Harmonization Risks and Rewards: Nano-QSAR for Agricultural Nanomaterials

This comprehensive review explores the emerging landscape of Nano-QSAR (quantitative structure-activity relationship) for assessing the risk and potency of nanomaterials in agricultural settings. The paper begins with an introduction to Nano-QSAR, providing background and rationale, and explicitly states the hypotheses guiding the review. The study navigates through various dimensions of nanomaterial applications in agriculture, encompassing their diverse properties, types, and associated challenges. Delving into the principles of QSAR in nanotoxicology, this article elucidates its application in evaluating the safety of nanomaterials, while addressing the unique limitations posed by these materials. The narrative then transitions to the progression of Nano-QSAR in the context of agricultural nanomaterials, exemplified by insightful case studies that highlight both the strengths and the limitations inherent in this methodology. Emerging prospects and hurdles tied to Nano-QSAR in agriculture are rigorously examined, casting light on important pathways forward, existing constraints, and avenues for research enhancement. Culminating in a synthesis of key insights, the review underscores the significance of Nano-QSAR in shaping the future of nanoenabled agriculture. It provides strategic guidance to steer forthcoming research endeavors in this dynamic field.

Exploring antibiofilm potential of some new imidazole analogs against C. albicans: synthesis, antifungal activity, molecular docking and molecular dynamics studies

A series of 1, 2, 4, 5-tetrasubstituted imidazole derivatives were synthesized and their antibiofilm potential against Candida albicans was evaluated in vitro. Two of the synthesized derivatives 5e (IC50 = 25 µg/mL) and 5m (IC50 = 6 µg/mL),displayed better antifungal and antibiofilm potential than the standard drug Fluconazole (IC50 = 40 µg/mL) against C. albicans. Based on the in vitro results, we escalated the real time polymerase chain reaction (RT-PCR) analysis to gain knowledge of the enzymes expressed in the generation and maintenance of biofilms and the mechanism of biofilm inhibition by the synthesized analogues. We then investigated the possible interactions of the synthesized compounds in inhibiting agglutinin-like proteins, namely Als3, Als4 and Als6 were prominently down-regulated using in-silico molecular docking analysis against the previously available crystal structure of Als3 and constructed structure of Als4 and Als6 using the SWISS-MODEL server. The stability and energy of the agglutinin-like proteins-ligand complexes were evaluated using molecular dynamics simulations (MDS). According to the 100 ns MDS, all the compounds remained stable, formed a maximum of 3, and on average 2 hydrogen bonds, and Gibb's free energy landscape analysis suggested greater affinity of the compounds 5e and 5m toward Als4 protein.Communicated by Ramaswamy H. Sarma.

Proteome dataset of Candida albicans (ATCC10231) opaque cell

OBJECTIVES

Candida albicans, a polymorphic yeast, is one of the most common, opportunistic fungal pathogens of humans. Among the different morphological forms, opaque form is one of the least-studied ones. This opaque phenotype is essential for mating and is also reported to be involved in colonizing the gastrointestinal tract. Considering the significance of the clinical and sexual reproduction of C. albicans, we have investigated the morphophysiological modulations in opaque form using a proteomic approach.

DATA DESCRIPTION

In the current investigation, we have used Micro-Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis to create a protein profile for opaque-specific proteins. Whole-cell proteins from C. albicans (ATCC10231) cells that had been cultured for seven days on synthetic complete dextrose (SCD) medium in both as an opaque (test) and as a white (control) form cells were extracted, digested, and identified using LC-MS/MS. This information is meant to serve the scientific community and represents the proteome profile (SWATH Spectral Libraries) of C. albicans opaque form.

