Browsing by Author "Karuna Singh"

Now showing 1 - 20 of 38

An overview of textile dyes and their removal techniques: Indian perspective
(EM International, 2017) Karuna Singh; Pankaj Kumar; Rajani Srivastava
Textile industry discharge a huge amount of dye containing waste water which pollutes water, soil and also have adverse affect on human health, animal and plants. Imperfection of dyeing process, approximately 10-15% of the synthetic dyes is released into the industrial waste, causing serious environmental problems, flora and fauna of aquatic ecosystems as well as terrestrial ecosystem. It causes contamination of surface water, accumulation of toxic and carcinogenic substance in water. Removal of dyes from dye containing waste water must be done by either physico-chemical or biological methods. Biological methods are dominant over physico-chemical methods, and involve fungi, algae, actinomycetes and bacteria. Biological method is considered to be more efficient in terms of its long lasting benefits, and no negative impact on environment. For complete treatment of textile waste water, integration of physical, chemical and biological methods are necessary. Biological method is considered to be more efficient in terms of its long lasting benefits, and no negative impact on environment. Careful selection of microbial strain is an important suggestion and recommendation. © Copyright EM International.
Antioxidant property of aerial parts and root of phyllanthus fraternus webster, an important medicinal plant
(2014) Richa Upadhyay; Jitendra Kumar Chaurasia; Kavindra Nath Tiwari; Karuna Singh
In present study free radical scavenging potential of aerial parts and root of Phyllanthus fraternus was investigated. Extraction was done in water and ethanol. Total antioxidant capacity was measured by DPPH free radical scavenging method; ethanolic extract of aerial part was most potent in activity with 50% inhibition at 258 μg/mL concentration. Lipid peroxidation (LPO) was measured in terms of thiobarbituric acid-reactive substances (TBARS) by using egg-yolk homogenates as lipid-rich media with ECof aerial part (ethanolic) 1522 μg/mL which was found to be most active. Superoxide (SO) radical scavenging activity was measured using riboflavin-light-nitroblue tetrazolium assay. Ethanolic and aqueous extract of both aerial part and root was almost similar in superoxide radical scavenging activity. Reducing power was determined on the basis of Fe 3 + - Fe 2 + transformation in the presence of extract. Total phenolic and flavonoid contents were also measured by spectroscopic method. Results showed that the ethanolic fraction of aerial part is most active towards antioxidant potential and this activity is related to its polyphenolic content and reducing potential. Thus, P. fraternus extract can be used as potent natural antioxidant. © 2014 Richa Upadhyay et al.
Assessment of factors on shoot proliferation potential of nodal explants of Phyllanthus fraternus and assessment of genetic fidelity of micropropagated plants using RAPD marker
(Versita, 2014) Richa Upadhyay; Sarvesh Pratap Kashyap; Chandrashekhar Singh; Kavindra Nath Tiwari; Karuna Singh; Major Singh
Phyllanthus fraternus is an important medicinal plant, popularly known for its hepatoprotective and antiviral activities since ancient times. Various physiological factors like carbon sources, concentration of agar, pH of the media and effect of season of explants collection were optimized for high frequency regeneration of P. fraternus. The frequency of regeneration, average number and length of shoots were highly influenced by the type and concentration of carbon sources (monosaccharides and disaccharides, 1 to 4%), agar concentration (0.2 to 1%) and pH (4.5 to 6.8) of the media. Media containing 3% sucrose, 0.6% agar at pH 5.8 was best for regeneration. Seasonal variation of explants collection significantly affected the axillary shoots proliferation from explants and best proliferation was observed from explants collected during April to June. Genetic fidelity of regenerated plants was assessed by random amplified polymorphic DNA markers. No polymorphism was detected in micropropagated plants and the mother plant, revealing the genetic homogeneity of the in vitro raised plantlets. This is the first report regarding establishment of genetic fidelity of micropropagated P. fraternus plants, which could be successfully applied for the mass multiplication, germplasm conservation and further genetic transformation assays to meet the ever increasing demand of this medicinally potent plant for industrial and pharmaceutical uses. © 2014, Versita Warsaw and Springer-Verlag Wien.
