study the effect of echinacea purpurea extract on cellular delayed type hypersensitivity and splenocyte proliferation in balb/c mice

objective: purple cone flower plant (echinacea purpurea) is one of the most important herbal products in many countries. up to now a lot of experiments demonstrated the controversial effects of this herb on immune system . in this research we study the in vivo and in vitro effect of iranian e.purpurea extract on cellular immunity. materials and methods: at first we determined the lethal dose of e.purpurea extract after intraperitoneal injection in balb/c mice. then we made five groups of mice and treat them by four times intraperitoneal injection of 1 ml extract at different doses (0, 0.4, 2, 10 and 50 mg/ml) during two weeks. splenocyte proliferation response to extract was assessed by mtt method. delayed-type hypersensitivity (dth) response was evaluated by priming mice with 1×108 sheep red blood cell (srbc) injected subcutaneously in the back on day 7after treatment. results: as a result no significant variation in weight and spleen index of test groups to control was observed. splenocyte proliferation and dth response of test groups to control increased significantly (p<0.05). conclusion: however these data confirmed the results of previous studies, in addition presented the first results about significant increase in dth response that could not be seen before. scince the main reason of this difference refers to active compounds of herb extract, comparing effective component of this extract with that of e.purpurea cultivated in other geographical condition will consider as the next studies.