Study On Isolation And Pharmacological Activity Of Polysaccharides From Cirsium Japonicum

Cirsium japonicum DC.is a kind of compositae plants of the genus thistle,playing important roles in anti-tumor,anti-oxidant,anti-diabetes and immune regulation.The active ingredients of Cirsium japonicum include flavonoids,flavonoid glycosides,volatile oils,polysaccharides and so on.Many studies aimed at the biological activities of Cirsium japonicum flavonoids while few research done on polysaccharides.Here,the polysaccharide was extracted from Cirsium japonicum,and its structural characteristics and pharmacological activities were studied.The crude polysaccharide was first extracted from Cirsium japonicum by using the hot water extraction method and the lipid and protein were then removed using diethyl ether.Together with dialyzing and freeze-drying methods,the crude polysaccharide was further purified by DEAE-Cellulose chromatographic method.Chemical composition analysis showed that the sample contains 2.9 % protein,10.4 % alduronic acid and 91.6% polysaccharide which consisted of three majorcomponents with molecular weight of 190.0 kDa,46.5 k Da and 3.9 kDa,respectively.The results of Periodate oxidation and Smith degradation showed that Cirsium japonicum polysaccharide had complex branch structure and contained lots of glycosidic bonds which can not be oxidized by Periodate.Infrared spectroscopic analysis indicated that Cirsium japonicum polysaccharide contained many kinds of functional groups,such as –OH,-COOH,-C≡C-,pyranoid ring and so on.The GSH,MDA,SOD,and ALT levels in mice treated with the Cirsium japonicum polysaccharide were deteted,and ability to clear DPPH·and ·OH free radicals were assayed.Results suggested that the Cirsium japonicum polysaccharide displayed good free radicals-clearing activity and also decreased the MDA level in liver of the Cirsium japonicum polysaccharide-treated mice.These results indicated that the Cirsium japonicum polysaccharide had good activity antioxidant.In addition,the immunologic cellular activity,spleen index,thymus gland index and complement C3 level in the Cirsium japonicum polysaccharide-treated mice were assayed.Results showed that the Cirsium japonicum polysaccharide enhanced the killing activity of NK cells obviously,promoted the proliferation and transformation of splenic lymphocytes,improved the phagocytotic ability of enterocoelia macrophage and increased the spleen index and the content of complement C3 in the blood.These data demonstrated that the Cirsium japonicum polysaccharidepossessed effective immune-modulating activities.Meanwhile,the biological function of the Cirsium japonicum polysaccharide was explored in Hela cells using reporter gene method.Data showed that the Cirsium japonicum polysaccharide significantly promoted the activation of Rb and p53 and inhibited the activation of ISRE,suggesting potential anti-tumor and immune-regulatory activity for the Cirsium japonicum polysaccharide.This study will greatly promote exploring the active constituents from Cirsium japonicum DC and research on their potential pharmacological activity,laying the experimental and theoretical basis for the clinical application of the Cirsium japonicum DC.