Fungal-Host Interaction: Curcumin Modulates Proteolytic Enzyme Activity ofCandida albicansand Inflammatory Host ResponseIn Vitro

Abstract

Current treatments for Candida albicans infection are limited due to the limited number of antifungal drugs available and the increase in antifungal resistance. Curcumin is used as a spice, food preservative, flavoring, and coloring agent that has been shown to have many pharmacological activities. Thus, this study evaluated the modulatory effects of curcumin on major virulence factors associated with the pathogenicity of C. albicans. The minimum inhibitory concentration (MIC) of curcumin against C. albicans (SC5314) was determined. Biofilm formation was quantified and the proteinase and phospholipase secretion was measured. The cytotoxicity was tested in oral fibroblast cells. A cocultured model was used to analyze the gene expression of proinflammatory cytokines (IL-1β, IL-1α, and IL-6) from host cells, as well SAP-1 and PLB-1 by RT-PCR. The MIC was between 6.25 and 12.5 µM, and the activity of proteinase enzyme was significantly decreased in biofilms treated with curcumin. However, proteinase gene expression was not downregulated after curcumin treatment. Furthermore, gene expressions of host inflammatory response, IL-1β and IL-1α, were significantly downregulated after exposure to curcumin. In conclusion, curcumin exhibited antifungal activity against C. albicans and modulated the proteolytic enzyme activities without downregulating the gene expression. In host inflammatory response, curcumin downregulated IL-1β and IL-1α gene expression.

In vitro immune responses of human PBMCs against Candida albicans reveals fungal and leucocyte phenotypes associated with fungal persistence

“…During the host-C. albicans interaction, several parameters predispose to fungal disease, in particular C. albicans pathogenicity and host risk factors, such as immunosuppression (co-infections, immunosuppressive treatments and medical interventions) 4,[33][34][35] . However, these factors alone do not fully explain why, under comparable risk factor conditions, only some patients develop infections [7][8][9] .…”

Yeast-Host Interactions: Anadenanthera colubrina Modulates Virulence Factors of C. albicans and Inflammatory Response In Vitro

“…Colony formation unit (CFU) was determined by submitting the bioifilm suspension to serial dilutions (10 −1 , 10 −2 , 10 −3 , 10 −4 ) and plating 10 µL of these dilutions on Sabouraud Dextrose Agar plates, which were incubated at 37°C in 5% CO 2 . After 24 h of incubation, the number of C. albicans colonies was counted and the data was normalized based on the CFU/ml/dry weight of biofilm sample ( Santana et al, 2013 ; Seleem et al, 2016a ; Seleem et al, 2016b ; Chen et al, 2018 ).…”

“…Proteinase and phospholipase enzyme secretion assays were conducted as previously performed by Santana et al (2013) , Chen et al (2018) . Biofilms of C. albicans were grown for 24 h in YNB Medium with 50 mM of glucose at 37°C in 5% CO 2 and treated with A. colubrina extract (156.2 μg/ml–10 × 15.62 μg/ml and 312.4 μg/ml–20 × 15.62 μg/ml).…”

“…The solution was centrifuged for 5 min at 10,000 rpm and 500 µL of the supernatant was combined with 500 µL of 0.5 M NaOH (Macron Fine Chemicals, Avantor VWR Life Science, Radnor, PA), which was incubated for 15 min at 37°C in 5% CO 2 . Absorbance was read in a spectrophotometer at 440 nm ( Pande et al, 2006 ; Gonçalves et al, 2012 ; Santana et al, 2013 ; Chen et al, 2018 ). The phospholipase enzyme activity was determined by mixing the supernatant of the biofilm solution (pH corrected to 7.5) with phosphatidylcholine substrate (Sigma Aldrich, San Luis, MO) at 9:1 (v/v) for 1 h at 37°C in 5% CO 2 and reading the absorbance in a spectrophotometer at 630 nm ( Taniguchi et al, 2009 ).…”

“…One enzyme unity was arbitrarily established as the absorbance shift, by minute of reaction, by biomass, multiplied by one thousand ( U = ΔODnm × min−1 × 1,000). The specific enzyme activity was defined as the amount of enzyme that elicited an increase of 0.001 units of absorbance/minute of digestion by biofilm dry weight (g) ( Taniguchi et al, 2009 ; Santana et al, 2013 ; Chen et al, 2018 ).…”