Antioxidant, antitumor and immunomodulatory activities of water-soluble polysaccharides in Abrus cantoniensis

• Two polysaccharides (ACP-I and ACP-II) were purified from A. cantoniensis.
• Their structural characterizations were elucidated by different techniques.
• Antioxidant, antitumor, immunomodulatory activity and the correlation were evaluated.
• ACP-I and ACP-II showed anti-migration on MCF-7 cells without any cytotoxicity.
• Polysaccharide fractions attributed to the observed bioactivities of A. cantoninesis.

Abrus cantoniensis is a vegetative food in tropical areas of Asia and claimed as folk beverages and soups consumed for cleansing liver toxicants and preventing liver diseases. Polysaccharides (ACP-І and ACP-II) were extracted with hot water from A. cantoniensis, and isolated by DEAE cellulose chromatography. The chemical properties as well as antioxidant, antitumor and immunomodulatory activities of ACP-I and ACP-II were investigated. The results showed that the ACP-I (9.09 kDa) contained only glucose and ACP-II (38.45 kDa) consisted of rhamnose, arabinose, galactose and glucose. ACP-II exhibited higher oxygen radical absorbance capacity (ORAC) and hydroxyl radical prevention capacity (HRPC) than ACP-I with ORAC values and HRPC values of 53.42 ± 3.32 μmol Trolox equiv./g DW and 34.84 ± 5.07 μmol Trolox equiv./g DW. Besides, in the wound healing assay, ACP-II exhibited potent migration inhibitory effects on MCF-7 cells. ACP-II could also significantly stimulate the proliferation of splenocytes and thymocytes, and enhanced NO production of peritoneal macrophages. These findings suggest that the polysaccharide ACP-II in A. cantoniensis could be served as a novel potential functional food.