Isolation, Characterization, and Pharmaceutical Applications of an Exopolysaccharide from Aerococcus Uriaeequi.

Many marine bacteria secrete exopolysaccharides (EPSs), which are made up of a substantial component of the macro-molecules surrounding cells. Recently, the wide demand for EPSs for food, cosmetics, pharmaceutical and other applications has led to great interest in them. In this study, an EPS produced by marine bacteria Aerococcus uriaeequi HZ strains (EPS-A) was isolated and purified to examine its structure and biological function. The molecular weight of EPS-A analyzed by high-performance liquid gel filtration chromatography (HPGFC) is found to have a number average of 2.22 × 105 and weight average of 2.84 × 105, respectively. High-performance liquid chromatography (HPLC) and Fourier-transform⁻infrared (FT⁻IR) analysis indicate that EPS-A was a polysaccharide composed of glucose and a little mannose. In addition, the flocculating rate of sewage of EPS-A was 79.90%. The hygroscopicity studies showed that hygroscopicity of EPS-A was higher than chitosan but lower than that of sodium hyaluronate. The moisture retention of EPS-A showed similar retention activity to both chitosan and sodium hyaluronate. EPS-A also can scavenge free radicals including both OH• free radical and O2•- free radical and the activity to O2•- free radical is similar to vitamin C. Safety assessment on mice indicated that the EPS-A is safe for external use and oral administration. EPS-A has great potential for applications in medicine due to its characteristics mentioned above.

Anti-atherosclerotic activity of platycodin D derived from roots of Platycodon grandiflorum in human endothelial cells.

This study examined the effects of platycodin D (PD), a triterpene saponin from the the root of Platycodon grandiflorum A.DC on human umbilical vein endothelial cells (HUVECs) in vitro, which were pre-treated with PD (0.01, 0.15, 0.25 mg/mL), respectively, and treated with 50 mg/L oxidized low-density lipoprotein (oxLDL). The levels of nitric oxide (NO) and malonaldehyde (MAD) in the culture medium, vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) mRNA expression in endothelium cells and the adhesion of monocytes to endothelial cells were measured. The results showed that PD increased NO concentration and decreased MDA level induced by oxLDL in the medium of endothelial cells. Moreover, PD significantly inhibited the oxLDL-induced increase in monocyte adhesion to endothelial cells as well as decreasing mRNA expression levels of VCAM-1 and ICAM-1 on these cells. Based on these results, it is suggested that PD is a promising anti-atherosclerotic activity, which is at least in part the result of its increasing NO concentration, reducing the oxLDL-induced cell adhesion molecule expression in endothelial cells and the endothelial adhesion to monocytes.