Potential shared pathogenic mechanisms between endometriosis and inflammatory bowel disease indicate a strong initial effect of immune factors

Introduction

Over the past decades, immune dysregulation has been consistently demonstrated being common charactoristics of endometriosis (EM) and Inflammatory Bowel Disease (IBD) in numerous studies. However, the underlying pathological mechanisms remain unknown. In this study, bioinformatics techniques were used to screen large-scale gene expression data for plausible correlations at the molecular level in order to identify common pathogenic pathways between EM and IBD.

Methods

Based on the EM transcriptomic datasets GSE7305 and GSE23339, as well as the IBD transcriptomic datasets GSE87466 and GSE126124, differential gene analysis was performed using the limma package in the R environment. Co-expressed differentially expressed genes were identified, and a protein-protein interaction (PPI) network for the differentially expressed genes was constructed using the 11.5 version of the STRING database. The MCODE tool in Cytoscape facilitated filtering out protein interaction subnetworks. Key genes in the PPI network were identified through two topological analysis algorithms (MCC and Degree) from the CytoHubba plugin. Upset was used for visualization of these key genes. The diagnostic value of gene expression levels for these key genes was assessed using the Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) The CIBERSORT algorithm determined the infiltration status of 22 immune cell subtypes, exploring differences between EM and IBD patients in both control and disease groups. Finally, different gene expression trends shared by EM and IBD were input into CMap to identify small molecule compounds with potential therapeutic effects.

Results

113 differentially expressed genes (DEGs) that were co-expressed in EM and IBD have been identified, comprising 28 down-regulated genes and 86 up-regulated genes. The co-expression differential gene of EM and IBD in the functional enrichment analyses focused on immune response activation, circulating immunoglobulin-mediated humoral immune response and humoral immune response. Five hub genes (SERPING1、VCAM1、CLU、C3、CD55) were identified through the Protein-protein Interaction network and MCODE.High Area Under the Curve (AUC) values of Receiver Operating Characteristic (ROC) curves for 5hub genes indicate the predictive ability for disease occurrence.These hub genes could be used as potential biomarkers for the development of EM and IBD. Furthermore, the CMap database identified a total of 9 small molecule compounds (TTNPB、CAY-10577、PD-0325901 etc.) targeting therapeutic genes for EM and IBD.

Discussion

Our research revealed common pathogenic mechanisms between EM and IBD, particularly emphasizing immune regulation and cell signalling, indicating the significance of immune factors in the occurence and progression of both diseases. By elucidating shared mechanisms, our study provides novel avenues for the prevention and treatment of EM and IBD.

Adenosine triphosphate induced cell death: Mechanisms and implications in cancer biology and therapy

Adenosine triphosphate (ATP) induced cell death (AICD) is a critical cellular process that has garnered substantial scientific interest for its profound relevance to cancer biology and to therapeutic interventions. This comprehensive review unveils the intricate web of AICD mechanisms and their intricate connections with cancer biology. This review offers a comprehensive framework for comprehending the multifaceted role of AICD in the context of cancer. This is achieved by elucidating the dynamic interplay between systemic and cellular ATP homeostasis, deciphering the intricate mechanisms governing AICD, elucidating its intricate involvement in cancer signaling pathways, and scrutinizing validated key genes. Moreover, the exploration of AICD as a potential avenue for cancer treatment underscores its essential role in shaping the future landscape of cancer therapeutics.

ATP-induced cell death: a novel hypothesis for osteoporosis

ATP-induced cell death has emerged as a captivating realm of inquiry with profound ramifications in the context of osteoporosis. This study unveils a paradigm-shifting hypothesis that illuminates the prospective involvement of ATP-induced cellular demise in the etiology of osteoporosis. Initially, we explicate the morphological attributes of ATP-induced cell death and delve into the intricacies of the molecular machinery and regulatory networks governing ATP homeostasis and ATP-induced cell death. Subsequently, our focus pivots towards the multifaceted interplay between ATP-induced cellular demise and pivotal cellular protagonists, such as bone marrow-derived mesenchymal stem cells, osteoblasts, and osteoclasts, accentuating their potential contributions to secondary osteoporosis phenotypes, encompassing diabetic osteoporosis, glucocorticoid-induced osteoporosis, and postmenopausal osteoporosis. Furthermore, we probe the captivating interplay between ATP-induced cellular demise and alternative modalities of cellular demise, encompassing apoptosis, autophagy, and necroptosis. Through an all-encompassing inquiry into the intricate nexus connecting ATP-induced cellular demise and osteoporosis, our primary goal is to deepen our comprehension of the underlying mechanisms propelling this malady and establish a theoretical bedrock to underpin the development of pioneering therapeutic strategies.

Machine learning-based integrated identification of predictive combined diagnostic biomarkers for endometriosis

