Microbial transformation of ginsenoside Rb1, Re and Rg1 and its contribution to the improved anti-inflammatory activity of ginseng

Scientific Reports, Mar 2017

Microbial transformation of ginsenosides to increase its pharmaceutical effect is gaining increasing attention in recent years. In this study, Cellulosimicrobium sp. TH-20, which was isolated from soil samples on which ginseng grown, exhibited effective ginsenoside-transforming activity. After protopanaxadiol (PPD)-type ginsenoside (Rb1) and protopanaxatriol (PPT)-type ginsenosides (Re and Rg1) were fed to C. sp. TH20, a total of 12 metabolites, including 6 new intermediate metabolites, were identified. Stepwise deglycosylation and dehydrogenation on the feeding precursors have been observed. The final products were confirmed to be rare ginsenosides Rd, GypXVII, Rg2 and PPT after 96 h transformation with 38–96% yields. The four products showed improved anti-inflammatory activities by using lipopolysaccharide (LPS)-induced murine RAW 264.7 macrophages and the xylene-induced acute inflammatory model of mouse ear edema. The results indicated that they could dramatically attenuate the production of TNF-α more effectively than the precursors. Our study would provide an example of a unique and powerful microbial cell factory for efficiently converting both PPD-type and PPT-type ginsenosides to rare natural products, which extends the drug candidates as novel anti-inflammatory remedies.

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Microbial transformation of ginsenoside Rb1, Re and Rg1 and its contribution to the improved anti-inflammatory activity of ginseng

Abstract Microbial transformation of ginsenosides to increase its pharmaceutical effect is gaining increasing attention in recent years. In this study, Cellulosimicrobium sp. TH-20, which was isolated from soil samples on which ginseng grown, exhibited effective ginsenoside-transforming activity. After protopanaxadiol (PPD)-type ginsenoside (Rb1) and protopanaxatriol (PPT)-type ginsenosides (Re and Rg1) were fed to C. sp. TH20, a total of 12 metabolites, including 6 new intermediate metabolites, were identified. Stepwise deglycosylation and dehydrogenation on the feeding precursors have been observed. The final products were confirmed to be rare ginsenosides Rd, GypXVII, Rg2 and PPT after 96 h transformation with 38–96% yields. The four products showed improved anti-inflammatory activities by using lipopolysaccharide (LPS)-induced murine RAW 264.7 macrophages and the xylene-induced acute inflammatory model of mouse ear edema. The results indicated that they could dramatically attenuate the production of TNF-α more effectively than the precursors. Our study would provide an example of a unique and powerful microbial cell factory for efficiently converting both PPD-type and PPT-type ginsenosides to rare natural products, which extends the drug candidates as novel anti-inflammatory remedies. Introduction Ginseng (Panax ginseng), one of the most well-known herbal medicines in the world, has gained increasing attention in the treatment of cardiovascular disease, diabetes and central nervous diseases1,2,3. Ginseng use is popular given its prominent effects on inflammation, which is the body’s response to injury and infection4. Ginsenosides are regarded as the main active components of ginseng. To date, more than 180 ginsenosides have been identified from ginseng. Ginsenosides can be divided into two groups: PPD-type and PPT-type ginsenosides according to their structures. PPD-type and PPT-type ginsenosides share a common dammarane triterpenoid structure. Rb1, Rd, Rc and Rb2 are PPD-type ginsenosides with sugar moieties attached to the β-OH at C-3 and/or C-20 in the aglycon PPD. Ginsenosides Re and Rg1 are PPT-type ginsenosides with sugar moieties linked to the α-OH at C-6 and/or β-OH at C-20 in the aglycon PPT. These ginsenosides differ in sugar types, numbers and attachment positions. Moreover, ginsenoside Rb1, Rb2, Rc, Re and Rg1 are major ginsenosides that account for more than 80% of total ginsenosides. In addition to major ginsenosides, rare ginsenosides with minimal levels in ginseng continue to be identified5. Transformation of major ginsenosides in vivo or in vitro can generate the formation of rare ginsenosides and leads to structural changes in the type of dammarane, the number of sugar moieties, and the substituent groups6,7,8. Furthermore, emerging evidences have demonstrated that these structural changes affect their pharmaceutical activities9. Wang et al. observed that transformation of ginsenosides by artificial gastric juice increase cytotoxicity toward cancer cells10. Kim et al. reported that thermal deglycosylation of ginsenoside Rd enhances the anticancer activity of ginsenoside11. Hence, these findings imply that structural changes of certain ginsenosides by transformation are significantly related to their improved pharmaceutical activities. Transformation of ginsenosides mainly occurs via deglycosylation at the sugar moieties. Therefore, previous studies have focused on converting major glycosylated ginsenosides to deglycosylated ginsenosides12. Various deglycosylation methods, including heat treatment13, mild acid hydrolysis14, enzymatic hydrolysis15, 16, and microbial transformation17, 18 were reported. Among the methods, microbial transformation and enzymatic deglycosylation were the most useful given high substrate specificity, lower byproducts and high production yields. Moreover, microbial transformation present unique advantages as its complex enzyme system can enrich reaction types and provide the possibility of obtaining novel ginsenosides, which may possess important pharmaceutical activities. Thus, research on the development of microbial transformation methods for increasing the pharmaceutical effect by structural modification of ginsenosides is gaining more attention. As mentioned above, the anti-inflammatory effects of major ginsenosides including Rb1, Re and Rg1 have been reported19. Moreover, recent research indicates that structural modification of the major ginsenosides may contribute to improved anti-inflammatory activity. For example, Joh et al. reported that ginsenoside Rb1 was transformed to compound K by gut microbiota. Compound K was more effective and inhibited the production of pro-inflammatory cytokines more potently compared with Rb120. Similarly, Lee et al. reported that 20(S)-protopanaxatriol, which is metabolized from ginsenoside Re, exhibited more potent anti-inflammatory effect compared with ginsenosides Re21. Kim et al. observed that 20(S)-protopana (...truncated)


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Shanshan Yu, Xiaoli Zhou, Fan Li, Chunchun Xu, Fei Zheng, Jing Li, Huanxi Zhao, Yulin Dai, Shuying Liu, Yan Feng. Microbial transformation of ginsenoside Rb1, Re and Rg1 and its contribution to the improved anti-inflammatory activity of ginseng, Scientific Reports, 2017, Issue: 7, DOI: 10.1038/s41598-017-00262-0