Phytochemical characterization and biological activities of Inula viscosa L. Aiton: a promising plant from Turkey

The methanol extract of Inula viscosa (IVM) was investigated for its antioxidant potential using the DPPH and ABTS radical scavenging as well as iron chelating assays (ICA). The total phenol (TPC) and flavonoid contents (TFC) of IVM were determined using the Folin-Ciocalteu and aluminum trichloride methods, respectively. Antimicrobial activity of different concentrations of I. viscosa methanol extract was investigated by disc diffusion and broth microdilution method. The IVM extract was found to be containing TPC (236.78 ± 7.63 mg GAE/g) and TFC (94.36 ± 1.86 mg QE/g). Antioxidant activity IC50 values for the DPPH, ABTS and ICA assays were found to be 277.7 ± 3.68, 2.44 ± 0.02, and 222.1 ± 0.71 µg/mL, respectively. The MIC values of the IVM on the tested microorganisms ranged from 0.48 to 7.81 mg/mL. Furthermore, IVM extract was demonstrated 18.32 ± 1.37%, 23.06 ± 1.05%, 4.72 ± 0.13%, 15.13 ± 0.37% and 37.64 ± 4.02% inhibition against tyrosinase, α-amylase, α-glucosidase, AChE and BChE, respectively. In the results of LC-MS/MS analysis, acacetin, quercetin, chlorogenic acid and protocatechuic acid were determined as most dominant compounds. These findings suggested that this plant may be a natural resource for creating novel medicinal compounds.