Antioxidant and Antimicrobial Activities, and Phenolic Compounds of Selected Inula species from Turkey

Abstract

Three Inula species, I. viscosa, I. helenium ssp. turcoracemosa and I. montbretiana, collected from different locations of Anatolia were investigated for their antioxidant and antimicrobial potential, and their total phenolic content and phenolic composition. Antioxidant activities of various extracts of the plant parts were measured using DPPH radical scavenging and ABTS assays. Antimicrobial potential of methanol extracts of the plant parts was determined by the agar dilution method against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Candida tropicalis. All the extracts were more active against Gram-positive bacteria and yeasts than Gram-negative bacteria. The extracts exhibited antioxidant and antimicrobial activities in different concentrations. Total phenolic concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard. The total phenolic content varied widely in different parts of the three tested Inula species, ranging from 21.1 ± 0.8 to 190.9 ± 6.1 mg GAE/g extract. Phenolic components, such as chlorogenic acid, caffeic acid, rutin, myricetin, quercetin, luteolin and kaempferol were quantified by HPLC-DAD in the methanol extracts of the Inula species. It was obvious that the antioxidant and antimicrobial properties of the plants were due to the phenolics.

Caffeoylquinic Acids, Cytotoxic, Antioxidant, Acetylcholinesterase and Tyrosinase Enzyme Inhibitory Activities of Six Inula Species from Bulgaria

“…turcoracemosa , I. montebriana , I.viscosa , I. peacockiana and I. thapsoides ssp. thapsoides varied in wide range from 0.03 to 0.82 % (w/w) . In another study, the average contents of 5‐CQA in 33 samples of I. britannica flowers, stems and aerial parts, 6 samples of I. japonica flowers and 6 samples of I. hupehensis flowers from China were found to be 323, 146, 302, 660 and 296 μg/g DM, respectively .…”

“…thapsoides roots (IC 50 0.14 and 0.11 mg/mL) exhibited the highest DPPH radical scavenging activity, while the water extracts of I. helenium flowers, I. thapsoides ssp. thapsoides roots and I. peacockiana leaves (IC 50 0.05, 0.01 and 0.04 mg/mL, respectively) were the best ABTS .+ scavengers . Recently, it has been found that TPC in the AcOEt extract of I. viscosa leaves from Algeria (299.1 mg GAE/g DE) was significantly higher than those reported for the methanol extracts from the flowers of same species, originating from Hebron and Tunisia (173.1 and 103 mg GAE/g DW, respectively) .…”

“…turcoracemosa , I. montbretiana , I. peacockiana and I. thapsoides ssp. thapsoides from Turkey ranging from 12.2 to 190.9 mg GAE/g extract . The water extract of I. viscosa flowers (IC 50 0.28 mg/mL) and the methanol extracts of I. helenium flowers and I. thapsoides ssp.…”

“…Plants belonging to this genus have shown to possess various biological activities–anti‐inflammatory, antitumor, antibacterial, antitussive, antiproliferative, antioxidant, antidiabetic and hepatoprotective, etc., which were attributed to the abundance of bioactive components mainly sesquiterpene lactones, phenolic acids, and flavonoids . Chlorogenic acid and dicaffeoyl esters of quinic acid have been also reported in some Inula species …”

Essential oil composition, phenolic compound, and antioxidant potential of Inulaviscosa as affected by extraction process

“…Indeed, the TPH amount showed significant differences due to solvent of extraction and to varieties. In this context, Gökbulutet al [33] found that the TPH contents of three Inula from Turkey were varied from 21.1 to 190.9 mg GAE/g extract.…”