Study of the composition and properties of extracts of Glycyrrhiza glabra grown in the Kaliningrad region and prospects of its use

Abstract

Licorice is scientifically known as Glycyrrhiza glabra; it belongs to the legume family. Glycyrrhiza glabra is a medicinal herb found throughout Asia and in some European regions. The aim of the present work was to study the chemical composition and biologically active properties of Glycyrrhiza glabra extracts produced by different methods. It has been established that Glycyrrhiza glabra raw materials (leaves) contain protein, fat, fiber and ash: 9.844±0.29%, 2.284±0.06%, 20.377±0.61% and 4.605±0.13%, respectively. In Glycyrrhiza glabra raw materials, mineral components were found, such as: Fe (289.00±8.67 mg/kg), Sr (165.00±4.95 mg/kg), Ca (89.0±0.6 mg/kg), Mn (18.00 ± 0.54 mg/kg) and Zn (23.00 ± 0.69 mg/kg). It is shown that Glycyrrhiza glabra raw materials contain vitamins: С (121.75 ± 3.62 mg/kg), В2 (49.59 ± 1.48 mg/kg) and В6 (21.99 ± 0.66 mg/kg). The highest yield of the Glycyrrhiza glabra extract (21.31 ± 0.64 mass%) was achieved when using the extraction method by Soxhlet with methanol. In these Glycyrrhiza glabra extracts, the highest amounts of biologically active substances were identified: 3,4-dihydroxybenzoic acid, p-coumaric acid, luteolin-7-glucoside, acacetin, apigenin-7-O-glucoside, chicoric acid and hesperetin. When using the maceration method with the mixture of solvents methanol+ NaOH, rosmarinic acid was identified, while in the extract obtained using maceration with the mixture of solvents methanol+ TFA, catechin was found in large quantities. Upon exposure to the Glycyrrhiza glabra extracts obtained by the Soxhlet method with methanol, the growth inhibition zones of test microorganisms were as follows: 13.6 ± 0.41 mm for Escherichia coli, 10.8 ± 0.32 mm for Pseudomonas aeruginosa, 16.1 ± 0.48 mm for Bacillus subtilis and 13.2 ± 0.39 mm for Candida albicans. The antioxidant activity of Glycyrrhiza glabra extracts obtained by the Soxhlet method was the highest in the ABTS method (117.62 ± 7.91 μmol Trolox eq/g) and the lowest in the FRAP method (23.91 ± 1.12 μmol Trolox eq/g). The antioxidant activity of the extracts in the DPPH method had the intermediate value: 58.16 ± 3.90 μmol Trolox eq/g. The antibacterial and antioxidant activities were manifested due to the presence of polyphenolic compounds and flavonoids in the Glycyrrhiza glabra methanol extract obtained by the Soxhlet method. Such an extract of Glycyrrhiza glabra can be a natural alternative to the existing therapy to eliminate bacterial diseases and early aging and oxidative stress of the human body emerging because of free radicals.