Background: Endometriosis (EM) is a common gynecological condition in women of reproductive age, with diverse causes and a not yet fully understood pathogenesis. Traditional diagnostics rely on single diagnostic biomarkers and does not integrate a variety of different biomarkers. This study introduces multiple machine learning techniques, enhancing the accuracy of predictive models. A novel diagnostic approach that combines various biomarkers provides a new clinical perspective for improving the diagnostic efficiency of endometriosis, holding significant potential for clinical application. Methods: In this study, GSE51981 was used as a test set, and 11 machine learning algorithms (Lasso, Stepglm, glmBoost, Support Vector Machine, Ridge, Enet, plsRglm, Random Forest, LDA, XGBoost, and NaiveBayes) were employed to construct 113 predictive models for endometriosis. The optimal model was determined based on the AUC values derived from various algorithms. These genes were then evaluated using nine machine learning algorithms (Random Forest, SVM, Gradient Boosting Machine, LASSO, XGB, NNET, Generalized Linear Model, KNN, and Decision Tree) to assess significance scores and identify diagnostic genes for each algorithm. The diagnostic value of these genes was further validated in external datasets from GSE7305, GSE11691, and GSE120103. Results: Analysis of the GSE51981 dataset revealed 62 DEGs. The Stepglm [Both] and plsRglm algorithms identified 30 genes with the most potential using the AUC evaluation. Subsequently, nine machine learning algorithms were applied to select diagnostic genes, leading to the identification of five key diagnostic genes using the LASSO algorithm. The ADAT1 gene exhibited the best single-gene predictive performance, with an AUC of 0.785. A combination of genes (FOS, EPHX1, DLGAP5, PCSK5, and ADAT1) achieves an AUC of 0.836 in the test dataset. Moreover, these genes consistently exhibited an AUC exceeding 0.78 in all validation datasets, demonstrating superior predictive performance. Furthermore, correlation analysis with immune infiltration strengthened their predictive value by demonstrating the close relationship of the diagnostic genes with immune infiltrating cells. Conclusion: A combination of biomarkers consisting of FOS, EPHX1, DLGAP5, PCSK5, and ADAT1 can serve as a diagnostic tool for endometriosis, enhancing diagnostic efficiency. The association of these genes with immune infiltrating cells reveals their potential role in the pathogenesis of endometriosis, providing new insights for early detection and treatment.

The Anticancer Potential of Psidium guajava (Guava) Extracts

The fruits, leaves, and bark of the guava (Psidium guajava) tree have traditionally been used to treat a myriad of ailments, especially in the tropical and subtropical regions. The various parts of the plant have been shown to exhibit medicinal properties, such as antimicrobial, antioxidant, anti-inflammatory, and antidiabetic activities. Recent studies have shown that the bioactive phytochemicals of several parts of the P. guajava plant exhibit anticancer activity. This review aims to present a concise summary of the in vitro and in vivo studies investigating the anticancer activity of the plant against various human cancer cell lines and animal models, including the identified phytochemicals that contributes to their activity via the different mechanisms. In vitro growth and cell viability studies, such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the sulforhodamine B (SRB) assay, and the trypan blue exclusion test, were conducted using P. guajava extracts and their biomolecules to assess their effects on human cancer cell lines. Numerous studies have showcased that the P. guajava plant and its bioactive molecules, especially those extracted from its leaves, selectively suppress the growth of human cancer cells without cytotoxicity against the normal cells. This review presents the potential of the extracts of P. guajava and the bioactive molecules derived from it, to be utilized as a feasible alternative or adjuvant treatment for human cancers. The availability of the plant also contributes towards its viability as a cancer treatment in developing countries.

Gynura procumbens ethanol extract and its fractions inhibit Th1, Th2 and Th17 but induce Treg cells differentiation during atherosclerosis development

Introduction: Gynura procumbens (Lorr.) Merr. (GP) displays cardio-protective effect, which may hinder atherogenesis induced by oxidized low-density lipoprotein (oxLDL) and leukocytes. The current study was undertaken to elucidate the chemical constituents of GP ethanol extract and its aqueous, chloroform, ethyl acetate, and hexane fractions, and their effects on CD4+ T cell differentiation during atherogenesis. Methods: Initially, the bioactive constituents in GP ethanol extract and its fractions were analyzed using gas chromatography-mass spectrometry (GC-MS). Generated mouse bone marrow dendritic cells (BMDC) were loaded with oxLDL and GP ethanol extract and its fractions for 24 hours and co-cultured with mouse CD4+ T cells for 72 hours. For the determination of T-bet, GATA-3, RORγt, Foxp3, DLL-3, and Jagged-1 mRNA gene expression, the floating cells (CD4+ T cells) and adherence cells (BMDC) were isolated from their total RNAs and reverse transcribed into cDNA.Results: GC-MS analysis showed that GP ethanol extract and its fractions contained various volatile compounds. GP ethanol extract and its fractions also increased the DLL-3 gene but suppressed Jagged-1 gene expression in oxLDL-treated BMDC. Furthermore, GP ethanol extract and its fractions suppressed T-bet, GATA-3, and RORγt gene expression but increased the expression of the Foxp3 gene in differentiated CD4 + T cells. Conclusion: GP ethanol extract and its fractions are composed of various bioactive chemical components that can induce anti-atherogenic effects by inhibiting pro-atherogenic cells such as Th1, Th2, and Th17 cells while increasing anti-atherogenic cells, Treg cells.

β-Caryophyllene Induces Apoptosis and Inhibits Angiogenesis in Colorectal Cancer Models

