The Antioxidant and Anti-Complementary Activities of Crude Polysaccharides from Trifoliate Orange (Poncirus trifoliate) Seeds

In this study, I extracted the crude polysaccharides from trifoliate orange (Poncirus trifoliate) seeds, known as TSCP, using water extraction and ethanol precipitation. The monosaccharide composition of TSCP was in the following order: arabinose (28.28 mol%)> galactose (16.76 mol%)> galacturonic acid+glucuronic acid (13.6 mol%)> glucose (12.45 mol%)> rhamnose (4.18 mol%)> mannose (0.57 mol%)> fucose (0.32 mol%). Its total polyphenol contents were 28.66 and 70.96 μg/mL at 1 and 10 mg/mL, respectively (P<0.01). Further, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity of 10 mg/mL TSCP (31.67%) was higher than that of 1 mg/mL TSCP (8.07%; P<0.01) and also higher than its 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (11.97%) at the same concentration (10 mg/mL; P<0.01). The anti-complementary property of TSCP increased in a concentration-dependent manner (P<0.001), and at 1,000 μg/mL, it was comparable (61.36%) to the positive control (60%) consisting of polysaccharide-K. In conclusion, TSCP might be a potential immune modulator.