Effect of phenylethanoid glycosides and polysaccharides from the seed of Plantago asiatica L. on the maturation of murine bone marrow-derived dendritic cells

The seed of Plantago asiatica L. is one of the most popular folk herbal medicines used in China and other Asian countries. In this study, phenylethanoid glycosides and polysaccharides were isolated from the seed of P.asiatica L. by using phytochemical investigation methods. A screening model of immunological activity by using dendritic cells as target cells was established to investigate the effects of these compounds on the phenotypic and functional maturation of dendritic cells. Compared with untreated cells, dendritic cells treated with acteoside, isoacteoside or polysaccharides expressed higher level of class II MHC and costimulatory molecule CD86 (B7-2). Functional maturation was confirmed by decreased endocytosis and increased naïve T cell stimulatory activity of dendritic cells. These results showed that acteoside, isoacteoside and polysaccharides from the seed of P.asiatica L. had significant immunoenhancing activity by inducing the maturation of dendritic cells.