Antifungal drug resistance in Candida: a special emphasis on amphotericin B

Invasive fungal infections in humans caused by several Candida species, increased considerably in immunocompromised or critically ill patients, resulting in substantial morbidity and mortality. Candida albicans is the most prevalent species, although the frequency of these organisms varies greatly according to geographic region. Infections with C. albicans and non-albicans Candida species have become more common, especially in the past 20 years, as a result of aging, immunosuppressive medication use, endocrine disorders, malnourishment, extended use of medical equipment, and an increase in immunogenic diseases. Despite C. albicans being the species most frequently associated with human infections, C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei also have been identified. Several antifungal drugs with different modes of action are approved for use in clinical settings to treat fungal infections. However, due to the common eukaryotic structure of humans and fungi, only a limited number of antifungal drugs are available for therapeutic use. Furthermore, drug resistance in Candida species has emerged as a result of the growing use of currently available antifungal drugs against fungal infections. Amphotericin B (AmB), a polyene class of antifungal drugs, is mainly used for the treatment of serious systemic fungal infections. AmB interacts with fungal plasma membrane ergosterol, triggering cellular ion leakage via pore formation, or extracting the ergosterol from the plasma membrane inducing cellular death. AmB resistance is primarily caused by changes in the content or structure of ergosterol. This review summarizes the antifungal drug resistance exhibited by Candida species, with a special focus on AmB.

Brain glucose induces tolerance of Cryptococcus neoformans to amphotericin B during meningitis

Antibiotic tolerance is the ability of a susceptible population to survive high doses of cidal drugs and has been shown to compromise therapeutic outcomes in bacterial infections. In comparison, whether fungicide tolerance can be induced by host-derived factors during fungal diseases remains largely unknown. Here, through a systematic evaluation of metabolite-drug-fungal interactions in the leading fungal meningitis pathogen, Cryptococcus neoformans, we found that brain glucose induces fungal tolerance to amphotericin B (AmB) in mouse brain tissue and patient cerebrospinal fluid via the fungal glucose repression activator Mig1. Mig1-mediated tolerance limits treatment efficacy for cryptococcal meningitis in mice via inhibiting the synthesis of ergosterol, the target of AmB, and promoting the production of inositolphosphorylceramide, which competes with AmB for ergosterol. Furthermore, AmB combined with an inhibitor of fungal-specific inositolphosphorylceramide synthase, aureobasidin A, shows better efficacy against cryptococcal meningitis in mice than do clinically recommended therapies.

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, β-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 β-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.

Retinoic acid shows direct parasiticidal activity by targeting ergosterol pathway in Leishmania donovani: a potential therapeutic advancement

Visceral leishmaniasis (VL) is an infectious disease caused by Leishmania donovani parasite in Indian subcontinent and is life-threatening. It primarily inflicts the malnourished population. There is little therapeutic advancement in the last one decade or more, as the available drugs show adverse effects, complex long treatment, high cost and drug resistance. Here, in a concerted approach, we intended to address the malnutrition as well as the parasite load with a single modality. Our earlier findings show the protective effects of retinoic acid (RA) in controlling the parasite load in infected macrophages (mφ) and restores their M1 phenotype. RA also restores the levels of cellular cholesterol in infected mφ. In this process, we observed loss of ergosterol in the parasite upon treatment with RA. Hence, we hypothesized that RA, besides boosting the parasiticidal mechanism in mφ, may also target the sterol pathway in the parasite by targeting sterol 24-C methyltransferase (SMT). SMT plays an essential role in the formation of ergosterol, required for growth and viability in Leishmania species. Therefore, we predicted as well as validated the 3D structure of SMT protein and performed the quality check. RA showed -9.9 free binding energy towards SMT which is higher than any of its derivatives. The molecular dynamics showed stable conjugate and the in vitro testing showed a reduction by ∼ twofold in the parasite number upon RA treatment. Importantly, it showed a loss of ergosterol possibly due to the inhibition of SMT protein. Our finding showed direct parasiticidal function of RA which is of significance in terms of therapeutic advancement.Communicated by Ramaswamy H. Sarma.

Alterations in the Level of Ergosterol in Candida albicans' Plasma Membrane Correspond with Changes in Virulence and Result in Triggering Diversed Inflammatory Response

Opportunistic pathogen Candida albicans possesses multiple virulence factors which enable colonization and infection of host tissues. Candida-related infections frequently occur in immunocompromised patients, which is related to an insufficient inflammatory response. Furthermore, immunosuppression and multidrug resistance of C. albicans clinical isolates make the treatment of candidiasis a challenge for modern medicine. The most common resistance mechanism of C. albicans to antifungals includes point mutations in the ERG11 gene, which encodes target protein for azoles. We investigated whether the mutations or deletion of the ERG11 gene influence the pathogen-host interactions. We prove that both C. albicans erg11∆/∆ and ERG11K143R/K143R exhibit increased cell surface hydrophobicity. Additionally, C. albicans KS058 has an impaired ability of biofilm and hyphae formation. Analysis of the inflammatory response of human dermal fibroblasts and vaginal epithelial cell lines revealed that altered morphology of C. albicans erg11∆/∆ results in a significantly weaker immune response. C. albicans ERG11K143R/K143R triggered stronger production of pro-inflammatory response. Analysis of genes encoding adhesins confirmed differences in the expression pattern of key adhesins for both erg11∆/∆ and ERG11K143R/K143R strains. Obtained data indicate that alterations in Erg11p consequence in resistance to azoles and affect the key virulence factors and inflammatory response of host cells.

