Strategies of targeting CYP51 for IFIs therapy: Emerging prospects, opportunities and challenges

Recent research frontiers of heterocycles as antifungal Agents: Insights from the past five years

This review explores the growing global concern of fungal infections, particularly in immunocompromised individuals, and highlights the critical need for improved antifungal therapies. With the rise of multidrug-resistant strains, such as Candida auris and Aspergillus fumigatus, current antifungal treatments face limitations, including toxicity, low bioavailability, and the development of resistance. Heterocyclic compounds, particularly those targeting key fungal enzymes and pathways, are emerging as promising candidates in the fight against these infections. The review focuses on the structural diversity and mechanisms of action of heterocyclic antifungal agents, including azoles, echinocandins, novel dual-target inhibitors, and more. Additionally, it discusses advancements in drug design, delivery systems, and the role of artificial intelligence in identifying new compounds. By addressing gaps in existing therapies and presenting new insights into heterocyclic drug development, this study aims to guide future research towards more effective and safer antifungal treatments.

Enhanced Resistance to Pokkah Boeng Disease in Sugarcane Through Host-Induced Gene Silencing Targeting FsCYP51 in Fusarium sacchari

Pokkah boeng disease (PBD), a common and highly destructive disease of sugarcane, is mainly caused by Fusarium sacchari. Breeding sugarcane resistant to PBD is challenging due to the limited availability of immune or highly resistant germplasm resources. Host-induced gene silencing (HIGS) based on RNA interference (RNAi) is a promising disease-control method that offers strong disease-targeting ability with low environmental impact. This study found that silencing either three FsCYP51 genes (FsCYP51A, FsCYP51B and FsCYP51C) simultaneous or two of them (FsCYP51A and FsCYP51C) could inhibit the growth, development, and virulence of F. sacchari. Subsequently, we developed CYP51-HIGS transgenic sugarcane lines using gene-gun genetic transformation and obtained seven lines expressing dsFsCYP51. Both the results of laboratory inoculation assays and field trials indicated that all the seven transgenic lines had significant resistance to PBD. Moreover, in the field trials, the yield losses of transgenic sugarcane due to PBD were reduced compared with those of the control. This is the first report using the HIGS strategy to inhibit PBD infection in sugarcane. This breakthrough provides clear guidelines and practical approaches for the future breeding of sugarcane varieties with strong antifungal resistance.

Multidimensional insights into squalene epoxidase drug development: in vitro mechanisms, in silico modeling, and in vivo implications

INTRODUCTION

Squalene epoxidase (SQLE) is a pivotal enzyme in sterol biosynthesis, catalyzing the conversion of squalene to 2,3-oxidosqualene. Beyond its core role in cholesterol homeostasis, SQLE is implicated in cancer, hypercholesterolemia, and fungal infections, positioning it as a valuable therapeutic target.

AREAS COVERED

We conducted a comprehensive literature search across primary databases to gather in vitro, in silico, and in vivo evidence on SQLE. This review explores the enzyme's structural and functional features, including substrate specificity and catalytic mechanisms, and examines inhibitor interactions. Computational methods predict enzyme - inhibitor dynamics, guiding drug design, while in vivo investigations clarify SQLE's role in metabolic disorders and tumorigenesis. Challenges include drug resistance and study discrepancies, but emerging technologies, such as cryo-electron microscopy and CRISPR editing, offer new avenues for deeper exploration.

EXPERT OPINION

SQLE is an underexplored yet promising therapeutic target, with particular relevance to oxidative stress, ferroptosis, and gut microbiota research. Overcoming current barriers through advanced technologies and multidisciplinary strategies could propel SQLE-targeted treatments into clinical practice, supporting precision medicine and broader translational applications.

Identification of Microbial-Based Natural Products as Potential CYP51 Inhibitors for Eumycetoma Treatment: Insights from Molecular Docking, MM-GBSA Calculations, ADMET Analysis, and Molecular Dynamics Simulations

Background/Objectives: Eumycetoma, caused by Madurella mycetomatis, is a chronic fungal infection with limited treatment options and increasing drug resistance. CYP51, a key enzyme in ergosterol biosynthesis, is a well-established target for azole antifungals. However, existing azole drugs demonstrate limited efficacy in treating eumycetoma. Microbial-based natural products, with their structural diversity and bioactivity, offer a promising source for novel CYP51 inhibitors. This study aimed to identify potential Madurella mycetomatis CYP51 inhibitors from microbial natural products using molecular docking, MM-GBSA calculations, ADMET analysis, and molecular dynamics (MD) simulations. Methods: Virtual screening was conducted on a library of microbial-based natural products using an in-house homology model of Madurella mycetomatis CYP51, with itraconazole as the reference drug. The top compounds from initial docking were refined through Standard and Extra Precision docking. MM-GBSA calculations assessed binding affinities, and ADMET analysis evaluated drug-like properties. Compounds with favorable properties underwent MD simulations. Results: The computational investigations identified 34 compounds with better docking scores and binding affinity than itraconazole. Of these, 9 compounds interacted with the heme group and key residues in the active site of Madurella mycetomatis CYP51. In silico pharmacokinetic profiling identified 3 compounds as promising candidates, and MD simulations confirmed their potential as CYP51 inhibitors. Conclusions: The study highlights microbial-derived natural products, particularly monacyclinone G, H, and I, as promising candidates for Madurella mycetomatis CYP51 inhibition, with the potential for treating eumycetoma, requiring further experimental validation.

