amphotericin-b--deoxycholate-drug-combination and thiazolyl-blue

Heat treatment of deoxycholate-amphotericin B (AmB-DOC) leads to a therapeutically interesting supramolecular rearrangement (h-AmB-DOC); this reformulation improves the therapeutic index of AmB-DOC by reducing amphotericin B (AmB) toxicity in mammalian cell lines from 3- to 10-fold. Its activity in experimentally induced fungal infection in mice remains unchanged compared with AmB-DOC, whereas its activity is 2.5 times higher in Leishmania donovani-infected mice. This work investigates the in vitro mechanism that allows this improvement.. In this study, we analysed the role of serum components on the interaction of h-AmB-DOC with two cultured cell lines: murine peritoneal macrophage cells (J774) and kidney epithelial cells (LLCPK1). The methods used were: spectrophotometry for AmB uptake; MTT assay for cell viability; and lactate dehydrogenase release for membrane damage.. In the presence of 10% fetal calf serum (FCS), the toxicity of AmB-DOC or h-AmB-DOC for both cell lines was null or weak. Interestingly, in J774 cells, the uptake of AmB in the form of h-AmB-DOC was much higher. In LLCPK1 cells, AmB uptake was more limited in both cases but remained higher with h-AmB-DOC. In the absence of FCS, no toxicity for either cell line was observed with h-AmB-DOC.. These findings confirm the importance of serum proteins in AmB biodistribution and suggest that, in vivo, the reduced toxicity and the improved antileishmanial activity of AmB-DOC after moderate heating may be the result of its increased uptake by macrophages.

Topics: Algorithms; Amphotericin B; Animals; Antifungal Agents; Cell Line; Cell Survival; Chemistry, Pharmaceutical; Deoxycholic Acid; Drug Combinations; Hot Temperature; L-Lactate Dehydrogenase; Lipoproteins, LDL; LLC-PK1 Cells; Macrophages; Mice; Swine; Tetrazolium Salts; Thiazoles

The in-vitro influence of cilofungin (LY121019) and amphotericin B on human polymorphonuclear leucocytes (PMNs) was studied by a multifunctional approach. Cilofungin at high concentration (greater than or equal to 20 mg/l) increased adherence to plastic and ingestion of Staphylococcus aureus by PMNs in suspension and Candida albicans by adherent PMNs, and slightly decreased MTT reduction and superoxide generation. Amphotericin B and amphotericin B-deoxycholate decreased adherence to plastic (IC50: 5.1 and 8.2 mg/l respectively) and superoxide generation induced by PMA and opsonized zymosan (IC50 1.1 mg/l for amphotericin B-deoxycholate). Variable results were observed for intra-cellular killing and ingestion. The functional assessment was made with four clinical isolates of yeasts (Can. albicans, Can. tropicalis, Can. Torulopsis) (glabrata, Cryptococcus neoformans). The inoculum was preincubated with the antifungals (PRE) or they were added during (PER) or after ingestion (POST) using PMNs in suspension (PRE and PER), or adhering to plastic (PRE, PER and POST). With the scheme PRE, killing was usually increased with amphotericin B-deoxycholate and cilofungin. With Crypt. neoformans, ingestion was also increased by the antifungals and sodium-deoxycholate, probably by altering the capsule. The results of the scheme POST showed that amphotericin B-deoxycholate, but not cilofungin, increased intracellular killing of Can. albicans, Can. tropicalis and Can. glabrata.

Topics: Amphotericin B; Antifungal Agents; Calcium; Chemotaxis; Deoxycholic Acid; Drug Combinations; Echinocandins; Humans; In Vitro Techniques; Microbial Sensitivity Tests; Neutrophils; Peptides; Peptides, Cyclic; Phagocytosis; Superoxides; Tetrazolium Salts; Thiazoles