Fermentation-assisted Extraction Of Panax Noto-ginseng Saponins And Their Bioactivity Evaluation

Panax notoginseng is a famous Chinese traditional herbal plant. Panax notoginseng saponins(PNS) which consisits of the dammarane type ginsenosides and the peculiar notoginseng R1is the principal compounds in notoginseng. Recent studies highlighted the importance of PNS and ginsenosides components in modern clinical practice due to the active compound have a number of significant cardiovascular-protective, anti-aging, immunological, and antitumor functions. The minor ginsenosides are being used along with chemotherapy as adjuvants and to reduce toxicity of chemotherapeutic drugs.However, ginsenosides was pointed out that low bioavailability and was metabolized to subprime ginsenosides and sapogenin in vivo after oral administration. In fact, it is these minor ginsenosides and sapogenin that are responsible for the pharmaceutical activities in the body. Besides the bioactivity of ginsenosides depends on the structure of side chain which is linked to the sapogenin such as the amount of carbohydrate chain and the binding site of carbohydrate chain and sapogenin. The structure-activity relationship of antitumor also revealed that minor ginsenosides and sapogenin have strong antitumor action. Nevertheless, minor ginsenosides such as Rg3, Rh2are present at low concentrations in the plant, and metabolin CK is not inherent in raw materials.In view of this, it is important to develop effective methods to extract active ingredients from the relevant plant sources and indentify suitable methods to produce minor ginsenosides via structural modification. The microbial fermentation-assisted extraction method is a combination of fermentation with traditional reflux extraction. In this process of solid state fermentation, the synergistic effect of microbial enzymes degrade the cellulose and hydrolyze the starch with a high dissolving capacity of PNS from the raw material for its destructive action on the compact texture of root. Further, the carbohydrate chains linked to the sapogenin will be partly hydrolyzed by the glycosidase such that minor ginsenoside with less carbohydrate chain and higher biological activity are produced via the biotransformation of partly major ginsenosides, and the reaction conditions are mild during the fermentation process.According to the preliminary optimization results from single factor experiment, further optimization of fermentation-assisted extraction of PNS was carried out using response surface Box-Benhnken design, and the total saponins contents (TPC), ginsenoside components biotransformation, antioxidant, antimicrobial, antitumor activities were also investigated compared with traditional extraction process (TEP). The results showed that at the optimum fermentation conditions which included31%bran addition level in the medium and1:1.2of the materials/water ratio at pH7.6and the extraction content of PNS was12.25±0.21%,35.36%increase in the final yield compared with traditional methods and the contents of protopanaxadiol-type ginsenoside Rb1, Rd was increased significantly. In addition, biotransformation was noted in the fermentation process and this transformation by the bacillus subtilis depends on the substrate specificities for protopanaxatriol-type ginsenosides that led to increased recovery of minor ginsenosides Rh1, F1from the raw material. Due to fermentation, IC50of DPPH radical scavenging capacity was reduced from1.226to0.337mg/mL, and reducing power on Fe3+and inhibitory activities to bacteria and fungi such as Staphylococcus aureus、 Penicillium sp. etc were enhanced, antitumor active to gastric cancer was improved. Finally, this study demonstrated that fermentation-assisted extraction could increase the dissolution of active constituents from the materials, insert biotransformation into the system, and improve their bioactivities. This novel method provides useful information for future application in natural products extraction.It was found that Panax notoginseng saponins plays an important role in the treatment of cardio-cerebrovascular diseases, and exerts protective effects on myocardial, arrhythmia and so on. By employing anoxia injury model using Na2S2O4and MTT assay, the effects of PNS for the anoxia injury to HUVEC cells was studied in this paper, and the mechanism of action of PNS to blood vessel endothelium was also discussed. PNS reveal the most protective effect to HUVEC against anoxia injury that accumulation level of MDA was decrease, SOD activity exhibited significantly increase, and at the High and Middle drug concentration, the release rate of NO showed an obvious increase.It was supposed that PNS function to HUVEC by the pathway of antioxidation and adjustment effect to ascular endothelial cells release of active substances. It is important to inhibit vascular endothelial dysfunction so as to reduce the pathogenic factor to atherosclerosis, further prevent the occurrence of cardiovascular diseases.