Background: Antimicrobial resistance is a major health problem. There is a current interest in the development of new drugs and optimization of their administration to avoid such cases. In this study, we used a cell culture model to investigate the pharmacokinetics/pharmacodynamics (PK/PD) of ellagic acid (EA). EA is a natural bioactive that has demonstrated a promising antifungal activity against Candida albicans. We have carried out experiments using in vitro models of intestinal cells (Caco-2), since this tissue is an initial site of this infection. Methods: Caco-2 cells were cultured with DMEM supplemented with 10% fetal bovine serum, in a humidified atmosphere of 95% air and 5% CO2 at 37ºC. The cells (300.000 cells/well) were cultured for 21 days and plated in the Transwell® permeable support (12 mm, 3.0μm, Corning©, NY) or in culture dishes of 12 wells. C. albicans ATCC18804 was grown in Sabouraud dextrose agar for 24 hours at 37 ° C. Cells were transferred to YPG medium (1% yeast extract, 2% peptone and 2% glucose) and cultured for another 24 h at 37 ° C. A concentration of 2x106/mL of fungal cells was inoculated in the apical compartment. The treatment with EA was performed with initial concentrations of 10, 60 and 120 μg/mL for PD studies and 3.2, 10, 30, 60 and 120 μg/mL for PK studies. The cells were incubated at 37 °C in an atmosphere of 5% CO2. Negative control did not receive treatment. After 24h, the number of CFU / mL and the EA concentration were determined. The killing was reported by the negative control. EA was measured by a microplate reader at 255 nm (Biotek SynergyTM HT, Winooski, VT, EUA). Results: The killing of C. albicans after 24h was 29.5, 45.7 and 75.4 % for 10, 60 and 120 μg/mL respectively. The concentrations of EA in the basolateral compartment after 1, 2, 3 and 24h were lower than the limit of quantification (1.8 μg/mL), which means that EA is probably not well absorbed through the intestinal epithelium, in agreement with previous in vivo studies. This result suggests that EA should be administrated by the intravenous route or suffers some modifications in order to improve its PK. Conclusions: In conclusion, EA presented a promising antifungal activity, but an unfavorable PK for oral administration. The present in vitro cell model of invasive candidiasis is useful to screen a molecule for the treatment of Candida infection by its PK/PD properties.
Full conference title:
- ASM Microbe 2nd (2017)