Ergosterol inhibits the proliferation of breast cancer cells by suppressing AKT/GSK-3beta/beta-catenin pathway.

Breast cancer is a prevalent malignancy affecting women globally, necessitating effective treatment strategies. This study explores the potential of ergosterol, a bioactive compound found in edible mushrooms, as a candidate for breast cancer treatment. Breast cancer cell lines (MCF-7 and MDA-MB-231) were treated with ergosterol, revealing its ability to inhibit cell viability, induce cell cycle arrest, and suppress spheroid formation. Mechanistically, ergosterol demonstrated significant inhibitory effects on the Wnt/beta-catenin signaling pathway, a critical regulator of cancer progression, by attenuating beta-catenin translocation in the nucleus. This suppression was attributed to the inhibition of AKT/GSK-3beta phosphorylation, leading to decreased beta-catenin stability and activity. Additionally, ergosterol treatment impacted protein synthesis and ubiquitination, potentially contributing to its anti-cancer effects. Moreover, the study revealed alterations in metabolic pathways upon ergosterol treatment, indicating its influence on metabolic processes critical for cancer development. This research sheds light on the multifaceted mechanisms through which ergosterol exerts anti-tumor effects, mainly focusing on Wnt/beta-catenin pathway modulation and metabolic pathway disruption. These findings provide valuable insights into the potential of ergosterol as a therapeutic candidate for breast cancer treatment, warranting further investigation and clinical application.

Mitochondrial targeted modification and anticancer mechanism of natural product ergosterol peroxide.

Ergosterol peroxide (EP) isolated from the edible medicinal fungus Pleurotus ferulae has a wide range of anti-tumor activity, but poor water solubility and low bioavailability limit further application. In this study, EP was structurally modified using triphenylphosphine (TPP+), which combines mitochondrial targeting, amphiphilicity, and cytotoxicity. A series of TPP+-conjugated ergosterol peroxide derivatives (TEn) with different length linker arms were synthesized. The structure-activity relationship showed that the anticancer activity of TEn gradually decreased with the elongation of the linker arm. The compound TE3 has the optimal and broadest spectrum of antitumor effects. It mainly through targeting mitochondria, inducing ROS production, disrupting mitochondrial function, and activating mitochondria apoptosis pathway to exert anti-cervical cancer activity. Among them, TPP+ only acted as a mitochondrial targeting group, while EP containing peroxide bridge structure served as an active group to induce ROS. In vivo experiments have shown that TE3 has better anti-cervical cancer activity and safety than the first-line anticancer drug cisplatin, and can activate the immune response in mice. Although TE3 exhibits some acute toxicity, it is not significant at therapeutic doses. Therefore, TE3 has the potential for further development as an anti-cervical cancer drug.

Ten ring-B aromatized ergosterols from Aspergillus spectabilis.

Spectasterols F-O (1-10), ten interesting ergosterols with an aromatized B ring, were obtained from Aspergillus spectabilis. Their structures and absolute configurations were determined using a combination of high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), nuclear magnetic resonance (NMR) spectroscopy, single-crystal X-ray diffraction analyses, and electronic circular dichroism (ECD) calculations. Structurally, these aromatic ergosterols feature versatile side chains. Notably, compound aromatic ergosterols featured versatile side chains, and compound 4 is an unusual C23 ergosterol characterized by a shorter side chain due to oxidative cleavage between C-23 and C-24. All compounds were evaluated for their neuroprotective activities, with compound 8 showing a dose-dependent ability to reduce apoptosis and protect mitochondrial function in glutamate-induced SH-SY5Y cells.

[Ergosterol peroxide inducing apoptosis of human hepatocellular carcinoma by regulating mitochondrial apoptosis pathway].

