Efficacy of ravuconazole in a murine model of vaginitis by Candida albicans

Physicochemical Evaluation and Pharmacodynamics of Itraconazole-loaded Liquid Crystal Precursor for Vaginal Delivery

PURPOSE

To develop liquid crystal (LC) precursor that can be used as a novel vaginal delivery system for Itraconazole (ITZ) and evaluate its pharmacodynamics. Methods: The LC precursor was prepared by using phytantriol (PYT) as lipid matrix and N, N-dimethylformamide (DMAC) as solvent. Swelling studies were performed to assess the phase conversion ability. The formulations were characterized by crossed polarized light microscopy (CPLM), small-angle X-ray scatterin (SAXS). Moreover, the rheological and in vitro drug release behavior were investigated. Then the vaginal retention time of ITZ in the optimal prescription was evaluated. Finally, the pharmacodynamics studies of the ITZ-loaded LC precursor were performed in a mouse model of vulvovaginal candidiasis (VVC). Results: The LC precursor could transform to LC gels after administration into the vagina. Based on PLM and SAXS, the LC gels, formed after phase-conversion, were cubic LC. The LC precursor was Non-Newtonian, while the LC gels exhibited a pseudo-plastic fluid behavior. In vitro release results revealed that F2 (68.0 %) had a higher cumulative drug release than that of F1 (59.17 %) at 72 h. Most of the LC gels could be retained in the vagina of mice for 24 - 36 h. Pharmacodynamics studies showed that there was only mild inflammation or no inflammatory stimulation in the control group. The ITZ-loaded LC precursor significantly improved the symptoms of vaginitis in mice and had a better therapeutic effect than that of positive control group. Conclusions: The ITZ-loaded LC precursor would be a promising formulation for vaginal drug delivery.

Thermosensitive hydrogels as a controlled release system for alkannin to improve localized treatment of Candida vaginitis after external beam radiotherapy in vitro and in vivo

External beam radiotherapy increases the risk of Candida vaginitis in cervical cancer patients, which brings a lot of insufferable influence to their life. Here, we explored the efficacy of alkannin in the treatment of Candida vaginitis after external beam radiotherapy. We exploit thermosensitive hydrogel-mediated alkannin as the topical formulation in a rat model established in our work. Periodic acid-Schiff of vaginas indicated little Candida albicans adhered to the vaginal tissue in treatment group. Additionally, hematoxylin and eosin stain revealed that inflammatory response of high dose alkannin was reduced. Above all, the animal model was first established in our work for the clinical desire. Our results suggested the promising application of alkannin for the disease with satisfying fungicidal activity and anti-inflammatory activity.

The in vitro and in vivo efficacy of fluconazole in combination with farnesol against Candida albicans isolates using a murine vulvovaginitis model

Farnesol is a quorum-sensing molecule that inhibits biofilm formation in Candida albicans. Previous in vitro data suggest that, in combination with certain antifungals, farnesol may have an adjuvant anti-biofilm agent. However, the in vivo efficacy of farnesol is very questionable. Therefore, the in vitro and in vivo activity of fluconazole combined with farnesol was evaluated against C. albicans biofilms using fractional inhibitory concentration index (FICI) determination, time-kill experiments and a murine vulvovaginitis model. The median biofilm MICs of fluconazole-sensitive C. albicans isolates ranged between 4 -> 512 mg/L and 150-300 μM for fluconazole and farnesol, respectively. These values were 512 -> 512 mg/L and > 300 μM for fluconazole-resistant clinical isolates. Farnesol decreased the median MICs of fluconazole by 2-64-fold for biofilms. Based on FICI, synergistic interaction was observed only in the case of the sessile SC5314 reference strain (FICIs: 0.16-0.27). In time-kill studies, only the 512 mg/L fluconazole and 512 mg/L fluconazole + 75 μM farnesol reduced biofilm mass significantly at each time point in the case of all isolates. The combination reduced the metabolic activity of biofilms for all isolates in a concentration- and time-dependent manner. Our findings revealed that farnesol alone was not protective in a murine vulvovaginitis model. Farnesol was not beneficial in combination with fluconazole for fluconazole-susceptible isolates, but partially increased fluconazole activity against one fluconazole-resistant isolate, but not the other one.

Targeting CYP51 for drug design by the contributions of molecular modeling

CYP51 is an enzyme of sterol biosynthesis pathway present in animals, plants, protozoa and fungi. This enzyme is described as an important drug target that is still of interest. Therefore, in this work, we reviewed the structure and function of CYP51 and explored the molecular modeling approaches for the development of new antifungal and antiprotozoans that target this enzyme. Crystallographic structures of CYP51 of some organisms have already been described in the literature, which enable the construction of homology models of other organisms' enzymes and molecular docking studies of new ligands. The binding mode and interactions of some new series of azoles with antifungal or antiprotozoan activities has been studied and showed important residues of the active site. Molecular modeling is an important tool to be explored for the discovery and optimization of CYP51 inhibitors with better activities, pharmacokinetics, and toxicological profiles.