Determination of metabolic profiling by LC-MS/MS, evaluation of antioxidant activities, and enzyme inhibition effects of Helichrysum plicatum subsp. pseudopliacatum

Abstract

Helichrysum species are traditionally used to treat many diseases. In this study, the antioxidant and enzyme inhibition abilities of methanol (MEHP) and water extracts (WEHP) from Helichrysum plicatum subsp. Pseudopliacatum was evaluated. Also, the phenolic compounds will be assessed and the quantities of total phenols and flavonoids will be calculated. For evaluation of antioxidant activity of both extracts was assessed using DPPH, ABTS and DMPD radical scavenging, FRAP, CUPRAC, and Fe3+ reduction methods were used. The inhibition effects of extracts were spectrophotometrically evaluated on the α-glucosidase (α-Gly), acetylcholinesterase (AChE), and carbonic anhydrase II (CA II) enzymes. These inhibition effects were compared to the standard inhibitors The qualitative and quantitative phenolic components in extracts were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), employing both methods. The IC50 value, which is the inhibitor concentration that causes 50% inhibition of MEHP and WEHP, is found as 2.39 and 2.97 μg mL-1 for α-gly, 2.48 and 3.59 μg mL-1 for AChE and 11.95 and 25.67 μg mL-1for CA II. The quantity of phenols in MEHP and WEHP were 46.00 and 33.50 μg GAE mg-1 extract, 62.13 and 103.93 μg QE mg-1 extract flavonoids, respectively. IC50 values of MEHP and WEHP were calculated as 40.77 and 49.51 μg mL-1 for DPPH radical scavenging, 10.50 and 17.77 μg mL-1 ABTS radical scavenging and 99.02 and 77.01 μg mL-1 DMPD radical scavenging. The absorbance values of reducing abilities of MEHP and WEHP were found as 0.555 and 0.495 Fe3+ reducing ability, 0.577 and 0.286 for FRAP reducing ability and 0.402 and 0.315 for Cu2+ reducing ability. As a result of the LC-MS/MS analysis, the levels of phenolic compounds such as chlorogenic acid, cyanidin-3-O-glucoside and quinic acid were found to be high in MEHP and WEHP. In this study, it was observed that MEHP and WEHP have strong antioxidant properties and effectively inhibited the enzymes activities. The findings clearly reveal the antioxidant and enzyme inhibition potential of Helichrysum species, which have been used in traditional medicine for a long time. Helichrysum plicatum extracts used in this study show that they are very effective against diabetes, glaucoma and Alzheimer's disease, which are global and common diseases.