Characterization of an arabinogalactan from the fruit hulls of Ficus pumila Linn. and its immunomodulatory effect

Ficus pumila Linn. fruits has a long history of use as a functional food in East Asia. The present study developed a consecutive process for the production of an arabinogalactan (FPW) from the fruit hulls of Ficus pumila Linn.. FPW was identified as a type II arabinogalactan with a 1,3-beta-D-Galp backbone with O-6 branching to 1,6-linked Gal side chains or terminal-beta-D-Galp, and has a molecular weight of 156 kDa. FPW was proved be capable of promoting NO production, phagocytic activity, and the secretion of cytokines including TNF-alpha, IL-1 beta and IL-6 without inducing substantial cytotoxicity on RAW 264.7 cells, suggesting the potential utilization of FPW as an immunomodulatory agent. The obtained results emphasize Ficus pumila L. fruit hulls as a potentially ideal source of viable and naturally-derived immunomodulatory materials, also providing a method for obtaining the active arabinogalactan from Ficus pumila L. fruit hulls.