An extract of Ulmus macrocarpa improves cellular immunity in immuno-suppressed models.

An extract ofUlmus macrocarpa Hance, commonly known as the large-fruited elm, has been prescribed as a traditional medicine. In this study, we aimed to investigate the cellular immune effects ofU. macrocarpastem cortex extracts on cyclophosphamide (CY)-treated splenocytes and mice. A methanol extract showed an improved survival rate of splenocytes after 72 h. The extract was successively partitioned with dichloromethane, ethyl acetate, n-butanol, and water; and the fractions so obtained were also examined for their proliferative activity. Among them, the water fraction ofU. macrocarpashowed the highest proliferation of splenocytes and was used throughout the present study. We tested the survival rate of splenocytes through dose-dependent treatment of CY and the suppression of the survival effect by CY was recovered by treatment with the water extract ofU. macrocarpa. To determine the mechanism involved, we examined the expression of B-cell lymphoma-extra large (Bcl-xL) anti-apoptotic protein. CY decreased Bcl-xL protein levels in resting splenocyte cultures, whereas splenocytes were exposed to water extracts ofU. macrocarpain the presence of CY; however, elevations in Bcl-xL were observed at 96 h. Mice splenocytes treated with water extract ofU. macrocarpafor cellular immunity showed an increase in the activity of the mixed lymphocyte reaction (MLR), cytotoxic T lymphocytes (CTLs), and natural killer (NK) cells. In addition, mice receiving a water extract ofU. macrocarparecovered the CTL, NK, and MLR activities suppressed by CY administration. Consequently,U. macrocarpaimproves the cell-mediated immune response and provides an insight on cell-based tonic materials. [ABSTRACT FROM PUBLISHER]