Comparative Antifungal Activity of Curcuma longa Ethanol Extract Alone and in Combination with Lactobacillus Metabolites on Clinical Isolates of Candida albicans

Abstract

Background: Candida albicans is a major opportunistic fungal pathogen whose management is increasingly challenged by antifungal resistance. The search for alternative antifungal agents has stimulated interest in medicinal plants and probiotics because of their antimicrobial properties. This study evaluated the antifungal activity of ethanol extract of Curcuma longa (turmeric) alone and in combination with metabolites of Lactobacillus bulgaricus against clinical isolates of Candida albicans.

Methods: Ethanol extract of C. longa rhizomes were prepared by maceration, yielding 3.43% crude extract. Cell-free metabolites of L. bulgaricus were obtained from cultured isolates. Five clinical isolates obtained from wound swab, high vaginal swab, ear swab, catheter tip, and urine were tested using agar well diffusion, minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC) assays. Data were analyzed using descriptive statistics and SPSS version 27.

Results: Turmeric extract demonstrated concentration-dependent antifungal activity, no inhibition was observed at concentrations below 200 mg/ml, while susceptibility increased from 20% at 200 mg/ml to 60% at 400mg/ml. The combination of C. longa extract and L. bulgaricus metabolites showed improved activity, inhibiting 40%, 80%, and 100% 0f isolates at 100 mg/ml, 200 mg/ml, and 400 mg/ml, respectively. MIC values for the extract alone ranged from 25 mg/ml to > 100 mg/ml, whereas the combination treatment reduced MIC values to 12.5-50 mg/ml, MFC values for the extract alone ranged from 50-200 mg/ml. High vaginal swab isolate exhibited the greatest susceptibility, while wound and catheter tip isolates were less susceptible. Ketoconazole demonstrated superior antifungal activity compared with both treatments.

Conclusion: Ethanol Curcuma longa extract possesses antifungal activity against clinical isolates of Candida albicans, and its activity appears to be enhanced when combined with Lactobacillus bulgaricus metabolites. These findings suggest that plant-probiotic combinations may have potential as complementary antifungal approaches and warrant further investigation using larger sample sizes and advanced interaction studies to validate the therapeutic potential of this plant-probiotic combination.