Free radical scavenging activity of aqueous and alcoholic extracts of Glycyrrhiza glabra Linn. measured by ferric reducing antioxidant power (FRAP), ABTS bleaching assay (αTEAC), DPPH assay and peroxyl radical antioxidant assay

Abstract

The present study evaluates the in vitro antioxidant free radical scavenging capacities of aqueous and alcoholic extracts of Glycyrrhiza glabra since this medicinal plant has been traditionally used in Ayurvedic system of medicine as a tonic, rejuvenator, demulcent and expectorant. Total phenolic content of alcoholic extract and aqueous extract was found as 18.70 and 23.26 Gallic acid equivalents/mg while the total flavonoid content was assessed as 15.03 and 6.62 Quercetin equivalents/mg respectively. IC50 (µg/ml) of alcoholic, aqueous extract and Ascorbic acid was found to be 65.064±3.538, 73.423±9.057 and 18.156±1.356 in Hydrogen Peroxide Radical Scavenging, 1.424±0.013, 1.632±0.052 and 0.879±0.273 in DPPH radical scavenging, and 335.948±29.040, 251.891±6.330 and 6.142±0.061 during FRAP essay. Similarly, during ABTS radical scavenging, IC50 (µg/ml) was assessed as 575±26.694, 683.9±49.220 and 6.337±0.167 for alcoholic, aqueous extract and Trolox respectively. While both the extracts showed substantial and significant free radical scavenging activity during the study which is compared to that of standard drug, the alcoholic extract of Glycyrrhiza glabra exhibits higher in vitro antioxidant activity than the aqueous extract in all assessment methods except FRAP, possibly due to higher concentrations of flavonoids in it, validating and confirming the therapeutic properties ascribed to it in Ayurvedic texts.

Antioxidant and antimicrobial assessment of licorice supercritical extracts

“…Based on the above inhibitory activities against bacteria, it has been suggested that licorice may have a therapeutic and/or preventive capacity for oral infections (Gafner et al, 2011). Supercritical fluid extraction (SFE) is an extraction technology also applied to obtain antioxidant and antimicrobial extracts from natural sources (Fornari et al, 2012). Supercritical fluids allow high extraction rates due to their high solvation power (liquid-like density), low viscosities and high diffusion coefficients.…”

Estimation of Total Flavonoid, Phenolic Content, and Free Radical Scavenging Potential of Glycyrrhiza Glabra Root Extract

“…There was a concentration-dependent inhibition against hydroxyl radical exhibited by G. glabra ethanolic extract and was in the range of 35.1% [33]. The percent scavenging of ABTS and H 2 O 2 radicals was also dose dependent indicating that the root sample exhibited maximum radical scavenging activity which was supported by Mradu Gupta et al [34]. The percentage inhibition as well as the low IC 50 values of DPPH, hydroxyl, superoxide, H 2 O 2 , NO, and ABTS assay of standard ascorbic acid and methanolic extract indicates that its very high antioxidant capacity in comparison with other solvent extract.…”

Assessment of in vitro activities and chemical profiling of Senecio hoggariensis growing in Algerian Sahara

“…ABTS •+ scavenging activity assay presents some advantages over DPPH scavenging test which is not convenient with water insoluble or bulky structures compounds. Therefore, the ABTS •+ scavenging activity of the extracts was also verified (Gupta et al 2016). Briefly, 7 mM of ABTS and 2.45 mM of potassium persulfate were dissolved in water, kept for 16 hours in the dark to provide ABTS •+ solution.…”