Isolation and immunosuppressive effects of 6″-O-acetylginsenoside Rb1 extracted from North American ginseng.

Extraction of medicinally active components from natural health products has become an emerging source for drug discovery. Of particular interest for this work was the finding and testing of a new ginsenoside from North American ginseng (Panax quinquefolius). In the present study, a large amount of 6″-O-acetylginsenoside Rb1, compound 7, was found using ultrasonic extraction of North American ginseng with DMSO aqueous solution. This new ginsenoside was well identified with MS, FTIR, and 1D (1H and 13C) and 2D (gCOSY, gHSQC, and gHMBC) NMR. Subsequent bioassay experiments confirmed that compound 7 demonstrated an additional immunosuppressive activity towards inhibiting the production of nitric oxide and tumor necrosis factor alpha in lipopolysaccharide-induced macrophage cells in a dose-dependent manner using murine macrophages. This new ginsenoside is encouraging for the further exploration and development of novel drugs.

Microfluidic Synthesis and Angiogenic Activity of Ginsenoside Rg1-Loaded PPF Microspheres.

Next generation drug-loaded polymer scaffolds for hard tissue engineering require unique structures to enhance release kinetics while enabling bone cell growth (osteogenesis). This study examined the encapsulation of the pro-angiogenic mediator, ginsenoside Rg1, into biodegradable poly(propylene fumarate) (PPF) microspheres to facilitate osteogenesis, while examining the release mechanism using advanced X-ray absorption near edge structure spectroscopy (XANES). Ginsenoside Rg1-loaded PPF microspheres were prepared using both an emulsion method and a microfluidic device, with the microfluidic technique providing tunable unimodal PPF spheres ranging in size from 3 to 52 µm by varying the flow rates. The morphology and composition of the Rg1-loaded PPF microspheres were characterized using FTIR, XRD, and XANES to examine the distribution of ginsenoside Rg1 throughout the polymer matrix. Encapsulation efficiency and release profiles were studied and quantified by UV-Vis spectrophotometry, showing high encapsulation efficiencies of 95.4 ± 0.8% from the microfluidic approach. Kinetic analysis showed that Rg1 release from the more monodisperse PPF microspheres was slower with a significantly smaller burst effect than from the polydisperse spheres, with the release following Fickian diffusion. The released Rg1 maintained its angiogenic effect in vitro, showing that the PPF microspheres are promising to serve as vehicles for long-term controlled drug delivery leading to therapeutic angiogenesis in bone tissue engineering strategies.