Beta-Caryophyllene (BCP), a naturally occurring sesquiterpene abundantly found in cloves, hops, and cannabis, is the active candidate of a relatively new group of vascular-inhibiting compounds that aim to block existing tumor blood vessels. Previously, we have reported the anti-cancer properties of BCP by utilizing a series of in-vitro anti-tumor-related assays using human colorectal carcinoma cells. The present study aimed to investigate the effects of BCP on in-vitro, ex-vivo, and in-vivo models of anti-angiogenic assays and evaluate its anti-cancer activity in xenograft tumor (both ectopic and orthotopic) mice models of human colorectal cancer. Computational structural analysis and an apoptosis antibody array were also performed to understand the molecular players underlying this effect. BCP exhibited strong anti-angiogenic activity by blocking the migration of endothelial cells, tube-like network formation, suppression of vascular endothelial growth factor (VEGF) secretion from human umbilical vein endothelial cells and sprouting of rat aorta microvessels. BCP has a probable binding at Site#0 on the surface of VEGFR2. Moreover, BCP significantly deformed the vascularization architecture compared to the negative control in a chick embryo chorioallantoic membrane assay. BCP showed a remarkable reduction in tumor size and fluorescence molecular tomography signal intensity in all the mice treated with BCP, in a dose-dependent relationship, in ectopic and orthotopic tumor xenograft models, respectively. The histological analysis of the tumor from BCP-treated mice revealed a clear reduction of the density of vascularization. In addition, BCP induced apoptosis through downregulation of HSP60, HTRA, survivin, and XIAP, along with the upregulation of p21 expressions. These results suggest that BCP acts at multiple stages of angiogenesis and could be used as a promising therapeutic candidate to halt the growth of colorectal tumor cells.

The assimilation of different carbon sources in Candida albicans: Fitness and pathogenicity

Candida albicans is a commensal yeast commonly found on the skin and in the body. However, in immunocompromised individuals, the fungi could cause local and systemic infections. The carbon source available plays an important role in the establishment of C. albicans infections. The fungi's ability to assimilate a variety of carbon sources plays a vital role in its colonization, and by extension, its fitness and pathogenicity, as it often inhabits niches that are glucose-limited but rich in alternative carbon sources. A difference in carbon sources affect the growth and mating of C. albicans, which contributes to its pathogenicity as proliferation helps the fungi colonize its environment. The carbon source also affects its metabolism and signaling pathways, which are integral parts of the fungi's fitness and pathogenicity. As a big percentage of the carbon assimilated by C. albicans goes to cell wall biogenesis, the availability of different carbon sources will result in cell walls with variations in rigidity, adhesion, and surface hydrophobicity. In addition to the biofilm formation of the fungi, the carbon source also influences whether the fungi grow in yeast- or mycelial-form. Both forms play different roles in C. albicans's infection process. A better understanding of the role of the carbon sources in C. albicans's pathogenicity would contribute to more effective treatment solutions for fungal infections.

Identification of Alkaloid Compounds Arborinine and Graveoline from Ruta angustifolia (L.) Pers for their Antifungal Potential against Isocitrate lyase (ICL1) gene of Candida albicans

Candida albicans has been reported globally as the most widespread pathogenic species contributing candidiasis from superficial to systemic infections in immunocompromised individuals. Their metabolic adaptation depends on glyoxylate cycle to survive in nutrient-limited host. The long term usage of fungistatic drugs and the lack of cidal drugs frequently result in strains that could resist commonly used antifungals and display multidrug resistance (MDR). In search of potential therapeutic intervention and novel fungicidals, we have explored a plant alkaloids, namely arborinine and graveoline for its antifungal potential. Alkaloids belongs to Rutaceae family have been reported with numerous antimicrobial activities. In this study, we aimed to isolate and identify the antifungal active alkaloids of R. angustifolia and assess antifungal effect targeting C. albicans isocitrate lyase (ICL) gene which regulates isocitrate lyase, key enzyme in glyoxylate cycle contributing to the virulence potential of C. albicans. Alkaloids were extracted by bioassay guided isolation technique which further identified by TLC profile and compared with the standard through HPLC and NMR analysis. The antifungal activities of the extracted alkaloids were quantified by means of MIC (Minimum Inhibitory Concentration). The gene expression of the targeted gene upon treatment was analysed using RT-qPCR and western blot. Additionally, this study looked at the drug-likeness and potential toxicity effect of the active alkaloid compounds in silico analysis. Spectroscopic analysis showed that the isolated active alkaloids were characterized as acridone, furoquinoline, 4-quinolone known as arborinine and graveoline. Results showed that each compound significantly inhibited the growth of C. albicans at the dose of 250 to 500 µg/mL which confirm its antifungal activity. Each alkaloid was found to successfully downregulate the expression of both ICL1 gene CaIcl1 protein. Finally, ADMET analysis suggests a good prediction of chemical properties, namely absorption, distribution, metabolism, excretion and toxicity (ADMET) that will contribute in drug discovery and development later on.

Transcriptomic and proteomic profiling revealed reprogramming of carbon metabolism in acetate-grown human pathogen Candida glabrata

BACKGROUND

Emergence of Candida glabrata, which causes potential life-threatening invasive candidiasis, has been widely associated with high morbidity and mortality. In order to cause disease in vivo, a robust and highly efficient metabolic adaptation is crucial for the survival of this fungal pathogen in human host. In fact, reprogramming of the carbon metabolism is believed to be indispensable for phagocytosed C. glabrata within glucose deprivation condition during infection.

METHODS

In this study, the metabolic responses of C. glabrata under acetate growth condition was explored using high-throughput transcriptomic and proteomic approaches.

RESULTS

Collectively, a total of 1482 transcripts (26.96%) and 242 proteins (24.69%) were significantly up- or down-regulated. Both transcriptome and proteome data revealed that the regulation of alternative carbon metabolism in C. glabrata resembled other fungal pathogens such as Candida albicans and Cryptococcus neoformans, with up-regulation of many proteins and transcripts from the glyoxylate cycle and gluconeogenesis, namely isocitrate lyase (ICL1), malate synthase (MLS1), phosphoenolpyruvate carboxykinase (PCK1) and fructose 1,6-biphosphatase (FBP1). In the absence of glucose, C. glabrata shifted its metabolism from glucose catabolism to anabolism of glucose intermediates from the available carbon source. This observation essentially suggests that the glyoxylate cycle and gluconeogenesis are potentially critical for the survival of phagocytosed C. glabrata within the glucose-deficient macrophages.

