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.

Particulate matter (PM) contributes to air pollution and primarily originates from unregulated industrial emissions and seasonal natural dust emissions. Fucoxanthin (Fx) is a marine natural pigment from brown macroalgae that has been shown to have various beneficial effects on health. However, the effects of Fx on PM-induced toxicities in cells and animals have not been assessed. In this study, we investigated the anti-inflammatory potential of the Fx-rich fraction (FxRF) of Sargassum fusiformis against PM-mediated inflammatory responses. The FxRF composition was analyzed by rapid-resolution liquid chromatography mass spectrometry. Fx and other main pigments were identified. FxRF attenuated the production of inflammatory components, including prostaglandin E2 (PGE 2 ), cyclooxygenase-2, interleukin (IL)-1β, and IL-6 from PM-exposed HaCaT keratinocytes. PM exposure also reduced the levels of nitric oxide (NO), tumor necrosis factor-α, inducible nitric oxide synthase (iNOS), and PGE 2 in PM-exposed RAW264.7 macrophages. Additionally, the culture medium from PM-exposed HaCaT cells induced upregulation of NO, iNOS, PGE 2 , and pro-inflammatory cytokines in RAW264.7 macrophages. FxRF also significantly decreased the expression levels of factors involved in inflammatory responses, such as NO, reactive oxygen species, and cell death, in PM-exposed zebrafish embryos. These results demonstrated the potential protective effects of FxRF against PM-induced inflammation both in vitro and in a zebrafish model.

Ginsenoside Rd, one of the ginsenosides with significant pharmaceutical activities, is getting more and more attractions on its biotransformation. In this study, a novel fungus mutant, the Aspergillus niger strain TH-10a, which can efficiently convert ginsenoside Rd from Rb1, was obtained through screening survival library of LiCl and ultraviolet (UV) irradiation. The transformation product ginsenoside Rd, generated by removing the outer glucose residue from the position C20 of ginsenoside Rb1, was identified through high-performance liquid chromatography (HPLC) analysis. Factors for the microbial culture and biotransformation were investigated in terms of the carbon sources, the nitrogen sources, pH values, and temperatures. This showed that maximum mycelia growth could be obtained at 28°C and pH 6.0 with cellobiose and tryptone as the carbon source and the nitrogen source, respectively. The highest transformation rate (∼86%) has been achieved at 32°C and pH 5.0 with the feeding time of substrate 48 hr. Also, Aspergillus niger strain TH-10a could tolerate even 40 mg/mL ginseng root extract as substrate with 60% bioconversion rate after 72 hr of treatment at the optimal condition. Our results highlight a novel ginsenoside Rd transformation fungus and illuminate its potentially practical application in the pharmaceutical industries.

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