This study aims to investigate the effect of ergosterol peroxide(EP) on the apoptosis of human hepatocellular carcinoma and its mechanism of action. The cell viability of HepG2 and SK-Hep-1 cells with 0(blank control), 2.5, 5, 10, 20, 40, and 80 µmol·L~(-1) of EP after 24, 48, and 72 h of action was detected by using CCK-8 assay, and the half inhibitory concentrations(IC_(50)) at 24, 48, and 72 h were calculated. Formal experiments were performed to detect the effect of EP on intracellular reactive oxygen species(ROS) using DCFH-DA staining, the effect of EP on intracellular mitochondrial membrane potential using JC-1 staining, the number of apoptotic cells using Annexin V-FITC/PI double-staining after HepG2 cells were co-cultured with 0(blank control), 10, 20, 40 µmol·L~(-1) EP for 48 h. The effects of EP at different concentrations on apoptotic morphology were detected using AO/EB staining. The effects of different concentrations of EP on the protein expression of mitochondrial apoptosis pathway-related proteins B cell lymphoma 2(Bcl-2), cytochrome C(Cyt-C), Bcl-2-related X protein(Bax), caspase-3, cleaved caspase-3, caspase-9, and cleaved caspase-9 were examined by using Western blot. The results showed that different concentrations of EP could inhibit the proliferation of hepatocellular carcinoma with concentration-and time-dependent trends. Compared with the blank control group, the ROS level in the EP-treated group increased significantly(P<0.05). The mitochondrial membrane potential decreased significantly(P<0.05). The total apoptosis rate increased significantly(P<0.05). The expression of Bcl-2 protein was significantly down-regulated, and the expression of Cyt-C, Bax, cleaved caspase-9, and cleaved caspase-3 were significantly up-regulated(P<0.05). In summary, EP may inhibit the proliferation of hepatocellular carcinoma by modulating the mitochondria-mediated apoptosis pathway and induce apoptosis.

[Mechanism of ergosterol peroxide on MCF-7 breast cancer cells based on network pharmacology and in vitro experiments].

This study investigated the effects of ergosterol peroxide(EP) on the proliferation and apoptosis of MCF-7 breast cancer cells, explored its possible mechanisms of action, and verified the effects and mechanisms by in vitro experiments. Network pharmaco-logy was used to screen the target proteins of EP and construct target networks and protein-protein interaction(PPI) networks to predict the potential target proteins and related pathways involved in EP anti-breast cancer effects. The MTT assay was performed to measure the inhibitory effect of EP on MCF-7 cell proliferation, and the colony formation assay was used to assess the cell cloning ability. Flow cytometry and laser confocal microscopy were employed to evaluate cell apoptosis, mitochondrial membrane potential and reactive oxygen species(ROS) levels. Western blot analysis was conducted to examine the expression levels of B-cell lymphoma 2(Bcl-2), Bcl-2-associated X protein(Bax), cytochrome C(Cyt C), caspase-7, cleaved caspase-7, phosphatidylinositol 3-kinase(PI3K), and se-rine/threonine kinase B(AKT) in MCF-7 cells treated with EP. The results of network pharmacology prediction yielded 173 common targets between EP and breast cancer; the results of Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis showed that EP treatment for breast cancer mainly affected the signaling pathways such as cancer pathway, PI3K-AKT signaling pathway, cellular senescence signaling pathway, and viral carcinogenesis pathway; and the MTT assay results showed that the viability of MCF-7 cells in the EP group was significantly lower than that in the control group, exhibiting a time-and concentration-dependent trend, and EP can inhibit colony formation of MCF-7 breast cancer cells. Treatment with 10, 20, and 40 µmol·L~(-1) EP for 24 h resulted in a significant increase in the total apoptosis rate of MCF-7 cells, a significant decrease in mitochondrial membrane potential, and a significant increase in ROS levels. In addition, treatment with EP led to an upregulation of Cyt C, Bax, and cleaved caspase-7 protein expression, and a downregulation of p-PI3K, p-AKT, and Bcl-2 protein expression in MCF-7 cells. Studies have shown that EP inhibits MCF-7 breast cancer cell proliferation and reduces colony formation by a mechanism that may be related to the PI3K-AKT pathway mediating the mitochondrial apoptotic pathway.

Ergosterol and its metabolites as agonists of Liver X receptor and their anticancer potential in colorectal cancer.

