Acetylsalicylic acid as antifungal in Eremothecium and other yeasts

Can nonsteroidal anti-inflammatory drugs (NSAIDs) be repurposed for fungal infection?

Nonsteroidal anti-inflammatory drugs (NSAIDs) are an important class of anti-inflammatory drugs widely used for the treatment of musculoskeletal disorders, mild-to-moderate pain, and fever. This review aimed to explain the functional role and possible mechanisms of the antifungal effects of NSAIDs alone or in combination with antifungal drugs in vitro and in vivo. Several studies reported that NSAIDs such as aspirin, ibuprofen, diclofenac, indomethacin, ketorolac, celecoxib, flurbiprofen, and nimesulide had antifungal activities in vitro, either fungistatic or fungicidal, against different strains of Candida, Aspergillus, Cryptococcus, Microsporum, and Trichophyton species. These drugs inhibited biofilm adhesion and development, and yeast-to-hypha conversion which may be related to a prostaglandin E2 (PGE2)/PGEx-dependent mechanism. Modulating PGE2 levels by NSAIDs during fungal infection can be introduced as a possible mechanism to overcome. In addition, some important mechanisms of the antifungal activities of NSAIDs and their new derivatives on fungi and host immune responses are summarized. Overall, we believe that using NSAIDs along with classical antifungal drugs has the potential to be investigated as a novel therapeutic strategy in clinical studies. Furthermore, combination therapy can help manage resistant strains, increase the efficacy of antifungal drugs, and reduce toxicity.

Aspirin and Infection: A Narrative Review

Acetylsalicylic acid (ASA) is one of the most commonly used drugs in the world. It derives from the extract of white willow bark, whose therapeutic potential was known in Egypt since 1534 BC. ASA’s pharmacological effects are historically considered secondary to its anti-inflammatory, platelet-inhibiting properties; however, human studies demonstrating a pro-inflammatory effect of ASA exist. It is likely that we are aware of only part of ASA’s mechanisms of action; moreover, the clinical effect is largely dependent on dosages. During the past few decades, evidence of the anti-infective properties of ASA has emerged. We performed a review of such research in order to provide a comprehensive overview of ASA and viral, bacterial, fungal and parasitic infections, as well as ASA’s antibiofilm properties.

Eremothecium coryli bloodstream infection in a patient with acute myeloid leukemia: first case report of human infection

Eremothecium coryli is a dimorphic fungus of the Saccharomycetes class. While species within this class are known to cause human infection, Eremothecium species have previously only been known as phytopathogens and never been isolated from a human sample. Here, we report the first known case of human E. coryli infection.

In Vitro Interactions between Non-Steroidal Anti-Inflammatory Drugs and Antifungal Agents against Planktonic and Biofilm Forms of Trichosporon asahii

Increasing drug resistance has brought enormous challenges to the management of Trichosporon spp. infections. The in vitro antifungal activities of non-steroidal anti-inflammatory drugs (NSAIDs) against Candida spp. and Cryptococcus spp. were recently discovered. In the present study, the in vitro interactions between three NSAIDs (aspirin, ibuprofen and diclofenac sodium) and commonly used antifungal agents (fluconazole, itraconazole, voriconazole, caspofungin and amphotericin B) against planktonic and biofilm cells of T. asahii were evaluated using the checkerboard microdilution method. The spectrophotometric method and the XTT reduction assay were used to generate data on biofilm cells. The fractional inhibitory concentration index (FICI) and the ΔE model were compared to interpret drug interactions. Using the FICI, the highest percentages of synergistic effects against planktonic cells (86.67%) and biofilm cells (73.33%) were found for amphotericin B/ibuprofen, and caspofungin/ibuprofen showed appreciable percentages (73.33% for planktonic form and 60.00% for biofilm) as well. We did not observe antagonism. The ΔE model gave consistent results with FICI (86.67%). Our findings suggest that amphotericin B/ibuprofen and caspofungin/ibuprofen combinations have potential effects against T. asahii. Further in vivo and animal studies to investigate associated mechanisms need to be conducted.

Beyond plant defense: insights on the potential of salicylic and methylsalicylic acid to contain growth of the phytopathogen Botrytis cinerea

Using Botrytis cinerea we confirmed in the present work several previous studies showing that salicylic acid, a main plant hormone, inhibits fungal growth in vitro. Such an inhibitory effect was also observed for the two salicylic acid derivatives, methylsalicylic and acetylsalicylic acid. In marked contrast, 5-sulfosalicylic acid was totally inactive. Comparative proteomics from treated vs. control mycelia showed that both the intracellular and extracellular proteomes were affected in the presence of salicylic acid or methylsalicylic acid. These data suggest several mechanisms that could potentially account for the observed fungal growth inhibition, notably pH regulation, metal homeostasis, mitochondrial respiration, ROS accumulation and cell wall remodeling. The present observations support a role played by the phytohormone SA and derivatives in directly containing the pathogen. Data are available via ProteomeXchange with identifier PXD002873.