Combined experimental and theoretical studies of diorganotin(IV) complexes of 1,2,4-triazole based Schiff base: Synthesis, spectroscopic investigation, DFT calculation, antifungal activity
(Elsevier B.V., 2024) Rachana Joshi; Sandeep Pokharia; Ajay Singh; Hirdyesh Mishra; Karuna Singh
Two novel diorganotin(IV) compounds of Schiff base (HL) with a general formula of R2Sn(L)Cl (where R equals n-Bu(1) or Ph (2)) have been formed and structurally identified. The identification was made through examination of various properties including elemental analysis, FT-IR, multinuclear NMR, 2D-HMQC, ESI-MS, and UV–vis analysis. The proposed structure for these organotin(IV) derivatives is a distorted tetrahedron surrounding tin, with the Schiff base ligand acting as a monoanionic monodentate by coordinating through the Ohydroxyl group. The density functional theory (DFT) calculation was accomplished at the B3LYP/6-31G(d,p)/Def2- SVP(Sn) level. The MEP map was used to recognize the reactive sites on the molecules, and atomic charges were determined at specific atoms. The global reactivity descriptors and the Frontier MO's were calculated using conceptual-DFT to understand the behavior of the structure and reactivity. We compared the experimental and simulated vibrational frequencies and found a strong correlation. A time-dependent DFT method utilizing the IEFPCM model was employed to determine the simulated UV–vis spectrum. Both of the analyzed complexes were tested for their ability to inhibit fungal growth in vitro against selected fungal strains. The significant antifungal effect of complexes could be observed against all strains. © 2023 Elsevier B.V.
Comparative antioxidant study of stem and stem induced callus of Phyllanthus fraternus webster - An important antiviral and hepatoprotective plant
(2013) Richa Upadhyay; Jitendra Kumar Chaurasia; Kavindra Nath Tiwari; Karuna Singh
Phyllanthus fraternus is widely used in the cure of various liver diseases and possess antiviral properties especially against hepatitis virus. In the present study, evaluation of the antioxidant activity of stem and calli induced from stem has been done by different assays. Extraction was done by standard method in water and ethanol. Total antioxidant capacity was measured by 1, 1-diphenyl-2-picrylhydrazyl free radical scavenging method. Lipid peroxidation was measured in terms of thiobarbituric acid-reactive substances (TBARS) by using egg yolk homogenates as lipid-rich media, and superoxide radical scavenging activity was measured using riboflavin-light-nitro blue tetrazolium assay. Reducing power was determined on the basis of Fe3+-Fe 2+ transformation in the presence of the extract. In addition to the antioxidant activity, polyphenolic compounds like total phenolics and flavonoids were also measured by spectroscopic method. Results showed that the ethanolic extract of stem is more potent in antioxidant activity than its aqueous extract and ethanolic extract of calli. A significant correlation between antioxidant capacity and polyphenolic content and reducing potential was observed, indicating that phenolic compounds and reducers present in extract are major contributors to the antioxidant potential. Thus, this plant extract could be used as a potent natural antioxidant. © Springer Science+Business Media New York 2013.
Cryptococcosis: Emergence of cryptococcus gattii in animals and zoonotic potential
(Springer International Publishing, 2018) Karuna Singh; Macit Ilkit; Tahereh Shokohi; Ali Tolooe; Richard Malik; Seyedmojtaba Seyedmousavi
Cryptococcosis is one of the most serious fungal diseases of animals worldwide, affecting a wide variety of mammals (including humans) and, occasionally, birds, reptiles, and amphibians. The disease is caused by pathogenic members of the encapsulated, melanin-forming, basidiomycetous yeast genus Cryptococcus, namely, Cryptococcus neoformans and Cryptococcus gattii species complexes. These two species have different ecological niches across climate zones: C. neoformans has been isolated primarily from soil and avian excrement, whereas C. gattii is mainly associated with decaying wood and other plant materials, particularly in and around various species of trees. Cryptococcosis, which appears to be acquired by the inhalation of yeasts from environmental niches and penetration into the sinonasal cavity (animals) or pulmonary alveoli (humans) of the host, followed by hematogenous dissemination (humans) or penetration of the cribriform plate of the ethmoid bones (many animals), often manifests as skin and soft tissue infections, rhinosinusitis, pneumonia, and meningoencephalitis. Animals and people may become infected via the same environmental source; however, no convincingmammal-to-mammal transmission has been documented to date. This chapter highlights the diseases and complications that Cryptococcus species may cause in invertebrates, cold- and warm-blooded animals, marine mammals, and nonhuman primates. The potential role of animal hosts as sentinels of human cryptococcosis is discussed. © Springer International Publishing AG, part of Springer Nature 2018.
