Effects of Magnolol and Honokiol on Adhesion, Yeast-Hyphal Transition, and Formation of Biofilm by Candida albicans

Abstract

BackgroundThe first step in infection by Candida albicans is adhesion to host cells or implanted medical devices and this followed by hyphal growth and biofilm formation. Yeast-to-hyphal transition has long been identified as a key factor in fungal virulence. Following biofilm formation, C. albicans is usually less sensitive or insensitive to antifungals. Therefore, development of new antifungals with inhibitory action on adhesion, yeast-hyphal transition and biofilm formation by C. albicans is very necessary.MethodsThe effects of magnolol and honokiol on hypha growth were investigated using different induction media. Their inhibitory effects were determined using the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5- carboxanilide assay, and biofilm thickness and viability were observed by a confocal scanning laser microscope. Mammalian cells were used in adhesion assays. Genes related to hyphae development and cell adhesions were analyzed by real-time reverse transcription-polymerase chain reaction. The exogenous cyclic adenosine monophosphate was used to determine the mechanisms of action of magnolol and honokiol. Caenorhabditis elegans was used as an in vivo model to estimate the antifungal activities of magnolol and honokiol.Results and conclusionsMagnolol and honokiol inhibited adhesion, the transition from yeast to hypha, and biofilm formation by C. albicans through the Ras1-cAMP-Efg1 pathway. Moreover, magnolol and honokiol prolonged the survival of nematodes infected by C. albicans. Magnolol and honokiol have potential inhibitory effects against biofilm formation by C. albicans.General SignificanceThis study provides useful information towards the development of new strategies to reduce the incidence of C. albicans biofilm-associated infection.

Efficacy of 7‐benzyloxyindole and other halogenated indoles to inhibit Candida albicans biofilm and hyphal formation

“…Similarly, it was reported that the survival rates of C. albicans ‐infected nematodes were increased by treatment with gymnemic acid (Vediyappan et al ., 2013), retigeric acid (Chang et al ., 2012) or polyphenolic compounds such as magnolol and honokiol (Sun et al ., 2015). This implies that 7‐benzyloxyindole could rescue the animals from Candida infection by preventing yeast‐hyphal transition (Fig.…”

Critical review on biofilm methods

“…Multi-acquisitions of such planes at different depths in the sample, combined with dedicated image analysis, make it possible to represent the 3-D architecture of the sample and to extract quantitative structural parameters such as the biofilm bio-volume, thickness and roughness (Bridier et al, 2010). It has been applied successfully in a wide range of biofilms (Guilbaud et al, 2015;Sun et al, 2015;Villacorte et al, 2015). Biofilm CLSM imaging can be performed with a range of fluorescent probes with unique specificities.…”

Quercetin Assists Fluconazole to Inhibit Biofilm Formations of Fluconazole-Resistant Candida Albicans in In Vitro and In Vivo Antifungal Managements of Vulvovaginal Candidiasis

“…The CLSM procedure were undertaken as described before with a few modifications [28]. Briefly, the C. albicans 04 (1 × 10 6 CFU/mL) was incubated with/without 64 µg/mL QCT and/or 128 µg/mL FCZ in RPMI-1640 medium at 37°C for 48 h. Then the supernatant was aspirated and the wells were rinsed by sterile PBS for several times.…”