The presence of 3-hydroxy oxylipins in pathogenic microbes

There is a sufficient body of work documenting the distribution of 3-hydroxy oxylipins in microbes. However, there is limited information on the role of these compounds in microbial pathogenesis. When derived from mammalian cells, these compounds regulate patho-biological processes, thus an understanding of 3-hydroxy oxylipin function and metabolism could prove important in shedding light on how these compounds mediate cellular pathology and physiology. This could present 3-hydroxy oxylipin biosynthetic pathways as targets for drug development. In this minireview, we interrogate the relevant yeast and bacterial 3-hydroxy oxylipin literature in order to appreciate how these compounds may influence the inflammatory response leading to disease development.

Gentisate and 3-oxoadipate pathways in the yeast Candida parapsilosis: identification and functional analysis of the genes coding for 3-hydroxybenzoate 6-hydroxylase and 4-hydroxybenzoate 1-hydroxylase

The pathogenic yeast Candida parapsilosis degrades various hydroxy derivatives of benzenes and benzoates by the gentisate and 3-oxoadipate pathways. We identified the genes MNX1, MNX2, MNX3, GDX1, HDX1 and FPH1 that code for enzymes involved in these pathways in the complete genome sequence of C. parapsilosis. Next, we demonstrated that MNX1, MNX2, MNX3 and GDX1 are inducible and transcriptionally controlled by hydroxyaromatic substrates present in cultivation media. Our results indicate that MNX1 and MNX2 code for flavoprotein monooxygenases catalysing the first steps in the 3-oxoadipate and gentisate pathways, respectively (i.e. 4-hydroxybenzoate 1-hydroxylase and 3-hydroxybenzoate 6-hydroxylase). Moreover, we found that the two pathways differ by their intracellular localization. The enzymes of the 3-oxoadipate pathway, Mnx1p and Mnx3p, localize predominantly in the cytosol. In contrast, intracellular localization of the components of the gentisate pathway, Mnx2p and Gdx1p, depends on the substrate in the cultivation medium. In cells growing on glucose these proteins localize in the cytosol, whereas in media containing hydroxyaromatic compounds they associate with mitochondria. Finally, we showed that the overexpression of MNX1 or MNX2 increases the tolerance of C. parapsilosis cells to the antifungal drug terbinafine.

Anti-inflammatory drugs selectively target sporangium development in Mucor

It is known that acetylsalicylic acid, an anti-inflammatory and anti-mitochondrial drug, targets structure development and functions of yeasts depending on elevated levels of mitochondrial activity. Using antibody probes, we previously reported that sporangia of Mucor circinelloides also contain increased mitochondrial activity, yielding high levels of 3-hydroxyoxylipins. This was, however, not found in Mortierella alpina (subgenus Mortierella ). In this study we report that acetylsalicylic acid (aspirin) also targets sporangium development of Mucor circinelloides selectively, while hyphae with lower levels of mitochondrial activity are more resistant. Similar results were obtained when the anti-inflammatory compounds benzoic acid, ibuprofen, indomethacin, and salicylic acid were tested. The anti-inflammatory drugs exerted similar effects on this dimorphic fungus as found under oxygen-limited conditions. Interestingly, sporangium development of Mortierella alpina was found not to be selectively targeted by these drugs. Mortierella alpina, which could not exhibit dimorphic growth under oxygen-limited conditions, was also more sensitive to the anti-inflammatory drugs when compared with Mucor circinelloides. These results prompt further research to assess the applicability of these antimitochondrial antifungals to protect plants and animals against Mucor infections.

Acetylsalicylic acid (aspirin) reduces damage to reconstituted human tissues infected with Candida species by inhibiting extracellular fungal lipases

A reconstituted human tissue model was used to mimic Candida albicans and Candida parapsilosis infection in order to investigate the protective effects of acetylsalicylic acid (aspirin, ASA). We found that therapeutic concentrations of ASA reduced tissue damage in the in vitro infection model. We further evaluated the lipase inhibitory effects of ASA by investigating the growth of C. albicans, C. parapsilosis and C. parapsilosis lipase negative (Deltacplip1-2/Deltacplip1-2) mutants in a lipid rich minimal medium supplemented with olive oil and found that a therapeutic concentration of ASA inhibited the growth of wild type fungi. The lipase inhibitors quinine and ebelactone B were also shown to reduce growth and protect against tissue damage from Candida species, respectively. A lipolytic activity assay also showed that therapeutic concentrations of ASA inhibited C. antarctica and C. cylindracea purified lipases obtained through a commercial kit. The relationship between ASA and lipase was characterized through a computed structural model of the Lipase-2 protein from C. parapsilosis in complex with ASA. The results suggest that development of inhibitors of fungal lipases could result in broad-spectrum therapeutics, especially since fungal lipases are not homologous to their human analogues.

