Inhibition Mechanism of Rohdea Rothon hypha formation by Candida albicans / 中国生化药物杂志

Objective To investigate the inhibition mechanism of rohdea roth on hyphae formation by Candida albicans.Methods MTT assay was used to detect the minimum inhibitory concentration(MIC)and minimum fungicidal concentration(MFC)of C.albicans.The inhibitory effect of fungicidal adherence was detected by MTT assay.Inverted fluorescence microscope was used to observe effect on hyphae formation.The influence on Efg1 and Hwp1gene expression were detected by RT-PCR method.ResultsMIC and MFC of C.albicans were 16 mg/mL and 32 mg/mL, respectively.The inhibitory effects of rohdea roth on C.albicans adherence and hyphae formation were significantly inhibited,and the concentration was dose-dependent.After the concentration of 16 mg/mL acted on C.albicans for 6 h, hyphae disappeared completely.The results of RT-PCR showed that the gene expression of Efg1 and Hwp1 could be inhibited by rohdea roth.Compared with the control group,the expression of Efg1 and Hwp1in the experimental groupwere reduced by 84.18% and 59.57%(P<0.01).Conclusion The inhibitory effect of rohdea roth on the adherence and hyphae formation of C.albicans is mainly through inhibiting the expression of Efg1 and Hwp1genes.

Removal of protein extract from moringa oleifera seed presscake on turbidity water / 中国生化药物杂志

Objective To study the removal effect of Moringa seedprotein on turbidity water. Methods The protein of Moringaoleifera seed was extracted by salting out and salting out methodand the protein concentration of Moringa oleifera seed wasdetermined by Coomassie blue staining;The removal effect of Moringa seed protein on turbidity water was determined by coagulation test.The contents of COD, ammonia nitrogen and nitrate nitrogen in the water were determined to determine the effect of Moringa seed protein on water quality. Results The experimental results showed that Moringa oleifera seed protein has good removal effect on high and medium turbidity water, and its removal effect is in a dose - dependent manner.The removal rate of 7 mg/L of Moringa seed protein to high and medium turbidity water reached 92.25 ％ and 64.71 ％ respectively. But the removal efficiency of low turbidity water was less than 7 mg/L, the removal rate of low turbidity water was only 31.91％.The results of determination of COD, ammonia nitrogen and nitrate nitrogen showed that the Moringa seed protein did not increase the content of organic matter in the water while removing turbidity effectively. Conclusion Moringa oleifera seed protein has a certain removal effect on turbidity water, among which the removal effect of high and medium turbidity water is strong, and the removal effect of low turbidity water is poor.Moringa oleifera seed protein had little effect on water quality.

Inhibition mechanism of gallnut on biofilm formation by methicillin-resistant Staphylococcus aureus / 中国生化药物杂志

Objective To investigate the inhibition mechanism of gallnut on biofilm formation by MRSA 41577.Methods TTC assay was used to detect inhibitory effects of biofilms formation and mature biofilms.The of PIA on biofilm formation was studied using Congo red agar method.Micro-Ultraviolet Spectrophotometer was used to detect inhibitory effects of the release of eDNA.The influence for Baicalein on icaA and cidA gene expression were detected by RT-PCR method.Results The inhibitory concentration (MIC) and minimum bactericidal concentration (MIC) of MRSA 41577 BF were 0.5 mg/mL and 1 mg/mL, respectively.The inhibitory effect of galla on MRSA 41577BF formation and mature BF was significantly inhibited.Inhibition of MRSA 41577,the MIC and MBC of mature BF were 4 mg/mL and 16 mg/mL.Congo red test results show that Galla can inhibit the synthesis of MRSA 41577 PIA, and the concentration was dose-dependent.The results showed that gallnut could inhibit the release of MRSA 41577 eDNA, and the release amount of eDNA was 3.61μg/OD595 and 11.91μg/OD595 , respectively, when the concentration of gall was 1/2MIC.The release of eDNA was reduced by 69.7% (P<0.01).The expression of icaA and cidA genes in the control group was 9.7% and 6.67%, respectively.The expression of icaA and cidA in the control group was significantly lower than that in the control group ( icaA and cidA, and cidA gene expression were 100%, the expression of icaA and cidA genes were reduced by 90.3%and 93.3%, respectively (P<0.01).Conclusion The inhibitory effect of gallnut on the biofilm of MRSA 41577 is mainly through inhibiting the expression of icaA and cidA genes, and then affecting the synthesis of PIA and the secretion of eDNA .

