Extraction, partial characterization and bioactivity of polysaccharides from Senecio scandens Buch.-Ham

Mechanochemistry was applied to improve the yield of bioactive acid polysaccharides obtained from low-cost Senecio scandens Buch.-Ham. The structural characteristics and biological activities of three novel polysaccharides from S. scandens (SP2-1, SP2-2 and SP3-2) were investigated. SP2-1 and SP2-2 with molecular weights of 267.6 and 253.1 kDa, respectively, were composed of L-rhamnose, D-arabinose, D-mannose, D-xylose, D-glucose and D-galactose in various ratios, whereas SP3-2 with molecular weight of 266.6 kDa was composed of D-arabinose, D-glucose and D-galactose. In vitro, SP3-2 presented the strongest DPPH, ABTS and O2- radicals scavenging activities, as well as Fe3+ reducibility. Immunological tests demonstrated that all polysaccharide fractions stimulated the production of nitric oxide (NO) and immunomodulatory cytokines (IL-1 beta and TNF-alpha) without cytotoxicity in macrophages and promoted splenocyte proliferation in different degree. These findings indicated that SP2-1, SP2-2 and SP3-2 have prominent antioxidant activity and potential immune response, which proved the possibility of S. scandens polysaccharides (SSP) applied in the field of functional food or medicine. (C) 2017 Elsevier B.V. All rights reserved.