Physicochemical Properties,Antioxidant And Anticancer Activities Of Polysaccharides Extracted From Peony Seed Dreg

Peonies?Paeonia suffruticosa Andr.?,in addition to their ornamental values,are widely used in Chinese medicine.Peonies also exhibit an array of biological activities that include antioxidant and immunomodulatory effects.This paper mainly examined physicochemical properties of peony seed dreg polysaccharides sequentially extracted from peony seed dreg,the rheological and emulsifying properties,the antioxidant and antitumor properties.Furthermore,the above properties of four peony seed dreg polysaccharide fractions were compared.The results provide a theoretical basis for the further development of peony seed dreg polysaccharides as functional food.The sequential extraction of peony seed dreg polysaccharides?PSDP?with hot buffer?HBSS?,chelating agent?CHSS?,dilute alkaline?DASS?and concentrated alkaline?CASS?yielded four different polysaccharide fractions.Based on their absorptions at 3600–3200 cm^-1 and 1200–800 cm^-1 by the fourier transform infrared spectrometer,these fractions were confirmed to be polysaccharides.Four polysaccharides fractions with respective molecular weights of 3467,4677,229 and 56 kDa by HPLC.HBSS consisted of Man and Glc;CHSS consisted of Gal and Ara;DASS consisted of Ara,Gal and Man;CASS consisted of Gal,Ara and Glc,respectively.The thermal characteristics of four PSDPs displayed some slight differences.The CASS showed the highest peak temperature and endothermic enthalpy.The rheological properties of PSDPs were investigated by steady-shear and oscillatory rheological measurements.The influence of concentration,pH,temperature and salt ions on the rheological properties of peony seed dreg polysaccharides was analyzed.The four PSDPs fractions in solution exhibited typical non-Newtonian and shear-thinning behavior.The viscosity of HBSS was higher than the rest of the fractions.While the viscosity value of CASS decreased dramatically at acid pH?4.0?and alkaline pH?10.0?.In the presence of Ca²⁺,the viscosity of polysaccharides solution decreased.And under high temperature?90°C?,the viscosity of CASS decreased slowly.CHSS increased in the presence of Na+.As opposed to heating,freezing of samples led to an increase in apparent viscosity.The modulus G' and G” of all PSDPs solution were increased with increasing oscillation frequency ranging between 0.01 and 100 Hz at each concentration.In all four cases,the crossover of G' and G” values decreased gradually with increasing concentration of samples.The properties of four PSDPs displayed some slight differences.The CASS showed the highest peak temperature and endothermic enthalpy.The emulsifying activity and emulsifying stability of four PSDPs exhibited a dose-dependent pattern;HBSS showed the highest emulsifying activity,and CHSS displayed the longest emulsifying stability.The four PSDPs also exhibited wide variations in their antioxidant activities.For example,CASS showed the highest DPPH radical scavenging activity,reducing power and ABTS radical scavenging activity;HBSS exhibited the highest hydroxyl radical scavenging activity;CHSS displayed the higher ferrous ions chelating ability than others.The effects of peony seed dreg polysaccharides on cytotoxicity,cell cycle and apoptosis in HCT-116,PC-3 and Hela cells were studied on this paper.The CASS showed remarkable anticancer activities.In addition,the CASS shown remarkable cytotoxic effects in Hela cells compared to 5-fluorouracil?5-FU?.Through further study found,CASS can cause cell cycle arrest in different cancer cells in G0/G1 phase.In addition,the proportion of apoptotic cells significantly increased in cells treated with CASS?200 mg/m L for 48 h?upto 30.94%?Hela?.These findings indicated that CASS has an antioxidant and anti-cancerous potential in the treatment of human cancers which make it a potent candidate in functional foods.