ABSTRACT
Aim To evaluate the inhibitive effects of celastrol on LDL oxidation and HAEC cell oxidative damage. Methods The Cu2+-induced LDL oxidation model was employed to evaluate celastrol inhibitive effect on LDL oxidation in vitro, the oxidative reaction kinetic curves were determined, and the AUC, lag time,TBARS value were assayed. The AAPH-induced HAEC damaging cellular model was employed to evalu-ate the effect of celastrol on oxidative cellular damage. The safe dose of celastrol on normal cells was deter-mined by MTT method, and the effects of celastrol on HAEC oxidative damage were evaluated at the range of this safe dose. The LDH leakage,ROS level,SOD and GPX enzymatic activity,Nrf2 and HO-1 mRNA expres-sion were determined. Results At the dose range of 100 nmol · L-1 to 1 μmol · L-1 , celastrol effectively extended the lag time of LDL oxidative process induced by Cu2+, reduced the AUC of oxidative reaction kinet-ic curve and reduced the generation of lipid peroxide in the LDL oxidative process. In the cellular experiment, celastrol effectively reduced the LDH leakage induced by AAPH, increased the integrity of cell membrane and nucleus, enhanced the antioxidative enzyme activi-ties of cellular SOD,GPX and increased the expressions of Nrf2,HO-1 mRNA, celastrol also maintained the in-tegrity of cellular structure. Conlusion Celastrol can effectively inhibit LDL oxidation induced by Cu2+, and can inhibit HAEC cell oxidative damage induced by AAPH at the dose range of 100 to 400 nmol·L-1 .
ABSTRACT
Objective To compare the immunogenicity of pneumococcal surface adhesion A (PsaA) and pneumococcal surface protein A (PspA). Methods The variability of the genes and the expressed pneumococcal proteins PsaA and PspA was investigated by electrophoresis. Cross-reactivity of proteins with the antibodies induced by the corresponding proteins of Streptococcus pneumoniae serotype 5, 6B,1, 19F and 23F was researched by Western blot. The enzyme-linked immunosorbent assay (ELISA) was adopted to detect the antibody subclasses and the accessibility of antibodies induced by PsaA and PspA to the surface of the above intact strains. Cross-protection against challenging with Streptococcus pneumoniae strains was indagated in mice. Results Both proteins showed to induce the similar level of antibody subclasses.This study demonstrated that cross-reactivity of pneumococcal PspA was restricted in the same clade, which showed less extensive than pneumococcal protein PsaA. But antibody induced by pneumococcal protein PspA could be bound to the surface of the intact strains, which conduced the stronger cross-protection against inva sive strains. Conclusion The mice immunized with PspA protein cross-protected well against the invasive strains in which PspA belonged to the same clade 1 of family 1. It showed that pneumococcal protein PspA was more effective than PsaA in protection as composition of vaccine.
ABSTRACT
Aim To investigate whether Rhizoma curcumaecould induce pregnane X receptor(PXR)-mediated transcriptional expression of CYP3A4 and study the modulatory effects on the enzyme activity and mRNA expression of CYP3A in the rat liver.Methods Transient cotransfection reporter gene assays were performed in HepG2 cells;the rat liver microsomal cytochrome P450 and CYP3A isoenzyme-erythromycin N-demethylase(ERD)activities were determined by UV chromatography;the mRNA expression level of CYP3A was detected by reverse transcriptase-polymerase chain reaction(RT-PCR).Results In vitroinvestigation showed Rhizoma curcumaeand its four selected constituents could induce the CYP3A4 transcriptional expression by activating PXR.In vivoinvestigation showed the CYP450 content of liver microsomes and enzyme activity of CYP3A were markedly increased and induced by Rhizoma curcumaeextract;at the mRNA level, the expression of CYP3A1 and CYP3A2 gene were markedly induced by Rhizoma curcumaeextract.Conclusions Rhizoma curcumaeand its four selected constituents could induce the expression of the CYP3A4 gene transcriptional expression through activating PXR;Rhizoma curcumaeextract could increase and induce the enzyme activity and mRNA expression of CYP3A.