Physicochemical properties, antioxidant activity and immunological effects in vitro of polysaccharides from Schisandra sphenanthera and Schisandra chinensis

Schisandra sphenanthera and Schisandra chinensis are widely consumed either as food or for medicinal purposes. Nevertheless, no detailed comparative assessments of their physicochemical properties and biological activity have been reported. In this paper, using hot-water extraction, alcohol precipitation, and deproteinization, we obtained polysaccharidic extracts from Schisandra sphenanthera and Schisandra chinensis (denoted as SSP and SCP, respectively) and investigated their antioxidant and immunological activities. The extracts were different from each other with regard to sugar, protein, and uronic acid contents. Both extracts were mainly composed of arabinose, glucose, and galactose, but their contents varied greatly; SSP had more galacturonic acid. Compared with SCP, SSP had stronger free radical scavenging ability, protective effects on biomolecules, cellular antioxidant activity, owing to its higher protein (35.35 ± 1.73%) and uronic acid (12.81 ± 1.15%) contents. With respect to cell viability, neutral red phagocytosis, NO production, and acid phosphatase activity, SCP had stronger effects than SSP; this was largely due to its high levels of mannose, galactose, arabinose, and glucose. These results provide evidence to support the use Schisandra-derived polysaccharides for several purposes, including clinical, agricultural, and industrial applications.