Effect of ethanolic extract of Omithogalum caudatum Ait on apoptosis of Candida albicans / 中国生化药物杂志

Objective To investigate the effect of Omithogalum caudatum Ait(OCA)on apoptosis of Candida albicans,illustrated the antifungal mechanism of OCA.Methods Annexin Ⅴ-FITC/PI double stainingwas used to detect the effect of OCA on the apoptosis of C.albicans;JC-1 and DCFH-DA staining were used to detectthe effect of OCA on mitochondrial membrane potential(MTP)and reactive oxygen species(ROS)of C.albicans.Results OCA had a good antifungal activity,the minimum inhibitory concentration(MIC)and the minimum fungicidal concentration(MFC)were 8mg/mL and 32mg/mL respectively.OCA could induceapoptosis of C.albicans,promote the reduction of MTP and increase of ROS.Conclusion OCA induced cell apoptosismainly through disrupting mitochondrial function.

Inhibition of gallnut extract on MRSA β-lactamase / 中国生化药物杂志

Objective Study on the inhibitory effect of gallnut extract extract on MRSA β-lactamase. Methods Determination of inhibitory effect of gallnut extract on MRSA3002 by TTC method. β-lactamase was repeated by freezing and thawing method . Synergistic effect of gallnut extract and gentamicin was detected by TTC. Results The MIC and MBC of MRSA3002 by gallnut extract were 8mg/mL and 32mg/mL.Gallnut extract can reduce strains of β-lactamase activity,the MRSA300224h 1/2MIC after the effect of gallnut extract, beta lactam enzyme activity inhibition compared with the control group there were significant differences (P<0.01),compared with the positive control group, the difference was not significant. Synergistic effect of gallnut extract and gentamicin can significantly reduce the MIC of MRSA3002. Conclusion Gallnut extract can reduce β-lactamase activity recovery sensitivity of drug-resistant bacteria.

The antimicrobial and antioxidant activity of the powder of Ganoderma lucidum / 中国生化药物杂志

Objective To investigate the antimicrobial and antioxidant activity of the water extract and ethanol extract of the powder of G.lucidum.Analysis and comparison of two kinds of antibacterial and antioxidative effects of the extracts.Methods G.lucidum powder was prepared by using a pulverizer and extracted with water and ethanol respectively.The inhibitory effects of water extract and alcohol extract of G.lucidum on the tested strains were determined by TTC method.The antioxidant activities of aqueous extract and ethanol extract of G.lucidum were determined by DPPH and FRAP.Results The minimum inhibitory concentration ( MIC) of the aqueous extracts and ethanol extracts of G.lucidum were 32 mg/mL and 16 mg/mL, respectively.The MIC for S.Aureus respectively was 64 mg/mL and 32 mg/mL, the MIC for M.luteus respectively was 32 mg/mL and 8 mg/mL, MIC for B.terom respectively was 64 mg/mL and 8 mg/mL, The MIC of B.subtilis respectively was 32 mg/mL and 8 mg/mL.The antioxidant activity of G.lucidum powder extract and ethanol extract showed good antioxidant activity, the scavenging radical capacities on DPPH of the water extract and ethanol extract were 56.22%and 20.67% at a concentration of 2 mg/mL ( P<0.5 ) , the FRAP value respectively were 3.52 and 3.77 mmol/mL. Conclusion The powder of G.lucidum has the effective antimicrobial activity and antioxidant activity.The two kinds of extracts extract of G.lucidum had good antibacterial activity and antioxidant activity.The ethanol extract of G.lucidum powder antimicrobial effect and total antioxidative ability in water extracts, aqueous extract of Ganoderma lucidum granules on DPPH free radical scavenging rate better than that of ethanol extract.

Inhibitory effects of andrographis paniculata and silybum marianum on the efflux pump of MRSA 41577 / 中国生化药物杂志

Objective To study the inhibitory effects of andrographis paniculata and silybum marianum on the efflux system of MRSA 41577. Methods Inhibitory effects of andrographis paniculata and silybum marianum on efflux system of MRSA 41577 was evaluated using fluorescence spectrophotometry.PCR was applied to detect the norA efflux gene.By RT-PCR method for detection of andrographis paniculata and silybum marianum influence of the expression of norA efflux gene.Results Andrographis paniculata and silybum marianum significantly increased the accumulation of ciprofloxacin in MRSA 41577 in a time-dependent manner.At 12 minute, andrographis paniculata and silybum marianum respectively increased ciprofloxacin in MRSA41577 by 49% and 76%( P <0.05 ) , which is superior to that of reserpine. Further mechanism studies indicated that andrographis paniculata and silybum marianumcould reduce the expression of norA in MRSA 41577.After incubated with andrographis paniculata and silybum marianum for 16 h, the relative expression of norA of MRSA41577 was respectively reduced by 35% and 42% ( P <0.05 ). Conclusion Andrographis paniculata and silybum marianumcould inhibit MRSA efflux system through reducing pathogen ’s expression of norA and NorA protein.

