| Cordyceps militaris stroma polysaccharides is an excellent health regulator, it can improve the body’s immune and antioxidant, and has no toxic effects on normal cells. In recent years, it has been found that the biological activity of a variety of fungal polysaccharides is closely related to their structures and molecules chain conformations in solution. Nano-Se is an efficient and low toxicity selenium forms, better than inorganic selenium and organic selenium, with unique photoelectric features and good biological activity. Nano-Se has become the focus and cutting-edge of materials, electronics, medicine, biology, chemistry and other subjects neighborhood research. We used abandoned Cordyceps militaris stroma as raw material to extract polysaccharides, then used the polysaccharides to prepare nanoparticles selenium in relatively mild redox system as a stabilizer and coating agents, and made a preliminary exploration of the biological activity of nanoparticles selenium.First we explored the methods of efficient-extraction of Cordyceps militaris stroma polysaccharides by complex enzymatic (cellulase, pectinase) with Ultrasonic, and optimized the extraction process. We used Box-benhnken central composite experimental design to optimize the extraction process of polysaccharide, to establish a regression model with four factors as complex enzyme dosage, reaction-ultrasound temperature, pH, reaction-ultrasonic time. Under the conditions of the solid-liquid ratio of 1:30, we can determine a optimal extraction process, the amount of enzyme added 3%, reaction-ultrasonic temperature 54℃, pH value 6.0, hydrolysis-ultrasonic time 50min. Under this extraction process,we got the polysaccharide with yield rate of 26.38%.Compared the Sevag method, TCA method, papain-Sevag method and papain-TCA method for the effects of removaling protein from the abandoned Cordyceps militaris stroma polysaccharides with the indexes of protein removal rate, polysaccharide loss rate, the DPPH radical removal rate. The results showed that:The effect of protein removal of papain-TCA method is best. After treatment by papain, TCA removal protein 1 time, the protein removal rate 92.90%, polysaccharide loss rate 9.82%,the DPPH radical removal rate 55.20%.In order to obtain the CMSP-SeNPs which can be stably stored with desired morphology and particle size, experiment on single factor with CMSP as regulating agent and modifying agent, depending on indicators of the particle size distribution of nano selenium, the average particle size, the dispersibility and stability. In the conditions of the polysaccharide concentration 10mg/mL, mixing time 4h, selenite concentration 1.0M, dropping rate 1.5rpm, it is possible to prepare the CMSP-SeNPs with the selenium content of 54.8mg/L.The CMSP-SeNPs showed in the presence of spherical particles uniformly dispersed, uniform particle size, dispersion, high stability, and the polysaccharide and nano-selenium particles are combined by weak physical adsorption methods.Investigate the antioxidation and antitumor capabilities in Vitro of four different particle sizes of CMSP-SeNPs, depending on the the indicators with DPPH and hydroxyl radical scavenging capacity and the cell cytotoxicity for Hela, MCF-7 and A549. The results showed that scavenging ability of the minimum size of CMSP-SeNPs (d) for DPPH and hydroxyl radical was more than CMSP, Na2SeO3, and reaching the highest clearance rate in a smaller concentration. CMSP-SeNPs had certain inhibition rate on Hela, MCF-7 and A549 cancer cells, and the cytotoxicity in a dose-dependent effect. The inhibition of the minimum size of CMSP-SeNPs (d) is also the most obvious, but inhibition rate of all samples for cancer is less than Na2SeO3. |
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