Send to

Choose Destination
Int J Antimicrob Agents. 2004 Nov;24(5):423-7.

Cyclic dipeptides exhibit synergistic, broad spectrum antimicrobial effects and have anti-mutagenic properties.

Author information

Department of Microbiology and Immunology, University of British Columbia, # 300-6174 University Blvd., Vancouver, BC, Canada V6T 1Z3.


Cyclic dipeptides are known to have antiviral, antibiotic and antitumour properties. The aim of this study was to determine the combined effects of cyclo(L-leucyl-L-prolyl) and cyclo(L-phenylalanyl-L-prolyl) on the growth of vancomycin-resistant enterococci (VRE) and pathogenic yeasts, as well as determining their anti-mutagenic effects. This drug combination was especially effective against five VRE strains: Enterococcus faecium (K-99-38), E. faecalis (K-99-17), E. faecalis (K-99-258), E. faecium (K-01-312) and E. faecalis (K-01-511) with MIC values of 0.25-1 mg/l. It was also effective against Escherichia coli, Staphylococcus aureus, Micrococcus luteus, Candida albicans and Cryptococcus neoformans with MIC values of 0.25-0.5 mg/l. In addition, the cyclic dipeptides exerted anti-mutagenic activity against Salmonella typhimurium TA98 and TA100 strains in a Salmonella mutation assay. The number of mutant colonies of S. typhimurium strains TA98 and TA100 induced by exposure to AF-2 (0.2 microg/plate) decreased in a concentration-dependent manner in the presence of the two cyclic dipeptides (correlation 0.72 and 0.78, respectively). Here, for the first time, we report synergistic effects of the cyclic dipeptides [cyclo(L-leu-L-pro) and cyclo(L-phe-L-pro)] in inhibiting the growth of pathogenic microorganisms, as well as their anti-mutagenic effects in Salmonella strains.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center