摘要
AIM To study the sensitivity and antioxidant enzyme response in two clinical isolates of Entamoeba histolytica(E. histolytica) during treatment with antiamoebic drugs,auranofin and metronidazole. METHODS E. histolytica were isolated from stool samples and maintained in Robinson's biphasic culture medium. Clinial isolates were maintained in xenic culture medium,and harvested for determination of minimum inhibitory concentrations to the two antiamoebic drugs,Metronidazole and Auranofin using microtiter plate tests. The percent survival of the two isolates were determined using the trypan blue cell count. Isolate 980 was treated with 70 μmol/L and 2 μmol/L while isolate 989 was treated with 20 μmol/L and 0.5 μmol/L of metronidazole and auranofin respectively for 24 h. Fifty thousand cells of each isolate were harvested after 24 h of treatment for analysis of the mRNA expressions of the antioxidant enzymes,thioredoxin reductase,peroxiredoxin and FeSOD using the specific primers. Cell lysate was used for determination of enzyme activity of thioredoxin reductase by measuring DTNB reduction spectrophotometrically at412 nm.RESULTS Minimum inhibitory concentration of the clinical isolates 980 and 989 for auranofin was 3 μmol/L and 1 μmol/L respectively while that for metronidazole was 80 μmol/L and 30 μmol/L respectively. Thioredoxin reductase,peroxiredoxin and FeSOD expression levels were significantly reduced in the isolate 980 when treated with Auranofin. Metronidazole treatment showed a down regulation of thioredoxin reductase. Though not significant both at the mRNA and the enzyme activity levels. Peroxiredoxin and FeSOD however remained unchanged. Auranofin treatment of isolate 989,showed an upregulation in expression of thioredoxin reductase while Peroxiredoxin and FeSOD did not show any change in expression. Upon treatment with metronidazole,isolate 989 showed an increase in thioredoxin reductase expression. Peroxiredoxin and FeSOD expressions however remain unchanged both at mRNA and enzyme activity level.CONCLUSION Clinical isolates from New Delhi NCR region show different sensitivities to antiamoebic drugs. Auranofin is effective against isolate showing higher tolerance to metronidazole as shown by its inhibition in thioredoxin reductase activity.
AIM To study the sensitivity and antioxidant enzyme response in two clinical isolates of Entamoeba histolytica(E. histolytica) during treatment with antiamoebic drugs,auranofin and metronidazole. METHODS E. histolytica were isolated from stool samples and maintained in Robinson's biphasic culture medium. Clinial isolates were maintained in xenic culture medium,and harvested for determination of minimum inhibitory concentrations to the two antiamoebic drugs,Metronidazole and Auranofin using microtiter plate tests. The percent survival of the two isolates were determined using the trypan blue cell count. Isolate 980 was treated with 70 μmol/L and 2 μmol/L while isolate 989 was treated with 20 μmol/L and 0.5 μmol/L of metronidazole and auranofin respectively for 24 h. Fifty thousand cells of each isolate were harvested after 24 h of treatment for analysis of the mRNA expressions of the antioxidant enzymes,thioredoxin reductase,peroxiredoxin and FeSOD using the specific primers. Cell lysate was used for determination of enzyme activity of thioredoxin reductase by measuring DTNB reduction spectrophotometrically at412 nm.RESULTS Minimum inhibitory concentration of the clinical isolates 980 and 989 for auranofin was 3 μmol/L and 1 μmol/L respectively while that for metronidazole was 80 μmol/L and 30 μmol/L respectively. Thioredoxin reductase,peroxiredoxin and FeSOD expression levels were significantly reduced in the isolate 980 when treated with Auranofin. Metronidazole treatment showed a down regulation of thioredoxin reductase. Though not significant both at the mRNA and the enzyme activity levels. Peroxiredoxin and FeSOD however remained unchanged. Auranofin treatment of isolate 989,showed an upregulation in expression of thioredoxin reductase while Peroxiredoxin and FeSOD did not show any change in expression. Upon treatment with metronidazole,isolate 989 showed an increase in thioredoxin reductase expression. Peroxiredoxin and FeSOD expressions however remain unchanged both at mRNA and enzyme activity level.CONCLUSION Clinical isolates from New Delhi NCR region show different sensitivities to antiamoebic drugs. Auranofin is effective against isolate showing higher tolerance to metronidazole as shown by its inhibition in thioredoxin reductase activity.
基金
Supported by WOS-A grant from Department of Science and Technology,New Delhi,Government of India to Iyer LR,No.SR/WOS-A/LS-98/2007
"Programme support on molecular parasitology",Department of Biotechnology,New Delhi,India to Paul J,No.BT/01/CEIB/11/v/08
