting into the left hind footpad and Footpad thickness was measured as above.Three groups of mice receiving hydroalcoholic extract (5, 10, 20 or 40 mg/kg). Betamethasone (4mg/kg, i.p.) and levamisol (4mg/kg, i.p) were used as positive control groups while normal saline was as negative control group. Data expressed as mean ± SEM (n=6) for each group of results. For statistical analysis one way analysis of variance (ANOVA) was used. This project was confirmed by the ethical committee of the university.Results: The results obtained indicated that levamizole potentiated the immune response while betamethasone inhibited both innate and adaptive immune responses. Hydroalcoholic extract of D. kotschyi markedly inhibited both innate and adaptive responses. The highest inhibitory effect was seen with extract dose of 20mg/kg (i.p.).Conclusion: This study confirms immunosuppressant effect of hydroalcoholic extract of D. kotschyi in inflammatory condition.