Aberrant cholesterol homeostasis is a well-recognized hallmark of cancer and is implicated in metastasis as well as chemotherapeutic resistance, the two major causes of cancer associated mortality. Liver X receptors (LXRs) are the key transcription factors that induce cholesterol efflux via enhancing the expression of ABCA1 and ABCG1. Therefore, a comprehensive analysis of several novel sterols namely ergosta-7,22,24(28)-trien-3ß-ol (Erg1), ergosta-5,22,25-trien-3-ol (Erg2), ergosta-5,7,22,24(28)-tetraen-3ß-ol (Erg3), and ergosta-7,22-dien-3ß-ol (Erg4) as LXR agonists has been performed. Molecular docking studies have shown that these sterols possess higher binding affinities for LXRs as compared to the reference ligands (GW3965 and TO901317) and also formed critical activating interactions. Molecular dynamic (MD) simulations further confirmed that docking complexes made of these sterols possess significant stability. To assess the extent of LXR activation, ABCA1 promoter was cloned into luciferase reporter plasmid and transfected into HCT116 cells. It was observed that treatment with Erg, Erg2 and Erg4 led to a significant LXR activation with an EC50 of 5.64 µM, 4.83 and 3.03 µM respectively. Furthermore, a significant increase in mRNA expression of NR1H2 and LXR target genes i.e. ABCA1, ABCG1 and ApoE was observed upon Erg treatment. Flow cytometric analysis have revealed a significant increase in the accumulation of ABCA1 upon Erg treatment. Cytotoxicity studies conducted on colorectal cancer cell and normal epithelial cell line showed that these sterols are selectively toxic towards cancer cells. Taken together, our findings suggests that ergosterol activates LXRs, have significant anticancer activity and could be a likely candidate to manage aberrant cholesterol homeostasis.

Psathrosterols C-E, highly conjugated ergosterol derivatives from Psathyrella rogueiana with anti-inflammatory and immunosuppressive activity.

Three new ergosterols featuring with a highly conjugated ring system, psathrosterols C-E (1-3), have been isolated from the fungus Psathyrella rogueiana. The structures with the absolute configurations were elucidated by means of spectroscopic methods and single crystal X-ray diffraction. Compounds 1-3 exhibit inhibitory activity against NO production with IC50 values ranging from 8.4 to 21.8 µM. Compound 1 inhibits the LPS-induced proliferation of B lymphocyte cells with an IC50 value of 12.3 µM.

Ergosterols with rare peroxide, oxetane ring moiety, and a lactone ring from Aspergillus spectabilis and their immunosuppressive activities.

Ten ergostane-type steroids, including seven undescribed ones named spectasteroids A-G, were obtained from Aspergillus spectabilis. Their structures and absolute configurations were determined based on HRESIMS, NMR, ECD calculations, and single-crystal X-ray diffraction analyses. Structurally, spectasteroid A was a unique example of aromatic ergostane-type steroid that featured a rare peroxide ring moiety; spectasteroid B contained a rare oxetane ring system formed between C-9 and C-14; and spectasteroid C was an unusual 3,4-seco-ergostane steroid with an extra lactone ring between C-3 and C-9. Spectasteroids F and G specifically showed inhibitory effects against concanavalin A-induced T lymphocyte proliferation and lipopolysaccharide-induced B lymphocyte proliferation, with IC50 values ranging from 2.33 to 4.22 µM. Spectasteroid F also showed excellent antimultidrug resistance activity, which remarkable enhanced the inhibitory activity of PTX on the colony formation of SW620/Ad300 cells.

Minor ergosteroids and a 19-nor labdane-type diterpenoid with anti-inflammatory effects from Ganoderma lucidum.

A chemical investigation on the fruiting bodies of Ganoderma lucidum led to the isolation and identification of five undescribed ergosteroids including two des-D-steroids (3 and 4) and one rare 6/6/7/5-fused carbon skeletal ergosterol (5) along with one 19-nor labdane-type diterpenoid (6). Their structures including their absolute configurations, were assigned by spectroscopic methods, ECD calculations, and X-ray diffraction analysis. In addition, the anti-inflammatory activities of all the isolates were evaluated. The results indicated that compound 1 can significantly down-regulate the protein expression of iNOS and COX-2 at 20 µM in LPS- stimulated RAW264.7 cells.

