Synthesis of Pseudostellaria heterophylla polysaccharide-gold nanocomposites and their antitumor effect through immunomodulation

Polysaccharides from natural sources have an excellent immune function and low toxicity; however, their limitations such as short half-life and instability limit their sustained pharmacological activity. In this context, the combination of polysaccharides and nanotechnology have been developed to promote the stability and prolong the immune activities of polysaccharides. To synthesize and explore the antitumor effect and immunomodulatory activity of PHP-AuNPs. Polysaccharides extracted from Pseudostellaria heterophylla were used to synthesize gold nanocomposites (PHP-AuNPs), and their physicochemical properties and immunoregulatory effect in vitro and in vivo were analyzed. The PHP-AuNPs were green synthesized with high biosafety. PHP-AuNPs can activate macrophages in vitro and decrease the tumor weight and volume, whereas they increase the immune organ index in vivo. Besides, PHP-AuNPs showed a beneficial effect for maintaining the immune balance of CD4(+)/CD8(+) T cells and modulating the release of cytokines such as TNF-alpha increase and IL-10 decrease in mice. All these results suggested that PHP-AuNPs exhibit a remarkable antitumor effect and stronger immunomodulatory activity than that of free PHP-1.