Evaluation of the proliferative activity of aqueous extracts from three medicinal plants in murine spleen cells

There are number of medicinal plant products (leaves, root, stem bark, seeds etc.) including its metabolites i.e. primary (protein) and secondary (flavonoids, terpenoids, glycosides etc.) that have been used as immunomodulatory (stimulatory, suppressive or adjuvant) agents. For the last several years, researchers focused on various immunopharmacological aspects especially its therapeutic action of these medicinal plants against various diseases. The objective of our study was to identify and evaluate the action of aqueous leaves extract from these medicinal plants i.e. Azadirachta indica, Syzygium cuminiand Prosopis spicigera on the development of spleen cells (ex vivo cellular proliferation assay) from mice using hepatitis B vaccine containing surface antigen (HBsAg; 20 µg/ml) and also estimated its pro-inflammatory (IFN-gamma and TNF alpha) cytokines from spleen cell culture supernatant. For these studies, mice were immunized subcutaneously with HBsAg on day 0. After three days, spleens were excised aseptically and prepared single cell suspension (106 cells/ml) using variable doses of aqueous leaves extract (0.625-5 mg; 50 µl) incubated with or without HBsAg. After 48 h, cell culture supernatant was collected for the estimation of Th1 (IFN-gamma and TNF alpha) cytokines. However, cell proliferation was revealed by blue tetrazolium reduction assay (MTT) and cytokines by ELISA. The results showed these aqueous leaves extracts showed dose-dependent reduction of cell proliferation including pro-inflammatory cytokines. Overall, these medicinal plants showed immunosuppressive activity in ex vivomurine model based studies