Antifungal activity and mode of action of thymol and its synergism with nystatin against Candida species involved with infections in the oral cavity: an in vitro study

Abstract

BackgroundLimitations of antifungal agents used in the treatment of oral candidiasis, as the development of resistant strains, are known by the scientific community. In this context, the aim of this study was to evaluate the antifungal activity of thymol against Candida albicans, Candida tropicalis and Candida krusei strains and to determine its mode of action and synergistic effect when combined with the synthetic antifungal nystatin.MethodsThe minimum inhibitory concentration (MIC) was determined using a microdilution technique, and the minimum fungicidal concentration (MFC) was determined via subculture sowing. The mode of action of thymol was established by verifying fungal growth in the presence of sorbitol or ergosterol. The fractional inhibitory concentration index (FIC) was determined using the checkerboard method.ResultsThymol presented an antifungal effect, with MICs of 39 μg/mL for C. albicans and C. krusei and 78 μg/mL for C. tropicalis. The results of the antifungal test remained unchanged in the presence of sorbitol; however, the MIC value of thymol against C. albicans increased eight times (from 39.0 to 312.5 μg/mL) in presence of exogenous ergosterol. The combination of thymol and nystatin reduced the MIC values of both products by 87.4 %, generating an FIC index of 0.25.ConclusionsThymol was found to have a fungicidal effect on Candida species and a synergistic effect when combined with nystatin.

Antifungal potential ofSideroxylon obtusifoliumandSyzygium cuminiand their mode of action againstCandida albicans

“…Hence, the Nb fraction and Sc may be of interest in both approaches, with particular focus on the denture disinfection protocol due to their potential toxicity toward host cells. In addition, several studies have also suggested the combination of synthetic drugs with natural products in order to improve the efficacy of both drugs and manage toxicity upon clinical use (Hemaiswaryaa et al 2008;Castro et al 2015).…”

Pharmacological activities and medicinal properties of endemic Moroccan medicinal plant Origanum compactum (Benth) and their main compounds

“…The antibacterial activity of thymol against S. typhimurium has been also studied by Palaniappan and Holley [97] and Chauhan and Kang [98], and the MIC values were respectively MIC = 2.5 mM and MIC = 750 mM. The antifungal activity of thymol has also been investigated by some works [101][102][103][104]. In some cases, this compound has inhibited Candida tropicalis at very low concentrations: MIC = 39 µg/mL [101], MIC = 0.12% (v/v) [102] and MIC = 350 µg/mL [103].…”

“…The antifungal activity of thymol has also been investigated by some works [101][102][103][104]. In some cases, this compound has inhibited Candida tropicalis at very low concentrations: MIC = 39 µg/mL [101], MIC = 0.12% (v/v) [102] and MIC = 350 µg/mL [103]. The anti-inflammatory and cicatrizing effects of thymol have also proved using rodents as a model study [105].…”

Phyto-Fungicides: Structure Activity Relationships of the Thymol Derivatives against <i>Rhizoctonia solani</i>

“…As a component of naturally occurring essential oil, thymol has been demonstrated as potent antifungal agent [2]. The chemical induces lipid peroxidation and disrupts fungal ergosterol biosynthesis and cell membrane integrity [1] [3] [4]. Thymol dissipates from soil within 5 days of treatment, also degrades faster; those features make it an ideal fumigant to control soilborne pathogens [5].…”

“…Recently submicron emulsion spray formulation of thymol was found to effectively control head blight of wheat caused by Fusarium graminearum [2]. Moreover, thymol was found to act synergistically with nystatin against Candida species [4].…”