A Novel Study of Correlation of Lipid Parameters with Clinical Profile, Staging and Onset of Rhino Orbito Cerebral Mucormycosis Covid 19 Pandemic

Mucormycosis is an angioinvasive disease caused by mold fungi of the genus Rhizopus, Mucor. India has reported surge in cases of COVID 19 associated Mucormycosis over the past few months due to the increasing frequency of risk factors like corticosteroid therapy, uncontrolled diabetes, neutropenia and obesity. Studies have shown that eukaryote cell membrane contains cholesterol and fungal cell wall contains ergosterol with lanosterol being precursor for both and ergosterol is essential for mitochondrial DNA maintenance in fungi, as cholesterol is in humans. The current study is based on the hypothesis that fungi can use human cholesterol as a raw material to maintain its cell function and accentuate its own multiplication and this can indirectly be shown by the association between deranged lipid parameters in an individual with severity of Mucormycosis. Thus present study aims to estimate the lipid parameters and correlate the serum lipid parameters with clinical profile, stage of the disease and duration of onset of mucormycosis in patients with COVID associated Mucormycosis.

MATERIAL

This is a cross sectional study conducted on 103 patients diagnosed with COVID 19 associated mucormycosis admitted to the hospitals attached to BMCRI from July 2021 to September 2021. Serum fasting lipid profile and other biochemical parameters were determined. The correlation of lipid levels with clinical profile, onset and staging of mucormycosis patients were obtained.

OBSERVATION

The age distribution varied from 22yrs to 75yrs of whom majority were males (83.4%). Among patients with mucormycosis of all severity stages, nasal block (79.6%) was found to be most common symptom followed by headache(75.7%). Among patients with mucormycosis most frequent associated comorbidity was Diabetes mellitus (DM) followed by hypertension (HTN) followed by DM and HTN followed by Ischemic Heart Disease (IHD) followed by DM,HTN and IHD. The study showed statistically significant correlation such that severity of mucormycosis increased with progressive worsening lipid parameters. It also showed statistically significant correlation such that patients with increasing TC,LDL,VLDL,TG levels had shorter COVID 19 onset to mucormycosis onset duration.

CONCLUSION

The study showed a positive correlation between serum lipid profile and staging of mucormycosis and negative correlation between lipid levels with duration between onset of COVID 19 to onset of mucormycosis. Hence serum lipid profile can be used as an excellent marker to predict the severity and prognosis of COVID 19 associated mucormycosis.

Separation and identification of tubocapsanolide MAP and tubocapsunolide A, and the structure-activity relationship of their anti-TNBC activity

A new withanolide, tubocaapsanolide MAP (MeOH addition product) (1), as well as its known precursor tubocaapsanolide A (2) were obtained from Tubocapsicum anomalum (Solanaceae). Compound 1 was a MeOH addition product transformed from compound 2 during the process of separation using MeOH as solvent. The structures of the two withanolides including absolute configuration were elucidated by extensive spectroscopic analysis and X-ray single crystal diffraction. In the test of anti-triple negative breast cancer (TNBC) effects, tubocapsusanlide A (2) showed potent inhibitory activity against four human TNBC cell lines, while tubocapsusanlide MAP (1) exhited significantly weaker inhibitory than that of tubocapsusanlide A (2), indicating that α-β unsaturated carbonyl unit contained in 2 was closely related to its anti-TNBC activity. The potent bioactivity displayed significant developing potential of withanolides as anti-TNBC lead compounds or drug candidates. And this report may provide some useful guidances for the preparation and bioactivity research of withanolides.

Ergosterol Peroxide from the Medicinal Mushroom Ganoderma lucidum Inhibits Differentiation and Lipid Accumulation of 3T3-L1 Adipocytes

Ergosterol peroxide is a natural compound of the steroid family found in many fungi, and it possesses antioxidant, anti-inflammatory, anticancer and antiviral activities. The anti-obesity activity of several edible and medicinal mushrooms has been reported, but the effect of mushroom-derived ergosterol peroxide on obesity has not been studied. Therefore, we analyzed the effect of ergosterol peroxide on the inhibition of triglyceride synthesis at protein and mRNA levels and differentiation of 3T3-L1 adipocytes. Ergosterol peroxide inhibited lipid droplet synthesis of differentiated 3T3-L1 cells, expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAT/enhancer-binding protein alpha (C/EBPα), the major transcription factors of differentiation, and also the expression of sterol regulatory element-binding protein-1c (SREBP-1c), which promotes the activity of PPARγ, resulting in inhibition of differentiation. It further inhibited the expression of fatty acid synthase (FAS), fatty acid translocase (FAT), and acetyl-coenzyme A carboxylase (ACC), which are lipogenic factors. In addition, it inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs) involved in cell proliferation and activation of early differentiation transcription factors in the mitotic clonal expansion (MCE) stage. As a result, ergosterol peroxide significantly inhibited the synthesis of triglycerides and differentiation of 3T3-L1 cells, and is, therefore, a possibile prophylactic and therapeutic agent for obesity and related metabolic diseases.

