ABSTRACT
Objective To study the effects of nano silver (Ag) and titanium dioxide (TiO2) on the content of nucleic acid in staphylococcus aureus in order to explore their antibacterial mechanisms.Methods After preparation of beef extract peptone liquid cultures,the effects of minimal inhibitory concentrations (MICs) of nano Ag and TiO2 on staphylococcus aureus strains were determined.With the 1/2 MICs nano Ag and TiO2,the contents of DNA and RNA macromolecules from staphylococcus aureus cultures were measured to determine the damage degree of staphylococcus aureus cell membranes by ultraviolet spectrophotometer,and then the fluorescence intensities of the staphylococcus aureus cells were observed under fluorescence microscope and the fluorescence values were tested by fluorescence spectrophotometer to determine the contents of nucleic acid DNA and RNA.Results The MICs of nano Ag and TiO2 were 1.6 mg/mL and 5.781 μg/mL.After treatment with the 1/2 MICs nano Ag and TiO2,nano Ag group and TiO2 group were compared with the control group (culture fluid without adding antibacterial agent),respectively,and there were no significant differences in the contents of DNA and RNA macromolecules from staphylococcus aureus cultures between n anoAg group and control group as well as between TiO2 group and control group were (P＞0.05),and there were significant decreases in fluorescence intensities and the contents of nucleic acid DNA and RNA (P＜0.01).Conclusions Nano Ag and TiO2 had obvious antibacterial effects on staphylococcus aureus and the antibacterial properties of nano Ag was stronger than that of TiO2.The antibacterial mechanisms of nano Ag and TiO2 against staphylococcus aureus may be associated with the inhibition of the synthesis of nucleic acid DNA and RNA,inhibiting protein synthesis and then bacterial growth.
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ObjectiveTo study the effects of Tanreqing injectio (a Chinese herb preparation acts as an anti-inflammatory agent to eliminate the pulmonary infection) on inflammatory cytokines of rats with acute lung injury (ALI). MethodsFifty-six clean grade healthy male SD rats were randomly (random number) divided into three groups: normal group, model group and treatment group. Rats in the model group and treatment group were injected with lipopolysaccharide (LPS) into tail vein. Rats in treatment group were treated with Tanreqing injection one hour after LPS injection. The observing intervals were respectively set in 2 h, 4 h and 6 h. At each observing interval, TNF-α, IL-1 β and IL-8 in brochoalveolar lavage fluid (BALF) were detected by radioimmunoassay, and the ratio of polymorphonuclear neutrophiles (ωPMN) in BALF were calculated by Wright-Giermsa staining, as well as to observe the pathological changes of lungs and to examine the lung wet/dry weight ratio (W/D). Data were analyzed with SPSS version 17.0 software. ResultsAt 2, 4 and 6 h intervals, TNF-α, IL-1β, IL-8 and ωPMN in BALF were significantly higher in model group than those in normal group (P ＜0. 05 or P ＜0. 01 ), the lung W/D in model group were obviously higher than those in normal group ( P ＜ 0. 01 ), and the pathological injury of lung tissue in model group were severe. At each observing interval, compared with model group,TNF-o, IL-1 β, IL-8 and oPMN in BALF were significantly reduced in treatment group ( P ＜ 0. 05 or P ＜0.01 ), the lung W/D in treatment group were obviously decreased ( P ＜0.01 ), and the lung injury were attenuated in treatment group. ConclusionsTanreqing injection could provide partly protection in rats with ALI by inhibiting inflammatory factor.
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[Objective]To observe the effects of qing-nao-ding-tong decoction on the levels of IL-6 and TNF-? in subarachnoid hemorrhage.[Methods]Cases were randomly divided into integrated traditional Chinese and western medicine (TCW) groups,western medicine group and control group.After 2w treatment,the levels of IL-6 and TNF-? were contrasted.[Results]The levels of IL-6 and TNF-? were both raised.Combined with western medicine,qing-nao-ding-tong decoction could effectively reduce the levels of IL-6 and TNF-?.[Conclusion]Combined with western medicine,qing-nao-ding-tong decoction can effectively reduce the levels of IL-6 and TNF-? in patients with subarachnoid hemorrhage,and there is synergistic reaction between TCM and WM.