Extract of Syzygium aromaticum suppress eEF1A protein expression and fungal growth

Clove extract has therapeutic potential as an antifungal drug, yet the mechanism of action remains ambiguous. Current study aimed to address the molecular process of the antifungal activity exerted by clove extract.

The antifungal assay results showed that clove extract had some effects on all of the tested yeast. Propidium iodide staining assay showed cell membrane damage in Saccharomyces cerevisiae after treatment of clove extract for 30 h. Interestingly, SDS-polyacrylamide gel electrophoresis assays revealed that the protein expression of eukaryotic elongation factor 1 alpha (eEF1A) was suppressed significantly after treatment with clove extract (not pure eugenol). Transcriptional analyses revealed that the TEF1 and TEF2 genes (translation elongation factor EF-1 alpha) encoding eEF1A were not disturbed with the addition of clove extract; however, the expression of related genes EFB1 (translation elongation factor 1 subunit beta), ENO2 (phosphopyruvate hydratase ENO2), GSP1 (Ran GTPase GSP1), RPP0 (ribosomal protein P0), YEF3 (translation elongation factor EF-3), TEF4 (translation elongation factor EF1B gamma), and RPS2 (ribosomal 40S subunit protein S2) increased significantly.

These results suggest that clove extract plays a role in disrupting growth and affecting yeast metabolism. eEF1A was affected by clove extract at the protein level but not at the transcriptional level.

This study is based on a detailed study of antifungal action exerted by clove extract, and proposed that down-regulation of eEF1A protein expression may contribute to its antifungal activity. These results may have clinical significance for future application of clove extract as a natural antifungal agent.