Compare anti-tumor activity and antioxidant activity of F.velutipes and A.auricula / 中国生化药物杂志

Objective To compare the anti-tumor activity and antioxidant activity of ethanol extracts of F.veluties and A.auricula.Methods Three human carcinoma cell lines, including MCF-7, HeLa and A375 were assessed by MTT assay to measure cell viability.The antioxidant activity was detected with a DPPH and RFAP assays.Results Two domestic fungus have different anti-tumor activity on the inhibition of MCF-7, HeLa and A375 cells at 25-400μg/mL concentration rage.F.velutipes was better than the A.auricula.The difference was statistically significant ( P<0.05 ).Compared with the control group, the inhibition of F.velutipes were 48.20%, 52.61%and 50.58%at the concentration of 400μg/mL, respectively (P<0.01).At the same concentration, the inhibition of A.auricula were 37.62%、50.21%and 41.59%, respectively (P<0.01).The ethanol extracts of two domestic fungus have significant antioxidant activity.F.velutipes was better than the A.auricula.The difference was statistically significant ( P<0.01 ).Compared with the control group, the scavenging radical capacities on DPPH of ethanol extracts of F.velutipes and A.auricula were 60.30%and 40.43%at the concentration of 1.6 mg/mL, respectively (P<0.01).At the same concentration FRAP value were 9.5 and 7.0 mmol/mL(P<0.01).Conclusion The F.velutipes and A.auricula both have strong anti-tumor and antioxidant activities, F.velutipes is better than A.auricula.

Inhibitory effects of Sanguisorba officinalis L.on MRSA biofilms formation / 中国生化药物杂志

Objective To investigate inhibitory effects of Sanguisorba officinalis L.on biofilms of MRSA41577.Methods Congo red agar method and crystal violet semi-quantitative method were used to detect the biofilms-forming ability of tested strains; TTC assay was used to detect inhibitory effects of Sanguisorba officinalis L.on biofilms formation and mature biofilms of MRSA41577,as well as effects of Sanguisorba officinalis L.in combination with vancomycin on mature biofilms of MRSA41577.Results Sanguisorba officinalis L.showed significant inhibitory both on biofilms formation and mature biofilms, minimum inhibitory concentration(MIC) and minimal bactericidal concentration(MBC) of biofilms formation were 1 mg/mL and 8 mg/mL,MIC of mature biofilms was 4 mg/mL.The sensitivity of mature biofilms to vancomycin was greatly increased when Sanguisorba officinalis L.was combined with vancomycin with subinhibitory concentrations.Sanguisorba officinalis L.at 1/4 MIC can inhibit mature biofilms when combined with vancomycin at 4 μg/mL, while vancomycin didn't show inhibitory effects on mature biofilms when concentrations were below 64 μg/mL. Conclusion Sanguisorba officinalis L.has significant inhibitory on biofilms formation, the mechanism may be related to Sanguisorba officinalis L.destroyed biofilms and make vancomycin penetrate into the biofilms to finish the bactericidal activity.

Antibacterial mechanism of emodin on methicillin staphyloccocusn aureus / 中国生化药物杂志

Objective To investigate effect of emodin on cell membrane, protein and nucleic acid synthesis of MRSA41577, and systematically investigate the anti-bacterial mechanism of emodin.Methods TTC assay was used to detected the anti-bacterial activity of emodin on MRSA 41577. Conductivity and macromolecular were detected to investigate the effect of emodin on MRSA41577 cell membrane .SDS-PAGE was used to detect the effect of emodin on the soluble protein synthesis.DAPI staining was used to detect the effect of emodin on nucleic acid synthesis.UV-visible spectrophotometric was used to detected the interaction between emodin and DNA.ResuIts Emodin has significant inhibitory activity on MRSA41577, and the minimum inhibitory concentration was 8μg/mL.After treated with 8 μg/mL emodin for 6h, compared with control group, the macromolecular and conductivity improved (71.48 ±0.026)% (P<0.01) and (2.39 ±0.102)%(P<0.05), sepreatly.Compared with control, after treated with 8μg/ml emodin for 16h,the protein reduced 32.8%, and the contents of DNA and RNA reduced (4.82 ±1.06)%(P<0.05,) and (6.67 ±0.36)%(P<0.053).The UV-visible spectrophotometric results indicated that emodin could integrate with DNA through hydrogen bond.ConcIusion The anti-bacterial mechanism of emodin mainly through damage the cell membrane , inhibit the replication and transcription of DNA through hydrogen bond , inhibit the synthesis of protein, and thus inhibit the biological function of bacteria.