Enrichment of drug resistance genes in human pathogenic bacteria showing antimicrobial resistance
(Elsevier, 2023) Karuna Singh; Radha Chaube
The recent past has witnessed the emergence of multidrug-resistant pathogenic bacteria posing a significant risk to human and animal health worldwide. During coevolvement, the pathogenic bacteria have modified their pathogenic potential to counteract the host defense systems. Moreover, the abusive use of antibiotics has significantly contributed to the emergence of antimicrobial resistance. The genes responsible for antibiotic resistance (ARGs) are not confined, to the bacterial population associated with human and animal healthcare systems; instead, they have been increasingly appearing in the environmental population and maybe partaken by horizontal gene transfer (HGT) from nonpathogenic to pathogenic isolates. Thus, detection of HGT-derived spread of ARGs, knowledge of the distribution pattern of resistance determinants in bacterial populations, determination of dissemination-promoting environmental factors of ARGs are necessary to understand the drug resistance mechanism of pathogenic bacteria. The present chapter will review the recent advancement in antibiotic resistance genes of pathogenic bacteria. © 2023 Elsevier Inc. All rights reserved.
Epitope prediction and designing of receptor inhibitor of Dengue Envelope Protein: An in silico approach
(Wolters Kluwer Medknow Publications, 2023) Gunjan Uttam; Ankita Kumari; Karuna Singh
Background & objectives: Dengue virus (DENV) is the causative agent of dengue fever (DF) and dengue hemorrhagic fever (DHF). It has four distinct serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) based on their antigenic properties. Mostly, the immunogenic epitopes are present in the envelope (E) protein of the virus. Heparan sulfate (HS) acts as a receptor and interacts with the E protein of the virus thus facilitating the entry of dengue virus into human cells. This study focuses on epitope prediction on the E protein of the DENV serotype. The non-competitive inhibitors of HS were designed using bioinformatics. Methods: In the present study, epitope prediction of the E protein of DENV serotypes was performed using the ABCpred server and IEDB analysis resource. The interactions of HS and viral E proteins (PDB ID: 3WE1 and PDB ID:1TG8) were evaluated through AutoDock. Subsequently, non-competitive inhibitors were designed to bind the E protein of DENV better than HS. All the docking results were validated by re-docking the ligand-receptor complexes and superimposing them onto their co-crystallized complexes using AutoDock and visualizing them in Discovery Studio. Results: The result predicted B-cell and T-cell epitopes on the E protein of DENV serotypes. The designed HS ligand 1 (non-competitive inhibitor) demonstrated potential binding with the DENV E protein, thereby inhibiting HS-E protein binding. The re-docked complexes were superimposed entirely onto the native co-crystallized complexes (low root mean square deviation values), which validates the docking protocols. Interpretation & conclusion: The identified B-cell and T-cell epitopes of the E protein and non-competitive inhibitors of HS (ligand 1) could be used in the designing of potential drug candidates against the dengue virus. © 2023 Wolters Kluwer Medknow Publications. All rights reserved.
EVALUATION OF ANTI-CRYPTOCOCCAL ACTIVITY OF BACITRACIN
(Slovak University of Agriculture, 2020) Neelabh; Karuna Singh
Cryptococcosis is amongst potentially deadly diseases whose impact has aggrandized with the advent of AIDS and antifungal resistance. Antifungals used presently are short of broad spectrum activity and furthermore are involved in several side effects. Henceforth, the present manuscript focuses on the evaluation of antifungal activity of bacitracin against Cryptococcus neoformans var. grubii, the causative agent of the disease. Minimum inhibitory concentration, flow cytometric analysis and confocal microscopy were used to determine the in-vitro fungal susceptibilities. Light microscopy was used to determine the changes in the micromorphology of the fungal organism. Swiss mice were used for testing the efficacy of bacitracin in-vivo.Bacitracin showed cidal activity against C. n. grubii at 5.5 mg/ml which is on the higher side but on testing under in-vivo conditions it was observed that doses as high as 15 mg/kg bw/day did not show any adverse effect in the body. Better survival rate of the bacitracin treated mice, lowering of the fungal load and changes showing improvement in the tissue morphology depicts the mild anticryptococcal activity of bacitracin. Although, bacitracin has proved to be a potent antifungal yet there are several limitations like low bioavailability and its peptide nature. However, these problems can be limited by developing suitable analogs of the compound. © 2020. All Rights Reserved.