Green synthesis of biogenic selenium nanoparticles functionalized with ginger dietary extract targeting virulence factor and biofilm formation in Candida albicans

To treat the systemic infections caused by Candida albicans (C. albicans), various drugs have been used, however, infections still persisted due to virulence factors and increasing antifungal resistance. As a solution to this problem, we synthesized selenium nanoparticles (SeNPs) by using Bacillus cereus bacteria. This is the first study to report a higher (70 %) reduction of selenite ions into SeNPs in under 6 h. The as-synthesized, biogenic SeNPs were used to deliver bioactive constituents of aqueous extract of ginger for inhibiting the growth and biofilm (virulence factors) in C. albicans. UV-visible spectroscopy revealed a characteristic absorption at 280 nm, and Raman spectroscopy showed a characteristic peak shift at 253 cm-1 for the biogenic SeNPs. The synthesized SeNPs are spherical with 240-250 nm in size as determined by electron microscopy. Fourier transform infrared spectroscopy confirmed the functionalization of antifungal constituents of ginger over the SeNPs (formation of Ginger@SeNPs nanoconjugates). In contrast to biogenic SeNPs, nanoconjugates were active against C. albicans for inhibiting growth and biofilm formation. In order to reveal antifungal mechanism of nanoconjugates', real-time polymerase chain reaction (RT-PCR) analysis was performed, according to RT-PCR analysis, the nanoconjugates target virulence genes involved in C. albicans hyphae and biofilm formation. Nanoconjugates inhibited 25 % growth of human embryonic kidney (HEK) 293 cell line, indicating moderate cytotoxicity of active nanoconjugates in an in-vitro cytotoxicity study. Therefore, biogenic SeNPs conjugated with ginger dietary extract may be a potential antifungal agent and drug carrier for inhibiting C. albicans growth and biofilm formation.

Proteomic dataset of Candida albicans (ATCC 10231) Biofilm

OBJECTIVES

The ability to form biofilm is considered as one of major virulence factors of Candida albicans, as biofilms form growth confers antifungal resistance and facilitate immune evasion. It is intriguing to understand morphophysiological modulations in the C. albicans cells growing under biofilm form growth.

DATA DESCRIPTION

In present study, we have profiled biofilm-specific proteins using LC-MS/MS analysis. Whole cell proteins of C. albicans cells grown under biofilm form growth (test) and planktonic (control) growth for 24 h were extracted, digested and identified using micro-Liquid Chromatography-Mass Spectrometry (LC-MS/MS). The present data represents proteomic profile (SWATH Spectral Libraries) of C. albicans biofilm intended to be useful to scientific community as it exhibits reuse potential.

Opaque Cell Specific Proteome of Candida albicans ATCC 10231

Candida albicans, a polymorphic opportunistic pathogen of humans, can exist in different morphological forms like yeast, hyphae, pseudohyphae, chlamydospores and white and opaque cells. Proteomic analysis of opaque form of C. albicans ATCC 10231 is carried out in the present study using micro-LC-MS/MS and validated using expression analysis of selected genes using RT-qPCR and mitochondrial membrane potential (MMP) assay. This is the first report identifying opaque cell-specific proteins of C. albicans. A total of 188 proteins were significantly modulated under opaque form compared to white cells, of which 110 were up-regulated, and 78 were down-regulated. It was observed that oxidative phosphorylation (OxPhos) and oxidative stress are enhanced in C. albicans cells growing under opaque form as proteins involved in OxPhos (Atp1, Atp3, Atp16, Atp7, Cox6, Nuc2, Qcr7 and Sdh12) and oxidative stress response (Gcs1, Gtt11, Gpx2, Sod1, Ccp1 and Lys7) were significantly up-regulated. The maximum up-regulation of 23.16 and 13.93-fold is observed in the case of Ccp1 and Nuc2, respectively. The down-regulation of proteins viz. Als1, Csh1, Sap9 and Rho1 determining cell surface chemistry indicates modulation in cell wall integrity and reduced adhesion of opaque cells compared to white cells. This study is significant as it is the first draft of the proteomic profile of opaque cells that suggests enhanced OxPhos, oxidative stress, and modulation in cell surface chemistry that indicates reduced adhesion and cell wall integrity that could be associated with reduced virulence in opaque form. However, a deeper investigation is needed to explore it further.

