Antifungal Action of Herbal Plants' Glycolic Extracts against Candida Species

Abstract

Candida spp. cause fungal infection that affects patients' oral health. This study aimed to evaluate the isolated and synergistic antifungal effect of Rosa centifolia L., Curcuma longa L., Rosmarinus officinalis L., and Punica granatum L. glycolic extracts against Candida albicans, Candida dubliniensis, Candida tropicalis, and Candida krusei planktonic and biofilm forms. The plant extracts were chemically characterized and the main compounds were quantified by high-performance liquid chromatography (HPLC-DAD) analysis. The minimum inhibitory and minimum fungicidal concentrations of the extracts were determined, and antibiofilm activity was evaluated by MTT assay. Data were analyzed by one-way ANOVA and Tukey's tests, and by Kruskal-Wallis and Dunn's tests, considering a significance level of 5%. The main compounds identified in each of the extracts were: p-coumaric acid (2153.22 μg/100 mL) in the rosemary extract, gallotannins (4318.31 μg/100 mL) in the pomegranate extract, quercetin derivatives (3316.50 μg/100 mL) in the extract of white roses, and curcumin (135.09 μg/100 mL) in the turmeric extract. The combination of R. centifolia and C. longa glycolic extracts was effective against C. albicans, C. dubliniensis, and C. tropicalis biofilms over different periods (p < 0.05). The combination of R. officinalis and P. granatum glycolic extracts was effective against C. albicans and C. krusei biofilms after 30 min, and against C. tropicalis after 24 h, with all combinations showing an average reduction of 50% in cell viability (p < 0.05). In conclusion, the combined plant extracts have antifungal and antibiofilm action against Candida spp. in different concentrations and times of action.

Keywords: Candida albicans; Candida dubliniensis; Candida krusei; Candida tropicalis; Curcuma longa; Punica granatum; Rosa centifolia; Rosmarinus.

Figure 1

C. albicans biofilm load reduction after treatment with R. centifolia, C. longa, R. officinalis, and P. granatum glycolic extracts, and their combinations, for 5 min, 30 min, and 24 h. Legend: Different upper-case letters indicate a statistically significant difference.

Figure 2

C. dubliniensis biofilm load reduction after treatment with R. centifolia, C. longa, R. officinalis, and P. granatum glycolic extracts, and their combinations, for 5 min, 30 min, and 24 h. Legend: Different upper-case letters indicate a statistically significant difference.

Figure 3

C. tropicalis biofilm load reduction after treatment with R. centifolia, C. longa, R. officinalis, and P. granatum glycolic extracts, and their combinations, for 5 min, 30 min, and 24 h. Legend: Different upper-case letters indicate a statistically significant difference.

Figure 4

C. krusei biofilm load reduction after treatment with R. centifolia, C. longa, R. officinalis, and P. granatum glycolic extracts, and their combinations, for 5 min, 30 min, and 24 h. Legend: Different upper-case letters indicate a statistically significant difference.