CONCLUSION

Here, we presented the first global metabolic responses of C. glabrata to alternative carbon source using transcriptomic and proteomic approaches. These findings implicated that reprogramming of the alternative carbon metabolism during glucose deprivation could enhance the survival and persistence of C. glabrata within the host.

Optimization of biogenic synthesis of silver nanoparticles from flavonoid-rich Clinacanthus nutans leaf and stem aqueous extracts

Background: Silver nanoparticles (AgNPs) are widely used in food industries, biomedical, dentistry, catalysis, diagnostic biological probes and sensors. The use of plant extract for AgNPs synthesis eliminates the process of maintaining cell culture and the process could be scaled up under a non-aseptic environment. The purpose of this study is to determine the classes of phytochemicals, to biosynthesize and characterize the AgNPs using Clinacanthus nutans leaf and stem extracts. In this study, AgNPs were synthesized from the aqueous extracts of C. nutans leaves and stems through a non-toxic, cost-effective and eco-friendly method. Results: The formation of AgNPs was confirmed by UV-Vis spectroscopy, and the size of AgNP-L (leaf) and AgNP-S (stem) were 114.7 and 129.9 nm, respectively. Transmission electron microscopy (TEM) analysis showed spherical nanoparticles with AgNP-L and AgNP-S ranging from 10 to 300 nm and 10 to 180 nm, with average of 101.18 and 75.38 nm, respectively. The zeta potentials of AgNP-L and AgNP-S were recorded at -42.8 and -43.9 mV. X-ray diffraction analysis matched the face-centred cubic structure of silver and was capped with bioactive compounds. Fourier transform infrared spectrophotometer analysis revealed the presence of few functional groups of phenolic and flavonoid compounds. These functional groups act as reducing agents in AgNPs synthesis. Conclusion: These results showed that the biogenically synthesized nanoparticles reduced silver ions to silver nanoparticles in aqueous condition and the AgNPs formed were stable and less toxic.

Glyoxylate cycle gene ICL1 is essential for the metabolic flexibility and virulence of Candida glabrata

The human fungal pathogen Candida glabrata appears to utilise unique stealth, evasion and persistence strategies in subverting the onslaught of host immune response during systemic infection. However, macrophages actively deprive the intracellular fungal pathogen of glucose, and therefore alternative carbon sources probably support the growth and survival of engulfed C. glabrata. The present study aimed to investigate the role of the glyoxylate cycle gene ICL1 in alternative carbon utilisation and its importance for the virulence of C. glabrata. The data showed that disruption of ICL1 rendered C. glabrata unable to utilise acetate, ethanol or oleic acid. In addition, C. glabrata icl1∆ cells displayed significantly reduced biofilm growth in the presence of several alternative carbon sources. It was also found that ICL1 is crucial for the survival of C. glabrata in response to macrophage engulfment. Disruption of ICL1 also conferred a severe attenuation in the virulence of C. glabrata in the mouse model of invasive candidiasis. In conclusion, a functional glyoxylate cycle is essential for C. glabrata to utilise certain alternative carbon sources in vitro and to display full virulence in vivo. This reinforces the view that antifungal drugs that target fungal Icl1 have potential for future therapeutic intervention.

Pleurotus sajor-caju can be used to synthesize silver nanoparticles with antifungal activity against Candida albicans

BACKGROUND

Green synthesis of silver nanoparticles (AgNPs) has become widely practiced worldwide. In this study, AgNPs were synthesized using a hot-water extract of the edible mushroom Pleurotus sajor-caju. The product, PSC-AgNPs, was characterized by using UV-visible spectra, dynamic light scattering analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectrometry. To assess its antifungal activity against Candida albicans, gene transcription and protein expression analyses were conducted for CaICL1 and its product, ICL, using real-time quantitative polymerase chain reaction and western blot, respectively.

RESULTS

PSC-AgNPs with an average particle size of 11.68 nm inhibited the growth of the pathogenic yeast C. albicans. Values for minimum inhibitory concentration and minimum fungicidal concentration were 250 and 500 mg L^-1 , respectively. TEM images revealed that the average particle size of PSC-AgNPs was 16.8 nm, with the values for zeta potential and the polydispersity index being -8.54 mV and 0.137, respectively. XRD and FTIR spectra showed PSC-AgNPs to have a face-centered cubic crystalline structure. The polysaccharides and amino acid residues present in P. sajor-caju extract were found to be involved in reducing Ag⁺ to AgNP. Both CaICL1 transcription and ICL protein expression were found to be suppressed in the cells treated with PSC-AgNPs as compared with the control.

CONCLUSION

Our PSC-AgNP preparation makes for a promising antifungal agent that can downregulate isocitrate lyase. © 2017 Society of Chemical Industry.