Recent Advances in Nano-Enabled Seed Treatment Strategies for Sustainable Agriculture: Challenges, Risk Assessment, and Future Perspectives

Agro seeds are vulnerable to environmental stressors, adversely affecting seed vigor, crop growth, and crop productivity. Different agrochemical-based seed treatments enhance seed germination, but they can also cause damage to the environment; therefore, sustainable technologies such as nano-based agrochemicals are urgently needed. Nanoagrochemicals can reduce the dose-dependent toxicity of seed treatment, thereby improving seed viability and ensuring the controlled release of nanoagrochemical active ingredients However, the applications of nanoagrochemicals to plants in the field raise concerns about nanomaterial safety, exposure levels, and toxicological implications to the environment and human health. In the present comprehensive review, the development, scope, challenges, and risk assessments of nanoagrochemicals on seed treatment are discussed. Moreover, the implementation obstacles for nanoagrochemicals use in seed treatments, their commercialization potential, and the need for policy regulations to assess possible risks are also discussed. Based on our knowledge, this is the first time that we have presented legendary literature to readers in order to help them gain a deeper understanding of upcoming nanotechnologies that may enable the development of future generation seed treatment agrochemical formulations, their scope, and potential risks associated with seed treatment.

Antifungal Properties of Biogenic Selenium Nanoparticles Functionalized with Nystatin for the Inhibition of Candida albicans Biofilm Formation

In the present study, biogenic selenium nanoparticles (SeNPs) have been prepared using Paenibacillus terreus and functionalized with nystatin (SeNP@PVP_Nystatin nanoconjugates) for inhibiting growth, morphogenesis, and a biofilm in Candida albicans. Ultraviolet-visible spectroscopy analysis has shown a characteristic absorption at 289, 303, and 318 nm, and X-ray diffraction analysis has shown characteristic peaks at different 2θ values for SeNPs. Electron microscopy analysis has shown that biogenic SeNPs are spherical in shape with a size in the range of 220-240 nm. Fourier transform infrared spectroscopy has confirmed the functionalization of nystatin on SeNPs (formation of SeNP@PVP_Nystatin nanoconjugates), and the zeta potential has confirmed the negative charge on the nanoconjugates. Biogenic SeNPs are inactive; however, nanoconjugates have shown antifungal activities on C. albicans (inhibited growth, morphogenesis, and a biofilm). The molecular mechanism for the action of nanoconjugates via a real-time polymerase chain reaction has shown that genes involved in the RAS/cAMP/PKA signaling pathway play an important role in antifungal activity. In cytotoxic studies, nanoconjugates have inhibited only 12% growth of the human embryonic kidney cell line 293 cells, indicating that the nanocomposites are not cytotoxic. Thus, the biogenic SeNPs produced by P. terreus can be used as innovative and effective drug carriers to increase the antifungal activity of nystatin.

Using NeuroPAL Multicolor Fluorescence Labeling to Identify Neurons in C. elegans

NeuroPAL (Neuronal Polychromatic Atlas of Landmarks) is a recently developed transgene that labels each of the 118 classes of neurons in C. elegans with various combinations of four fluorescent proteins. This neuron-type-specific labeling helps identify neurons that could otherwise be confused with neighboring neurons. Neuron identification enables researchers to combine new data that they generate on a C. elegans neuron with existing datasets on that same neuron, such as its synaptic connections, neurotransmitters, and transcriptome. An impediment to using NeuroPAL, however, is overcoming the steep learning curve for interpreting three-dimensional (3D) fluorescence images of crowded neural ganglia within which different neurons may be similarly colored, some neurons are only very faintly labeled, and the positions of some neurons are variable. Here, we provide protocols that allow researchers to learn to accurately identify neurons within 3D images of NeuroPAL-labeled animals. We provide 3D reference images that illustrate NeuroPAL labeling of each body region, and additional 3D images as training exercises to learn to accurately carry out C. elegans neuron identifications. We also provide tools to annotate images in 3D, and suggest that such 3D annotated images should be the standard for documenting C. elegans neuron identifications for publication. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Using Imaris software to view and annotate images of NeuroPAL-labeled animals in 3D Alternate Protocol: Using FIJI/ImageJ software to view and annotate images of NeuroPAL-labeled animals in 3D Basic Protocol 2: Identifying tail neurons-an introduction to identifying neurons Basic Protocol 3: Identifying midbody neurons Basic Protocol 4: Identifying anterior head neurons Basic Protocol 5: Identifying posterior head neurons Basic Protocol 6: Identifying ventral head and retrovesicular ganglion neurons.

