In vitro inhibitory activities of magnolol against Candida spp.

Figures & data

Figure 1 Structures of magnolol and fluconazole.

Table 1 Activities of magnolol against planktonic-mode and 48-h biofilm production of various Candida spp.

	Planktonic-mode (MIC, μg/mL)				Biofilm (BMIC90, μg/mL)
	C. albicans	C. krusei	C. dubliniensis	C. glabrata	C. albicans	C. krusei	C. dubliniensis	C. glabrata
Magnolol	40	40	10	20	160	80	20	40
Fluconazole	0.25	32	0.5	2	>128	>128	>128	>128

Notes: MIC is the minimum concentration of the drugs that inhibited 100% of the yeast growth on visual inspection. BMIC₉₀ is the minimum concentration of the drugs that produced 90% reduction of optical density value compared with the drug-free control.

Abbreviations: MIC, minimum inhibitory concentration; BMIC₉₀, the minimum concentration with 90% Candida biofilm inhibited.

Figure 2 The inhibitory effects of magnolol on planktonic-mode Candida cells using the CLSI M-27A broth microdilution method.

Notes: The quantity of Candida cells was reduced as the drug concentrations of the wells increased. At the MICs or over, no yeast cells were observed to grow. (A) Results for magnolol; (B) results for fluconazole; (C) the MICs of magnolol and fluconazole for C. albicans, C. krusei, C. dubliniensis, and C. glabrata.
Abbreviation: MICs, minimum inhibitory concentrations.

Figure 3 Inhibitory activities of magnolol against Candida biofilm formation at different time-points using the XTT reduction assay.

Notes: (A) C. albicans; (B) C. krusei; (C) C. dubliniensis; (D) C. glabrata.
Abbreviations: BMIC₉₀, the minimum concentration with 90% Candida biofilm inhibited; XTT, 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide.

Figure 4 Influence of different concentrations of magnolol on Candida biofilm activity during biofilm maturation, as assessed by the XTT reduction assay.

Note: Assessed at 6 (A), 12 (B), 24 (C), and 48 (D) h.
Abbreviation: OD, optical density.