ANTIMICROBIAL AND ANTIOXIDANT SCREENING, SYNERGY STUDIES OF HELICHRYSUM CHIONOPHILUM EXTRACTS AGAINST TO RESISTANT MICROBIAL STRAINS

In this study, the antimicrobial activities and antioxidant properties of five different extracts of Helichrysum chionophilium plants from Gumushane/Turkey were investigated. To determine the antimicrobial activity disc diffusion and microdilution methods were used against to fifteen microorganisms. The effect of plant extracts and antibiotic combinations against to vancomycin-resistant Enterococcus faecium and methicillin-resistant Staphylococcus aureus were investigated as well. Total phenolic and flavonoid contents were determined by spectrophotometric techniques. Antioxidant properties of plant extracts evaluated by free radical scavenging assays which ABTS and DPPH. The plant ethyl acetate extract showed the highest level of total phenolic (423.01 +/- 0.8 mg GAE/g extract) and flavonoid contents (100.18 +/- 1.4 mg QE/g extract). Similarly, ethyl acetate extract exhibited the highest level of DDPH (IC50: 67.44 +/- 0.9 mu g/ml). However, hexane extract exhibited the highest level activity of ABTS (IC50: 55.20 +/- 1.3 mu g/ml). The highest MIC value was determined as 8 mu g/ml against to Pseudomonas aeruginosa on ethyl acetate extract. Besides, all of extracts exhibited antimicrobial activity on at least one test organism. Plant extracts with some antibiotic combinations generated synergies or partial synergic activity against to VREF and MRSA. These findings revealed that the plant has strong antimicrobial and antioxidant properties. Finally, using the plant extracts and antibiotic combinations might be a good tool in fighting with antibiotic resistance strains.