Ergosteryl 2-naphthoate, An Ergosterol Derivative, Exhibits Antidepressant Effects Mediated by the Modification of GABAergic and Glutamatergic Systems

Phytosterols are a kind of natural component including sitosterol, campesterol, avenasterol, ergosterol (Er) and others. Their main natural sources are vegetable oils and their processed products, followed by grains, by-products of cereals and nuts, and small amounts of fruits, vegetables and mushrooms. In this study, three new Er monoester derivatives were obtained from the reflux reaction with Er: organic acids (furoic acid, salicylic acid and 2-naphthoic acid), 1-Ethylethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride (EDCI) and 4-dimethylaminopyridine (DMAP) in dichloromethane. Their chemical structures were defined by IR and NMR. The present study was also undertaken to investigate the antidepressant-like effects of Er and its derivatives in male adult mice models of depression, and their probable involvement of GABAergic and glutamatergic systems by the forced swim test (FST). The results indicated that Er and its derivatives display antidepressant effects. Moreover, one derivative of Er, ergosteryl 2-naphthoate (ErN), exhibited stronger antidepressant activity in vivo compared to Er. Acute administration of ErN (5 mg/kg, i.p.) and a combination of ErN (0.5 mg/kg, i.p.), reboxetine (2.5 mg/kg, i.p.), and tianeptine (15 mg/kg, i.p.) reduced the immobility time in the FST. Pretreatment with bicuculline (a competitive γ-aminobutyric acid (GABA) antagonist, 4 mg/kg, i.p.) and N-methyl-d-aspartic acid (NMDA, an agonist at the glutamate site, 75 mg/kg, i.p.) effectively reversed the antidepressant-like effect of ErN (5 mg/kg, i.p.). However, prazosin (a α1-adrenoceptor antagonist, 1 mg/kg, i.p.) and haloperidol (a non-selective D2 receptor antagonist, 0.2 mg/kg, i.p.) did not eliminate the reduced immobility time. Altogether, these results indicated that ErN produced antidepressant-like activity, which might be mediated by GABAergic and glutamatergic systems.

Cytotoxic effects of ergone, a compound isolated from Fulviformes fastuosus

BACKGROUND

Mushrooms inspired the cuisines of many cultures and conventional medicaments for cancer. However, a substantial number of mushroom species are yet unexplored, possessing an unknown chemical, biological and pharmacological profiles. Fulviformes fastuosus is a terrestrial mushroom, which is commonly found in Sri Lankan woodlands. The current study was aimed at isolation and characterization of a potent cytotoxic compound from F. fastuosus and investigating the apoptotic effect induced by the active principle against cancer and normal cell lines.

METHODS

Bioactivity guided isolation of active principles from the methanol extract of F. fastuosus was performed by a rapid extraction and isolation method using different chromatographic techniques. Potential cytotoxic compound was identified using one and two dimensional nuclear magnetic resonance spectroscopy and mass spectrometry. Isolated compound was screened for in vitro cytotoxicity against Hepatocellular carcinoma (HepG-2), Muscle rhabdomyosarcoma (RD) and Rat Wistar liver normal (CC-1) cell lines using 3 4, 5-(dimethylthiazol-2-yl) 2-5-diphenyl tetrazolium bromide (MTT) cell viability assay. Apoptotic features of cells were observed via microscopic examination and ethidium bromide/acridine orange fluorescent staining.

RESULTS

The interpretation of spectral data resulted in the identification of the chemical structure as ergosta-4,6,8 (14),22-tetraen-3-one (ergone). Ergone exhibited promising cytotoxic properties against RD cells with less cytotoxicity effect on CC-1 cells. In addition, ergone also possesses a strong cytotoxic effect against HepG-2 cells showing low toxic level for CC-1 cells. Apoptotic features of treated cells were detected via morphological characterization and ethidium bromide/acridine orange staining.

CONCLUSION

The present study elaborates the isolation of a potent cytotoxic compound; ergone, from F. fastuosus via a rapid and efficient isolation method. Importantly, ergone has exhibited greater cytotoxic activity against RD cells with high selectivity index compared to cytotoxicity against HepG-2 cells. Ergone can be used in the development of therapeutic strategies for curbing rhabdomyosarcoma.

Anti-inflammatory effects of Antrodia camphorata, a herbal medicine, in a mouse skin ischemia model

ETHNOPHARMACOLOGICAL EVIDENCE

Antrodia camphorata, a highly valued polypore mushroom native only to Taiwan, has been traditionally used as a medicine for anti-inflammation.

AIM OF THE STUDY

In this study, anti-inflammatory effects of Antrodia camphorata (AC) and its active compound, ergostatrien-3β-ol (ST1), were investigated in a mouse skin ischemia model induced by skin flap surgery on the dorsal skin.

MATERIALS AND METHODS

A U-shaped flap was elevated on the dorsal skin of the nine-week-old male mice. Mice were randomly assigned to six groups for treatment (n=6) including normal skin/propylene glycol (PG), surgical skin flap/PG, solid-state-cultured AC (S/AC), wood-cultured AC (W/AC), high-dose ST1 (H-ST1), low-dose ST1 (L-ST1). Antrodia camphorata was dissolved in 25μL PG and smeared on the skin flap every six hours for 24h. At the end of the experiment, each mouse was anesthetized, and skin tissues were collected from their back for histopathological analysis, extracting RNA and protein according to our previous reports.