Evaluation of antifungal activity of cinnamaldehyde against Cryptococcus neoformans var. grubii
(Springer Science and Business Media B.V., 2020) Neelabh; Karuna Singh
Cryptococcosis is a potentially fatal fungal disease which has aggrandized with the emergence of AIDS and antifungal resistance. The currently used antifungals lack the broad-spectrum activity and result in several toxicities during long treatment regimens. Thus, the present study aims to evaluate the antifungal activity of cinnamaldehyde against Cryptococcus neoformans var. grubii, the etiological agent of the disease. Quantitative and qualitative in vitro fungal susceptibilities were carried out by minimum inhibitory concentration assay, flow cytometric analysis, and confocal microscopy. Micromorphological alterations were studied through scanning electron and light microscopies. “In vivo” antifungal efficacy of cinnamaldehyde was assessed. Cinnamaldehyde showed antifungal activity against C. neoformans in a dose-dependent manner. A concentration of 1.37 mg/mL of cinnamaldehyde was found to be inhibitory and fungicidal while the low concentration (0.68 mg/mL) was found to induce micromorphological changes and formation of giant/titan-like cells in this pathogen. The reparative activity of cinnamaldehyde and its ability to prolong the life even after the advent of cryptococcal meningitis in mice was also noticed. This study suggests potent anti-cryptococcal activity of cinnamaldehyde. Though, it has a couple of limitations like allergy and low bioavailability. However, these problems can be circumvented by developing suitable analogs of the compound. It, therefore, could be used as a therapeutic option against cryptococcosis and cryptococcal meningitis. Moreover, the evaluation of its pharmacokinetic and pharmacodynamic properties is desirable. © 2020, Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.
Evaluation of prophylactic efficacy of cinnamaldehyde in murine model against Paradendryphiella arenariae mycotoxin tenuazonic acid-induced oxidative stress and organ toxicity
(Nature Research, 2021) Ankita Kumari; Karuna Singh
Cinnamaldehyde (Cin) is a natural product obtained from cinnamon and is reported to have a potential anti-fungal, anti-oxidant, anti-inflammatory and anticancer effect. The present study investigated the possible protective role of Cin against tenuazonic acid-induced mycotoxicity in the murine model. Tenuazonic acid (TeA), a toxin produced by Alternaria is a common contaminant in tomato and tomato-based products. Here, Swiss male mice were administered with TeA isolated from Paradendryphiella arenariae (MW504999) (source-tomato) through injection (238 µg/kg BW) and ingestion (475 µg/kg BW) routes for 2 weeks. Thereafter, the prophylaxis groups were treated with Cin (210 mg/kg BW). The experiment was carried out for 8 weeks. The treated groups were compared to the oral and intra-peritoneal experimental groups that received the toxin solely for 8 weeks. Haematological, histopathological and biochemical aspects of the experimental and the control mice were analysed. Sub-chronic intoxication of mice with TeA showed elevated malondialdehyde (MDA), reduced catalase (CAT) and superoxide dismutase (SOD) production; abnormal levels of aspartate transaminase (AST) and alanine transaminase (ALT). Treatment with Cin reversed TeA-induced alterations of antioxidant defense enzyme activities and significantly prevented TeA-induced organ damage. Thus, cinnamaldehyde showed therapeutic effects and toxicity reduction in TeA induced mycotoxicosis. © 2021, The Author(s).