Effects of Tripleurospermum caucasicum, Salvia rosmarinus and Tanacetum fruticulosum essential oils on aflatoxin B1 production and aflR gene expression in Aspergillus flavus.

Aflatoxin B1 (AFB1) is one of the most hazardous mycotoxins for humans and livestock that mainly produced by members of the genus Aspergillus in a variety of food commodities. In this study, the effect of S. rosmarinus, T. fruticulosum, and T. caucasicum essential oils (EOs) was studied on fungal growth, AFB1 production and aflR gene expression in toxigenic A. flavus IPI 247. The AFB1 producer A. flavus strain was cultured in YES medium in presence of various two-fold concentrations of the plant EOs (62.5-500 µg/mL) for 4 days at 28 °C. EO composition of plants was analyzed by Gas Chromatography/Mass Spectrometry (GC/MS). The amount of fungal growth, ergosterol content of fungal mycelia and AFB1 content of EO-treated and non-treated controls were measured. The expression of aflR gene was evaluated using Real-time PCR in the fungus exposed to minimum inhibitory concentration (MIC50) of EOs. The main constituents of the oils analyzed by GC/MS analysis were elemicin (33.80 %) and 2,3-dihydro farnesol (33.19 %) in T. caucasicum, 1,8-cineole (17.87 %), trans-caryophyllene (11.14 %), α and ẞ-pinene (10.92 and 8.83 %) in S. rosmarinus, and camphor (17.65 %), bornyl acetate (15.08 %), borneol (12.48 %) and camphene (11.72 %) in T. fruticulosum. The results showed that plant EOs at the concentration of 500 µg/mL suppressed significantly the fungal growth by 35.24-71.70 %, while mycelial ergosterol content and AFB1 production were inhibited meaningfully by 36.20-65.51 % and 20.61-89.16 %. T. caucasicum was the most effective plant, while T. fruticulosum showed the lowest effectiveness on fungal growth and AFB1 production. The expression of aflR in T. caucasicum and S. rosmarinus -treated fungus was significantly down-regulated by 2.85 and 2.12 folds, respectively, while it did not change in T. fruticulosum-treated A. flavus compared to non-treated controls. Our findings on the inhibitory activity of T. caucasicum and S. rosmarinus EOs toward A. flavus growth and AFB1 production could promise these plants as good candidates to control fungal contamination of agricultural crops and food commodities and subsequent contamination by AFB1. Down-regulation of aflR as the key regulatory gene in AF biosynthesis pathway warrants the use of these plants in AF control programs. Further studies to evaluate the inhibitory activity of studied plants EOs in food model systems are recommended.

The Zanthoxylum armatum fruit's oil exterminates Candida cells by inhibiting ergosterol biosynthesis without generating reactive oxygen species.

Candida spp. is a significant cause of topical and fungal infections in humans. In addition to Candida albicans, many non-albicans species such as C. krusei, C. glabrata, C. parapsilosis, C. tropicalis, C. guilliermondii cause severe infections. The main antifungal agents belong to three different classes, including azoles, polyenes, and echinocandins. However, resistance to all three categories of drugs has been reported. Therefore, there is an urgent need to search for other alternatives with antifungal activity. Many herbal extracts and compounds from natural sources show excellent antifungal activity. In this study, we used an oil extract from the fruits of Zanthoxylum armatum, which showed significant antifungal activity against various Candida spp. by two different methods-minimum inhibitory concentration (MIC) and agar diffusion. In addition, we attempted to explore the possible mechanism of action in C. albicans. It was found that the antifungal activity of Z. armatum oil is fungicidal and involves a decrease in the level of ergosterol in the cell membrane. The decrease in ergosterol level resulted in increased passive diffusion of a fluorescent molecule, rhodamine6G, across the plasma membrane, indicating increased membrane fluidity. The oil-treated cells showed decreased germ tube formation, an important indicator of C. albicans' virulence. The fungal cells also exhibited decreased attachment to the buccal epithelium, the first step toward invasion, biofilm formation, and damage to oral epithelial cells. Interestingly, unlike most antifungal agents, in which the generation of reactive oxygen species is responsible for killing, no significant effect was observed in the present study.

Efficacy and toxic action of the natural product natamycin against Sclerotinia sclerotiorum.