Oxylipin and mitochondrion probes to track yeast sexual cells

When oxylipin and mitochondrion probes, i.e., fluorescing antibodies specific for 3-hydroxy fatty acids (3-OH oxylipins) and rhodamine 123 (Rh123), were added to yeast cells, these probes accumulated mainly in the sexual cells (i.e., both associated with ascospores) and not in the vegetative cells. This suggests increased mitochondrial activity in asci, since 3-OH oxylipins are mitochondrially produced and it is known that Rh123 accumulates selectively in functional mitochondria that maintain a high transmembrane potential (ΔΨm). This increased activity may be necessary for the production and effective release of the many spores found in single-celled asci. These results may be useful in the rapid identification of asci and in yeast sexual spore mechanics, which may find application in yeast systematics as well as hydro-, aero-, and nano-technologies.

The influence of acetylsalicylic acid on oxylipin migration in Cryptococcus neoformans var. neoformans UOFS Y-1378

In this paper we report the influence of acetylsalicylic acid on oxylipin migration in Cryptococcus neoformans var. neoformans UOFS Y-1378, previously isolated from human bone lesion. Transmission electron microscopy suggests that osmiophilic material originates in mitochondria and is deposited inside the yeast cell wall, from which it is excreted into the environment, along capsule protuberances, or through capsule detachments. Previous studies using immunogold labeling indicate that these osmiophilic layers contain 3-hydroxy oxylipins. In this study, the addition of acetylsalicylic acid (an inhibitor of mitochondrial function) in increasing amounts to the cells abrogated the migration of osmiophilic material, as well as capsule detachment from cell walls, and hence, oxylipin excretion. Consequently, we hypothesize that 3-hydroxy oxylipins are produced in mitochondria, probably via incomplete beta-oxidation or fatty acid synthesis, from which they are deposited inside the cell wall and excreted through tubular protuberances attached to the surrounding capsules and (or) through detachment of these oxylipin-containing capsules.

Distribution of 3-hydroxy oxylipins and acetylsalicylic acid sensitivity in Cryptococcus species

Using a well tested antibody specific for 3-hydroxy oxylipins, we mapped the presence of these oxylipins in selected Cryptococcus ( Filobasidiella ) species. Immunofluorescence microscopy studies revealed that these compounds are deposited on cell wall surfaces, appendages, and collarettes. In vitro studies revealed that growth of Cryptococcus species was inhibited by acetylsalicylic acid (which is known to inhibit mitochondrial function, including the production of 3-hydroxy oxylipins) at concentrations as low as 1 mmol/L. The results suggest that acetylsalicylic acid is effective in controlling the growth of tested pathogens, probably by targeting their mitochondria. This study further expands the known function of this anti-inflammatory drug as anti-fungal agent.

3-hydroxy fatty acids found in capsules of Cryptococcus neoformans

Using immunofluorescence confocal laser scanning microscopy, immunogold transmission electron microscopy and gas chromatography--mass spectrometry, we demonstrated the presence of 3-hydroxy fatty acids in Cryptococcus neoformans. Our results suggest that these oxylipins accumulate in capsules where they are released as hydrophobic droplets through tubular protuberances into the surrounding medium.

Oxylipin studies expose aspirin as antifungal

The presence of aspirin-sensitive 3-hydroxy fatty acids (i.e. 3-OH oxylipins) in yeasts was first reported in the early 1990s. Since then, these oxidized fatty acids have been found to be widely distributed in yeasts. 3-OH oxylipins may: (1) have potent biological activity in mammalian cells; (2) act as antifungals; and (3) assist during forced spore release from enclosed sexual cells (asci). A link between 3-OH oxylipin production, mitochondria and aspirin sensitivity exists. Research suggests that: (1) 3-OH oxylipins in some yeasts are probably also produced by mitochondria through incomplete beta-oxidation; (2) aspirin inhibits mitochondrial beta-oxidation and 3-OH oxylipin production; (3) yeast sexual stages, which are probably more dependent on mitochondrial activity, are also characterized by higher 3-OH oxylipin levels as compared to asexual stages; (4) yeast sexual developmental stages as well as cell adherence/flocculation are more sensitive to aspirin than corresponding asexual growth stages; and (5) mitochondrion-dependent asexual yeast cells with a strict aerobic metabolism are more sensitive to aspirin than those that can also produce energy through an alternative anaerobic glycolytic fermentative pathway in which mitochondria are not involved. This review interprets a wide network of studies that reveal aspirin to be a novel antifungal.