Background:
Glycyrrhiza glabra L. is an important medicinal plant endowed with various
pharmacological virtues. This study aimed to investigate the antioxidant, antibacterial, and anticholinesterase
activities of the Algerian Glycyrrhiza glabra L. roots extracts.
Methods:
The chemical composition of both chloroformic (LCh) and ethyl acetate (LAE) extracts were
analyzed by RP-HPLC-PDA and 1H NMR spectroscopy. The antioxidant activity was evaluated using
hydrogen atoms transfer methods (DPPH) and single electron transfer (ABTS and CUPRAC assays).
The antibacterial activity was realized against different strains via the Minimal Inhibitory Concentration
(MIC), when the anticholinesterase activity was performed through the acetylcholinesterase and butyrylcholinesterase
enzymes inhibition.
Results:
The chemical analysis revealed the presence of phenolic acids (gallic acid, p-coumaric acid)
and a hydroxycinnamic compound (ferulic acid). However, flavonoids were represented by quercetin,
rutin (flavonol), and glabridin (isoflavane). The 1H NMR of the L4 fraction from LCh extract allowed to
characterize the structure of glabridin.
:
The antioxidant assays revealed that LCh extract is the best among other extracts with IC50 DPPH of
33.94 μg/mL, IC50 ABTS of 3.45 μg/mL and CUPRAC A0.5 of 21.78 μg/mL. The LCh extract displayed
an effective antibacterial activity with MIC’s of 19.5 μg/mL against seven gram positive and negative
bacteria strains. The same extract showed a potent butyrylcholinesterase inhibitory activity with IC50=
4.72 ± 0.72 μg/mL, which is too strong than the standard drug.
Conclusion:
The study demonstrated that G. glabra root extracts had a high antibacterial, and free radical
scavenging. It was also able to inhibit cholinesterase enzymes, which confirm the effectiveness of
phytoconstituents present in the plant, especially flavonoids.