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Published on: April 23, 2019
Antifungal photodynamic activities of phthalocyanine derivatives on Candida albicans
Ismail Ozturk1, Ayça Tunçel2, Fatma Yurt2
1Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Izmir Katip Celebi University, Izmir, 35620, Turkey.
Abstract:
Antimicrobial resistance is one of the most important causes of morbidity and mortality in the treatment of infectious diseases worldwide. Candida albicans is one of the most virulent and common species of fungi to cause invasive fungal infections on humans. Alternative treatment strategies, including photodynamic therapy, are needed for controlling these infectious diseases. The aim of this study was to investigate the antifungal photodynamic activities of phthalocyanine derivatives on C. albicans. The minimum inhibitory concentration (MIC) values of compounds were determined by the broth microdilution method. Uptake of the compounds in C. albicans and dark toxicity of the compounds were also investigated. Photodynamic inhibition of growth experiments was performed by measuring the colony-forming unit/mL (CFU/mL) of the strain. Maximum uptake into the cells was observed in the presence of 64 μg/mL concentration for each compound except for ZnPc. Compounds did not show dark toxicity/inhibitory effects at sub-MIC concentrations on C. albicans when compared to the negative control groups. Zn(II)Pc, ZnPc, and ZnPc-TiO2 showed fungicidal effect after irradiation with the light dose of 90 J/cm2 in the presence of the compounds. In addition to the fungicidal effects, SubPc, SubPc-TiO2, Es-SiPc, and Es-SubPc compounds were also found to have inhibitory effects on the growth of yeast cells after irradiation.
Insights
Phthalocyanine derivatives show promise as photodynamic therapies against Candida albicans infections. These compounds effectively inhibit fungal growth and demonstrate fungicidal effects after light activation, offering a potential alternative to conventional treatments.
Area of Science:
- Photochemistry
- Antimicrobial Research
- Mycology
Background:
- Antimicrobial resistance poses a significant global health threat, increasing morbidity and mortality.
- Candida albicans is a prevalent fungal pathogen causing invasive infections.
- Novel therapeutic strategies, such as photodynamic therapy, are crucial for combating resistant microbes.
Purpose of the Study:
- To evaluate the antifungal photodynamic activity of phthalocyanine derivatives against Candida albicans.
- To determine the minimum inhibitory concentration (MIC) and cellular uptake of these compounds.
- To assess the dark toxicity and photodynamic inhibition of C. albicans growth.
Main Methods:
- Broth microdilution method for MIC determination.
- Measurement of compound uptake by C. albicans.
- Assessment of dark toxicity at sub-MIC concentrations.
- Colony-forming unit (CFU/mL) assays to evaluate photodynamic growth inhibition after light irradiation.
Main Results:
- Phthalocyanine derivatives exhibited varying degrees of cellular uptake, with maximum uptake observed at 64 μg/mL for most compounds.
- No significant dark toxicity was observed for the compounds at sub-MIC concentrations.
- Zn(II)Pc, ZnPc, and ZnPc-TiO2 demonstrated fungicidal effects post-irradiation (90 J/cm²).
- SubPc, SubPc-TiO2, Es-SiPc, and Es-SubPc showed significant inhibitory effects on yeast growth after photodynamic treatment.
Conclusions:
- Phthalocyanine derivatives possess potent antifungal photodynamic activity against Candida albicans.
- These compounds can be effective in inhibiting or eliminating fungal growth upon light activation.
- Phthalocyanine-based photodynamic therapy represents a promising alternative strategy for treating C. albicans infections.
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