RESULTS

Skin-flap-induced ischemia damage significantly increased the expression of the iNOS, COX2, and IL-6 proteins and decreased the expression of IκB protein. In addition, focal, moderate coagulative necrosis with inflammatory cell infiltration was found in the epidermis, and moderate inflammatory cells and necrosis with slight edema was noted in the sub-dermis at 24h after skin flap surgery. However, treatment with solid-state-cultured or wood-cultured AC, or with its derived ST1 active compound, significantly reduced the necrosis and inflammatory cell infiltration in both the epidermis and sub-dermis of the skin flap. The treatments also reduced the inflammatory response by decreasing the expression of inflammation-related genes including iNOS, IL-6, TNF-α, and NF-κB, as shown by changes in RNA and protein expression, when compared with the surgical skin flap procedure alone.

CONCLUSIONS

These results demonstrated that methanolic extracts of wood-cultured fruiting bodies and solid-state-cultured mycelia from Antrodia camphorata have excellent anti-inflammatory activities and thus have great potential as an addition for hydrocolloid dressings.

The anti-promyelocytic leukemia mode of action of two endophytic secondary metabolites unveiled by a proteomic approach

As a result of a program to find antitumor compounds of endophytes from medicinal Asteraceae, the steroid (22E,24R)-8,14-epoxyergosta-4,22-diene-3,6-dione (a) and the diterpene aphidicolin (b) were isolated from the filamentous fungi Papulaspora immersa and Nigrospora sphaerica, respectively, and exhibited strong cytotoxicity against HL-60 cells. A proteomic approach was used in an attempt to identify the drugs' molecular targets and their respective antiproliferative mode of action. Results suggested that the (a) growth inhibition effect occurs by G2/M cell cycle arrest via reduction of tubulin alpha and beta isomers and 14-3-3 protein gamma expression, followed by a decrease of apoptotic and inflammatory proteins, culminating in mitochondrial oxidative damage that triggered autophagy-associated cell death. Moreover, the decrease observed in the expression levels of several types of histones indicated that (a) might be disarming oncogenic pathways via direct modulation of the epigenetic machinery. Effects on cell cycle progression and induction of apoptosis caused by (b) were confirmed. In addition, protein expression profiles also revealed that aphidicolin is able to influence microtubule dynamics, modulate proteasome activator complex expression, and control the inflammatory cascade through overexpression of thymosin beta 4, RhoGDI2, and 14-3-3 proteins. Transmission electron micrographs of (b)-treated cells unveiled dose-dependent morphological characteristics of autophagy- or oncosis-like cell death.

Ergosterol peroxide from Cordyceps cicadae ameliorates TGF-β1-induced activation of kidney fibroblasts

Chronic kidney disease is a growing public health problem with an urgent need for new pharmacological agents. Ergosterol peroxide (EP) is the major sterol produced by Cordyceps cicadae Shing (C. cicadae), a widely used traditional Chinese medicine. C. cicadae has been used to treat many kinds of diseases and has a potential benefit on renoprotection. This study aimed to investigate the anti-fibrotic effects of EP as well as the underlying mechanisms. A normal rat kidney fibroblast cell line (NRK-49F) was stimulated to undergo fibroblast activation by transforming growth factor-β1 (TGF-β1) and EP treatment was applied to explore its potential anti-fibrotic effects. Cell proliferation was investigated using MTT analysis. Fibrosis-associated protein expression was analyzed using immunohistochemistry and/or Western blotting. EP treatment attenuated TGF-β1-induced renal fibroblast proliferation, expression of cytoskeleton protein and CTGF, as well as ECM production. Additionally, EP blocked TGF-β1-stimulated phosphorylation of ERK1/2, p38 and JNK pathway. Moreover, the TGF-β1-induced expression of fibronectin was attenuated by either inhibition of MAPKs or by EP treatment. In conclusion, our findings demonstrate that EP is able to suppress TGF-β1-induced fibroblasts activation in NRK-49F. This new information provides a line of theoretical evidence supporting the use of C. cicadae in the intervention of kidney disease and suggests that EP has the potential to be developed as a therapeutic agent to prevent renal fibrosis.

Structure-activity relationship (SAR) of withanolides to inhibit Hsp90 for its activity in pancreatic cancer cells

Withaferin A (WA), a naturally occurring steroidal lactone, directly binds to Hsp90 and leads to the degradation of Hsp90 client protein. The purpose of this study is to investigate the structure activity relationship (SAR) of withanolides for their inhibition of Hsp90 and anti-proliferative activities in pancreatic cancer cells. In pancreatic cancer Panc-1 cells, withaferin A (WA) and its four analogues withanolide E (WE), 4-hydroxywithanolide E (HWE), 3-aziridinylwithaferin A (AzWA) inhibited cell proliferation with IC50 ranged from 1.0 to 2.8 μM. WA, WE, HWE, and AzWA also induced caspase-3 activity by 21-, 6-, 11- and 15-fold, respectively, in Panc-1 cells, while withaperuvin (WP) did not show any activity. Our data showed that WA, WE, HWE, and AzWA, but not WP, all directly bound to Hsp90 and induced Hsp90 aggregation,hence inhibited Hsp90 chaperone activity to induce degradation of Hsp90 client proteins Akt and Cdk4 through proteasome-dependent pathway in pancreatic cancer cells. However, only WA, HWE and AzWA disrupted Hsp90-Cdc37 complexes but not WE and WP. SAR study suggested that the C-5(6)-epoxy functional group contributes considerably for withanolide to bind to Hsp90, inhibit Hsp90 chaperone activity, and result in Hsp90 client protein depletion. Meanwhile, the hydroxyl group at C-4 of ring A may enhance withanolide to inhibit Hsp90 activity and disrupt Hsp90-Cdc37 interaction. These SAR data provide possible mechanisms of anti-proliferative action of withanolides.

