From Multiple Protein Docking to Protein-Protein Docking at Interactome Level.

Molecular docking is used to anticipate the optimal orientation of a particular molecule to a target to form a stable complex. It makes predictions about the 3D structure of any complex based on the binding characteristics of the ligand and the target receptor usually a protein. It is an exceptionally useful tool, which is used as a model to study how ligands attach to proteins. Docking can also be used for studying the interaction of ligands and proteins to analyze inhibitory efficacy. The ligand may also be a protein, making it possible to study interactions between two different proteins using the numerous docking tools available for basic research on protein interactions. The protein-protein docking is a crucial approach to understanding the protein interactions and predicting the structure of protein complexes that have not yet been experimentally determined. Moreover, the protein-protein interactions can predict the function of target proteins and the drug-like properties of molecules. Therefore, protein docking assists in uncovering insights into protein interactions and also aids in a better understanding of molecular pathways/mechanisms. This chapter comprehends the various tools for protein-protein docking (pairwise and multiple), including their methodologies and analysis of output as results.

An Insight into Emerging Phytocompounds for Glioblastoma Multiforme Therapy.

Despite intense research in the field of glioblastoma multiforme (GBM) therapeutics, the resistance against approved therapy remains an issue of concern. The resistance against the therapy is widely reported due to factors like clonal selection, involvement of multiple developmental pathways, and majorly defective mismatch repair (MMR) mediated by O6- methylguanine DNA methyltransferase (MGMT). Phytotherapy is one of the most effective alternatives to overcome resistance. It involves plant-based compounds, divided into several classes: alkaloids; phenols; terpenes; organosulfur compounds. The phytocompounds comprised in these classes are extracted or processed from certain plant sources. They can target various proteins of molecular pathways associated with the progression and survival of GBM. Phytocompounds have also shown promise as immunomodulatory agents and are being explored for immune checkpoint inhibition. Therefore, research and innovations are required to understand the mechanism of action of such phytocompounds against GBM to develop efficacious treatments for the same. This review gives insight into the potential of phytochemical-based therapeutic options for GBM treatment.

MicroRNA as a potential biomarker for systemic lupus erythematosus: pathogenesis and targeted therapy.

Systemic lupus erythematosus (SLE) is an autoimmune disease associated with hyperactive innate and adaptive immune systems that cause dermatological, cardiovascular, renal, and neuropsychiatric problems in patients. SLE's multifactorial nature and complex pathogenesis present significant challenges in its clinical classification. In addition, unpredictable treatment responses in patients emphasize the need for highly specific and sensitive SLE biomarkers that can assist in understanding the exact pathogenesis and, thereby, lead to the identification of novel therapeutic targets. Recent studies on microRNA (miRNA), a non-coding region involved in the regulation of gene expression, indicate its importance in the development of the immune system and thus in the pathogenesis of various autoimmune disorders such as SLE. miRNAs are fascinating biomarker prospects for SLE categorization and disease monitoring owing to their small size and high stability. In this paper, we have discussed the involvement of a wide range of miRNAs in the regulation of SLE inflammation and how their modulation can be a potential therapeutic approach.

Comparative analysis of α-pinene alone and combined with temozolomide in human glioblastoma cells.

α-Pinene (PEN) is a phyto compound present in terpene plants. In traditional medicine, PEN has been used for its anti-inflammatory, pain-relieving, and bronchodilator properties. The effect of PEN in combination with temozolomide (TMZ) in glioblastoma multiforme (GBM) cells has been evaluated. The action of the PEN + TMZ combination on cell migration, soft-agar, and cell death was determined in LN229 and U87MG human glioblastoma cells. In combination, PEN with TMZ showed a synergistic inhibitory effect in the GBM cells. The PEN + TMZ treatment showed a higher fluorescent intensity and reduced the percentage of wound area closure compared to the compound alone. The compounds in combination also resulted in a reduction in single-cell colony formation. To conclude, the study showed that plant-derived PEN enhanced the effectiveness of standard chemotherapeutic, TMZ, in LN229 and U87MG cells.

In vitro & in vivo evaluations of PLGA nanoparticle based combinatorial drug therapy for baclofen and lamotrigine for neuropathic pain management.

