Abstract:

Rhododendron moulmainense has the effects of astringent，hemostasis，swelling and pain relief，promoting blood circulation and removing blood stasis，dispelling wind and removing dampness，lightening spots and whitening. To explore the preparation methods and immunosuppressive activities of different extraction parts and components of R. moulmainense，the dried flower powder of R.moulmainense was used as raw material，and the volume fraction of 95% ethanol was used as the extraction agent under the condition of 60 ℃ and solid-liquid ratio of 1∶10，and the condensation reflux extraction was carried out for 2 h. The extract was collected by filtration，and concentrated under vacuum and pressure to obtain the extract of R.moulmainense. At a mass concentration of 100 μg· mL^-1，the ethyl acetate extract EADJ-H exhibited inhibition rates of 73.87% and 56.97% on T lymphocyte proliferation induced by concanavalin A and B lymphocyte proliferation induced by lipopolysaccharide，respectively，and had no cytotoxicity to spleen lymphocytes of normal mouse，indicating that the extract of R.moulmainense had strong immunosuppressive activity，and had potential application value in the development of new immunosuppressive agents.

Key words: Rhododendron moulmainense, active ingredient, extraction, pharmacological activity, immunosuppression, lymphocyte proliferation, cytotoxicity