Effect of dihydroartemisinin supplementation on inflammation and lipid metabolism induced by lipopolysaccharide in liver of weaned piglets / 中国中药杂志

To study the effect of dihydroartemisinin(DHA) on hepatic inflammation and lipid metabolism in weaned piglets, a liver injury model of weaned piglets was established by lipopolysaccharide(LPS)-induced method. In this study, 30 healthy weaned piglets were selected and randomly divided into control group(CON), model group(LPS) and treatment group(LD, LPS+DHA), with 10 in each group. The CON group and the LPS group were fed with a basal diet, and the LD group was fed with a basal diet+80 mg·kg~(-1) DHA. The test period was 21 days. The LPS group and the LD group were intraperitoneally injected with 100 μg·kg~(-1) LPS at 4 hours before slaughter, and the CON group was injected with the same dose of sterile physiological saline. The results showed that compared with the CON group, contents of TC, AST activity and AST/ALT ratio were significantly increased in the serum of LPS piglets(P<0.05), content of HDL-c was significantly decreased(P<0.05). In addition, in the liver, the levels of TG, NEFA, IL-1β, IL-6 and TNF-α were increased significantly(P<0.05), and activities of LPL, HL and TL were decreased significantly(P<0.05). Compared with LPS group, content of TC, activities of AST and ALT and the AST/ALT ratio were decreased significantly(P<0.05), and HDL-c content increased significantly in the serum of LD piglets(P<0.05). The contents of TG, NEFA, IL-1β, IL-6 and TNF-α and activity of FAS in the liver were decreased significantly(P<0.05), and the activities of LPL, HL and TL were increased significantly(P<0.05). Compared with the CON group, the mRNA expressions of IL-1β, IL-6, TNF-α, ACCβ and SREBP-1 c in the LPS group were significantly increased(P<0.05), the mRNA expressions of AMPKα, SIRT1, CPT-1 and SCD were decreased significantly(P<0.05). The above indicators were improved in the LD group compared with the LPS group. These results indicated that DHA had a certain effect in recovering LPS-induced liver inflammation and abnormal lipid metabolism.

Effect of NaCl in outer water phase on the characteristics of BSA-loaded PLGA sustained-release microspheres fabricated by a solid-in-oil-in-water emulsion technique / 药学学报

The aim of this study is to investigate the critical factor affecting the properties of PLGA microspheres fabricated by a solid-in-oil-in-water (S/O/W) emulsion technique with BSA as a model protein. Prior to encapsulation, the BSA microparticles were fabricated by a modified freezing-induced phase separation method. The microparticles were subsequently encapsulated into PLGA microspheres by S/O/W emulsion method, then Motic BA200 biological microscope, confocal laser scanning microscope, scanning electron microscope were used to observe the structure of S/O/W emulsion and PLGA microspheres. The protein content extracted or released from BSA microspheres was measured by Bradford protein assay method. It was found that NaCl added in the outer aqueous phase effectively suppressed material exchange between the inner and outer phase of S/O/W emulsion. Then, the structure and permeability of obtained microspheres were influenced. As a result, with the increase of NaCl concentration in the outer aqueous phase, the encapsulation efficiency of microspheres significantly increased from 60% to more than 85%, the burst release of microspheres reduced from 70% to 20%, and the particle size decreased from 103 microm to 62 microm. Furthermore, the rehydration of encapsulated protein was also retarded and then integrity of BSA was successfully protected during encapsulation process. In vitro release test showed that BSA released from PLGA microspheres in a sustained manner for more than 30 days.

Preparation and characterization of PLGA microspheres containing a staphylokinase variant (K35R) / 药学学报

<p><b>AIM</b>To produce poly (lactic-co-glycolic acid) (PLGA) microspheres, containing a staphylokinase variant (K35R, DGR) with reduced immunogenecity and antiplatelet aggregation activities, which allowed the preservation of protein stability during both particle processing and drug release.</p><p><b>METHODS</b>DGR-loaded microspheres were fabricated using a double emulsion-solvent evaporation technique. The effects of preparative parameters, such as stirring rate, polymer concentration, and the excipients of both internal and external aqueous phase (W2), on DGR encapsulation efficiency and microsphere characteristics were investigated. In vitro and in vivo release of DGR were conducted and the cause for instability of DGR during release was also investigated.</p><p><b>RESULTS</b>Moderate ultrasonic treatment of aqueous DGR/dichloromethane mixtures caused approximately. Eighty four per cent DGR denaturation. However, the activity recovery of DGR almost amounted to 100% when 2% polyvinyl alcohol (PVA) was addled into the aqueous phase. It was found that NaCl in the external water phase significantly increased DGR encapsulation efficiency. Furthermore, NaCl in the external water phase played a role in determining size and surface morphology of microsphere. In vitro release test showed a burst release of DGR from microspheres, followed by sustained release of 50% total activity over 15 days. In vivo experiments showed that DGR released from microspheres sustained 5 days. Denaturation of DGR within microspheres might be resulted from acidic microclimate.</p><p><b>CONCLUSION</b>The stability of DGR was effectively protected during microencapsulation and a relatively high encapsulation efficiency of DGR was obtained. PLGA microspheres could be an effective carrier for DGR.</p>