Inhibition of butanol extract from Paris polyphylla var. yunnanensis against Candida albicans biofilm formation / 中草药

Objective: To investigate the effects of butanol extract from Paris polyphylla var. yunnanensis (BEPP) on the biofilm formation of Candida albicans in vitro. Methods: Microdilution method was used to determine the minimum inhibitory concentration (MIC). XTT assay was used to determine the SMIC80. Flat band method was used to protract the time-kill curve. Scanning electron microscopy (SEM) was used to observe the morphological changes of the biofilm. Confocal laser scanning microscopy (CLSM) was used to detect the thickness of the biofilm. The quantification real-time PCR (qRT-PCR) was used to detect the expression changes of genes (EAP1, MP65, and SUN41) of the biofilm cells. Results: The MIC of BEPP against C. albicans strains was determined as 32-128 μg/mL. The SMIC80 of BEPP against the biofilm of C. albicans strains was determined as 128-512 μg/mL. Time-sterilization curve results indicated that BEPP had a promise bactericidal effect. SEM results showed that the formation of C. albicans biofilm was inhibited by BEPP, and the morphology of biofilm was also affected by BEPP. The thickness of C. albicans biofilm was reduced by BEPP according to CLSM results. Furthermore, qRT-PCR results indicated that expressions of EAP1, MP65, and SUN41 were significantly down-regulated by BEPP. Conclusion: Our results demonstrate that BEPP inhibits the biofilm formation of C. albicans in vitro.

Inhibitory effects of butyl alcohol extract of Baitouweng decoction on virulence factors of Candida tropicalis / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of butyl alcohol extract of baitouweng decoction (BAEB) on the fungal cell surface hydrophobicity (CSH), filamentation and biofilm formation of Candida tropicalis.</p><p><b>METHOD</b>Gradual dilution method was used to determine the MIC. XTT assay was applied to determine the SMIC80. Time-Kill assay was employed to draw the Time-Kill curve. The water-hydrocarbon two-phase assay was used to measure the cell surface hydrophobicity. Scanning electron microscopy (SEM) was applied to observe the morphological changes of the biofilm. Confocal laser scanning microscopy (CLSM) was applied to determine the thickness of the biofilm. The quantification real-time PCR (qRT-PCR) was used to detect expression changes of releated genes (UME6, ALST3 and NRG1). result: The MICs of BAEB against C. tropicalis strains are determined as 64-128 mg x L(-1). The SMIC80 s of BAEB against the biofilm of Candida tropicalis strains are determined as 256-512 mg x L(-1). Time-Kill curve results indicate that BAEB has a promise fungicidal effect at 256 and 512 mg x L(-1). SEM results shows that 512 mg x L(-1) BAEB can inhibit the formation of C. tropicalis biofilm on Silicone catheter, and the morphology of biofilm is also affected by BAEB. The thickness of C. tropicalis biofilm is reduced by BAEB according to CLSM results. Furthermore, qRT-PCR results indicate that expression of UME6 and ALST3 are significantly down-regulated by BAEB 256,512 mg x L(-1), and NRG1 is not affected by BAEB.</p><p><b>CONCLUSION</b>BAEB inhibits effectively the CSH, filamentation and biofilm formation of VVC strains of C. tropicalis.</p>

Effect of andrographolide on quorum sensing and relevant virulence genes of Candida albicans / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of andrographolide (AG) on quroum sensing (QS) and relevant virulence genes of Candida albicans.</p><p><b>METHOD</b>Gas-chromatography-mass spectrometry (GC-MS) was applied to detect the changes in the content of farnesol and tyrosol in C. albicans intervened by AG. The real-time quantitative PCR (qRT-PCR) was adopted to inspect the expressions of relevant virulence genes such as CHK1, PBS2 and HOG1 regulated by QS.</p><p><b>RESULT</b>At 2 h after the growth of C. albican, the farnesol and tyrosol secretions reduced, without notable change after intervention with AG. The secretions were highest at 12 h and decreased at 24 h. After the intervention with different concentrations of AG, the farnesol content reduces, whereas tyrosol increased, indicating a dose-dependence, particularly with 1 000 mg x L(-1) AG. qRT-PCR revealed that 1 000 mg x L(-1) AG could down-regulate CHK1 by 2.375, 3.330 and 4.043 times and PBS2 by 2.010, 4.210 and 4.760 times, with no significant change in HOG1.</p><p><b>CONCLUSION</b>AG could inhibit the farnesol secretion, promote the tyrosol secretion and down-regulate QS-related virulence genes CHK1 and PBS2 expressions.</p>