BACKGROUND: Sclerotinia stem rot caused by Sclerotinia sclerotiorum seriously endangers oilseed rape production worldwide, and the occurrence of fungicide-resistant mutants of S. sclerotiorum leads to control decline. Thus, it is critical to explore new green substitutes with different action mechanisms and high antifungal activity. Herein, the activity and the action mechanism of natamycin against S. sclerotiorum were evaluated. RESULTS: Natamycin showed potent inhibition on the mycelial growth of S. sclerotiorum, and half-maximal effective concentration (EC50 ) values against 103 S. sclerotiorum strains ranged from 0.53 to 4.04 µg/mL (mean 1.44 µg/mL). Natamycin also exhibited high efficacy against both carbendazim- and dimethachlone-resistant strains of S. sclerotiorum on detached oilseed rape leaves. No cross-resistance was detected between natamycin and carbendazim. Natamycin markedly disrupted hyphal form, sclerotia formation, integrity of the cell membrane, and reduced the content of oxalic acid and ergosterol, whereas it increased the reactive oxygen species (ROS) and malondialdehyde content. Interestingly, exogenous addition of ergosterol could reduce the inhibition of natamycin against S. sclerotiorum. Importantly, natamycin significantly inhibited expression of the Cyp51 gene, which is contrary to results for the triazole fungicide flusilazole, indicating a different action mechanism from triazole fungicides. CONCLUSION: Natamycin is a promising effective candidate for the resistance management of S. sclerotiorum. © 2023 Society of Chemical Industry.

Two highly conjugated ergosterols from the fungus Psathyrella rogueiana and their anti-inflammatory activity.

Two previously undescribed ergosterols containing a highly conjugated ring system, psathrosterols A and B (1 and 2), have been isolated from the fungus Psathyrella rogueiana. Their structures with absolute configurations were established by extensive spectroscopic methods, as well as single crystal X-ray diffraction. Compounds 1 and 2 showed inhibitory activity against NO production with IC50 values of 22.3 and 16.4 µM, respectively.

Comparative study on the anti-tumor effect of steroids derived from different organisms in H22 tumor-bearing mice and analysis of their mechanisms.

This study aimed to comparatively investigate the anti-tumor mechanisms of steroids including ergosterol, ß-sitosterol, cholesterol, and fucosterol. The model of H22 tumor-bearing mice was constructed based on histopathological data and biochemical parameters, while serums were subjected to metabolomics analysis to study the potential anti-tumor mechanisms. The results indicated that the four steroids exhibited different degrees of anti-tumor effects on H22 mice. The tumor inhibition rates were 63.25% for ergosterol, 56.41% for ß-sitosterol, 61.54% for cholesterol, and 72.65% for fucosterol. Metabolomic analyses revealed that 87, 71, and 129 differential metabolites were identified in ergosterol, cholesterol, and fucosterol treatment groups, respectively. The fucosterol treatment group had the highest number of differential metabolites. At the same time, it mainly inhibited purine and amino acid metabolism to exert anti-tumor effects. Ergosterol enhanced immunity and affected pyruvate metabolism, and cholesterol inhibited purine metabolism. The chemical structure difference among ergosterol, cholesterol, and fucosterol is mainly at the number and position of sterol double bonds and the number and length of side chain carbons. Therefore, there is a structure-activity relationship between the structure of steroid compounds and their efficacy. This study provides a key foundation for the exploitation of the anti-tumor effects of steroids derived from different organisms.

ROS mediated anticandidal efficacy of 3-Bromopyruvate prevents vulvovaginal candidiasis in mice model.

