Polysaccharides obtained from certain plants have been reported to have immunomodulatory properties. As a consequence of these reports the aim of this study was to investigate some immunomodulatory properties of water extracts ofAlcea roseaL. (ARE),Malva sylvestrisL. (MSE) andSalvia libanoticaL. (SLE).
Groups of egg albumin (EA)-immunized and -non-immunized Balb/c mice were treated with the carbohydrate-rich water extracts. Mice from each group were bled and their spleens removed at 3, 6 and 10 days post-immunization/treatment. Anti-egg albumin antibody levels in the processed sera were determined by an enzyme linked immunosorbent assay (ELISA). RNA was extracted from spleen cells and interleukin-4 (IL-4), interleukin-12 (IL-12) andγ-interferon transcripts were determined by the reverse transcription polymerase chain reaction (RT-PCR).
ARE appeared to boost the antibody response to EA, but had no effect on IL-4 andγ-interferon gene transcription. MSE and SLE appeared to have no effect on anti-EA antibody production, but enhanced IL-12 andγ-interferon gene transcription. MSE appeared to switch off, and SLE had no effect on, IL-4 transcription.
In conclusion, it appears that ARE is a B-lymphocyte polyclonal activator, and MSE and SLE are macrophage and T helper-1 (Th-1) activators. Copyright © 2008 John Wiley & Sons, Ltd.