Effect of Huanglian Jiedu decoction in combination with fluconazole on ergosterol of fluconazole-resistant Candida albicans / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of ethyl acetate extract of Huanglian Jiedu decoction (EAHD) , alone and in combination with fluconazole (FLZ) on FLZ-resistant Candida albicans.</p><p><b>METHOD</b>The minimum inhibitory concentrations (MIC) and sessile MIC80 (SMIC80) of EAHD and FLZ to FLZ-resistant C. albicans were determined by CLSI M27-A3 microdilution method, and the synergy of EAHD combined with FLZ were examined by the checkerboard microdilution assay. Agar plate-method was adopted to observe the rate of antifungal activity according to time-kill curve. HPLC and qRT-PCR were utilized to evaluate the changes of ergosterol content and expressions of related genes, respectively.</p><p><b>RESULT</b>MICs of EAHD ranged from 156 to 1,250 mg · L(-1), those of FLZ from 256 to above 2,048 mg · L(-1) with FICI approximate 0.066 in combination; SMIC80 of EAHD were higher than 1,250 mg · L(-1), SMIC80 of FLZ were higher than 512 mg · L(-1) and up to above 2,048 mg · L(-1). Combination group also showed synergy effect except one group showing addition effect. The results of T-K experiment also confirmed obviously fungicidal effect when treated for 12 h. When compared with control groups, the ergosterol was reduced 85% and 50% in the treatments of combination and EAHD alone by HPLC, respective- ly. The expressions of ERG1, ERG2, ERG6, ERG7 and ERG11 were upregulated, and ACS1, ACS2, MET6 were downregulated when exposed to FLZ. The expressions of the above genes were downregulated by treatment of EAHD. The expressions of ERG2, ERG6, ERG11 were upregulated, while ERG1, ERG7, ACS1, ACS2, MET6 were downregulated in combination group.</p><p><b>CONCLUSION</b>The combination of EAHD and FLZ exhibited synergy against FLZ-resistant C. albicans through decreasing the synthesis of ergosterol, and resulting in the breakage of cell membrane.</p>

Effect of andrographolide on Candida albicans biofilm dispersion / 中国中药杂志

Along with the increase in fungal infections, Candida albicans prevention and control become the focus of anti-fungal infection at present. This study aims to discuss the effect monomer andrographolide (AG) on C. albicans biofilm dispersion. In the experiment, micro-well plates and medical catheter pieces were used to establish the C. albicans biofilm model. It was discovered by XTT assay and flat band method that 1 000, 500, 250 mg x L(-1) AG could impact the activity of C. albicans biofilm dispersion cells. The morphological structures of residual biofilms on catheter pieces were observed with scanning electron microscopy, which showed that 1 000, 500, 250 mg x L(-1) AG could induce C. albicans biofilm dispersion in a dose-dependent manner, and the dispersed cells were dominated by the yeast phase. According to the real-time fluorescence quantification PCR (qRT-PCR) test, AG could up-regulate HSP90 expression and down-regulate UME6 and PES1 expressions. This study demonstrates that AG could induce C. albicans biofilm dispersion to some extent.

Study on inhibitory effect of different extract fractions from longdan xiegan decoction on biofilms of Candida albicans / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the inhibitory effect of different extract fractions from Longdan Xiegan decoction on biofilms of Candida albicans, and discuss its possible mechanism.</p><p><b>METHOD</b>The micro-dilution method and the XTT reduction assay were adopted to explore the antifungal activity of different extract fractions from Longdan Xiegan decoction and detect the inhibitory effect of different extracts on biofilms of C. albicans. The expression quantity of the adhesion related gene ALS1 and hypha formation SUN41 were detected by qRT-PCR.</p><p><b>RESULT</b>The MICs of extracts from Longdan Xiegan decoction, including petroleum ether, water, butanol, methanol and ethyl acetate, against C. albicans were > 1 000, > 1 000, > 1 000, 125, 125 mg x L(-1). The SMIC50 against biofilms of C. albicanswere > 1 000, > 1000, > 1 000, 500, 500 mg x L(-1). The SMIC50 were > 1 000, > 1 000, > 1 000, > 1 000 and 1 000 mg x L(-1). 1 000 mg x L(-1) ethyl acetate extracts could considerably inhibit the expression of the adhesion related gene ALS1 and hypha formation SUN41.</p><p><b>CONCLUSION</b>The ethyl acetate extract showed the greatest activity against Candida albicans biofilms.</p>

Effect of andrographolide derivative Yanhuning on in vivo Candida albicans biofilms in rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of andrographolide derivative Yanhuning (YHN) on Candida albicans biofilms in rats.</p><p><b>METHOD</b>The rat C. albicans biofilms subcutaneous catheter model was established by intraperitoneally injecting YHN (40, 20, 10, 5, 2.5 mg x kg (-1)), with the FLC (80 mg x kg(-1)) positive group as the control group. After 7 d, CFU counting and XTT assay were used to evaluate the effect of YHN on C. albicans biofllms in vivo. Scanning electron microscopy (SEM) was applied to observe the morphological changes in rat biofilms intervened by YHN. The real-time fluorescence quantification PCR was adopted to detect expressions of C. albicans adhesion-related genes, such as ALS1, ALS3, HWP1, EAP1 and MP65.</p><p><b>RESULT</b>The YHN group showed much less CFUs on catheter pieces and lower XTT metabolic activity than the blank group, with dosage dependence. SEM also showed that YHN could obviously decrease C. albicans adhesion on subcutaneous catheters in rats. According to qRT-PCR's results, YHN can down-regulate expressions of ALS1, ALS3, HWP1, EAP1 and MP65.</p><p><b>CONCLUSION</b>YHN could inhibit C. albicans biofilms in rats.</p>