curcumin and Cryptococcosis

The pathogenic fungus Cryptococcus neoformans delivers virulence factors such as capsule polysaccharide to the cell surface to cause disease in vertebrate hosts. In this study, we screened for mutants sensitive to the secretion inhibitor brefeldin A to identify secretory pathway components that contribute to virulence. We identified an ortholog of the cell division control protein 50 (Cdc50) family of the noncatalytic subunit of type IV P-type ATPases (flippases) that establish phospholipid asymmetry in membranes and function in vesicle-mediated trafficking. We found that a cdc50 mutant in C. neoformans was defective for survival in macrophages, attenuated for virulence in mice and impaired in iron acquisition. The mutant also showed increased sensitivity to drugs associated with phospholipid metabolism (cinnamycin and miltefosine), the antifungal drug fluconazole and curcumin, an iron chelator that accumulates in the endoplasmic reticulum. Cdc50 is expected to function with catalytic subunits of flippases, and we previously documented the involvement of the flippase aminophospholipid translocases (Apt1) in virulence factor delivery. A comparison of phenotypes with mutants defective in genes encoding candidate flippases (designated APT1, APT2, APT3, and APT4) revealed similarities primarily between cdc50 and apt1 suggesting a potential functional interaction. Overall, these results highlight the importance of membrane composition and homeostasis for the ability of C. neoformans to cause disease.

Topics: Animals; Antifungal Agents; Bacteriocins; Brefeldin A; Cell Division; Cell Membrane; Cryptococcosis; Cryptococcus neoformans; Curcumin; Endoplasmic Reticulum; Female; Fluconazole; Fungal Polysaccharides; Fungal Proteins; Iron; Macrophages; Mice; Mice, Inbred BALB C; P-type ATPases; Peptides, Cyclic; Phospholipid Transfer Proteins; Phosphorylcholine; Virulence; Virulence Factors

The aim of this study was to investigate the in vitro and in vivo activities of pure curcumin, as well as its combination with fluconazole, against Cryptococcus gattii.. The minimal inhibitory concentrations (MIC) of curcumin and its interactions with fluconazole against C. gattii were assessed in vitro using standard methods. This same combination was used to treat C. gattii-induced cryptococcosis in mice. The behavioural and functional assessment of the mice during treatment was also performed. The average MIC for curcumin was 19·8 μg ml(-1) . Its combination with fluconazole resulted in FICΣ (fractional inhibitory concentration index) values between 0·79 and 2·29. Curcumin (alone or combined with fluconazole) significantly reduced pulmonary damage and fungal burden in the brain. No colonies were found in the brain following combination treatment, which was also confirmed by the improved behaviour of mice.. The combination therapy with curcumin and fluconazole was the most effective among the treatments tested, as in addition to reducing the fungal burden and damage on lung tissues, it was able to eliminate the fungal burden in the brain, enhancing the survival of mice.. This study points to the possibility of using curcumin in combination with fluconazole as a clinical treatment of cryptococcosis.

Topics: Animals; Antifungal Agents; Cryptococcosis; Cryptococcus gattii; Curcumin; Drug Synergism; Drug Therapy, Combination; Female; Fluconazole; Humans; Mice; Mice, Inbred C57BL