Micropatterned Neurovascular Interface to Mimic the Blood–Brain Barrier’s Neurophysiology and Micromechanical Function: A BBB-on-CHIP Model

A hybrid blood–brain barrier (BBB)-on-chip cell culture device is proposed in this study by integrating microcontact printing and perfusion co-culture to facilitate the study of BBB function under high biological fidelity. This is achieved by crosslinking brain extracellular matrix (ECM) proteins to the transwell membrane at the luminal surface and adapting inlet–outlet perfusion on the porous transwell wall. While investigating the anatomical hallmarks of the BBB, tight junction proteins revealed tortuous zonula occludens (ZO-1), and claudin expressions with increased interdigitation in the presence of astrocytes were recorded. Enhanced adherent junctions were also observed. This junctional phenotype reflects in-vivo-like features related to the jamming of cell borders to prevent paracellular transport. Biochemical regulation of BBB function by astrocytes was noted by the transient intracellular calcium effluxes induced into endothelial cells. Geometry-force control of astrocyte–endothelial cell interactions was studied utilizing traction force microscopy (TFM) with fluorescent beads incorporated into a micropatterned polyacrylamide gel (PAG). We observed the directionality and enhanced magnitude in the traction forces in the presence of astrocytes. In the future, we envisage studying transendothelial electrical resistance (TEER) and the effect of chemomechanical stimulations on drug/ligand permeability and transport. The BBB-on-chip model presented in this proposal should serve as an in vitro surrogate to recapitulate the complexities of the native BBB cellular milieus.

Investigation of the Associations between a Nanomaterial's Microrheology and Toxicology

With the advent of Nanotechnology, the use of nanomaterials in consumer products is increasing on a daily basis, due to which a deep understanding and proper investigation regarding their safety and risk assessment should be a major priority. To date, there is no investigation regarding the microrheological properties of nanomaterials (NMs) in biological media. In our study, we utilized in silico models to select the suitable NMs based on their physicochemical properties such as solubility and lipophilicity. Then, we established a new method based on dynamic light scattering (DLS) microrheology to get the mean square displacement (MSD) and viscoelastic property of two model NMs that are dendrimers and cerium dioxide nanoparticles in Dulbecco's Modified Eagle Medium (DMEM) complete media at three different concentrations for both NMs. Subsequently, we established the cytotoxicological profiling using water-soluble tetrazolium salt-1 (WST-1) and a reactive oxygen species (ROS) assay. To take one step forward, we further looked into the tight junction properties of the cells using immunostaining with Zonula occluden-1 (ZO-1) antibodies and found that the tight junction function or transepithelial resistance (TEER) was affected in response to the microrheology and cytotoxicity. The quantitative polymerase chain reaction (q-PCR) results in the gene expression of ZO-1 after the 24 h treatment with NPs further validates the findings of immunostaining results. This new method that we established will be a reference point for other NM studies which are used in our day-to-day consumer products.