A novel steroid from Elephantopus scaber L. an ethnomedicinal plant with antidiabetic activity

Acetone extract of Elephantopus scaber, an ethnomedicnal plant, reduced the blood glucose levels in streptozotocin-induced diabetic rats significantly. Acute toxicity studies revealed the non-toxic nature of the crude extract. Fractionation of the acetone extract yielded a new steroid, 28Nor-22(R)Witha 2,6,23-trienolide. Biological testing of the compound demonstrated a significant antidiabetic activity by reducing the elevated blood glucose levels and restoring the insulin levels in streptozotocin-induced diabetic rats. This compound can be a useful candidate to treat diabetes.

Protective effect of Withaferin-A on tumour formation in 7,12-dimethylbenz[a]anthracene induced oral carcinogenesis in hamsters

With an aim to investigate the protective effect of Withaferin-A on 7,12-dimethylbenz[a]anthracene (DMBA) induced oral carcinogenesis in Syrian golden hamsters, tumour incidence, tumour volume and tumour burden and status of detoxication agents, lipid peroxidation and antioxidants in DMBA administered (3 times/week for 14 weeks) hamsters were assessed. Hundred percent tumour formation in DMBA alone administered animal was observed. Oral administration of Withaferin-A (20 mg/kg body weight) to DMBA administered animals for 14 weeks completely prevented the tumour incidence, tumour volume and tumour burden. Also, Withaferin-A showed significant anti-lipid peroxidative and antioxidant properties and maintained the status of phase-I and phase-II detoxication agents during DMBA-induced oral carcinogenesis. The results thus indicate that the protective effect of Withaferin-A is probably due to its anti-lipid peroxidative and antioxidant functions as well as modulating effect on carcinogen detoxication during DMBA-induced oral carcinogenesis.

The tumor inhibitor and antiangiogenic agent withaferin A targets the intermediate filament protein vimentin

The natural product withaferin A (WFA) exhibits antitumor and antiangiogenesis activity in vivo, which results from this drug's potent growth inhibitory activities. Here, we show that WFA binds to the intermediate filament (IF) protein, vimentin, by covalently modifying its cysteine residue, which is present in the highly conserved alpha-helical coiled coil 2B domain. WFA induces vimentin filaments to aggregate in vitro, an activity manifested in vivo as punctate cytoplasmic aggregates that colocalize vimentin and F-actin. WFA's potent dominant-negative effect on F-actin requires vimentin expression and induces apoptosis. Finally, we show that WFA-induced inhibition of capillary growth in a mouse model of corneal neovascularization is compromised in vimentin-deficient mice. These findings identify WFA as a chemical genetic probe of IF functions, and illuminate a potential molecular target for withanolide-based therapeutics for treating angioproliferative and malignant diseases.

Anti-inflammatory ergostanes from the basidiomata of Antrodia salmonea

Three new anti-oxidative ergostanes, methyl antcinate L (1), antcin M (2), and methyl antcinate K (3), together with nine additional known compounds, 3-ketodehydrosulphurenic acid, sulphurenic acid, dehydrosulphurenic acid, 3beta,15alpha-dihydroxylanosta-7,9(11),24-trien-21-oic acid, zhankuic acid A, zhankuic acid B, zhankuic acid C, antcin C, and antcin K were isolated from the basidiomata of Antrodia salmonea, a newly identified species of Antrodia (Polyporaceae) in Taiwan. These three new compounds were identified as methyl 3alpha,7alpha,12alpha-trihydroxy-4alpha-methylergosta-8,24(29)-dien-11-on-26-oate (1), 3alpha,12alpha-dihydroxy-4alpha-methylergosta-8,24(29)-dien-11-on-26-oic acid (2), and methyl 3alpha,4beta,7beta-trihydroxy-4alpha-methylergosta-8,24(29)-dien-11-on-26-oate (3) by spectroscopic analysis. We studied their antioxidative potential on the production of reactive oxygen species and nitric oxide (NO) in neutrophils and microglial cells, respectively. Compounds 1-3 displayed potent antioxidative activity with IC50 values of around 2.0-8.8 microM that was partially due to inhibition (6-67%) of NADPH oxidase activity but not through direct radical-scavenging properties. Compounds 1-3 also inhibited NO production with IC50 values of around 1.7-16.5 microM and were more potent than a non-specific NOS inhibitor. We conclude that these three new compounds 1, 2, and 3 exhibit anti-inflammatory activities in activated inflammatory cells.

