Isolation And Purification Of Rehmannia Glutinosa And Its Protective Effect On Mouse Liver And Vascular Endothelium

Many Researchs have found that oligosaccharides have a variety of biological activity, such as anti-tumor, improving immune function, anti-oxidation, anti-aging, hyperglycemic and preventing diarrhea and so on. It is widely used in medicine, food, agriculture and other fields.There for, we selected Rehmannia glutinosa Libosch of Henan as the the research object, and employed the50%aqueous ethanol as extracting agent. It was purified by column chromatography which was packed with diatomaceous earth and charcoal. The quantification of the component oligosaccharides in Rehmannia glutinosa oligosaccharides (RGOs) was carried out using a high performance liquid chromatography, and its pharmacological activity was further evaluated.The main conclusions and results of this study were as follows:1R. glutinosa roots was crushed and defatted, and then the50%aqueous ethanol as extraction agent. The crude Rehmannia glutinosa oligosaccharides was obtained by alcohol precipitation and deproteinization. The best purification conditions was confirmed by high performance liquid chromatography, and the best purification conditions was as follows:firstly, the6%aqueous ethanol was employed as the eluent to remove monosaccharides, and then the60%aqueous ethanol as an eluent to obtain Rehmannia glutinosa oligosaccharides, and the yield of RGOs was31.3%(w/w) of the dried R. glutinosa roots.2The quantification and component of RGOs was by the HPLC-RI analyzed and HPLC analysis showed that RGOs were mainly composed of stachyose (61.7%, w/w), followed by23.7%raffinose and7.1%sucrose. The results indicate that RGOs are of a typical raffinose family oligosaccharide mixture.3Administration of RGOs orally daily in mice for21days significantly reduced the impact of CC14toxicity on the serum markers of liver damage, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total-cholesterol (TC) and triglycerides (TG). RGOs also increased antioxidant levels of hepatic glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and total antioxidant capacity (T-AOC), and ameliorated the elevated hepatic formation of malonaldehyde (MDA) induced by CC14in mice. Analysis concluded that RGOs have the protective effect of liver injury in mice and increased with samples concentration, which was coincided with the histological alteration.4The biochemical analysis have shown that L-carnitine can increase the lipid levels in mice, cause inflammation of the artery walls, after mice have freely drinking3%L-carnitine, for a long-term (10weeks). However, the content level of the high density lipoprotein (HDL), nitric oxide (NO) and6keto prostaglandin Fla (6-keto-PGF1a) in the serum of the mice have increased, and the levels of low-density lipoprotein (LDL), total cholesterol (TC), triglyceride (TG), endothelin-1(ET-1), C-reactive protein (CRP), thromboxane B2(TXB2) have decreased, after administration of RGOs orally daily in mice for10weeks. Interestingly, the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and nitric oxide (NO) levels or activity were decreased compared with the normal group, and the malondialdehyde (MDA), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were increased compared with the normal group. So, the L-carnitine can leads to reduce anti-oxidative capacity of the liver and increase oxygen free radicals and injure the mice liver. However, administration of RGOs orally daily in mice for10weeks significantly reduced the impact of the L-carnitine, and increased with samples concentration. The histological results of oil red staining and H&E staining indicated that fat accumulation in the liver and the nuclei shrunked of the liver cell and apart of hepatocyte necrosis. However, administration of RGOs orally daily in mice for10weeks significantly reduced the impact of the L-carnitine, and increased with samples concentration.