Regulation of Ergosterol Biosynthesis in Pathogenic Fungi: Opportunities for Therapeutic Development

Ergosterol plays a dual role in fungal pathogenesis and azole resistance, driving key advancements in the understanding of its biosynthesis regulation. This review integrates the latest research progress on the regulation of fungal ergosterol biosynthesis and its role in drug resistance and pathogenicity. We comprehensively discuss the functions of key enzymes (such as Erg11p/Cyp51A, Erg6p, Erg3p, and Erg25p) in the mevalonate, late, and alternative pathways. Notably, we highlight the complex regulation of cyp51A expression by factors such as SrbA, AtrR, CBC, HapX, and NCT in Aspergillus fumigatus, and elucidate the distinctive roles of Upc2, Adr1, and Rpn4 in Candida species. Importantly, we summarize recent discoveries on the CprA-dependent regulation of Cyp51A/Erg11p and heme-mediated stability control. Based on these findings, we propose innovative antifungal strategies, including dual-target inhibition and multi-enzyme inhibition by natural products, which provide novel insights and potential directions for the development of next-generation antifungal therapies.

Lanosterol 14α-Demethylase (CYP51)/Heat Shock Protein 90 (Hsp90) Dual Inhibitors for the Treatment of Invasive Candidiasis

Invasive candidiasis has attracted global attention with a high incidence and mortality. Current antifungal drugs are limited by unfavorable therapeutic efficacy, significant hepatorenal toxicity, and the development of drug resistance. Herein, we designed the first generation of lanosterol 14α-demethylase (CYP51)/heat shock protein 90 (Hsp90) dual inhibitors on the basis of antifungal synergism. Among them, dual inhibitor MM4 exhibited potent in vitro and in vivo antifungal activity against Candida albicans and effectively inhibited important fungal virulence factors (e.g., hyphae, biofilm). Therefore, CYP51/Hsp90 dual inhibitors show great promise in the development of novel antifungal drugs to combat invasive candidiasis.

Discovery of highly potent triazole derivatives with broad-spectrum antifungal activity based on Iodiconazole

The widespread use of broad-spectrum antibiotics, the growing number of immunocompromised individuals, and the emergence of drug-resistant strains have resulted in the increasing incidence and mortality of invasive fungal infections. Azole drugs are the primary treatment for invasive fungal infections, and Iodiconazole is a potent azole drug with strong antifungal activity, but its stability is poor. In order to improve stability, a series of triazole compounds containing ethynyl group were designed and synthesized. Most of the compounds showed strong inhibitory activity against pathogenic fungi, among which compound 20l showed excellent inhibitory activity against pathogenic fungi and drug-resistant fungi. Importantly, and the stability of 20l (T1/2 = 30.2 min) was obviously improved compared with Iodiconazole (T1/2 = 4.39 min). In addition, the preferred compound 20l can prevent fungal phase transition and the formation of fungal biofilm, and show satisfactory fungicidal activity. In addition, the compound 20l was almost non-toxic to mammalian HUVEC cell and 293T cell. In vivo pharmacokinetic studies showed that 20l had acceptable pharmacokinetic properties. These results strongly demonstrate that compound 20l was worth further investigation as a potential antifungal inhibitor.

Identification of novel and potent triazoles targeting CYP51 for antifungal: Design, synthesis, and biological study

Invasive fungal infections (IFIs) are emerging as a serious infectious disease worldwide. Due to the lack of effective antifungal drugs and serious drug resistance, the number of people with low immunity is increasing, leading to high morbidity and mortality. Azole drugs targeting CYP51 are widely used in the treatment of invasive fungal infections. By analyzing representative azole antifungal drugs, the characteristics of pharmacophore were summarized. The binding mode of lead compound Iodiconazole was analyzed, and it was found that the narrow hydrophobic cavity was not fully occupied. Therefore, a series of triazole compounds were designed and synthesized by fragment growth strategy. Most of the compounds showed strong inhibitory activity against pathogenic fungi, among which compound A33 showed excellent inhibitory activity against pathogenic fungi and drug-resistant strains. In addition, the preferred compound A33 can prevent fungal phase transition, the formation of fungal biofilm, and show satisfactory fungicidal activity. In addition, the compound A33 was almost non-toxic to mammalian HUVEC cell. These results strongly suggested that compound A33 was worth further investigation as a potential azole inhibitor.