Candidal infections, particularly vulvovaginal candidiasis (VVC), necessitate effective therapeutic interventions in clinical settings owing to their intricate clinical nature and elusive understanding of their etiological mechanisms. Given the challenges in developing effective antifungal therapies, the strategy of repurposing existing pharmaceuticals has emerged as a promising approach to combat drug-resistant fungi. In this regard, the current study investigates molecular insights on the anti-candidal efficacy of a well-proven anticancer small molecule -3-bromopyruvate (3BP) against three clinically significant VVC causing Candida species viz., C. albicans, C. tropicalis and C. glabrata. Furthermore, the study validates 3BP's therapeutic application by developing it as a vaginal cream for the treatment of VVC. 3BP exhibited phenomenal antifungal efficacy (killing >99%) with minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) of 256 µg/mL against all tested Candida spp. Time killing kinetics experiment revealed 20 min as the minimum time required for 3BP at 2XMIC to achieve complete-killing (99.9%) in all Candida strains. Moreover, the ergosterol or sorbitol experiment explicated that the antifungal activity of 3BP does not stem from targeting the cell wall or the membrane component ergosterol. Instead, 3BP was observed to instigate a sequence of pre-apoptotic cascade events, such as phosphatidylserine (PS) externalization, nuclear condensation and ROS accumulations, as evidenced by PI, DAPI and DCFH-DA staining methods. Furthermore, 3BP demonstrated a remarkable efficacy in eradicating mature biofilms of Candida spp., achieving a maximum eradication level of 90%. Toxicity/safety profiling in both in vitro erythrocyte lysis and in vivo Galleria mellonella survival assay authenticated the non-toxic nature of 3BP up to 512 µg/mL. Finally, a vaginal cream formulated with 3BP was found to be effective in VVC-induced female mice model, as it significantly decreasing fungal load and protecting vaginal mucosa. Concomitantly, the present study serves as a clear demonstration of antifungal mechanistic action of anticancer drug -3BP, against Candida species. This finding holds significant potential for mitigating candidal infections, particularly VVC, within healthcare environments.

Diterpenes and triterpenes show potential as biocides against pathogenic fungi and oomycetes: a screening study.

OBJECTIVES: The aim was to screen di- and triterpenes as potential biocides against fungal pathogens (Alternaria sp., Fusarium avenaceum, F. sambucinum, Botrytis cinerea, Botryotina fuckeliana, Mycocentrospora acerina, Cylindrocarpon sp.) and oomycetes (Phytophthora cactorum, P. fragariae). Results We measured the antifungal activity of terpenes by estimating the growth area, ergosterol content and level of lipid peroxidation. Fungi and oomycetes were grown on solid media in Petri dishes. As a positive control, we used a common synthetic fungicide, fosetyl-Al. Di- and triterpenes showed promising potential as biocides against most of the studied species. The responses of fungi and oomycetes were dependent on the specific type of terpenes and identity of the fungi. Compared to synthetic fungicide, terpenes were equally effective as antifungal agents and even more effective for some species, especially for oomycetes. The terpene mode of action includes inhibition of ergosterol synthesis and increased lipid peroxidation. Conclusions Di- and triterpenes, natural compounds that are very abundant in northern countries, are excellent candidates for biocides.

Antiparasitic effect of Farnesol against Leishmania major: A rationale from in vitro and in silico investigations.

Leishmaniasis is a vector-borne parasitic infection caused by the infective bite of female Phlebotomine sandflies. Treatment of leishmaniasis by conventional synthetic compounds is met by challenges pertaining to adverse effects which call for the discovery of newer anti-leishmanial molecules. This study was performed to evaluate the effect and modes of action of a sesquiterpene alcoholic molecule Farnesol on Leishmania major, the causative agent of Zoonotic CL. The cytotoxic effect of Farnesol against L.major promastigotes, amastigotes and macrophages was assessed by MTT test and counting. The IC50 on promastigotes by Farnesol on L.major was also evaluated by flow cytometry. In the findings, promastigotes were reduced at 167µM. The mean numbers of L.major amastigotes in macrophages were significantly decreased on exposure to Farnesol at 172µM. In addition, Farnesol induced significant apoptosis dose-dependent on L.major promastigotes. In silico protein-ligand_binding analyses indicated the effect of Farnesol in perturbation of the ergosterol synthesis pathway of Leishmania with attributes suggesting inhibition of Lanosterol-α-demethylase, the terminal enzyme of ergosterol synthesis machinery. Findings from flow cytometry reveal the role of Farnesol in apoptosis-induced killing in promastigotes. Farnesol was effective at very lower concentrations when compared to Paromomycin. Further studies are crucial to evaluate the therapeutic potential of Farnesol alone or in combination with other conventional drugs in animal models.