AIM: Baclofen and Lamotrigine via PLGA nanoparticles were developed for nose-to-brain delivery for the treatment of Neuropathic pain. METHODS: Nanoparticles were prepared using the modified nano-precipitation method. The prepared NPs were characterised and further in vitro and in vivo studies were performed. RESULTS: The Bcf-Ltg-PLGA-NPs were ∼177.7 nm with >75%(w/w) drugs encapsulated. In vitro dissolution studies suggested zero-order release profiles following the Korsmeyer-Peppas model. In vitro cytotoxicity and staining studies on mammalian cells showed dose dependant cytotoxicity where nanoparticles were significantly less toxic (>95% cell-viability). ELISA studies on RAW-macrophages showed Bcf-Ltg-PLGA-NPs as a potential pro-inflammatory-cytokines inhibitor. In vivo gamma-scintigraphy studies on rats showed intra-nasal administration of 99mTc-Bcf-Ltg-PLGA-NPs showed Cmax 3.6%/g at Tmax = 1.5h with DTE% as 191.23% and DTP% = 38.61% in brain. Pharmacodynamics evaluations on C57BL/6J mice showed a significant reduction in licks/bites during inflammation-induced phase II pain. CONCLUSION: The findings concluded that the combination of these drugs into a single nanoparticle-based formulation has potential for pain management.

Baclofen and Lamotrigine loaded PLGA nanoparticles were prepared with a size of 177.7nm, PDI 0.057 and Zeta Potential −15.8 mVIn vitro cell lines based studies showed dose dependant cytotoxicity and Bcf-Ltg-PLGA-NPs were found to be pro-inflammatory cytokines inhibitorsIn vivo Pharmacokinetic studies showed C_max 3.6%/g at T_max = 1.5 h with Drug Targeting Efficiency 191.23% and Drug Target Organ Transport 38.61% in the brain for prepared nanoparticlesIn vivo pharmacodynamics studies showed a significant reduction in licks/bites during inflammation-induced phase II pain.

Combinatorial Effect of Temozolomide and Naringenin in Human Glioblastoma Multiforme Cell Lines.

Glioblastoma multiforme (GBM) is a grade IV, lethal, and the most common type of brain tumor. GBM can acquire resistance to temozolomide (TMZ) recommended for its treatment. Naringenin (NAG), a flavonoid generally found in grapefruit, has antioxidant, anti-proliferative, and anti-inflammatory properties. It has been reported that phytochemicals can reduce resistance and improve the efficacy of a chemo-resistant drug. The combinatorial effect of TMZ and NAG on cell proliferation was evaluated using 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay, and the apoptosis in the U87MG and LN229 GBM cells were evaluated by change in fluorescence intensity. The effect of NAG and TMZ on anchorage-independent single-cell colony formation and cell migration was investigated. NAG and TMZ demonstrated enhanced cytotoxic effects on U87MG and LN229 cell lines. The combination index value being less than one indicated the synergistic action of the two drugs in restricting the growth of the cells. The NAG and TMZ together resulted in higher fluorescence intensity as compared to the alone drug. Further, the study showed a marked reduction in the migration of the cells and the formation of a single cell colony.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1952438.

Computational analysis of human host binding partners of chikungunya and dengue viruses during coinfection.

Mosquito-borne viral diseases like chikungunya and dengue infections can cause severe illness and have become major public health concerns. Chikungunya virus (CHIKV) and dengue virus (DENV) infections share similar primary clinical manifestations and are transmitted by the same vector. Thus, the probability of their coinfection gets increased with more severe clinical complications in the patients. The present study was undertaken to elucidate the common human interacting partners of CHIKV and DENV proteins during coinfection. The viral-host protein-protein interactome was constructed using Cytoscape. Subsequently, significant host interactors were identified during coinfection. The network analysis elucidated 57 human proteins interacting with both CHIKV and DENV, represented as hub-bottlenecks. The functional and biological analyses of the 40 hub-bottlenecks revealed that they are associated with phosphoinositide 3-kinases (PI3K)/AKT, p53 signaling pathways, regulation of cell cycle and apoptosis during coinfection. Moreover, the molecular docking analysis uncovered the tight and robust binding of selected hub-bottlenecks with CHIKV/DENV proteins. Additionally, 23 hub-bottlenecks were predicted as druggable candidates that could be targeted to eradicate the host-viral interactions. The elucidated common host binding partners during DENV and CHIKV coinfection as well as indicated approved drugs can support the therapeutics development.

Computational approach to decipher cellular interactors and drug targets during co-infection of SARS-CoV-2, Dengue, and Chikungunya virus.