Polymer scaffolds delineate healthy from diseased states at sites distal from the pancreas in two models of type 1 diabetes

Type 1 diabetes (T1D) prevention is currently limited by the lack of diagnostic tools able to identify disease before autoimmune destruction of the pancreatic β cells. Autoantibody tests are used to predict risk and, in combination with glucose dysregulation indicative of β cell loss, to determine administration of immunotherapies. Our objective was to remotely identify immune changes associated with the disease, and we have employed a subcutaneously implanted microporous poly(e-caprolactone) (PCL) scaffold to function as an immunological niche (IN) in two models of T1D. Biopsy and analysis of the IN enables disease monitoring using transcriptomic changes at a distal site from autoimmune destruction of the pancreas, thereby gaining cellular level information about disease without the need for a biopsy of the native organ. Using this approach, we identified gene signatures that stratify healthy and diseased mice in both an adoptive transfer model and a spontaneous onset model of T1D. The gene signatures identified herein demonstrate the ability of the IN to identify immune activation associated with diabetes across models.

Study of transport, tissue distribution, depletion, and hepatotoxicity of Cyadox, a quinoxaline-1,4-dioxide derivative

Background

Cyadox (CYA) is a derivative of quinoxaline 1,4-dioxide and a safe and effective synthetic antibacterial agent.

Objective

This study aimed to explore the drug transport in blood, distribution, depletion and hepatotoxicity of drugs in animals.

Methods

The transport of CYA in blood was studied using fluorescence, circular dichroism (CD) and molecular docking methods. Tissue distribution and depletion of CYA in rats were evaluated following oral administration of [3H]-CYA at different doses. Hepatotoxicity of drugs evaluated by transcriptomics.

Results

During transport in the bloodstream, the drug binds to bovine serum albumin (BSA) by hydrogen bonding and has only one binding site. Hydrogen bonds were formed between O (2) of CYA and ARG208, O (3) of CYA and LEU480, VAL481. The secondary protein conformation of BSA changed after binding with an increase in α-helix and a decrease in β-strand. After a single oral administration of [3H]-CYA, it was excreted rapidly within 7 days, with 34.81% from the urine and 60.25% from the feces. Higher and sustained levels of radioactivity were detected in the liver during the post-dose period, suggesting that the drug may concentrate in the liver. The transcriptomic data indicates that CYA exhibits low hepatotoxicity. However, there are indications that it may have an impact on steroid biosynthesis.

Conclusion

This study could serve as a basis for conducting further studies on the use of CYA in food animals and improving the pharmacologic, pharmacokinetic, and toxicologic effects of CYA on food animals.

Synthesis and antifungal evaluation of novel triazole derivatives bearing a pyrazole-methoxyl moiety

Life-threatening invasive fungal infections pose a serious threat to human health. A series of novel triazole derivatives bearing a pyrazole-methoxyl moiety were designed and synthesized in an effort to obtain antifungals with potent, broad-spectrum activity that are less susceptible to resistance. Most of these compounds exhibited moderate to excellent in vitro antifungal activities against Candida albicans SC5314 and 10,231, Cryptococcus neoformans 32,609, Candida glabrata 537 and Candida parapsilosis 22,019 with minimum inhibitory concentration (MIC) values of ≤0.125 μg/mL to 0.5 μg/mL. Use of recombinant Saccharomyces cerevisiae strains showed compounds 7 and 10 overcame the overexpression and resistant-related mutations in ERG11 of S. cerevisae and several pathogenic Candida spp. Despite being substrates of the C. albicans and Candida auris Cdr1 drug efflux pumps, compounds 7 and 10 showed moderate potency against five fluconazole (FCZ)-resistant fungi with MIC values from 2.0 μg/mL to 16.0 μg/mL. Growth kinetics confirmed compounds 7 and 10 had much stronger fungistatic activity than FCZ. For C. albicans, compounds 7 and 10 inhibited the yeast-to-hyphae transition, biofilm formation and destroyed mature biofilm more effectively than FCZ. Preliminary mechanism of action studies showed compounds 7 and 10 blocked the ergosterol biosynthesis pathway at Erg11, ultimately leading to cell membrane disruption. Further investigation of these novel triazole derivatives is also warranted by their predicted ADMET properties and low cytotoxicity.

