Immunomodulatory effects of proanthocyanidin A-1 derived in vitro from Rhododendron spiciferum

The objective of this study was to evaluate the immunomodulatory effects of proanthocyanidin A-1 (PAA-1) from leaves of Rhododendron spiciferum (Ericaceae). In vitro tests showed that PAA-1 stimulated cell proliferation of splenocytes and peritoneal macrophages significantly enhanced the cytotoxicity of natural killer (NK) cells and increased CD4+ and CD8+ cell populations. PAA-1 also regulated the expression of Th1- and Th2-related cytokines. Moreover, this study showed that PAA-1 exhibited a significant effect on NBT dye reduction and lysosomal enzyme activity responses in macrophages, indicating effective phagocytic activation. These results revealed that PAA-1 exhibits immunomodulatory activity without a clear dose response.

Proanthocyanidin A-1 was first isolated from Rhododendron spiciferum. It exhibited immunomodulatory activities with respect to activated splenocytes and peritoneal macrophages, enhanced the cytotoxicity of natural killer cells in vitro.Figure optionsDownload as PowerPoint slide