Metabolic adaptation via regulated enzyme degradation in the pathogenic yeast Candida albicans

The virulence of Candida albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility. The assimilation of carbon sources is important for growth and essential for the establishment of infections by C. albicans. Previous studies showed that the C. albicans ICL1 genes, which encode the glyoxylate cycle enzymes isocitratelyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid and were repressed by 2% glucose. In contrast to S. cerevsiae, the enzyme CaIcl1 was not destabilised by glucose, resulting with its metabolite remaining at high levels. Further glucose addition has caused CaIcl1 to lose its signal and mechanisms that trigger destabilization in response to glucose. Another purpose of this study was to test the stability of the Icl1 enzyme in response to the dietary sugars, fructose, and galactose. In the present study, the ICL1 mRNAs expression was quantified using Quantitative Real Time PCR, whereby the stability of protein was measured and quantified using Western blot and phosphoimager, and the replacing and cloning of ICL1 ORF by gene recombination and ubiquitin binding was conducted via co-immuno-precipitation. Following an analogous experimental approach, the analysis was repeated using S. cerevisiaeas a control. Both galactose and fructose were found to trigger the degradation of the ICL1 transcript in C. albicans. The Icl1 enzyme was stable following galactose addition but was degraded in response to fructose. C. albicans Icl1 (CaIcl1) was also subjected to fructose-accelerated degradation when expressed in S. cerevisiae, indicating that, although it lacks a ubiquitination site, CaIcl1 is sensitive to fructose-accelerated protein degradation. The addition of an ubiquitination site to CaIcl1 resulted in this enzyme becoming sensitive to galactose-accelerated degradation and increases its rate of degradation in the presence of fructose. It can be concluded that ubiquitin-independent pathways of fructose-accelerated enzyme degradation exist in C. albicans.

Cat's whiskers (Orthosiphon stamineus) tea modulates arthritis pathogenesis via the angiogenesis and inflammatory cascade

Background

Orthosiphon stamineus is used traditionally to treat gout, arthritis, and inflammatory related conditions. The in vitro anti-inflammatory effects of the plant have been scientifically investigated. The goal of the present study was to evaluate the potential of the 50% ethanol extract of O. stamineus (EOS) to treat rheumatoid arthritis.

Methods

Anti-arthritic activity was assessed using the in vitro heat denaturation test and the (FCA)-induced arthritis model. Efficacy was assessed by measurements of paw edema and granulation, X-ray radiography, fluorescence molecular tomography (FMT), and histological evaluation. Levels of (TNF-α), interleukin-1 (IL-1), and (COX-1 and COX-2) were analyzed in vitro in lipopolysaccharide (LPS)-stimulated human macrophage (U937). TNF-α and IL-1 levels in the serum samples of arthritic rats were also measured using an ELISA kit.

Results

Treatment with EOS resulted in dose-dependent inhibition of paw edema in acute and chronic models of inflammation. It also inhibited significantly the production of TNF-α, IL-1 COX-1, and COX-2 in the LPS-stimulated U937 macrophages. EOS significantly suppressed FCA-induced paw edema as well as the serum levels of TNF-α and IL-1. X-rays of the synovial joint of the hind leg showed considerable improvement in joint integrity and recovery of tibia-talus bones from degeneration and osteoporotic lesions. Histology of proximal interphalangeal joints of EOS-treated animals showed obvious protection of cartilage and soft tissue. Finally, FMT analysis strongly supported the anti-arthritic effect of EOS. EOS had high phenolic and total flavonoid content as well as strong antioxidant activity.

Conclusions

Results illustrated that the anti-arthritic properties of O. stamineus could be beneficial for prevention and management of rheumatoid arthritis and other chronic inflammatory disorders.

Graphical abstract

Illustration of the Anti- arthritis efficacy of Orthosiphon Stamineus standardized extract.

Resistance of Candida albicans Biofilms to Drugs and the Host Immune System

Background

Candida albicans is a commensal fungus that resides on mucosal surfaces and in the gastrointestinal and genitourinary tracts in humans. However, it can cause an infection when the immune system of the host is impaired or if a niche becomes available. Many C. albicans infections are due to the organism’s ability to form a biofilm on implanted medical devices. A biofilm represents an optimal medium for the growth of C. albicans as it allows cells to be enclosed by a self-produced extracellular matrix (ECM).

Objectives

The present work investigated certain aspects of the resistance of C. albicans biofilms to drugs and the host immune system.

Results

An ECM was found to provide the infrastructure for biofilm formation, prevent disaggregation, and shield encapsulated C. albicans cells from antifungal drugs and the host’s immune system. By influencing FKS1 and upregulating multiple glucan modification genes, β-1, 3-glucan, an important component of ECM, was shown to be responsible for many of the biofilm’s drug-resistant properties. On being engulfed by ECM, the fungal cell was found to switch from glycolysis to gluconeogenesis. Resembling the cellular response to starvation, this was followed by the activation of the glyoxylate cycle that allowed the use of simple molecules as energy sources.

Conclusion

Mature biofilms were found to be much more resistant to antifungal agents and the host immune system than free cells. The factors responsible for high resistance included the complex architecture of biofilms, ECM, increased expression of drug efflux pumps, and metabolic plasticity.

Scopoletin, an active principle of tree tobacco (Nicotiana glauca) inhibits human tumor vascularization in xenograft models and modulates ERK1, VEGF-A, and FGF-2 in computer model