Ex Situ Conservation of Phyllanthus fraternus Webster and Evaluation of Genetic Fidelity in Regenerates Using DNA-Based Molecular Marker
(Humana Press Inc., 2014) Richa Upadhyay; Sarvesh Pratap Kashyap; Chandra Shekhar Singh; Kavindra Nath Tiwari; Karuna Singh; Major Singh
Germplasm storage of Phyllanthus fraternus by using synseed technology has been optimized. Synseeds were prepared from nodal segments taken from in vitro-grown plantlets. An encapsulation matrix of 3 % sodium alginate and 100 mM calcium chloride with polymerization duration up to 15 min was found most suitable for synseed formation. Maximum plantlet conversion (92.5 ± 2.5 %) was obtained on a growth regulator-free ½-strength solid Murashige and Skoog (MS) medium. Multiple shoot proliferation was optimum on a ½ MS medium containing 0.5 mg/l 6-benzylaminopurine (BAP). Shoots were subjected to rooting on MS media containing 1 mg/l α-naphthaleneacetic acid (NAA) and acclimatized successfully. Encapsulated nodal segments can be stored for up to 90 days with a survival frequency of 47.33 %. The clonal fidelity of synseed-derived plantlets was also assessed and compared with that of the mother plant using rapid amplified polymorphic DNA and inter-simple sequence repeat analysis. No changes in molecular profiles were observed among the synseed-derived plantlets and mother plant, which confirms the genetic stability of regenerates. This synseed production protocol could be useful for in vitro multiplication, short-term storage, and exchange of germplasm of this important antiviral and hepatoprotective plant. © 2014, Springer Science+Business Media New York.
Fungal infections in animals: A patchwork of different situations
(Oxford University Press, 2018) Seyedmojtaba Seyedmousavi; Sandra Bosco; Sybren De Hoog; Frank Ebel; Daniel Elad; Renata R. Gomes; Ilse D. Jacobsen; An Martel; Bernard Mignon; Frank Pasmans; Elena Piecková; Anderson Messias Rodrigues; Karuna Singh; Vania A. Vicente; Gudrun Wibbelt; Nathan P. Wiederhold; Jacques Guillot
The importance of fungal infections in both human and animals has increased over the last decades. This article represents an overview of the different categories of fungal infections that can be encountered in animals originating from environmental sources without transmission to humans. In addition, the endemic infections with indirect transmission from the environment, the zoophilic fungal pathogens with near-direct transmission, the zoonotic fungi that can be directly transmitted from animals to humans, mycotoxicoses and antifungal resistance in animals will also be discussed. Opportunistic mycoses are responsible for a wide range of diseases from localized infections to fatal disseminated diseases, such as aspergillosis, mucormycosis, candidiasis, cryptococcosis and infections caused by melanized fungi. The amphibian fungal disease chytridiomycosis and the Bat White-nose syndrome are due to obligatory fungal pathogens. Zoonotic agents are naturally transmitted from vertebrate animals to humans and vice versa. The list of zoonotic fungal agents is limited but some species, like Microsporum canis and Sporothrix brasiliensis from cats, have a strong public health impact. Mycotoxins are defined as the chemicals of fungal origin being toxic for warm-blooded vertebrates. Intoxications by aflatoxins and ochratoxins represent a threat for both human and animal health. Resistance to antifungals can occur in different animal species that receive these drugs, although the true epidemiology of resistance in animals is unknown, and options to treat infections caused by resistant infections are limited. © Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology 2017.
High frequency shoots regeneration for mass multiplication of Phyllanthus fraternus Webster - An important antiviral and hepatoprotective plant
(2013) Richa Upadhyay; Kavindra Nath Tiwari; Karuna Singh
An efficient, rapid, and highly reproducible regeneration protocol was successfully developed for Phyllanthus fraternus from the field-derived mature nodal segments. The explants induced multiple shoots on cytokinin containing medium. The highest frequency (99 %) and maximum number of shoots (19.75) were induced on Murashige and Skoog's (MS) medium supplemented with 2.22 μM 6-benzylaminopurine after 3-4 weeks of culture initiation. The elongated shoots were rooted on MS medium supplemented with indol-3-butyric acid (IBA) or α-naphthalene acetic acid. Pulse treatment of microshoots promoted significant increase in the percentage of rooting and number of root regeneration per shoot. The highest rooting (100 %) and maximum number of roots (8.75) per shoot was obtained when shoots were dipped in IBA solution (0.98 mM) for 5 min and further subcultured on MS basal medium. Plantlets were successfully acclimatized and established in soil. Regenerated plants were grown normally in the field without showing any morphological variations. This cost-effective protocol will help the mass multiplication of P. fraternus for commercial propagation and high biomass production of this valuable medicinal plant. © 2013 Springer Science+Business Media.
