Immunomodulatory effects of Alhagi honey polysaccharides encapsulated into PLGA nanoparticles

Alhagi honey polysaccharides (AHP) have been widely studied as immunomodulators. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles have been frequently used to control the release of drugs. In this study, AHP was extracted and encapsulated within PLGA (AHPP). Enhancement of immune activity in vitro and the adjuvanticity when inoculated with OVA were evaluated. The results demonstrated that the average molecular weight of AHP was 46.8 kDa and possessed typical polysaccharide absorption peaks. The entrapment efficiency for AHP within AHPP was 65.76 ± 3.31%. AHPP significantly stimulated phagocytic activity, MHCII and CD86 expression in macrophages. Further investigation showed that AHPP/OVA significantly enhanced lymphocyte proliferation and improved the CD4+/CD8+ T cell ratio. Moreover, AHPP/OVA treatment significantly increased IgG levels and up-regulated Th-associated cytokines with overall Th1 polarization. These studies demonstrated that AHP encapsulated within PLGA as a vaccine delivery system enhanced adaptive immunity.