We recently reported the antineovascularization effect of scopoletin on rat aorta and identified its potential anti-angiogenic activity. Scopoletin could be useful as a systemic chemotherapeutic agent against angiogenesis-dependent malignancies if its antitumorigenic activity is investigated and scientifically proven using a suitable human tumor xenograft model. In the present study, bioassay-guided (anti-angiogenesis) phytochemical investigation was conducted on Nicotiana glauca extract which led to the isolation of scopoletin. Further, anti-angiogenic activity of scopoletin was characterized using ex vivo, in vivo and in silico angiogenesis models. Finally, the antitumorigenic efficacy of scopoletin was studied in human colorectal tumor xenograft model using athymic nude mice. For the first time, an in vivo anticancer activity of scopoletin was reported and characterized using xenograft models. Scopoletin caused significant suppression of sprouting of microvessels in rat aortic explants with IC50 (median inhibitory concentration) 0.06μM. Scopoletin (100 and 200mg/kg) strongly inhibited (59.72 and 89.4%, respectively) vascularization in matrigel plugs implanted in nude mice. In the tumor xenograft model, scopoletin showed remarkable inhibition on tumor growth (34.2 and 94.7% at 100 and 200mg/kg, respectively). Tumor histology revealed drastic reduction of the extent of vascularization. Further, immunostaining of CD31 and NG2 receptors in the histological sections confirmed the antivascular effect of scopoletin in tumor vasculature. In computer modeling, scopoletin showed strong ligand affinity and binding energies toward the following angiogenic factors: protein kinase (ERK1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2). These results suggest that the antitumor activity of scopoletin may be due to its strong anti-angiogenic effect, which may be mediated by its effective inhibition of ERK1, VEGF-A, and FGF-2.

The Role of Isocitrate Lyase (ICL1) in the Metabolic Adaptation of Candida albicans Biofilms

Background

A major characteristic of Candida biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility.

Objectives

This study evaluated the roles of metabolic processes (in particular the glyoxylate cycle) on biofilm formation, antifungal drug resistance, morphology, and cell wall components.

Methods

Growth, adhesion, biofilm formation, and cell wall carbohydrate composition were quantified for isogenic Candida albicans ICL1/ICL1, ICL1/icl1, and icl1/icl1 strains. The morphology and topography of these strains were compared by light microscopy and scanning electron microscopy. FKS1 (glucan synthase), ERG11 (14-α-demethylase), and CDR2 (efflux pump) mRNA levels were quantified using qRT-PCR.

Results

The ICL1/icl1 and icl1/icl1 strains formed similar biofilms and exhibited analogous drug-tolerance levels to the control ICL1/ICL1 strains. Furthermore, the drug sequestration ability of β-1, 3-glucan, a major carbohydrate component of the extracellular matrix, was not impaired. However, the inactivation of ICL1 did impair morphogenesis. ICL1 deletion also had a considerable effect on the expression of the FKS1, ERG11, and CDR2 genes. FKS1 and ERG11 were upregulated in ICL1/icl1 and icl1/icl1 cells throughout the biofilm developmental stages, and CDR2 was upregulated at the early phase. However, their expression was downregulated compared to the control ICL1/ICL1 strain.

Conclusions

We conclude that the glyoxylate cycle is not a specific determinant of biofilm drug resistance.

Mutagenicity and preclinical safety assessment of the aqueous extract of Clinacanthus nutans leaves

CONTEXT

Clinacanthus nutans (CN) is used traditionally for treating various illnesses. Robust safety data to support its use is lacking.

OBJECTIVE

To evaluate the adverse effects of aqueous extract of CN leaves (AECNL).

MATERIALS AND METHODS

The oral toxicity of the AECNL was tested following Organisation for Economic Co-operation and Development (OECD) guidelines. Mutagenicity (Ames test) of AECNL was evaluated using TA98 and TA100 Salmonella typhimurium strains.

RESULTS

No mortality or morbidity was found in the animals upon single and repeated dose administration. However, significant body weight loss was observed at 2000 mg/kg during sub-chronic (90 d) exposure. In addition, increased eosinophil at 500 mg/kg and decreased serum alkaline phosphatase levels at 2000 mg/kg were observed in male rats. Variations in glucose and lipid profiles in treated groups were also observed compared to control. Ames test revealed no evidence of mutagenic or carcinogenic effects at 500 μg/well of AECNL.

CONCLUSION

The median lethal dose (LD50) of the AECNL is >5000 mg/kg and the no-observed-adverse-effect level is identified to be greater than 2000 mg/kg/day in 90-d study.

Yeast Infection and Diabetes Mellitus among Pregnant Mother in Malaysia

BACKGROUND

Vaginal yeast infection refers to irritation of the vagina due to the presence of opportunistic yeast of the genus Candida (mostly Candida albicans). About 75% of women will have at least one episode of vaginal yeast infection during their lifetime. Several studies have shown that pregnancy and uncontrolled diabetes increase the infection risk. Reproductive hormone fluctuations during pregnancy and elevated glucose levels characteristic of diabetes provide the carbon needed for Candida overgrowth and infection. The goal of this study was to determine the prevalence of vaginal yeast infection among pregnant women with and without diabetes.

METHODS

This was a case-control study using cases reports from Kepala Batas Health Clinic, Penang State, Malaysia from 2006 to 2012. In total, 740 pregnant ladies were chosen as sample of which 370 were diabetic and 370 were non-diabetic cases.

RESULTS

No relationship between diabetes and the occurrence of vaginal yeast infection in pregnant women was detected, and there was no significant association between infection and age group, race or education level.

CONCLUSION

In conclusion, within radius of this study, vaginal yeast infection can occur randomly in pregnant women.

