Curcuma longa L.Constituents Inhibit Sortase A and Staphylococcus aureus Cell Adhesion to Fibronectin

摘要

The inhibitory activity of Curcuma longa L.(turmeric)rhizome constituents against sortase A,a bacterial surface protein anchoring transpeptidase,from Staphylococcus aureus ATCC 6538p was evaluated.The activity of the isolated compounds(1-4)was compared to that of the positive control,p-hydroxymecuribenzoic acid(pHMB).The biologically active components of C.longa rhizome were characterized by spectroscopic analysis as the curcuminoids curcumin(1),demethoxycurcumin(2),and bisdemethoxycurcumin(3).Curcumin was a potent inhibitor of sortase A,with an IC_(50)value of 13.8 +-0.7mug/mL.Bisdemethoxycurcumin(IC_(50)=31.9 +-1.2 mug/mL)and demethoxycurcumin(IC_(50)=23.8 +-0.6 mug/mL)were more effective than pHMB(IC_(50)=40.6 +-1.2 muglmL).The three isolated compounds(1-3)showed no growth inhibitory activity against S.aureus strain Newman,with minimum inhibitory concentrations(MICs)greater than 200 mug/mL.Curcumin also exhibited potent inhibitory activity against S.aureus cell adhesion to fibronectin.The suppression of fibronectin-binding activity by curcumin highlights its potential for the treatment of S.aureus infections via inhibition of sortase activity.These results indicate that curcumin is a possible candidate in the development of a bacterial sortase A inhibitor.