Chemical Composition, Antioxidant, Antibacterial, and Anticancer Activities of Scorzonera calyculata Boiss. and Centaurea irritans Wagenitz. Extracts, Endemic to Iran

Background & Purpose: This research focused on the composition for the essential oils, which was obtained by solvent-free microwave extraction (SFME) from the aerial parts of Scorzonera calyculata, and hydrodistilled oils from the aerial parts and roots of Centaurea irritans, from Astraceae family, were investigated by gas chromatography (GC) and GC/mass spectrometry (MS). In addition, the biological activities of the methanolic extracts from the aerial parts of S. calyculata and C. irritans were determined. 
Methods: Total phenolic content was determined by the Folin–Ciocalteu procedure. Antibacterial activity of the methanolic extracts was carried out by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Cytotoxicity of the methanolic extract of S. calyculata against human lung cancer cells (A549) and the methanolic extract of C. irritans against breast lung cancer cells (MCF-7) were measured using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. 
Results: The obtained results of GC/MS technique showed that the SFME oil of S. calyculata, was rich in regard to nonterpenoid and sesquiterpene components. Both oils from the aerial parts and roots of C. irritans were rich in regard to oxygenated monoterpenes. The S. calyculata and C. irritans extracts showed moderate antioxidant activities with an inhibitory concentration (IC50) value of 1.48 and 1.99 mg/mL, using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and 73.51 and 44.48 μmol Fe (II)/g dry mass using ferric-reducing antioxidant power (FRAP) assay, respectively. The extracts showed high toxicity against gram-positive bacteria and the IC50 value of extracts cytotoxicity was found to be 9.8 and 10.3 mg/mL, respectively. 
Conclusion: It appeared that the investigated samples could be as a promising drug for pharmaceutical industry.