SNF3 as High Affinity Glucose Sensor and Its Function in Supporting the Viability of Candida glabrata under Glucose-Limited Environment

Candida glabrata is an emerging human fungal pathogen that has efficacious nutrient sensing and responsiveness ability. It can be seen through its ability to thrive in diverse range of nutrient limited-human anatomical sites. Therefore, nutrient sensing particularly glucose sensing is thought to be crucial in contributing to the development and fitness of the pathogen. This study aimed to elucidate the role of SNF3 (Sucrose Non Fermenting 3) as a glucose sensor and its possible role in contributing to the fitness and survivability of C. glabrata in glucose-limited environment. The SNF3 knockout strain was constructed and subjected to different glucose concentrations to evaluate its growth, biofilm formation, amphotericin B susceptibility, ex vivo survivability and effects on the transcriptional profiling of the sugar receptor repressor (SRR) pathway-related genes. The CgSNF3Δ strain showed a retarded growth in low glucose environments (0.01 and 0.1%) in both fermentation and respiration-preferred conditions but grew well in high glucose concentration environments (1 and 2%). It was also found to be more susceptible to amphotericin B in low glucose environment (0.1%) and macrophage engulfment but showed no difference in the biofilm formation capability. The deletion of SNF3 also resulted in the down-regulation of about half of hexose transporters genes (four out of nine). Overall, the deletion of SNF3 causes significant reduction in the ability of C. glabrata to sense limited surrounding glucose and consequently disrupts its competency to transport and perform the uptake of this critical nutrient. This study highlighted the role of SNF3 as a high affinity glucose sensor and its role in aiding the survivability of C. glabrata particularly in glucose limited environment.

Phylogenetic and Transcripts Profiling of Glucose Sensing Related Genes in Candida glabrata

Background:

The sensing mechanism of glucose in Saccharomyces cerevisiae is well studied. However, such information is scarcely found in other yeast species such as Candida glabrata.

Objectives:

This study aimed to identify the glucose sensing pathway related genes of C. glabrata and to analyze the regulation pattern of these genes in response to different surrounding glucose concentrations through the quantitative real time polymerase chain reaction (qRT-PCR).

Materials and Methods:

Phylogenetic analysis was carried out on predicted amino acid sequences of C. glabrata and S. cerevisiae to compare their degree of similarity. In addition, the growth of C. glabrata in response to different amounts of glucose (0%, 0.01%, 0.1%, 1% and 2%) was evaluated via the spot dilution assay on prepared agar medium. Besides, the SNF3 and RGT2, which act as putative glucose sensors, and the RGT1 and MIG1, which act as putative transcriptional regulators and selected downstream hexose transporters (HXTs), were analysed through qRT-PCR analysis for the gene expression level under different glucose concentrations.

Results:

Comparative analysis of predicted amino acids in the phylogenetic tree showed high similarity between C. glabrata and S cerevisiae. Besides, C. glabrata demonstrated the capability to grow in glucose levels as low as 0.01% in the spot dilution assay. In qRT-PCR analysis, differential expressions were observed in selected genes when C. glabrata was subjected to different glucose concentrations.

Conclusions:

The constructed phylogenetic tree suggests the close evolutionary relationship between C. glabrata and S. cerevisiae. The capability of C. glabrata to grow in extremely low glucose environments and the differential expression of selected glucose-sensing related genes suggested the possible role of these genes in modulating the growth of C. glabrata in response to different glucose concentrations. This study helps deepen our understanding of the glucose sensing mechanism in C. glabrata and serves to provide fundamental data that may assist in unveiling this mechanism as a potential drug target.

Growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of Candida glabrata are affected by different glucose concentrations

Glucose is an important fuel source to support many living organisms. Its importance in the physiological fitness and pathogenicity of Candida glabrata, an emerging human fungal pathogen has not been extensively studied. The present study aimed to investigate the effects of glucose on the growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of C. glabrata. In addition, its effect on the expression of a putative high affinity glucose sensor gene, SNF3 was also investigated. Glucose concentrations were found to exert effects on the physiological responses of C. glabrata. The growth rate of the species correlated positively to the amount of glucose. In addition, low glucose environments were found to induce C. glabrata to form biofilm and resist amphotericin B. Conversely, high glucose environments promoted oxidative stress resistance of C. glabrata. The expression of CgSNF3 was found to be significantly up-regulated in low glucose environments. The expression of SNF3 gene in clinical isolates was found to be higher compared to ATCC laboratory strains in low glucose concentrations, which may explain the better survivability of clinical isolates in the low glucose environment. These observations demonstrated the impact of glucose in directing the physiology and virulence fitness of C. glabrata through the possible modulation by SNF3 as a glucose sensor, which in turn aids the species to adapt, survive and thrive in hostile host environment.

In vitro modulation of probiotic bacteria on the biofilm of Candida glabrata

A conspicuous new concept of pathogens living as the microbial societies in the human host rather than free planktonic cells has raised considerable concerns among scientists and clinicians. Fungal biofilms are communities of cells that possess distinct characteristic such as increased resistance to the immune defence and antimycotic agents in comparison to their planktonic cells counterpart. Therefore, inhibition of the biofilm may represent a new paradigm for antifungal development. In this study, we aim to evaluate the in vitro modulation of vulvovaginal candidiasis (VVC)-causing Candida glabrata biofilms using probiotic lactobacilli strains. Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 were shown to have completely inhibited C. glabrata biofilms and the results were corroborated by scanning electron microscopy (SEM), which revealed scanty structures of the mixed biofilms of C. glabrata and probiotic lactobacilli strains. In addition, biofilm-related C. glabrata genes EPA6 and YAK1 were downregulated in response to the probiotic lactobacilli challenges. The present study suggested that probiotic L. rhamnosus GR-1 and L. reuteri RC-14 strains inhibited C. glabrata biofilm by partially impeding the adherence of yeast cells and the effect might be contributed by the secretory compounds produced by these probiotic lactobacilli strains. Further investigations are required to examine and identify the biofilm inhibitory compounds and the mechanism of probiotic actions of these lactobacilli strains.

Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 exhibit strong antifungal effects against vulvovaginal candidiasis-causing Candida glabrata isolates

Aims

This study investigates the antagonistic effects of the probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 against vulvovaginal candidiasis (VVC)-causing Candida glabrata.

