licochalcone-a and glabridin

"Licorice oil extract" (LOE) (antioxidant agent) is described in the notice of Japanese food additive regulations as a material obtained from the roots and/or rhizomes of Glycyrrhiza uralensis, G. inflata or G. glabra. In this study, we aimed to identify the original Glycyrrhiza species of eight food additive products using LC/MS. Glabridin, a characteristic compound in G. glabra, was specifically detected in seven products, and licochalcone A, a characteristic compound in G. inflata, was detected in one product. In addition, Principal Component Analysis (PCA) (a kind of multivariate analysis) using the data of LC/MS or (1)H-NMR analysis was performed. The data of thirty-one samples, including LOE products used as food additives, ethanol extracts of various Glycyrrhiza species and commercially available Glycyrrhiza species-derived products were assessed. Based on the PCA results, the majority of LOE products was confirmed to be derived from G. glabra. This study suggests that PCA using (1)H-NMR analysis data is a simple and useful method to identify the plant species of origin of natural food additive products.

Topics: Chalcones; Chromatography, Liquid; Ethanol; Food Additives; Glycyrrhiza; Isoflavones; Magnetic Resonance Spectroscopy; Mass Spectrometry; Phenols; Plant Extracts; Plant Oils; Plant Roots; Protons

Candida albicans is the predominant causal agent of candidiasis. Its ability to form hyphae and biofilm has been suggested to be key virulence factors. In this study, we investigated the effect of major licorice compounds licochalcone A, glabridin and glycyrrhizic acid on growth, biofilm formation and yeast-hyphal transition of C. albicans. The synergistic effect of licorice compounds with the antifungal drug nystatin was also evaluated. Minimal inhibitory concentrations (MICs) for C. albicans were determined using a microplate dilution assay. The synergistic effect with nystatin was determined similarly. The effect of licorice compounds on biofilm formation was evaluated using a microplate assay and crystal violet staining. The effect of licorice compounds on yeast-hyphal transition was determined by microscopic observation. The toxicity of licorice compounds towards oral epithelial cells was evaluated with an MTT assay. Glabridin and licochalcone A showed antifungal activity on C. albicans while glycyrrhizic acid had no effect. Complete growth inhibition occurred with sub-inhibitory concentrations of nystatin with either glabridin or licochalcone A. Biofilm formation was inhibited by 35-60% in the presence of licochalcone A (0.2 μg ml(-1)). A strong inhibitory effect (>80%) on hyphal formation was observed with licochalcone A or glabridin (100 μg ml(-1)). Glabridin and licochalcone A at high concentrations showed toxicity towards oral epithelial cells. In summary, glabridin and licochalcone A are potent antifungal agents and may act in synergy with nystatin to inhibit growth of C. albicans. Licochalcone A has a significant effect on biofilm formation, while both licochalcone A and glabridin prevented yeast-hyphal transition in C. albicans. These results suggest a therapeutic potential of licochalcone A and glabridin for C. albicans oral infections.

Topics: Antifungal Agents; Biofilms; Candida albicans; Cell Survival; Chalcones; Drug Synergism; Epithelial Cells; Glycyrrhiza; Glycyrrhizic Acid; Humans; Hyphae; Isoflavones; Microbial Sensitivity Tests; Nystatin; Phenols; Virulence

Constituent properties of licorices derived from Glycyrrhiza uralensis, G. glabra, and G. inflata are revealed by comparing 117 of licorice identified using four genetic markers; internal tracscribed spacer (ITS) on nuclear ribosomal DNA, rbcL gene, matK gene, and trnH-trnK1 intergenic region on chloroplast DNA. Regarding six main constituents of licorice; glycyrrhizin, liquiritin, liquiritin apioside, isoliquiritin, isoliquiritin apioside, and liquiritigenin, the constituent property of G. glabra resembles to that of G. inflata. On the other hand, the constituent property of G. uralensis is not similar to that of G. glabra or G. inflata and is characterized by a wide content variation of the six constituents compared to those of G. glabra and/or G. inflata. The mean contents of liquiritin, isoliquiritin, or liquilitigenin in G. uralensis are significantly higher than those of G. glabra or G. inflata. Therefore, the licorice species should be selected depending on these constituent properties for the traditional Chinese medicines or the Japanese Kampo medicines. Additionally, glycycoumarin, glabridin, and licochalcone A were reconfirmed as the species-specific typical constituents of G. uralensis, G. glabra, and G. inflata respectively. Therefore, it is resulted that the determination of the three species-specific constituents may be useful for the species identification of licorice. However, since 6% of licorice examined and hybrids were exceptions to the rule, their genetic information is necessary for the accurate species identification of licorice.

Topics: Chalcones; Coumarins; Genetic Markers; Glycyrrhiza; Glycyrrhiza uralensis; Isoflavones; Phenols; Species Specificity