Eriodictyol protects against Staphylococcus aureus-induced lung cell injury by inhibiting alpha-hemolysin expression.

Staphylococcus aureus (S. aureus) is a common pathogenic bacterium that causes various diseases in both humans and animals. With the increased prevalence of methicillin-resistant S. aureus, the therapeutic effects of commonly used antibiotics are limited against S. aureus infection. Novel treatment strategies and new antibiotics are needed urgently to address this concern. Many studies have shown that virulence factors secreted from S. aureus play vital roles in their pathogenic processes. Alpha-hemolysin (Hla), an important exotoxin in S. aureus, is one such virulence factor that increases sensitivity of multiple host cells to S. aureus resulting in various diseases. Eriodictyol is a flavonoid compound that exists in many fruits and vegetables. In this study, eriodictyol was demonstrated to inhibit the expression of Hla by hemolysis assays, western blotting, and RT-qPCR at the sub-minimal inhibitory concentration. In live/dead and cytotoxicity assays, the results showed that eriodictyol protected A549 cells against Hla-induced injury in a dose-dependent manner. The minimal inhibitory concentration of eriodictyol against S. aureus was 512 µg/mL. Eriodictyol can downregulate S. aureus Hla at both the expressional and transcriptional levels without affecting S. aureus growth. In addition, cell assays had proved that eriodictyol could protect A549 cells against Hla damage. Eriodictyol could therefore have the potential to treat S. aureus infection targeting Hla.

Sclareol Protects Staphylococcus aureus-Induced Lung Cell Injury via Inhibiting Alpha-Hemolysin Expression.

Staphylococcus aureus (S. aureus) is a common gram-positive bacterium that causes serious infections in humans and animals. With the continuous emergence of methicillin-resistant S. aureus (MRSA) strains, antibiotics have limited efficacy in treating MRSA infections. Accordingly, novel agents that act on new targets are desperately needed to combat these infections. S. aureus alpha-hemolysin plays an indispensable role in its pathogenicity. In this study, we demonstrate that sclareol, a fragrant chemical compound found in clary sage, can prominently decrease alpha-hemolysin secretion in S. aureus strain USA300 at sub-inhibitory concentrations. Hemolysis assays, western-blotting, and RT-PCR were used to detect the production of alpha-hemolysin in the culture supernatant. When USA300 was co-cultured with A549 epithelial cells, sclareol could protect the A549 cells at a final concentration of 8 µg/ml. The protective capability of sclareol against the USA300-mediated injury of A549 cells was further shown by cytotoxicity assays and live/dead analysis. In conclusion, sclareol was shown to inhibit the production of S. aureus alpha-hemolysin. Sclareol has potential for development as a new agent to treat S. aureus infections.

Effect of Chuanmingshen violaceum polysaccharides and its sulfated derivatives on immunosuppression induced by cyclophosphamide in mice / 中国免疫学杂志

Objective:In oder to investigate the effect of Chuanmingshen violaceum polysaccharides ( CVP) and Solfated Chua-nmingshen violaceum polysaccharides ( SCVP) on immunosuppression induced by cyclophosphamide ( CY) in mice.Methods: CY were used to induce immunosuppression in mice;Spleen and thymus indexes were used to evaluate the immune organs indexes;the [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltet-razolium bromide,MTT] method was used to detect the proliferation of spleen lymphocytes of each group;the concentrations of IFN-γand IL-2 were assayed by ELISA kit.Results: SCVP and CVP could resist immunosuppression by promoting lymphocyte proliferation, increasing the contents of IFN-γ and IL-2, promoting immune organs development in immunosuppressive mice induced by CY.Conclusion:SCVP and CVP exhibited the potential to used as immunopotentiator.

Molecular characterization of duck enteritis virus CHv strain UL49.5 protein and its colocalization with glycoprotein M

The UL49.5 gene of most herpesviruses is conserved and encodes glycoprotein N. However, the UL49.5 protein of duck enteritis virus (DEV) (pUL49.5) has not been reported. In the current study, the DEV pUL49.5 gene was first subjected to molecular characterization. To verify the predicted intracellular localization of gene expression, the recombinant plasmid pEGFP-C1/pUL49.5 was constructed and used to transfect duck embryo fibroblasts. Next, the recombinant plasmid pDsRed1-N1/glycoprotein M (gM) was produced and used for co-transfection with the pEGFP-C1/pUL49.5 plasmid to determine whether DEV pUL49.5 and gM (a conserved protein in herpesviruses) colocalize. DEV pUL49.5 was thought to be an envelope glycoprotein with a signal peptide and two transmembrane domains. This protein was also predicted to localize in the cytoplasm and endoplasmic reticulum with a probability of 66.7%. Images taken by a fluorescence microscope at different time points revealed that the DEV pUL49.5 and gM proteins were both expressed in the cytoplasm. Overlap of the two different fluorescence signals appeared 12 h after transfection and continued to persist until the end of the experiment. These data indicate a possible interaction between DEV pUL49.5 and gM.

Effects of flavonoids from Prinsepia utilis Royle on the histomorphology of kidney in alloxan-induced diabetic mice / 中国药理学通报

Aim To investigate the effect of flavonoids from Prinsepia utilis Royle( FPR) on the histomorphol-ogy of kidney in diabetic mice, and to investigate its protective mechanism. Methods Diabetic mice in-duced by alloxan were given FPR orally each day for four weeks. After the administration for two and four weeks, ten mice in each group were randomly sacri-ficed. The kidneys were removed and weighed. The extracted renal tissue was embedded with paraffin and sectioned, the sections were stained with Hematoxylin and Eosin(HE)、Periodic acid Schiff(PAS) and Go-mori, and then observed under the microscopy. 1mm3 of renal cortex fixed with glutaral in four centi-degree , and then the ultrastructure of each group was observed under the electron microscope respectively after four weeks′ treatment. Results Compared with the model control group, in the treatment group, observation un-der the microscopy showed that glomerular volume and mesangial cells reduced, FPR could relieve thickening of the glomerular basement membrane ( GBM ) , little inflammatory cells infiltrated in the interstitium,tubular epithelial cells almost became normal, renal tubule had little glucogen, fiber decreased in the interstitium of renal tubule. Observation under the electron micro-scope indicated that foot process in podocytes lined up in order, mitochondria of the renal tubule’ s epithelial cell almost recovered. Conclusion FPR can relieve the changes of renal pathology,improve renal function, and delay the progression of pathologic changes of kid-ney in diabetic mice partly through reducing the blood glucose and the blood lipid.

Preparation of contraceptive pill microcapsule and its anti-fertility effect / 生物医学工程学杂志

The main component of this pill is 2-Octadecanoic acid-4-Palmitic acid-2, 4-Pentanediyl ester separated from chloroform extract of neem oil. The microcapsules coated by the re-curdle method were fabricated with an average particle size of 100-180 microm. The morphological characteristics, incorporation efficiency, carrier reclamation efficiency of the microcapsule were investigated. Kunming mice were used in the experiment, and the anti-fertility effect of the microcapsule on the histology and apoptosis was studied by light and electron microscopy and the flow cytometry. The data obtained clearly indicated that the microcapsule could lead to the payload of medicine, the incorporation efficiency being 90%. After the microcapsules were given to the male mice orally, its anti-fertility effect came into being and could keep the mice in a state of reversible infertility for a long time. The results of histological study and flow cytometry indicate that the mechanism of its anti-fertility effect involves mainly the inhibition of sperm motility and the arrest of spermatogenic process.