Abstract:

The purpose of this study was to investigate the antioxidant, antimicrobial activities and total phenolic contents of ten methanol extracts obtained by maceration from capitulums and aerial parts (except for capitulum) of five Centaurea species (C.stenolepis, C.kilaea, C.cuneifolia, C.iberica, C.solstitialis subsp. solstitialis). Free radical scavenging activities and total phenolic contents of the species were assayed by DPPH method and Folin–Ciocalteu method, respectively. The antimicrobial activity of the extracts were tested by the micro-broth dilution method against seven microbial species. In the DPPH radical scavenging assay, the IC50 values of tested ten methanol extracts were in range 1.767-4.665 mg while the total phenol contents of four extracts were found to range between 4.825 and 12.460 mg GAE/g dry material. Four extract showed moderate activity against Pseudomonas aeruginosa (MIC: 312 μg/ml), while six out of ten extracts exhibited moderate activity against Candida albicans (MIC: 312 μg/ml). The methanol extract prepared from the aerial parts of C.cuneifolia possessed weak activity against Staphylococcus aureus (MIC: 625 μg/ml).

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