Antibacterial activity of ergosterol peroxide against Mycobacterium tuberculosis: dependence upon system and medium employed

Ergosterol peroxide, cycloart-23-en-3beta,25-diol, vanillin and 4-hydroxybenzaldehyde have been isolated and characterized from a crude methanol extract of Euphorbia lagascae. Previous studies have shown contradictory results about the antibacterial activity of ergosterol peroxide against Mycobacterium tuberculosis. In order to clarify this question, the activity of this compound was tested against Mycobacterium tuberculosis H37Rv ATCC 27294 strain using two different systems: BACTEC 460TB (Bactec 460) and BACTEC MGIT 960 system (Bactec 960). The results obtained show that significant activity was demonstrable only with the Bactec 460 system. The lack of activity noted with the Bactec 960 system appears to be due to the much faster growth rate of the organism in the medium of this system as opposed to that of the Bactec 460 system. Ergosterol peroxide is also shown by the current study to be devoid of any activity against an antibiotic sensitive ATCC strain of Staphylococcus aureus.

Withanoside IV improves hindlimb function by facilitating axonal growth and increase in peripheral nervous system myelin level after spinal cord injury

Although methylprednisolone is the clinically standard medication and almost the only therapy for spinal cord injury (SCI), its effect on functional recovery remains questionable. Transplantation strategies using sources such as neural stem cells and embryonic spinal cord still have some hurdles to overcome before practical applications become available. We therefore aimed to develop a practical medication for SCI. Per oral treatment with withanoside IV, which was previously shown to regenerate neuronal networks in the brain, improved locomotor functions in mice with SCI. In the spinal cord after SCI, axons were crushed in the white matter and gray matter, and central nervous system (CNS) myelin level decreased. In mice treated with withanoside IV (10micromol/kg body weight/day, for 21 days), axonal density and peripheral nervous system (PNS) myelin level increased. The loss of CNS myelin and increase in reactive gliosis were not affected by withanoside IV. These results suggest that oral administration of withanoside IV may ameliorate locomotor functions by facilitating both axonal regrowth and increase in PNS myelin level.

Ixocarpalactone A isolated from the Mexican tomatillo shows potent antiproliferative and apoptotic activity in colon cancer cells

Physalis philadelphica Lam, commonly known as a tomatillo, is a staple of the Mesoamerican cuisine. In our laboratory, an ethyl acetate-soluble extract and four withanolides [ixocarpalactone A (IxoA), ixocarpalactone B, philadelphicalactone B, and withaphysacarpin] were isolated. Studies conducted on Hepa-1c1c7 hepatoma cells revealed that withanolides were potent inducers of quinone reductase, suggesting possible cancer chemoprotective activity. Here we evaluated the antiproliferative properties of the withanolides in SW480 human colon cancer cells. IxoA, which is present in the edible part of the tomatillo, was selected for further evaluation. SW480 cells treated with IxoA showed cell cycle arrest in the G2/M phase, up-regulation of hyper-phosphorylated retinoblastoma, and down-regulation of E2F-1 and DP-1. On the basis of flow cytometry analysis, ethidium bromide/acridine orange, and 4',6-diamidino-2-phenylindole staining, it was found that IxoA induces apoptosis in SW480 cells. Moreover, increased concentrations of the pro-apoptotic protein, BIM/BOD, were found by western blot analysis and immunocytochemistry. Morphological examination revealed vacuole formation in cells treated with IxoA, and Oil Red O staining showed that the vacuole content was nonlipid. Furthermore, immunocytochemistry demonstrated increased concentrations of mucin 3 in IxoA-treated SW480 cells. These findings suggest that chemicals present in tomatillos (e.g. IxoA) may have cancer chemopreventive properties.

The tumor proteasome is a primary target for the natural anticancer compound Withaferin A isolated from "Indian winter cherry"

Withaferin A (WA) is a steroidal lactone purified from medicinal plant "Indian Winter Cherry" that is widely researched for its variety of properties, including antitumor effects. However, the primary molecular target of WA is unknown. By chemical structure analysis, we hypothesized that Withaferin A might be a natural proteasome inhibitor. Computational modeling studies consistently predict that C1 and C24 of WA are highly susceptible toward a nucleophilic attack by the hydroxyl group of N-terminal threonine of the proteasomal chymotrypsin subunit beta5. Furthermore, WA potently inhibits the chymotrypsin-like activity of a purified rabbit 20S proteasome (IC50=4.5 microM) and 26S proteasome in human prostate cancer cultures (at 5-10 microM) and xenografts (4-8 mg/kg/day). Inhibition of prostate tumor cellular proteasome activity in cultures and in vivo by WA results in accumulation of ubiquitinated proteins and three proteasome target proteins (Bax, p27, and IkappaB-alpha) accompanied by androgen receptor protein suppression (in androgen-dependent LNCaP cells) and apoptosis induction. Treatment of WA under conditions of the aromatic ketone reduction, or reduced form of Celastrol, had significantly decreased the proteasome-inhibitory and apoptosis-inducing activities. Treatment of human prostate PC-3 xenografts with WA for 24 days resulted in 70% inhibition of tumor growth in nude mice, associated with 56% inhibition of the tumor tissue proteasomal chymotrypsinlike activity. Our results demonstrate that the tumor proteasome beta5 subunit is the primary target of WA, and inhibition of the proteasomal chymotrypsin-like activity by WA in vivo is responsible for, or contributes to, the antitumor effect of this ancient medicinal compound.

