Structure And Anti-inflammatory Effect Of A Polysaccharide From Tetraploid Gynostemma Pentaphyllum Makino

Gynostemma pentaphyllum (Thunb.) Makino, known as jiaogulan inChina, is a kind of perennial herbs climbing shrub of G. pentaphyllumgenus of gourd family. G. pentaphyllum has used to prevent and treatcardiovascular disease, cancer, hepatitis, hypertension, hyperlipidaeminand diabetes. Many research has focus on G. pentaphyllum and itsbiological activities are mainly attributed to gypenosides. Nowadays, manycommercial jiaogulan products are available in China and other countries,and the most popular one is “jiaogulan tea”. Besides saponins,polysaccharides are another group of important components contributed totheir beneficial functions with minimal potential toxicity. Furthermore,polysaccharides could be water soluble or partially water soluble, and maybe easily soaked out into the aqueous phase such as tea. In this study, anovel polysaccharide (GPP-S) was isolated from the tetraploidGynostemma pentaphyllum Makino by alkali extraction and its structureand biological activity were analyzed.1. The method to extract crude polysaccharide of Gynostemmapentaphyllum Makino. After refluxing with methanol to removeoligosaccharides, ground G. pentaphyllum was extracted by distilled waterand then decocted with2%NaOH at80°C for three times and2h for eachtime. The combined supernatants were neutralized with HCl and dialyzedin water. Hydrogen peroxide was added to remove the pigment and crudepolysaccharide was obtained by alcohol precipitation.2. The purification of crude polysaccharide. GPP-S was obtainedusing DEAE and Sephacry S-400column chromatographies. The averagemolecular weight of GPP-S was calculated as1.2×106Da based on thestandard curve of a series of standard dextran. 3. The structure of GPP-S. According to iditol acetate derivatives ofGPP-S hydrolysate in GC, GPP-S consisted of rhamnose, arabinose,glucose and galactose with a molar ratio of1.00:3.72:19.49:7.82. PMPdemonstrated this result and suggested no presence of uronic acid. GC-MSresult showed four major peaks which was identified as1,4-Glc：1,4,6-Glc：1,6-Gal：1-Ara=17.1:2.78:1.51:1.00. With the result of NMR, the predictedstructure of GPP-S was shown as:4. Antioxidant and anti-inflammation activity of GPP-S. GPP-Sshowed scavenging ability against DPPH, HO and O2-. It also hadsignificant inhibition of IL-1β, IL-6and COX-2gene expressions in RAW264.7mouse macrophage cells, suggesting its potential application infunctional food and dietary supplemental products.