Effect of licorice compounds licochalcone A, glabridin and glycyrrhizic acid on growth and virulence properties of Candida albicans

Abstract

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.

Synergistic Antifungal Effect of Glabridin and Fluconazole

“…Here, we demonstrated that Gla had weak antifungal activity against different fungi such as Candida species and C. neoformans, consisting with the previous reports [24], [25],[29],[30]. When combining with FLC, Gla exerted a strong synergistic antifungal effects at lower concentrations.…”

“…Previous studies have been reported that the alcohol or ethanol extract of the roots of G. glabra possessed weak antifungal activity against C. albicans , Arthrinium sacchari , Chaetonmium funicola and various filamentous fungi [24], [29], [30]. Synergistic activity of Gla and nystatin against oral C. albicans has been demonstrated previously [25]. But to our knowledge, there was no investigation on the combination of Gla and FLC against fungi.…”

“…It has been reported that Gla had numerous beneficial properties, including antioxidant, anticancer, neuroprotective, anti-inflammatory activities, inhibiting fatigue or reversing learning and memory deficits in diabetic rats [16]–[23]. It possessed weak activity against C. albicans , C. krusei , C. neoformans and other filamentous fungi [24], [25]. However, to our knowledge, no study to date has focused on its interaction with FLC.…”

Licochalcone-A induces intrinsic and extrinsic apoptosis via ERK1/2 and p38 phosphorylation-mediated TRAIL expression in head and neck squamous carcinoma FaDu cells

“…The main active ingredient in licorice is Licochalcone-A (Lico-A; (E)-3-[4-hydroxy-2-methoxy-5-(2-methylbut-3-en-2-yl)phenyl]-10-(4-hydroxyphenyl)prop-2-en-1-one), a natural phenolic chalconoid (Cho et al, 2014). According to recent studies, Lico-A has antioxidant (Fu et al, 2013), antiviral (Adianti et al, 2014), anti-inflammatory (Chu et al, 2012; Fu et al, 2013), antimicrobial (Messier and Grenier, 2011), antimalarial (Mishra et al, 2009), antiangiogenic (Kim et al, 2010), and osteogenic activities (Kim et al, 2012). Furthermore, Lico-A reportedly has anticancer activity in various cancers types such as oral (Kim et al, 2014), bladder (Yuan et al, 2013), ovarian (Lee et al, 2012), gastric (Xiao et al, 2011), colon (Lee et al, 2008), and prostate (Fu et al, 2004; Yo et al, 2009) cancer as well as in hepatocellular carcinoma (Choi et al, 2014).…”

Anti-biofilm Activities and Chemical Composition of Essential Oil from Burdock Leaf

“…Searching for new strategies for inhibition of biofilm are becoming highly necessary (Kiedrowski and Horswill, 2011;Shunmugaperumal, 2010). In recent years, the efficiency of plant components on inhibition of biofilm has attracted more and more attention (Messier and Grenier, 2011;Sandasi et al, 2010;Xing et al, 2012). Essential oils from plants have been known to possess antibacterial, antifungal and antioxidant activities.…”