Discovery of a Hybrid Molecule with Phytotoxic Activity by Genome Mining, Heterologous Expression, and OSMAC Strategy

Genome mining in association with the OSMAC (one strain, many compounds) approach provides a feasible strategy to extend the chemical diversity and novelty of natural products. In this study, we identified the biosynthetic gene cluster (BGC) of restricticin, a promising antifungal agent featuring a reactive primary amine, from the fungus Aspergillus sclerotiorum LZDX-33-4 by genome mining. Combining heterologous expression and the OSMAC strategy resulted in the production of a new hybrid product (1), along with N-acetyl-restricticin (2) and restricticinol (3). The structure of 1 was determined by spectroscopic data, including optical rotation and electronic circular dichroism (ECD) calculations, for configurational assignment. Compound 1 represents a fusion of restricticin and phytotoxic cichorin. The biosynthetic pathway of 1 was proposed, in which the condensation of a primary amine of restricticin with a precursor of cichorine was postulated. Compound 1 at 5 mM concentration inhibited the growth of the shoots and roots of Lolium perenne, Festuca arundinacea, and Lactuca sativa with inhibitory rates of 71.3 and 88.7% for L. perenne, 79.4 and 73.0% for F. arundinacea, and 58.2 and 52.9% for L. sativa. In addition, compound 1 at 25 μg/mL showed moderate antifungal activity against Fusarium fujikuroi and Trichoderma harzianum with inhibition rates of 22.6 and 31.6%, respectively. These results suggest that heterologous expression in conjunction with the OSMAC approach provides a promising strategy to extend the metabolite novelty due to the incorporation of endogenous metabolites from the host strain with exogenous compounds, leading to the production of more complex compounds and the acquisition of new physiological functions.

Discovery of Novel α,β-Unsaturated Amide Derivatives as Candidate Antifungals to Overcome Fungal Resistance

In our previous study, coumarin-containing CYP51 inhibitor A32 demonstrated potent antiresistance activity. However, compound A32 demonstrated unsatisfied metabolic stability, necessitating modifications to overcome these limitations. In this study, α,β-unsaturated amides were used to replace the unstable coumarin ring, which increased metabolic stability by four times while maintaining antifungal activity, including activity against resistant strains. Subsequently, the sterol composition analysis and morphological observation experiments indicated that the target of these novel compounds is lanosterol 14α-demethylase (CYP51). Meanwhile, biofilm growth was inhibited and resistance genes (ERG11, CDR1, CDR2, and MDR1) expression was downregulated to find out how the antiresistance works. Importantly, compound C07 demonstrated the capacity to stimulate reactive oxygen species, thus displaying potent fungicidal activity. Moreover, C07 exhibited encouraging effectiveness in vivo following intraperitoneal administration. Additionally, the most potent compound C07 showed satisfactory pharmacokinetic properties and low toxicity. These α,β-unsaturated amide derivatives, particularly C07, are potential candidates for treating azole-resistant candidiasis.

Corn stigma ameliorates hyperglycemia in zebrafish and GK rats of type 2 diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Cornstigma (CS), derived from the stigma and style of gramineous plant Zeamays. The medicinal use of CS can be traced back to DianNanMateriaMedica. LingnanMedicinalPlantsCompendium records its effectiveness in ameliorating diabetes. Diabetes is a metabolic disorder characterized by hyperglycemia and the consequent chronic complications of kidney, heart, brain and other organs, which pose a significant threat to human health. CS has shown great potential in relieving hyperglycemia associated with diabetes. However, the mechanism of CS in treating diabetes remains unclear.

AIM OF THE STUDY

To explore the pathogenesis of diabetes and the mechanism of CS improving hyperglycemia in diabetes.

MATERIALS AND METHODS

We measured apigenin and luteolin contents in CS by UPLC/MS/MS method. Selecting Wistar rats as normal group, and GK rats as model group. For rats, we detected glucose and lipid metabolism indicators, including GHb, AST, ALT, U-Glu, UA, U-TP, U-ALB, and ACR after treatment. For zebrafish, we utilized alloxan and sucrose to establish the diabetes model. Measuring zebrafish blood glucose is employed to evaluate the hypoglycemic capability of CS. In order to explore the mechanism of CS in treating diabetes, we sequenced the transcriptome of zebrafish, compared differentially expressed genes of normal, diabetic, and CS-treated group, and validated multiple enrichment pathways by PCR.

RESULTS

CS can improve blood glucose levels in both GK rats and diabetic zebrafish. For rats, CS partially restored glucose and lipid metabolism indicators. Transcriptome data from zebrafish showed a close correlation with steroid biosynthesis. The RNA-Sequencing was consistent with PCR results, indicating that CS downregulated gene (fdft1,lss,cyp51) expression concerned with steroid biosynthesis pathway in the diabetes model.

CONCLUSION

CS effectively improved blood glucose levels, regulated glucose and lipid metabolism by suppressing gene expression in steroid biosynthesis pathway, and ameliorated hyperglycemia. Our research provides valuable insights for CS in the treatment of diabetes, and proposes a new strategy for selecting clinical medications for diabetes.