In silico designing and interaction of coumarin-amino acid(S) conjugates with integrin like protein of cryptococcus neoformans: Insights on antifungal drug design
(AMG Transcend Association, 2021) Neha Tiwari; Gunjan Uttam; Priyanka; Karuna Singh; Diksha Katiyar
In the present work, a library of 117 coumarin-amino acid(s) conjugates was designed, and molecular docking study was performed to investigate their possible role as fungal integrin like receptor antagonists. The objective of this study is in-silico designing and docking of coumarin-amino acid conjugates against integrin like protein of Cryptococcus neoformans. In the absence of a crystallographic structure of integrin of the fungal pathogen, a homology model of protein OXH63806.1 of Cryptococcus neoformans was developed using the currently available X-ray structure of human integrin as a template. The quality of the 3D model obtained by homology modeling was evaluated by the PROCHECK program. A docking study using coumarin-amino acid(s) conjugates as ligands on the binding site of the modeled receptor was carried out to understand the protein-ligand binding interactions. Some of the compounds have shown very good binding energies ranging from-10.32 to-10.94 Kcal/mol towards the target receptor. These results may be helpful in the designing and development of new antifungal agents as integrin like protein antagonists. © 2020 by the authors.
In silico studies on the effect of griseofulvin on tubulin protein of Cryptococcus neoformans and its in vitro validation
(Slovak University of Agriculture, 2017) Neelabh; Karuna Singh
Griseofulvin is a well known drug against dermatophytes. It is particularly prescribed for an infection called scrap ringworm or tinea capitis. In general, griseofulvin inhibits the tubulin protein that is responsible for the cell division. Not much is known about the effect of griseofulvin on Cryptococcus neoformans. Therefore, the authors made an effort to check the activity of griseofulvin against it. The webservers (T-Coffee, Bluues simulation and CASTp) and software (Autodock 4.0) have been used in order to determine the activity of griseofulvin against the beta subunit of tubulin protein of C. neoformans. The results obtained from the in silico studies show a high affinity of griseofulvin towards the beta chain of tubulin protein. The negative value of binding energy (-9.02 kcal/mol) also shows that the complex is thermodynamically favourable and stable. These in silico results were further validated by MIC assay showing 74.1% inhibition of C. neoformans (isolate no. 5) against griseofulvin. The present study reports that apart from dermatophytes, the drug has significant effect on C. neoformans and it may be used in the combinatorial therapy against the same.
In Silico Study Highlighting the Interactions Between the Active Sites of Steroidogenic Enzymes and Endocrine Disruptors Found in Daily Use Products
(AMG Transcend Association, 2024) Saloni; Karuna Singh; Geeta J. Gautam
Endocrine-disrupting chemicals (EDC) mimic steroid hormones; they can get easily bonded with enzymes even if their affinity is somewhat similar to natural reactants of the respective enzyme, forming subsequent hormones. This study aims to show the interactions between the active sites of key steroidogenic enzymes and endocrine disruptors. The main method used to reach the objective was molecular docking to study the relationship between the receptors and ligands and the binding affinity between EDC and Steroidogenic enzymes' active site amino acids. Molecular docking was also performed between the natural reactants of steroidogenesis and their respective steroidogenic enzymes so that a comparison could be made between the binding affinities of endocrine-disrupting chemicals and natural reactants with the respective steroidogenic enzymes. All the EDCs showed an affinity for the active site amino acids of key steroidogenic enzymes. Triclosan showed the highest affinity with the lowest binding energy required for all three key steroidogenic enzymes, while nitrate had the lowest affinity with the highest binding energy required. In comparison with the affinities showed by the reference reactants, all the EDCs studied show low affinities. Still, since EDCs tend to accumulate in the tissues, as their amount increases, it would surpass the reference reactants and would bind more efficiently, leading to endocrine disruption. © 2024 by the authors.
