Evaluation of antioxidant and antimicrobial properties of )Echinacea purpurea( extract and identification of extract compounds by gas chromatography-mass spectrometry (GC-MS)

This study aimed to investigate the antioxidant and antimicrobial properties of Echinacea purpurea, which is used as an antiseptic, immune system booster, antimicrobial, antioxidant and anti-poisoning herbaceous plant. Antioxidant and antimicrobial properties, total phenolic compounds and DPPH radical scavenging of the extract were measured. Antimicrobial properties of the extract were assessed using well-diffusion method. The components of the extract were identified using gas chromatography-mass spectrometry (GC MS). The data were analyzed using SPSS and Duncan's statistical test. The plant extract showed high level of phenolic compounds. The DPPH radical scavenging of the extract was tested at concentrations of 0.22, 0.25, 0.27, 0.31, 0.35, 0.41, 0.50 g/ml. The concentration of IC50 indicated sufficient inhibitory potential of the extract. The diameter (means ± SD) of the growth inhibition zone for Staphylococcus aureus, Escherichia coli and Aspergillus niger was estimated at 4.67 ± 1.24, 3.11 ± 0.84 and 1.78 ± 0.89 mm, respectively. Based on well-diffusion assay, S. aureus was found more sensitive than E. coli, and E. coli was more sensitive than A. niger. Using the gas chromatography-mass spectrometry, 81.38% of the total extract compounds were identified. Important components of the extract consisted of germacrene D (21.67%), paracetamol (5.53%), Bernoulli (4.58%), respectively. The results showed that Echinacea extract had excellent antioxidant and antimicrobial effects.