Isolation, Purification Of Angelica Sinensis Polysaccharides And Its Role In Different Chemical Liver Injuries

Liver injury is a common clinical symptom, which can be induced by many factors, such as viruses, drugs, alcohol and traumas. If treated not appropriately, liver injury would develop to liver failure, and result in serious consequences. To date, there is no innocuous special medication in clinic.Angelica sinensis (Oliv.) Diels is a valuable Chinese traditional medicine from natural source. It possesses properties such as tonifying the blood, promoting blood circulation, moistening the bowels, regulating menses and so on. Angelica sinensis polysaccharides (ASP) is the water-soluble part of Angelica sinensis, which has exhibited various bioactivities, namely stimulating hematopoietic system, enhancing immune functions, depressing tumors and healing gastric ulcer. However, there are few reports about its hepatoprotective effect.Thus, in present study, we investigated the role of purified ASP in different chemical liver injuries. The study includes two aspects.1. To isolate and purify the polysaccharides fractions from Angelica Sinensis, and to determine the partial characters. Hot water extracting and ethanol precipitating method was employed to isolate polysaccharides from fresh Angelica Sinensis. Removal of protein by Sevag method and drying by freezone drier , the purified ASP was obtained. The amount of total carbohydrates of ASP was measured with phenol-sulfuric acid method. FT-IR spectrometry, UV-spectrophotometer, and automatic spectropolarimeter were used to determine the characteristic absorption and optical rotation of the polysaccharide, respectively. Size exclusion chromatography with laser light scattering (SEC-LLS) technology was employed to measure the molecular masses . The monosaccharides contained in ASP were analysed by HPLC. The amount of total carbohydrates of ASP was 96.8%; Both of UV and FT-IR displayed representative polysaccharide properties. The molecular weight distribution was in the range of 10,000 ~ 110,000, and 80% was distributed in 43,210. The monosaccharide constituents of ASP were glucose, arabinose, galactose, rhamnose and xylose, and their molar proportion were 17.8 : 5.8 : 12 : 1 : 2.2. These results show that ASP obtained by water extracting-ethanol precipitating and drying method has high amount of total carbohydrates. The range of molecular weight andmonosaccharide constituents of ASP were affirmed.2. To investigate the protective roles of ASP in different chemical compound-induced liver injury. Three chemical liver damage models were established by ethanol, carbon tetrachloride and dexamethasone in mice, respectively. ASP 100mg.kg"\ 200mg.kg' were pretreated by i.g. X lOd . Hepatotoxicity were assayed by plasma enzymes (sALT , sAST), liver index and histopathological examinations. The activities of SOD, MDA , GSH and ADH were measured . The levels of blood sugar and hepatin also were determined . Meanwhile, aniline hydroxylase (ANH) was assayed to represent the activities of CYP2E1, and CYP2E1 mRNA expression was detected by RT-PCR. Treated with ASP, the levels of sALT, sAST were all significantly decreased and histopathological impairments were alleviated in different degrees in three models. The changes in blood sugar, hepatin and indexes of antioxidation can be reversed by ASP partly. Furthermore, ASP restrained the rising of ADH and CYP2E1 induced by ethanol. The results indicated that ASP possesses hepatoprotective effects to different chemical liver injury.