Methods and Results

Growth inhibitory activities of Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains against C. glabrata were demonstrated using a spot overlay assay and a plate-based microtitre assay. In addition, these probiotic lactobacilli strains also exhibited potent candidacidal activity against C. glabrata, as demonstrated by a LIVE/DEAD yeast viability assay performed using confocal laser scanning microscopy. The metabolic activities of all C. glabrata strains were completely shut down in response to the challenges by the probiotic lactobacilli strains. In addition, both probiotic lactobacilli strains exhibited strong autoaggregation and coaggregation phenotypes in the presence of C. glabrata, which indicate that these lactobacilli strains may exert their probiotic effects through the formation of aggregates and, thus the consequent prevention of colonization by C. glabrata.

Conclusions

Probiotic Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains exhibited potent antagonistic activities against all of the tested C. glabrata strains. These lactobacilli exhibited antifungal effects, including those attributed to their aggregation abilities, and their presence caused the cessation of growth and eventual cell death of C. glabrata.

Significance and Impact of the Study

This is the first study to report on the antagonistic effects of these probiotic lactobacilli strains against the non-Candida albicans Candida (NCAC) species C. glabrata.

Stress adaptation in a pathogenic fungus

Candida albicans is a major fungal pathogen of humans. This yeast is carried by many individuals as a harmless commensal, but when immune defences are perturbed it causes mucosal infections (thrush). Additionally, when the immune system becomes severely compromised, C. albicans often causes life-threatening systemic infections. A battery of virulence factors and fitness attributes promote the pathogenicity of C. albicans. Fitness attributes include robust responses to local environmental stresses, the inactivation of which attenuates virulence. Stress signalling pathways in C. albicans include evolutionarily conserved modules. However, there has been rewiring of some stress regulatory circuitry such that the roles of a number of regulators in C. albicans have diverged relative to the benign model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. This reflects the specific evolution of C. albicans as an opportunistic pathogen obligately associated with warm-blooded animals, compared with other yeasts that are found across diverse environmental niches. Our understanding of C. albicans stress signalling is based primarily on the in vitro responses of glucose-grown cells to individual stresses. However, in vivo this pathogen occupies complex and dynamic host niches characterised by alternative carbon sources and simultaneous exposure to combinations of stresses (rather than individual stresses). It has become apparent that changes in carbon source strongly influence stress resistance, and that some combinatorial stresses exert non-additive effects upon C. albicans. These effects, which are relevant to fungus–host interactions during disease progression, are mediated by multiple mechanisms that include signalling and chemical crosstalk, stress pathway interference and a biological transistor.

Tualang honey improves human corneal epithelial progenitor cell migration and cellular resistance to oxidative stress in vitro

Stem cells with enhanced resistance to oxidative stress after in vitro expansion have been shown to have improved engraftment and regenerative capacities. Such cells can be generated by preconditioning them with exposure to an antioxidant. In this study we evaluated the effects of Tualang honey (TH), an antioxidant-containing honey, on human corneal epithelial progenitor (HCEP) cells in culture. Cytotoxicity, gene expression, migration, and cellular resistance to oxidative stress were evaluated. Immunofluorescence staining revealed that HCEP cells were holoclonal and expressed epithelial stem cell marker p63 without corneal cytokeratin 3. Cell viability remained unchanged after cells were cultured with 0.004, 0.04, and 0.4% TH in the medium, but it was significantly reduced when the concentration was increased to 3.33%. Cell migration, tested using scratch migration assay, was significantly enhanced when cells were cultured with TH at 0.04% and 0.4%. We also found that TH has hydrogen peroxide (H2O2) scavenging ability, although a trace level of H2O2 was detected in the honey in its native form. Preconditioning HCEP cells with 0.4% TH for 48 h showed better survival following H2O2-induced oxidative stress at 50 µM than untreated group, with a significantly lower number of dead cells (15.3 ± 0.4%) were observed compared to the untreated population (20.5 ± 0.9%, p<0.01). Both TH and ascorbic acid improved HCEP viability following induction of 100 µM H2O2, but the benefit was greater with TH treatment than with ascorbic acid. However, no significant advantage was demonstrated using 5-hydroxymethyl-2-furancarboxaldehyde, a compound that was found abundant in TH using GC/MS analysis. This suggests that the cellular anti-oxidative capacity in HCEP cells was augmented by native TH and was attributed to its antioxidant properties. In conclusion, TH possesses antioxidant properties and can improve cell migration and cellular resistance to oxidative stress in HCEP cells in vitro.

Inhibitors of the glyoxylate cycle enzyme ICL1 in Candida albicans for potential use as antifungal agents

Candida albicans is an opportunistic pathogen that causes candidiasis in humans. In recent years, metabolic pathways in C. albicans have been explored as potential antifungal targets to treat candidiasis. The glyoxylate cycle, which enables C. albicans to survive in nutrient-limited host niches and its. Key enzymes (e.g., isocitrate lyase (ICL1), are particularly attractive antifungal targets for C. albicans. In this study, we used a new screening approach that better reflects the physiological environment that C. albicans cells experience during infection to identify potential inhibitors of ICL. Three compounds (caffeic acid (CAFF), rosmarinic acid (ROS), and apigenin (API)) were found to have antifungal activity against C. albicans when tested under glucose-depleted conditions. We further confirmed the inhibitory potential of these compounds against ICL using the ICL enzyme assay. Lastly, we assessed the bioavailability and toxicity of these compounds using Lipinski's rule-of-five and ADMET analysis.