Cyclosporin A treatment and decreased fungal load/antigenemia in experimental murine paracoccidioidomycosis

Medicines for Malaria Venture COVID Box: a source for repurposing drugs with antifungal activity against human pathogenic fungi

BACKGROUND

Treatment of mycoses is often ineffective, usually prolonged, and has some side effects. These facts highlight the importance of discovering new molecules to treat fungal infections.

OBJECTIVES

To search the Medicines for Malaria Venture COVID Box for drugs with antifungal activity.

METHODS

Fourteen human pathogenic fungi were tested against the 160 drugs of this collection at 1.0 µM concentration. We evaluated the ability of the drugs to impair fungal growth, their fungicidal nature, and morphological changes caused to cells.

FINDINGS

Thirty-four molecules (21.25%) presented antifungal activity. Seven are antifungal drugs and one is the agricultural fungicide cycloheximide. The other drugs with antifungal activity included antibiotics (n = 3), antimalarials (n = 4), antivirals (n = 2), antiparasitcs (n = 3), antitumor agents (n = 5), nervous system agents (n = 3), immunosuppressants (n = 3), antivomiting (n = 1), antiasthmatic (n = 1), and a genetic disorder agent (n = 1). Several of these drugs inhibited Histoplasma capsulatum and Paracoccidioides brasiliensis growth (15 and 20, respectively), while Fusarium solani was not affected by the drugs tested. Most drugs were fungistatic, but niclosamide presented fungicidal activity against the three dimorphic fungi tested. Cyclosporine affected morphology of Cryptococcus neoformans.

MAIN CONCLUSIONS

These drugs represent new alternatives to the development of more accessible and effective therapies to treat human fungal infections.

Immunosuppression in the Management of Presumed Non-infective Uveitis; Are We Sure What We are Treating? Notes on the Antimicrobial Properties of the Systemic Immunosuppressants

PURPOSE

To describe the antimicrobial effects of immunosuppressants used for presumed autoimmune uveitis, and to discuss the potential importance of these effects in the context of increasing knowledge of the human microbiomes and their influence on inflammation.

METHODS

Literature review.

REVIEW OF EVIDENCE

All immunosuppressants have intrinsic antimicrobial effects; these vary considerably between drugs, and include antibacterial, antiviral and antifungal action. Immunosuppression is known to affect the composition of the gut microbiome, and alterations in microbiome composition are known to affect inflammations including uveitis.

CONCLUSIONS

Oral immunosuppressants are assumed to act on presumed autoimmune uveitis by downregulation of, or other interference with, an aberrant immune response. However, their antimicrobial properties are usually forgotten, and in the context of increasing knowledge of the involvement of microbes in the initiation of, and also potentially the perpetuation of, tissue inflammation, these effects may prove to be a fundamental part of their action.

Impact of a Single Oral Acute Dose of Aflatoxin B₁ on Liver Function/Cytokines and the Lymphoproliferative Response in C57Bl/6 Mice

Aflatoxin B₁ (AFB₁), a mycotoxin found in food and feed, exerts harmful effects on humans and animals. The liver is the earliest target of AFB₁, and its effects have been evaluated in animal models exposed to acute or chronic doses. Considering the possibility of sporadic ingestion of AFB₁-contaminated food, this study investigated the impact of a single oral dose of AFB₁ on liver function/cytokines and the lymphoproliferative response in mice. C57BL/6 mice were treated with a single oral AFB₁ dose (44, 442 or 663 μg AFB₁/kg of body weight) on the first day. Liver function (ALT, γ-GT, and total protein), cytokines (IL-4, IFN-γ, and IL-17), histopathology, and the spleen lymphoproliferative response to mitogens were evaluated on the 5th day. Although AFB₁ did not produce any significant changes in the biochemical parameters, 663 μg AFB₁/kg-induced hepatic upregulation of IL-4 and IFN-γ, along with liver tissue injury and suppression of the lymphoproliferative response to ConA (p < 0.05). In conclusion, a single oral dose of AFB₁ exposure can induce liver tissue lesions, liver cytokine modulation, and immune suppression in C57BL/6 mice.

Animal Models and Antifungal Agents in Paracoccidioidomycosis: An Overview

Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis, the most prevalent systemic mycosis in Latin America. The morbidity and mortality associated with paracoccidioidomycosis necessitate our understanding of fungal pathogenesis and discovering of new agents to treat this infection. Animal models have contributed much to the knowledge of fungal infections and their corresponding therapeutic treatments. This is true for animal models of the primary fungal pathogens such as P. brasiliensis. This review describes the development, details and utility of animal models of paracoccidioidomycosis for studying and developing the current antifungal agents used for therapy of this fungal disease and novel agents with antifungal properties against P. brasiliensis.

Effect of cyclosporin A intervention on the immunological mechanisms of coronary heart disease and restenosis

The present study aimed to investigate the effect of cyclosporin A (CSA) intervention on the immunological mechanisms underlying coronary heart disease (CHD) and restenosis (RS) in rabbits. A total of 48 rabbits were randomly divided into normal control (N), N + CSA, CHD model, CHD + CSA, RS model and RS + CSA groups. Rabbits in the respective groups received different treatments prior to sacrifice at the end of week 12. Iliac arteries were harvested from the rabbits for morphological analysis and to determine the mRNA and protein expression levels of cluster of differentiation (CD) 40/CD40 ligand (CD40L), CD134/CD134 ligand (CD134L) and inflammatory factors, including matrix metalloproteinase (MMP)-1, MMP-9, vascular cell adhesion protein (VCAM)-1, interleukin (IL)-6 and tumor necrosis factor (TNF)-α, by reverse transcription-quantitative polymerase chain reaction and immunohistochemical staining. As compared with the N group, the mRNA expression levels of MMP-9, VCAM-1 and TNF-α were significantly increased in the CHD and RS groups (P<0.05), but were significantly decreased in the groups with CSA intervention, as compared with those without CSA intervention (P<0.05). Conversely, there were no significant differences in the expression levels of MMP-1 and IL-6 among the six groups, although a decreasing trend of IL-6 expression was observed following intervention with CSA. Furthermore, there were significant differences in the mRNA and protein expression levels of CD40/CD40L and CD134/CD134L among the N, CHD and RS groups (P<0.05), and between the groups with and without CSA intervention. The present study demonstrated that CSA intervention exerted beneficial effects on CHD and RS, and further studies are required to investigate the mechanisms underlying the effects of CSA on CHD.