Effect of emodin on mice immune cells and its hemolysis in vitro / 中国生化药物杂志

Objective To investigate effect of emodin on mice immune function and its hemolysis toxicity.Methods The mouse specific immune cells of T, B lymphocytes and nonspecific immune cell of macrophages and NK cells were prepared and incubated in vitro.The different immune cells were treated by emodin with different concentrations of 5,10,15 and 20μM, and DMSO as control group.The effect of emodin on immune cells function was detected by neutral red assay and MTT assay.The hemolysis test in vitro was conducted by emodin with different concentrations of 20, 40, 60 and 80μM, physiological saline as blank control group and sterile distilled water as positive control group, then the hemolysis toxicity of emodin was observed. Results There were no significant difference of T and B lymphocyte proliferation among control group, 5, 10, 15 and 20 μM group(F=0.009,P=1.000;F=0.003,P=1.000), the phagocytic ability of macrophages enhanced in each dose group and was concentration dependent(F=665.525,P=0.000), the proliferation rate of macrophages enhanced and was concentration dependent(F=134.812,P=0.000), the activity of NK cells enhanced and was concentration dependent(F=200.190,P=0.000).Hemolysis test results showed the hemolysis rate was less than 5% in the range of 20 to 80μM emodin.Conclusion Emodin could significantly promote the nonspecific immune cells activity.Within the concentration of experiment, emodin has no hemolysis toxicity.

Antibacterial activity and mechanism of baicalein / 药学学报

Baicalein (BAI) is an effective bactericide. The antibacterial activity and mechanism experiments were carried out by determining conductivity and content of macromolecules of membrane penetrability, the oxidative respiratory metabolism and protein synthesis changes and the inhibition of DNA topoisomerase activities. Electrical conductivity and the number of large molecules of BAI increased 2.48% and 1.8%, respectively, than that of the control. However, the membrane integrity did not destroyed by BAI directly. With BAI treatment, inhibition rates of activities for SDH and MDH were 56.2% and 57.4%, respectively, demonstrating that BAI could inhibit cell respiratory. After treated with BAI for 20 h, the total soluble content of proteins decreased by 42.83%. Moreover, the activities of DNA topoisomerase I and II were inhibited completely by 0.2 mmol x L(-1) BAI. These results indicated that BAI had obvious antibacterial activity on Staphylococcus aureus. The mechanism is that it could affect bacterial membrane penetrability, inhibit protein synthesis and influence SDH, MDH and DNA topoisomerase I and II activities to exert its antibacterial functions.

Detection and identification of viable Listeria monocytogenes by real-time PCR / 中华微生物学和免疫学杂志

Objective To establish a rapid,sensitive and specific assay based on real-time PCR combined with reverse transcription for detecting and identifying viable Listeria monocytogenes.Methods The hlyA gene of Listeria monocytogenes was chosen as target,and then the primers and TaqMan probe were designed.Both ends of probe were modified with two different fluorescence groups.The PCR reaction was optimized systematically.The mRNA of Listeria monocytogenes was extracted,and then reverse transcription was performed through random primer.The cDNA Was detected by real-time PCR.Then the specificity,sensitivity and reproducibility of real-time PCR were estimated.In final,real-time PCR was applied to detect 20 mocked double-blind samplea.Results Viable Listeria monocytogenes were detected by real-time PCR accurately and quickly,and meanwhile,none of other bacteria and non-viable Listeria monocytogenes could be identified.The sensitivity was 10 CFU/ml in pure culture and 103CFU/ml for mocked samples respectively.The coefficient of variation of intra-assay and inter-assay Was less than 5%.When this assay was applied directly to identify 20 mocked double-blind samples,10 of these were positive to viable Listeria monocytogenes,5 were negative to non-viable Listeria monocytogenes,and 5 were negative to other pathogens.Conclusion It is demonstrated that real-time PCR is a reliable,accurate and feasible assay for viable Listeria monocytogenes.The establishment of this assay provided complete data for analysis and diagnosis in the field of food safety and epidemiologic survey.

STUDY ON ANTI-MICROBIAL ACTIVITY OF GENISTEIN AND ITS MECHANISM / 营养学报

Objective To investigate the anti-microbial activity of genistein and its mechanism. Method The anti-microbial experiment was carried out by utilizing scanning and transmission electron microscope(SEM and TEM) ,and further analyzing the respiratory metabolism and change of SDS-PAGE protein spectra. Results Genistein could inhibit several kinds of bacteria obviously.The erose structures such as rugae and bubbles were observed on the surface of cells by SEM after 24h. Moreover,with TEM,we detected the shrinkage of cytoplasm,the plasmolyses,and then the breach of wall and membrane along with the outflow of protoplasm in Staphylococcus aureus treated with genistein for 4h,14h and 24h respectively. Notablely the respiratory inhibition experiment revealed that the genistein mainly inhibits the TCA cycle of bacteria. Besides,the SDS-PAGE elucidated that the total expression of proteins was decreased in the cell treated with genistein,and especially the larger proteins were reduced with 90.1%. Conclusion Genistein showed obvious anti-microbial activity to Staphylococcus aureus. It could destroy the integrity of cell wall and membrane,prevent the respiratory metabolism and protein synthesis of the bacteria.