Evaluation of aqueous-extracts from four aromatic plants for their activity against Candida albicans adhesion to human HEp-2 epithelial cells

The present study was aimed to examine the aqueous extracts of Eugenia caryophyllata, Cichorium intybus, Punica granatum and Rhus coriaria as anti-adhesion agents of Candida albicans (C. albicans) to human epithelial type 2 (HEp-2) cells. The anti-C. albicans activity of extracts was evaluated using two methods including a standard agar well diffusion assay and monitoring C. albicans growth in the presence of extracts via optical density. The cytotoxic concentrations of the obtained aqueous extracts against HEp-2 cells were assessed using the MTT assay. Sub-cytotoxic concentrations of extracts were evaluated for their effect on the adhesion of C. albicans to HEp-2 cells. The aqueous extract of Cichorium intybus showed a promising inhibitory activity on the growth of C. albicans in a concentration-dependent manner. In addition, these plant extracts did not show cytotoxic activity against HEp-2 cells at the specific concentration. Among the four extracts, Rhus coriaria was more effective in reducing adhesion. It seems that anti-adhesion activities of the extracts could be attributed to further mechanisms rather than their anti-Candida activities. No direct correlation was found between the examined biological activities and total polyphone content in all samples. Our data demonstrate that Rhus coriaria can interfered with the growth of C. albicans and its adhesion to the epithelial cells, which could motivate researchers to make more use it in potential clinical applications.