| Endophytic fungi of medicinal plants is a kind of potential and unexploited microbial resources. In our country, Gynostemma Pentaphyllum, which is a traditional Chinese herbal medicine plant, has many active ingredients and regulating function called “adaption source”. Gynostemma Pentaphyllum polysaccharides have many kinds of biological activities, such as hypoglycemic effect, lowering blood pressure, anticancer, antioxidation, immunity enhancement etc. The active constituents from endophytic fungi JY25 are not only many but also better than those from host medicinal plant. The study on the polysaccharides construction and biological activity of endophytic fungi from Gynostemma Pentaphyllum have great important significance to its development and utilization, and provide the reference data for the natural active substances and biological activity research of other endophytic fungi from medicinal plants.First of all, we analyzed the polysaccharides molecular structure of endophytic fungi JY25 from Gynostemma Pentaphyllum. The refined polysaccharides were obtained by deproteinization with sevage method, ethanol precipitation and gel chromatography from the fermentation broth of JY25. The polysaccharides structures were measured by the means of thermogravimetric analysis, infrared spectroscopy and gas chromatography-mass spectrometry technology. The results showed that the refined polysaccharides contained much more adsorbed of water and crystal of water. And, the refined polysaccharide was a glycoprotein possessed α-D-glucofuranose and β-D-glucopyranose, which mainly composed of four kinds of monosaccharide: glucose(78.29 %), mannose(8.99 %), arabinose(8.64 %), galactose(4.08 %).The second, we studied on the biological activities of JY25 polysaccharides, including antioxidation, anticancer, inhibiting α-glycosidase activity and the interference in glucose absorption. The phenanthroline-Fe2+ and DPPH method were employed to explore the antioxidant activity of JY25 polysaccharides. The anticancer effect of JY25 polysaccharides on lung cancer A549 cell were studied by the MTT method. The effect of JY25 polysaccharides on α-glycosidase in vitro were explored by the PNPG colorimetric method. The Caco-2 cells intestinal model was established to measure JY25 polysaccharides absorption characteristics and its interference in glucose absorption. The data confirmed that JY25 polysaccharides had obviously capacities of free radical scavenge of·?DPPH and·?OH. Moreover, when the concentration of JY25 polysaccharides was 10 mg/mL, the free radical scavenging activity of ?DPPH and ?OH separately reached 37.4 % and 99.6 %, the inhibition rate of JY25 polysaccharides on lung cancer A549 cells(12 h) was 92.1 %, and these biological activities had the character of concentration-dependent. The optimizing conditions of the JY25 polysaccharides inhibition on α-glycosidase enzymes determined by the single facter analysis and orthogonal experiment, were that the concentration of PNPG was 5 mmol/L, the time was 30 min, the temperature was 44 °C and the pH was 6.8. The JY25 polysaccharides had competitive inhibitory activity of the IC50 2.460 mg/mL, Ki 1.145 mg/mL than the acarbose control of IC50 1.189 μg/mL, Ki 1.789 mg/mL on α-glycosidase. When the polysaccharides concentration was 10 mg/mL, its inhibition rate on the α-glycosidase enzymes, which come from Caco-2 cells grew 16 days was 16.5%. These results proved that the JY25 polysaccharides had inhibitory activity on α-glycosidase. In monosaccharide absorption experiment based on Caco-2 cell intestinal model, the absorption rates of JY25 polysaccharides, glucose, glucose + JY25 polysaccharides had increased with the prolongation of time, the order was JY25 polysaccharides < glucose < JY25 polysaccharides + glucose. At the same time, the apparent permeability coefficient showed the similar trend which the Papp of JY25 polysaccharides was 2.962×10-7/s·cm2, the Papp of polysaccharides + glucose group was 5.886×10-7/s·cm2, and also conformed that the JY25 polysaccharides had the lowest transport rate and absorption rate among the three groups. However, when the polysaccharides mixed with glucose the absorption rate of glucose was increased, it seemed that the JY25 polysaccharides had accelerated role to glucose absorption.The polysaccharides of JY25 endophytic fungi from medicinal plant Gynostemma Pentaphyllum had a variety of biological activities and potential prospect of application. This paper provided methods and ideas for the study of active components and biological activity of endophytic fungi from medicinal plants. |
PDF Full Text Request