DNA topoisomerase I inhibitor, ergosterol peroxide from Penicillium oxalicum

Recently, we found that the MeOH extract of Penicillium oxalicum showed inhibitory activity towards DNA topoisomerase I. Subsequently, ergosterol peroxide, ergosterol, palmitoleic acid, and linoleic acid were isolated from the cultured mycelia of P. oxalicum. The structural determinations were based on physical and spectral analyses. Biological evaluation revealed that ergosterol peroxide inhibited the relaxation of supercoiled DNA (pBR322) induced by DNA topoisomerase I, and also showed marginal, selective cytotoxic activity against human colon tumor cells [COLO-205 (ED50=8.56 microg/mL].

The treatment of skin carcinoma, induced by UV B radiation, using 1-oxo-5beta, 6beta-epoxy-witha-2-enolide, isolated from the roots of Withania somnifera, in a rat model

Histopathological studies of the cutaneous tissues of Wistar rats exposed to UV B radiation (294 nm) for 20 days and rats exposed to UV B radiation for 20 days, followed by topical treatment with benzoyl peroxide, a tumor promoter (20 mg/animal/0.2 ml acetone) twice a week for 1 month, and kept under observation for 12 weeks, demonstrate the development of malignancy. Pretreatment of the animals with 1-oxo-5beta, 6beta-epoxy-witha-2-enolide (20 mg/kg bwt.), isolated from the roots of Withania somnifera, prior to exposing the animals to UV B radiation, prevents the incidence of skin carcinoma. The administration of 1-oxo-5beta, 6beta-epoxy-witha-2-enolide, to the animals after exposing them to UV B radiation/UV B radiation and benzoyl peroxide also prevents the occurrence of malignancy in the cutaneous tissue. Immunohistochemical staining of the cutaneous tissues of rats exposed to UV B radiation show the presence of p53 + foci (clusters of cells containing the mutated p53 protein), whereas an absence of p53 + foci is observed in animals pretreated with 1-oxo-5beta, 6beta-epoxy-witha-2-enolide. These results prove that 1-oxo-5beta, 6beta-epoxy-witha-2-enolide has the potential for acting as an effective agent to prevent the incidence of skin carcinoma induced by UV B radiation.

Evaluation of the anti-inflammatory activity of zhankuic acids isolated from the fruiting bodies of Antrodia camphorata

We have previously shown that a concentrated ethanol extract of the fruiting bodies of Antrodia camphorata exhibited immunomodulating effects in human leukocytes and fourteen compounds including zhankuic acids A, B, C, and antcin K were identified in the extract. In this study, an acute cellular model in isolated peripheral human neutrophils was established to elucidate the anti-inflammatory effects of these compounds. Reactive oxygen species (ROS) production and firm adhesion by neutrophils display two important responses during inflammation. To evaluate whether these compounds could prevent inflammatory responses by neutrophils, their effects on N-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol 12-myristate-13-acetate (PMA)-activated peripheral human neutrophils were examined. Pretreatment with 1 - 25 microM of zhankuic acids A, B, C, or antcin K concentration-dependently diminished fMLP- or PMA-induced ROS production, as measured by a lucigenin-amplified chemiluminescence, with IC (50) (microM) around 5 - 20 microM. Zhankuic acids A, B, C, or antcin K also effectively inhibited the fMLP- or PMA-induced firm adhesion without interfering with the up-expression of surface Mac-1 (CD11b/CD18), a beta2 integrin mediating the firm adhesion of neutrophils to endothelium. The anti-inflammatory actions of these drugs were not due to cytotoxic effects because no significant difference in cell viability was observed compared to vehicle control. These data suggest that inhibition of both ROS production and firm adhesion by neutrophils has no significant cytotoxic effect that could give these drugs the potential to be anti-inflammatory agents for the clinical treatment.

Radiosensitizing effect of withaferin A combined with hyperthermia on mouse fibrosarcoma and melanoma

The effect of withaferin A, a plant withanolide, alone or in combination with acute and fractionated radiotherapy and/or hyperthermia, was tested on two mouse tumors, B16F1 melanoma and fibrosarcoma, grown in C57BL and Swiss albino mice, respectively. Tumors were exposed locally to 30 or 50 Gy gamma radiation as acute dose, or 5 fractions of 10 Gy. Withaferin A, 40 mg/kg, was injected intraperitoneally, 1h before acute irradiation, or 30 mg/kg before every 10 Gy fraction. Local hyperthermia, 43 degrees C for 30 min, followed acute RT or first fraction of 10 Gy. Withaferin A, radiation and hyperthermia, individually and in bimodality treatments, produced no complete response (CR) in melanoma. Some CR were seen in fibrosarcoma, which increased after bimodality treatments. Trimodality treatment synergistically increased CR to 37% in melanoma and to 64% in fibrosarcoma. Fractionated radiotherapy (10 Gy x 5) was more effective (25% CR) than acute dose of 50 Gy (0% CR) on melanoma, while there was no difference between the response of fibrosarcoma to the two regimens. Withaferin A with fractionated radiotherapy synergistically increased the CR of both tumors; hyperthermia further enhanced this effect. Utility of withaferin A in increasing the clinical response of radioresistant tumors to fractionated radiotherapy has to be explored.

