In vitro antimicrobial activity of extracts and their fractions from three Eryngium L. species
Introduction: Due to increasing resistance against antibiotics and antifungal agents, crude plant extracts, fractions, and isolated pure compounds became a new interest as antimicrobial agents. Objectives: The antimicrobial activity of methanolic extracts and fractions of Eryngium planum L., E. campestre L., and E. maritimum L. was evaluated against selected bacteria, yeast and mould, and compared in tested Eryngium species and in their organs. Methods: The antimicrobial activity was studied with use of broth microdilution method. The antibacterial (Staphylococcus aureus, Pseudomonas aeruginosa) and antifungal (Candida albicans, Aspergillus niger) activity of selected extracts and fractions compared with the reference substance was expressed by Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal/Fungicidal Concentration (MBC/MFC).The extract and fraction compounds were identified on the basis of TLC examination. Results: The saponin-phenolic acid fractions of E. maritimum and E. planum and a saponin fraction of E. planum showed the highest activity against S. aureus (MIC = 1–2.5 mg·ml-1). The growth of C. albicans was inhibited by methanolic extract of E. planum cell suspension culture (MIC = 7.8 mg·ml-1). Conclusion: The antimicrobial activity depends on the Eryngium species, tested biomass, and microorganism.