Characterization of phenolic compounds and antioxidant properties of Glycyrrhiza glabra L. rhizomes and roots

Abstract

The present work aims to characterize and quantify the phenolic composition and to evaluate the antioxidant activity of Glycyrrhiza glabra L. (commonly known as licorice) rhizomes and roots. The antioxidant potential of its methanol/water extract could be related to flavones (mainly apigenin derivatives), flavanones (mainly liquiritin derivatives), a methylated isoflavone and a chalcone, identified in the extract. Lipid peroxidation inhibition was the most pronounced antioxidant effect (EC 50 ). In this sense, licorice extract could be used as a source of antioxidants for the pharmaceutical, cosmetic and/or food industries.

Phytopharmacologic preparations as predictors of plant bioactivity: A particular approach to Echinacea purpurea (L.) Moench antioxidant properties

“…, where A S is the absorbance of the solution containing the sample at 515 nm, and A DPPH is the absorbance of the DPPH solution [29].…”

“…The final mixture (0.8 mL) was put in a 48-wells, and also deionised water (0.8 mL) and ferric chloride (0.1 % w/v, 0.16 mL) was joined. Finally, the absorbance was measured at 690 nm [29].…”

“…The neutralization of linoleate free radicals avoids β-carotene bleaching, which is measured by the formula: β-carotene absorbance after 2h of assay/initial absorbance) × 100 [29].…”

“…sample concentration providing 50% of antioxidant activity or 0.5 of absorbance in the reducing power assay [29]. Trolox was used as positive control.…”

Susceptibility testing of Candida albicans and Candida glabrata to Glycyrrhiza glabra L.

“…Considering the previous results obtained to licorice extract (completely characterized in terms of phenolic composition), namely antioxidant (Martins et al, 2015a) and anti-Candida (Martins et al, 2016) activities, the present study aims to access the effect of licorice extract on cell integrity and cultivability of the most problematic and virulent Candida species, namely Candida albicans and Candida glabrata species (Martins et al, 2015c). The main aspects that triggered the development of this experiment was to understand in which manner licorice exerted its anti-Candida potential, once no visible effects were observed when isolated phenolic compounds present in the extract were tested separately, while with the whole extract a prominent effect was reached.…”