Ergosterol (major sterol of baker's and brewer's yeast extracts) inhibits the growth of human breast cancer cells in vitro and the potential role of its oxidation products

The derivation of chemopreventive agents from dietary sources has been the subject of considerable attention in recent years. Yeast extracts have been used as nutritional supplements for a number of years. In this communication we show that ergosterol (a 28-carbon sterol found in baker's and brewer's yeast) can prevent growth of breast cancer cells in vitro in the presence of estradiol-17 beta. Estrogen receptor (+) MCF-7 cells appear to be more sensitive to ergosterol than estrogen receptor (-) MDA-231 cells. However, MDA-231 cells were more sensitive to ergosterol in terms of apoptotic effects than MCF-7 cells, indicating that other mechanisms (antiestrogenic activity) may also be operative in estrogen receptor (+) cells. Compared to freshly prepared ergosterol, stored preparations were more potent in inhibiting growth of cancer cells, indicating that oxidation product(s) of ergosterol may be responsible for the noted effects. Further studies on in vivo effects of ergosterol and lipid extracts of yeast in animal models are warranted to determine their potential for use as supplements in humans.

Effect of Withania somnifera glycowithanolides on iron-induced hepatotoxicity in rats

Glycowithanolides, consisting of equimolar concentrations of sitoindosides VII-X and withaferin A, isolated from the roots of Withania somnifera Dunal, have been reported to have an antioxidant effect in the rat brain frontal cortex and striatum. In the present study, the effect of 10 days of oral administration of these active principles, in graded doses (10, 20 and 50 mg/kg), was noted on iron overload (FeSo(4), 30 mg/kg, i.p.) induced hepatotoxicity in rats. Apart from hepatic lipid peroxidation (LPO), the serum enzymes, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase, were assessed as indices of hepatotoxicity. Silymarin (20 mg/kg, p.o.) was used for comparison. Iron overload induced marked increase in hepatic LPO and serum levels of the enzymes, which was attenuated by WSG in a dose-related manner, and by silymarin. The results indicate that the reported use of WS in Ayurveda for hepatoprotection against heavy metals and other environmental toxins, may be due the antioxidant action of WSG.

Inhibitory effects of sterols isolated from Chlorella vulgaris on 12-0-tetradecanoylphorbol-13-acetate-induced inflammation and tumor promotion in mouse skin

Inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice was observed in the methanol extract of Chlorella vulgaris, a green alga. The hexane soluble fraction obtained from the methanol extract exhibited marked inhibitory activity from which were isolated two delta(5,7)-sterols (ergosterol and 7-dehydroporiferasterol), two delta(5,7,9(11))-sterols [7,9(11)-dehydroergosterol and 7,9(11)-bisdehydroporiferasterol], two 5 alpha, 8 alpha-epidioxy-delta(6)-sterols (ergosterol peroxide and 7-dehydroporiferasterol peroxide), and a 7-oxo-delta(5)-sterol (7-oxocholesterol), among others. The delta 5'7-sterols, 5 alpha, 8 alpha-epidioxy-delta(6)-sterols and 7-oxo-delta 5-sterol inhibited TPA-induced inflammation in mice. The 50% inhibitory dose of these compounds for TPA-induced inflammation was 0.2-0.7 mg/ear. Furthermore, ergosterol peroxide markedly inhibited the tumor-promoting effect of TPA in 7,12-dimethylbenz[a]anthracene-initiated mice.

Antitumor and radiosensitizing effects of withaferin A on mouse Ehrlich ascites carcinoma in vivo

The antitumor and radiosensitizing effects of withaferin A (WA), a steroidal lactone from Withania somnifera, was studied on Ehrlich ascites carcinoma in vivo. The acute LD50(14) for WA in Swiss mice was approximately 80 mg/kg. Twenty-four hours after i.p. inoculation of 10(6) tumor cells, WA was injected i.p. at different dose fractions (5 or 7.5 mg/kg x 8, 10 mg/kg x 5, 20 or 30 mg/kg x 2) with or without abdominal gamma irradiation (RT, 75. Gy) after the first drug dose. Increase in life span and tumor-free survival were studied up to 120 days. The drug inhibited tumor growth and increased survival, which was dependent on the WA dose per fraction rather than the total dose. Combination of RT with all the drug schedules increased tumor cure and tumor-free survival, the best effect seen after 2 fractions of 30 mg/kg each. In another experiment WA was given as 2 (40 mg/kg x 2), 3 (30 mg/kg x 3) or 4 (20 mg/kg x 4) fractions at 5, 7 or 10 days after tumor inoculation with or without RT after the first drug dose. At 7 and 10 days after inoculation the drug was effective only at 40 mg/kg x 2, but with RT 30 mg/kg x 3 produced an equal effect (20% survival) on 7 day old tumors.

[Clinical study on the effectiveness of Insadol]

The effectiveness of Insadol (Laroche-Navarron, Paris) was submitted to a clinical test. The following indexes and measurements were considered: Sulcus fluid, P-Index, Plaque-Index, Pocket Depth, Tooth Mobility, Bone Loss. The measurement of the Sulcus Fluid revealed a small, but significant decrease in the medicament group. The other considered parameters showed no change in the medicament group, which makes any therapeutical effect appear doubtful.