In-silico and in-vitro studies on fungal chitinase as a target enzyme for antifungal activity of closantel
(Slovak University of Agriculture, 2018) Neelabh; Neha Nidhi Tirkey; Karuna Singh
Drug development is a dynamic field which undergoes changes continuously. The past decade or so has witnessed huge strides in the field of screening of the drugs as well as target and ligand identifications but unfortunately this has not led to useful drugs. Many diseases still remain untreatable because we do not have proper drugs against them. In case of fungi the situation is graver due to the limited drug targets peculiar to fungi. Thus, in order to combat the fungal diseases the need of the hour is to develop new antifungals that have fewer side effects and broad spectrum activity. The current work deals with closantel, a veterinary drug targeting chitinase, which is utilized as a therapeutic option against helminths. The fact that chitin is an important constituent of the cell wall of the fungi also and it undergoes regular degradation and remodelling through an enzyme called fungal chitinase motivated the authors to test the efficacy of closantel against fungal chitinase. In the present study Cryptococcus neoformans has been used as a model organism against which the antifungal activity of closantel has been tested. In-silico studies carried out using PatchDock and FireDock predicted the global energy (binding energy)involved in docking closantel on chitinase as -47.58 Kcal/mol. Further, the results obtained through the in-silico studies were validated by the minimum inhibitory concentration assay (MIC). It was observed that 736 (±7.024) μg/ml of closantel can inhibit the cryptococcal growth by 80% (MIC80). © 2018, Slovak University of Agriculture.
In-silico prediction of T and B cell epitopes in the evolutionary conserved pathway of glycolysis for human pathogens: Coccidiodes immitis, Histoplasma capsulatum and Pneumocystis carnii
(Association of Biotechnology and Pharmacy, 2017) Neelabh; Karuna Singh
Fungal diseases are amongst the emerging diseases to which humans are most susceptible pertaining to the present day life style. New drugs are being made but at a slow pace, not matching the resistance developing capacity of the fungal pathogens. Therefore, it is important to choose new drug targets peculiar to fungi but absent in humans.A common practice till date has been to use the virulence proteins in order to devise medicines against micro-organisms. However, we have used in-silico techniques to analyze enzymes involved in the evolutionary conserved pathway of glycolysis which is the most primitive pathway for ATP production in aerobic as well as anaerobic organisms. Therefore, on successfully targeting these enzymes microorganism can be killed. We have chosen 3 fungal pathogens viz.Coccidiodes immitis, Histoplasma capsulatum and Pneumocystis carnii that cause serious diseases in human beings and their effect on the morbidity and mortality of humans has been substantial. MEME-Motif discovery tool was used to devise a single motif sequence per glycolytic enzyme from the three fungi. Further, online servers such as ABCpred, Bcepred, BepiPred and Tools from Immunomedicine group have been used in order to predict the linear epitopes from the motif sequences of the different glycolytic enzymes. Analysis of these epitopes was performed through PepCalc and NetSurfP in terms of parameters such as hydrophilicity, coil forming residues and exposed residues. Analysis of ten proteins of glycolysis from each fungus reveals the regions that can elicit an immunological response. This study most importantly projects aldolase to be an enzyme of importance which in future can be used as a potential vaccine target for these three fungi. © 2017, Association of Biotechnology and Pharmacy. All rights reserved.
In-silico studies of some natural, synthetic and semi-synthetic antifungal drugs for their multi-targeting nature
(Slovak University of Agriculture, 2018) Neelabh; Karuna Singh
Research has shown that drugs or therapeutic agents which are directed at a particular target often undergo a reduction in efficacy, undesired safety profiles, compensatory and neutralizing effects, anti-target and counter target activities and also resistance against the drug. Proper utilization of multiple targets can lead to a perfect blend between the efficacy and safety when compared against single-targeted drug design. The authors have utilized this concept in case of the antifungal drugs which generally act against one of the targets amongst chitinase, chitin synthase, 1, 3 beta glucan synthase and lanosterol 14 a-demethylase. Henceforth, the present study is an attempt to screen the known drugs for their multi-targeting nature, and to compare natural product based drugs with semi-synthetic and synthetic drugs in-silico. In the present study, eleven (7 synthetic and 4 natural) drugs namely Allosamidine, Methylxanthine, Acetozolamide, Nikkomycin Z, Polyoxin L, Caspofungin, Fluconazole, Argifin, Obovatol, Papulacandin and Ro-091470 have been chosen to study their effect against different targets. This exciting and unique in-silico study provides insight that some drugs can function equally good against all targets, while some have a better efficiency against a different target than the known one. All four studied natural product based drugs are found to be good at multi-targeting. All the drugs that were shown to have a good multi-targeting efficiency bind at the same region where the known drugs against that target bind. Furthermore, lanosterol 14 a-demethylase is found to be the best target amongst all the aforesaid fungal targets. © 2018 Journal of Microbiology, Biotechnology and Food Sciences.