Synergistic in vitro activity of sodium houttuyfonate with fluconazole against clinical Candida albicans strains under planktonic growing conditions

Abstract

Context: Fluconazole resistance is an intractable problem of treating Candida albicans, calling for more antifungal agents to enhance the activity of fluconazole.Objective: This work investigates the anti-C. albicans activities of sodium houttuyfonate (SH) and/or fluconazole and the associated mechanism.Materials and methods: The minimum inhibitory concentrations (MICs) of SH and fluconazole both ranging from 0.5 to 1024 μg/mL were determined by broth microdilution method in 19 C. albicans isolates, and their fractional inhibitory concentration index (FICI) was evaluated by checkerboard assay. After MICSH and/or MICfluconazole treatments, the expressions of IFD6, PHR1, ZAP1, ADH5, BGL2, XOG1 and FKS1 were analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in C. albicans 1601.Results and conclusion: The MICs of SH alone ranged from 32 to 256 μg/mL and decreased 2–16-fold in combination. SH showed strong synergism with fluconazole with FICI <0.13–0.5. In C. albicans 1601, we observed that (i) the expression of the seven genes increased notably in a range between 3.71- and 12.63-fold (p < 0.05) when SH was used alone, (ii) the combined use of SH and fluconazole slightly inhibited the expression of IFD6 and PHR1 by 1.23- and 1.35-fold (p > 0.05), but promoted evidently the expression of ZAP1, ADH5, XOG1 and FKS1 by 1.98-, 3.56-, 4.10- and 2.86-fold (p < 0.05). The results suggested SH to be a potential synergist to enhance the antifungal activity of fluconazole in C. albicans resistant isolates, and the underlying mechanism may be associated with β-1,3-glucan synthesis and transportation.

Antifungal Activity of Carvacrol on Ergosterol Synthesis in Multidrug Resistant Candida albicans

“…Fluconazole was effective at concentrations ranging from 2×MIC to ¼×MIC and caused 64 to 42% reduction in total ergosterol content in C. albicans CBS 5982 ( Figure 3). throughput screening has emerged as a tool for biological investigation that could be used to treat the infections (2,5,23). In this study, we show that carvacrol displays potential anti-Candida activity which has been earlier reported to active against C. albicans (6,8).…”

Antifungal Compounds againstCandidaInfections from Traditional Chinese Medicine

“…Recently, a novel terpene antifungal SCY-078 demonstrated fungicidal activity against C. albicans through inhibiting glucan synthase [ 42 ]. Sodium houttuyfonate, a derivative from Houttuynia cordata Thunb., might exert its synergistic effect with fluconazole through interfering with β -1,3-glucan synthesis and transportation [ 43 ].…”

Sodium Houttuyfonate Inhibits Voltage-Gated Peak Sodium Current and Anemonia Sulcata Toxin II-Increased Late Sodium Current in Rabbit Ventricular Myocytes

“…The KB solution contained (in mmol/L) KOH 70, KCl 40, KH 2 PO 4 20, MgSO 4 1, taurine 20, glutamic acid 50, EGTA 0.5, HEPES 10, glucose 10, and HEPES 10 (pH adjusted to 7.4 with KOH).…”

“…Recently, SH was reported to be effective against Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans [1][2][3][4]. In addition to its antibacterial and antifungal effects, SH was also reported to be a cardioprotective compound.…”