Emerging cold plasma treatment and machine learning prospects for seed priming: a step towards sustainable food production

Seeds are vulnerable to physical and biological stresses during the germination process. Seed priming strategies can alleviate such stresses. Seed priming is a technique of treating and drying seeds prior to germination in order to accelerate the metabolic process of germination. Multiple benefits are offered by seed priming techniques, such as reducing fertilizer use, accelerating seed germination, and inducing systemic resistance in plants, which are both cost-effective and eco-friendly. For seed priming, cold plasma (CP)-mediated priming could be an innovative alternative to synthetic chemical treatments. CP priming is an eco-friendly, safe and economical, yet relatively less explored technique towards the development of seed priming. In this review, we discussed in detail the application of CP technology for seed priming to enhance germination, the quality of seeds, and the production of crops in a sustainable manner. Additionally, the combination treatment of CP with nanoparticle (NP) priming is also discussed. The large numbers of parameters need to be monitored and optimized during CP treatment to achieve the desired priming results. Here, we discussed a new perspective of machine learning for modeling plasma treatment parameters in agriculture for the development of synergistic protocols for different types of seed priming.

Identification of potential antileishmanial 1,3-disubstituted-4-hydroxy-6-methylpyridin-2(1H)-ones, in vitro metabolic stability, cytotoxicity and molecular modeling studies

We report the synthesis and in vitro evaluation of 1,3-disubstituted-4-hydroxy-6-methylpyridin-2(1H)-one derivatives against Leishmania donovani. Amongst the compound library synthesized, molecules 3d, 3f, 3h, 3i, 3l, and 3m demonstrated substantial dose-dependent killing of the promastigotes. Their IC₅₀ values range from 55.0 to 77.0 μg/ml, with 3m (IC₅₀ 55.75 μg/ml) being equipotent with amphotericin B (IC₅₀ 50.0 μg/ml, used as standard). The most active compound 3m, is metabolically stable in rat liver microsomes. Furthermore, the molecules are highly specific against leishmania as shown by their weak antibacterial and antifungal activity. In vitro cytotoxicity studies show the compounds lack any cytotoxicity. Furthermore, molecular modeling studies show plausibility of binding to Leishmania donovani topoisomerase 1 (LdTop1). Structure activity relationships reveal bulky substitutions on the pyridone nitrogen are well-tolerated, and such compounds have better binding affinity. Intramolecular hydrogen bonds confer some rigidity to the molecules, rendering a degree of planarity akin to topotecan. Taken together, we emphasis the merits of molecules possessing the 1,3-disubstituted-4-hydroxy-6-methylpyridin-2(1H)-one skeleton as potential antileishmanial agents warranting further investigation.

Sustainable Agriculture through Multidisciplinary Seed Nanopriming: Prospects of Opportunities and Challenges

The global community decided in 2015 to improve people's lives by 2030 by setting 17 global goals for sustainable development. The second goal of this community was to end hunger. Plant seeds are an essential input in agriculture; however, during their developmental stages, seeds can be negatively affected by environmental stresses, which can adversely affect seed vigor, seedling establishment, and crop production. Seeds resistant to high salinity, droughts and climate change can result in higher crop yield. The major findings suggested in this review refer nanopriming as an emerging seed technology towards sustainable food amid growing demand with the increasing world population. This novel growing technology could influence the crop yield and ensure the quality and safety of seeds, in a sustainable way. When nanoprimed seeds are germinated, they undergo a series of synergistic events as a result of enhanced metabolism: modulating biochemical signaling pathways, trigger hormone secretion, reduce reactive oxygen species leading to improved disease resistance. In addition to providing an overview of the challenges and limitations of seed nanopriming technology, this review also describes some of the emerging nano-seed priming methods for sustainable agriculture, and other technological developments using cold plasma technology and machine learning.

