Preparation Of Vanadyloxy Cordyceps Militaris Polysaccharide And Its Organ Protective Effect On Hyperglycemia Mice

Cordyceps militaris（L.ex Fr.）Link.,an edible and medicinal fungus,is rich in C.militaris polysaccharides（CMP）,cordycepic acid,cordycepin,ergosterol,etc.It has hypoglycemic,anti-inflammatory,anti-oxidation and anti-tumor effects.Vanadium compounds have insulin-like effects,which can promote glycogen formation and improve the uptake and utilization of glucose in blood by insulin-sensitive tissues such as muscle and fat,so as to regulate blood glucose.Complexes of oxovanadium ions,especially organic matrices and oxovanadium ions,have higher safety and insulin-like activity.In this study,the extraction conditions of CMP were optimized,and vanadyl（IV）-oxygen C.militaris polysaccharides（VCMP）was obtained by complexing CMP with vanadyl sulfate.The structure of VCMP was preliminarily analyzed,and its antioxidant activity in vitro was detected.The effects of VCMP on the injury indexes of serum,liver,kidney and other tissues and organs of diabetic mice were analyzed.The main results are as follows:（1）CMP was extracted by water extraction and alcohol precipitation.The extraction temperature was 75°C,the ethanol concentration was 85%,the extraction time was 2 h,and the yield was 8.07%.The results of high performance liquid chromatography showed that CMP was composed of 10 monosaccharides,the molecular weight of CMP was determined to be 1.46×10⁶ Da.（2）VCMP polysaccharide was prepared under the conditions of reaction temperature of40°C,reaction time of 6 h,reaction p H of 13 and CMP:VOSO₄ with a ratio of 4:1.The mass ratio of vanadium was about 9.5%.Infrared spectroscopy showed that VCMP had a special absorption peak of polysaccharide,which was pyranose,and successfully formed a complex with oxovanadium ions.（3）The scavenging rates of VCMP on DPPH and hydroxyl radicals were 40.58±2.88%and 33.76±2.56%,respectively,and the reducing power was 0.71±0.03,indicating that VCMP had strong antioxidant activity in vitro.（4）Acute toxicity test in mice showed that the LD50 of VCMP was>2000 mg/kg,which was much more than that of vanadium sulfate LD50=153.23 mg/kg.（5）VCMP can significantly improve the body condition of type I diabetic mice.（1）VCMP can effectively improve diabetes-induced polydipsia,polyphagia,polyuria and weight loss.（2）VCMP can significantly reduce fasting blood glucose and improve glucose tolerance in mice.VCMP had insulin-like effect and had no direct effect on insulin levels in mice.It was less likely to cause hypoglycemia than taking glibenclamide and injecting insulin,and had higher safety.（3）VCMP can significantly improve the levels of high density lipoprotein cholesterol（HDL-C）,low density lipoprotein cholesterol（LDL-C）and triglyceride（TG）in the blood,reduce blood lipids and promote the transport of cholesterol to the liver.（4）VCMP can reduce the activity of aspartate aminotransferase（AST）and alanine aminotransferase（ALT）in serum,reduce the concentration of creatinine（CREA）,repair and alleviate liver damage,kidney damage and increase glomerular filtration.（5）VCMP can increase the activity of glutathione peroxidase（GSH-Px）,superoxide dismutase（SOD）,catalase（CAT）and the level of malondialdehyde（MDA）in the liver,which can improve the body’s resistance to free radicals and peroxide oxidation.（6）The pathological sections of liver and kidney in mice showed that VCMP could improve the cell infiltration of hepatocytes and the congestion of hepatic lobules and the vacuoles in the wall of renal corpuscles.VCMP had the effect of repairing renal injury and liver injury.In summary,VCMP had the effects of anti-oxidation and alleviating and repairing the body damage of type I diabetic mice,which provided a reference for the adjuvant treatment of type I diabetes and the development of organic vanadium complex drugs.