Resveratrol Inhibits Propagation of Chlamydia trachomatis in McCoy Cells

Resveratrol (RESV), an antifungal compound from grapes and other plants, has a distinct ability to inhibit the Chlamydia (C.) trachomatis developmental cycle in McCoy cells, a classic cell line used for chlamydial research. Inoculation of C. trachomatis with increasing amounts of RESV (from 12.5 to 100 μM) gave a dose-dependent reduction in the number of infected McCoy cells visualized by using monoclonal antibodies against chlamydial lipopolysaccharide. A similar trend has been observed with immunoassay for major outer membrane protein (MOMP). Furthermore, there was a step-wise reduction in the number of C. trachomatis infective progenies caused by the increasing concentrations of RESV. The ability of RESV to arrest C. trachomatis growth in McCoy cells was confirmed by a nucleic acid amplification protocol which revealed dose-dependent changes in mRNAs for different genes of chlamydial developmental cycle (euo, incA, and omcB). Although the precise nature of the antichlamydial activity of RESV is yet to be determined and evaluated in future studies, the observed effect of RESV on C. trachomatis infection was not related to its potential effect on attachment/entry of the pathogen into eukaryotic cells or RESV toxicity to McCoy cells. Similar inhibitory effect was shown for C. pneumoniae and C. muridarum.