Oxidative stress induced by piperine leads to apoptosis in Candida albicans

Candida albicans is a member of pathogens with potential drug resistance threat that needs novel chemotherapeutic strategies. Considering the multifarious biological activities including bioenhancer activity, anti-Candida potential of piperine was evaluated against planktonic/biofilm and hyphal growth of C. albicans alone or in combination as a synergistic agent with fluconazole. Piperine inhibits planktonic growth at or less than 15 μg/ml, hyphae induction at 5 μg/ml concentration, and exhibits stage-dependent activity against biofilm growth of a fluconazole-resistant strain of C. albicans (ATCC10231). Though piperine couldn't kill inoculum completely at minimum inhibitory concentration (MIC), it is fungicidal at higher concentrations, as shown in apoptosis assay. FIC index values indicate that piperine exhibits excellent synergistic activity with fluconazole against planktonic (0.123) and biofilm (0.215) growth of an FLC resistant strain. Mode of anti-Candida activity was studied by identifying piperine responsive proteins wherein the abundance of 25 proteins involved in stress response, signal transduction and cell cycle were modulated (22 up and 3 down-regulated) significantly in response to piperine (MIC50). Modulation of the proteins involved suggests that piperine affects membrane integrity leading to oxidative stress followed by cell cycle arrest and apoptosis in C. albicans. Flow cytometry-based mitochondrial membrane potential (MMP), cell cycle and apoptosis assay, as well as real-time quantitative polymerase chain reaction analysis of selected genes, confirms piperine induced oxidative stress (TRR1), cell cycle arrest and apoptosis (CaMCA1). Based on our results, we conclude that piperine inhibits planktonic and difficult-to treat-biofilm growth of C. albicans by affecting membrane integrity thereby inducing oxidative stress and apoptosis.

LAY ABSTRACT

Piperine inhibit Candida albicans growth (planktonic and biofilm) significantly in our study. Piperine exhibits excellent synergistic potential with fluconazole The proteome analysis suggests that piperine induced membrane damage leads to oxidative stress followed by cell cycle arrest and apoptosis.

Helminthicidal and Larvicidal Potentials of Biogenic Silver Nanoparticles Synthesized from Medicinal Plant Momordica charantia

BACKGROUND

The drug formulations used to control mosquito vectors and helminth infections have resulted in the development of resistance, and negative impact on non-target organisms and environment.

OBJECTIVE

Plant-mediated synthesis of silver nanoparticles (P-AgNPs) using aqueous fruit peel extract of M. charantia, applications of P-AgNPs for helminthicidal activity against Indian earthworms (P. posthuma) and larvicidal activity against larvae of mosquito A. albopictus and A. aegypti.

METHODS

Aqueous fruit peel extract of Momordica charantia was used to reduce silver ions to silver nanoparticles (P-AgNPs). UV-Visible (UV-Vis) Spectroscopy, X-ray diffraction, Fourier Transform Infrared Spectroscopy and Transmission Electron Microscopy characterize synthesized P-AgNPs. The motility and survival rate of the worms were recorded for the helminthicidal activity. Percent mortality of larvae of A. albopictus and A. aegypti was recorded for larvicidal activity.

RESULTS

The UV-Vis absorption spectrum of P-AgNPs showed a strong surface plasmon absorption band in the visible region with a maximum absorption at 445 nm indicating the synthesis of silver nanoparticles by the addition of aqueous fruit peel extract. The XRD spectrum of P-AgNPs showed Bragg's reflection peaks 2θ value characteristics for the Face-Centered Cubic (FCC) structure of silver. The sharp absorption peak in FTIR at 1659 cm-1 assigned to C=O stretching vibration in carbonyl compounds represents terpenoids, flavonoids and polyphenols in the corona of PAgNPs; a 2 mg/mL of P-AgNPs. The concentration aqueous extract and P-AgNPs showed complete death of worms (the morphological alteration/coiling of body). A 20 ppm concentration of PAgNPs showed 85% mortality in larvae of Ae. albopictus and Ae. aegypti. P-AgNPs were nontoxic at low concentrations.

CONCLUSION

The aqueous extracts played a dual role as reducing and capping agent during the biosynthesis of AgNPs as per FTIR and XRD results. The surface reactivity facilitated by biomolecule corona attached to silver nanoparticles can further help to functionalize AgNPs in various pharmaceuticals, biomedicals, and environmental applications.