Effects of Long-Term High-Ergosterol Intake on the Cholesterol and Vitamin D Biosynthetic Pathways of Rats Fed a High-Fat and High-Sucrose Diet.

Dyslipidemia is a lifestyle-related (physical inactivity or obesity) disease; therefore, dietary foods that can easily be consumed in daily life is important to prevent dyslipidemia. Ergosterol, a precursor of vitamin D2, is a fungal sterol present in the membranes of edible mushrooms and other fungi. Ergosterol is converted to brassicasterol by 7-dehydrocholesterol reductase (DHCR7), a cholesterol biosynthesis enzyme that converts 7-dehydrocholesterol (a precursor of vitamin D3) into cholesterol. Previously, we reported that ergosterol increases 7-dehydrocholesterol, decreases cholesterol levels by competitive effect of DHCR7, and reduces DHCR7 mRNA and protein levels in human HepG2 hepatoma cells. Here, we investigated the effects of long-term high ergosterol intake on the cholesterol, vitamin D2, and D3 biosynthetic pathways of rats fed a high-fat and high-sucrose (HFHS) diet using GC-MS and LC with tandem mass spectrometry. In HFHS rats, oral ergosterol administration for 14 weeks significantly decreased plasma low-density lipoprotein cholesterol, total bile acid, and cholesterol precursor (squalene and desmosterol) levels and increased 7-dehydrocholesterol levels compared to HFHS rats without ergosterol. Ergosterol, brassicasterol, and vitamin D2 were detected, cholesterol levels were slightly decreased, and levels of vitamin D3 and its metabolites were slightly increased in rats fed HFHS with ergosterol. These results showed that ergosterol increased vitamin D2 levels, inhibited the cholesterol biosynthetic pathway, and possibly promoted vitamin D3 biosynthesis in vivo. Therefore, daily ergosterol intake may aid in the prevention of dyslipidemia.

Quadristerols A-G: Seven undescribed ergosterols from Aspergillus quadrilineata.

Quadristerols A-G, seven undescribed ergosterols, were obtained from Aspergillus quadrilineata. Their structures and absolute configurations were determined based on HRESIMS, NMR, quantum-chemical calculations, and single-crystal X-ray diffraction analyses. Quadristerols A-G featured ergosterol skeletons with different attachments; quadristerols A-C were three diastereoisomers possessing a 2-hydroxy-propionyloxy group at C-6, and quadristerols D-G were two pairs of epimers with a 2,3-butanediol group at C-6. All of these compounds were evaluated for their immunosuppressive activities in vitro. Quadristerols B and C showed excellent inhibitory effects against concanavalin A-induced T lymphocyte proliferation with IC50 values of 7.43 and 3.95 µM, respectively, and quadristerols D and E strongly inhibited lipopolysaccharide-induced B lymphocyte proliferation with IC50 values of 10.96 and 7.47 µM, respectively.

Fingerprint Stimulated Raman Scattering Imaging Unveils Ergosteryl Ester as a Metabolic Signature of Azole-Resistant Candida albicans.

Candida albicans (C. albicans), a major fungal pathogen, causes life-threatening infections in immunocompromised individuals. Fluconazole (FLC) is recommended as first-line therapy for treatment of invasive fungal infections. However, the widespread use of FLC has resulted in increased antifungal resistance among different strains of Candida, especially C. albicans, which is a leading source of hospital-acquired infections. Here, by hyperspectral stimulated Raman scattering imaging of single fungal cells in the fingerprint window and pixel-wise spectral unmixing, we report aberrant ergosteryl ester accumulation in azole-resistant C. albicans compared to azole-susceptible species. This accumulation was a consequence of de novo lipogenesis. Lipid profiling by mass spectroscopy identified ergosterol oleate to be the major species stored in azole-resistant C. albicans. Blocking ergosterol esterification by oleate and suppressing sterol synthesis by FLC synergistically suppressed the viability of C. albicans in vitro and limited the growth of biofilm on mouse skin in vivo. Our findings highlight a metabolic marker and a new therapeutic strategy for targeting azole-resistant C. albicans by interrupting the esterified ergosterol biosynthetic pathway.