Limonene inhibits Candida albicans growth by inducing apoptosis

Anti-Candida potential of limonene was evaluated against planktonic growth, biofilm (adhesion, development and maturation) and morphogenesis of Candida albicans in this study. Limonene is a major constituent of citrus oil and most frequently used terpene in food and beverage industry due to its pleasant fragrance, nontoxic, and is generally recognized as safe (GRAS) flavoring agent as well as treatment option in many gastrointestinal diseases.Limonene exhibited excellent anti-Candida activity and was equally effective against planktonic growth of C. albicans isolates differentially susceptible to FLC (N = 35). Limonene inhibited morphogenesis significantly at low concentration. However, it showed stage dependent activity against biofilm formation, that is, it was more effective against adhesion followed by development and maturation. Limonene also exhibited excellent synergy with FLC against planktonic and biofilm growth. SWATH-MS analysis led to identification of limonene responsive proteins that provided molecular insight of its anti-Candida activity. Proteomic analysis revealed upregulation of proteins involved in cell wall glucan synthesis (Kre6); oxidative stress (Rhr2, Adh7 and Ebp1); DNA damage stress (Mbf1 and Npl3); nucleolar stress (Rpl11, Rpl7, Rpl29, Rpl15) and down regulation of cytoskeleton organization (Crn1, Pin3, Cct8, Rbl2), and so forth, in response to limonene. Limonene mediated down regulation of Tps3 indicates activation of caspase (CaMca1) and induction of apoptosis in C. albicans. These results suggest that limonene inhibits C. albicans growth by cell wall/membrane damage induced oxidative stress that leads to DNA damage resulting into modulation of cell cycle and induction of apoptosis through nucleolar stress and metacaspase dependent pathway.

The human muscarinic acetylcholine receptor antagonist, Dicyclomine targets signal transduction genes and inhibits the virulence factors in the human pathogen, Candida albicans

Dicyclomine is a human muscarinic acetylcholine receptor antagonist used for the treatment of abdominal cramps. We are reporting here that dicyclomine can inhibit the in vitro growth and virulence factors of the human pathogen Candida albicans very effectively. Dicyclomine inhibited adhesion, early biofilm, mature biofilm, and planktonic growth. Yeast to hyphal form transition of C. albicans in various inducer media such as serum, proline, glucose, and N-acetylglucosamine was inhibited. Dicyclomine also could kill C. albicans cells within 15 min of exposure. Dicyclomine appears to inhibit the yeast to hyphal conversion by affecting signal transduction pathway. The expression of selected genes associated with yeast to hyphal form transition in serum in presence of dicyclomine was studied using real-time polymerase chain reaction (RtPCR). The RtPCR analysis showed that dicyclomine targets both cAMP pathway as well as MAPK cascade. Eight genes were upregulated. Out of these, three major upregulated genes were Bcy1, Tup1, and Mig1. Dicyclomine downregulated Ume6, Ece1, and Pde2 genes which are involved in cAMP signaling pathway and also downregulated the DNA binding protein gene, Rfg1. Dicyclomine significantly upregulated the master negative regulator of hyphal formation, Tup1. Based on this study we suggest that the muscarinic acetylcholine receptor antagonist, dicyclomine could be repositioned as a potential anti-Candida albicans as well as anti-virulence agent.

The antibacterial agent, moxifloxacin inhibits virulence factors of Candida albicans through multitargeting

Fluoroquinolines are broad spectrum fourth generation antibiotics. Some of the Fluoroquinolines exhibit antifungal activity. We are reporting the potential mechanism of action of a fluoroquinoline antibiotic, moxifloxacin on the growth, morphogenesis and biofilm formation of the human pathogen Candida albicans. Moxifloxacin was found to be Candidacidal in nature. Moxifloxacin seems to inhibit the yeast to Hyphal morphogenesis by affecting signaling pathways. It arrested the cell cycle of C. albicans at S phase. Docking of moxifloxacin with predicted structure of C. albicans DNA Topoisomerase II suggests that moxifloxacin may bind and inhibit the activity of DNA Topoisomerase II in C. albicans. Moxifloxacin could be used as a dual purpose antibiotic for treating mixed infections caused by bacteria as well as C. albicans. In addition chances of developing moxifloxacin resistance in C. albicans are less considering the fact that moxifloxacin may target multiple steps in yeast to hyphal transition in C. albicans.