The world is reeling under severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, and it will be frightening if compounded by other co-existing infections. The co-occurrence of the Dengue virus (DENV) and Chikungunya virus (CHIKV) has been into existence, but recently the co-infection of DENV and SARS-CoV-2 has been reported. Thus, the possibility of DENV, CHIKV, and SARS-CoV-2 co-infection could be predicted in the future with enhanced vulnerability. It is essential to elucidate the host interactors and the connected pathways to understand the biological insights. The in silico approach using Cytoscape was exploited to elucidate the common human proteins interacting with DENV, CHIKV, and SARS-CoV-2 during their probable co-infection. In total, 17 interacting host proteins were identified showing association with envelope, structural, non-structural, and accessory proteins. Investigating the functional and biological behaviour using PANTHER, UniProtKB, and KEGG databases uncovered their association with several cellular pathways including, signaling pathways, RNA processing and transport, cell cycle, ubiquitination, and protein trafficking. Withal, exploring the DrugBank and Therapeutic Target Database, total seven druggable host proteins were predicted. Among all integrin beta-1, histone deacetylase-2 (HDAC2) and microtubule affinity-regulating kinase-3 were targeted by FDA approved molecules/ drugs. Furthermore, HDAC2 was predicted to be the most significant target, and some approved drugs are available against it. The predicted druggable targets and approved drugs could be investigated to obliterate the identified interactions that could assist in inhibiting viral infection.

Deciphering the human cellular interactors of alphavirus unique domain of chikungunya virus.

The life-threatening re-emerged chikungunya virus (CHIKV) can cause an epidemic outbreak and still has no vaccine available so far. Alphavirus unique domain (AUD) of CHIKV nsP3 is a multifunctional domain that remains conserved among alphaviruses and is critical for CHIKV replication. The understanding of AUD-host protein-protein interactions and their association with the cellular processes concerning CHIKV infection are not well studied. In the current study, the protein-protein interactions of AUD and its human host were elucidated by screening of universal human cDNA library using yeast two-hybrid system. The chosen interactions were further validated by GST pull-down assay, and their network mapping was analyzed. The study revealed that the identified interactors are linked with the vesicle trafficking and transcription corepressor activities. Further, the interfacial residues of interactions between viral and host proteins were predicted, which will further provide the new platform to develop novel antivirals.

Antiviral Peptides: Identification and Validation.

Despite rapid advances in the human healthcare, the infection caused by certain viruses results in high morbidity and mortality accentuate the importance for development of new antivirals. The existing antiviral drugs are limited, due to their inadequate response, increased rate of resistance and several adverse side effects. Therefore, one of the newly emerging field "peptide-based therapeutics" against viruses is being explored and seems promising. Over the last few years, a lot of scientific effort has been made for the identification of novel and potential peptide-based therapeutics using various advanced technologies. Consequently, there are more than 60 approved peptide drugs available for sale in the market of United States, Europe, Japan, and some Asian countries. Moreover, the number of peptide drugs undergoing the clinical trials is rising gradually year by year. The peptide-based antiviral therapeutics have been approved for the Human immunodeficiency virus (HIV), Influenza virus and Hepatitis virus (B and C). This review enlightens the various peptide sources and the different approaches that have contributed to the search of potential antiviral peptides. These include computational approaches, natural and biological sources (library based high throughput screening) for the identification of lead peptide molecules against their target. Further the applications of few advanced techniques based on combinatorial chemistry and molecular biology have been illustrated to measure the binding parameters such as affinity and kinetics of the screened interacting partners. The employment of these advanced techniques can contribute to investigate antiviral peptide therapeutics for emerging infections.

Identification of Peptide Binders to Truncated Recombinant Chikungunya Virus Envelope Protein 2 Using Phage Display Technology and Their In Silico Characterization.

AIM: To identify and characterize peptide binders to truncated recombinant chikungunya virus envelope protein 2. BACKGROUND: Despite extensive research on the chikungunya virus (CHIKV), the specific antiviral treatment's unavailability has stressed the need for the urgent development of therapeutics. The Envelope protein 2 (E2) of CHIKV that displays putative receptor binding sites and specific epitopes for virus neutralizing antibodies is a critical target for the therapeutic intervention. OBJECTIVE: The study aims to identify the unique peptides that can bind to truncated E2 protein of CHIKV and further explore their properties as potential therapeutic candidate. METHODS: A stretch of CHIKV-E2 (rE2), which is prominently exposed on the surface of virion, was used as bait protein to identify peptide binders to the CHIKV-rE2 using a 12-mer phage display peptide library. Three rounds of biopanning yielded several peptide binders to CHIKV-rE2 and their binding affinities were compared by phage ELISA. Additionally, a fully flexible-blind docking simulation investigated the possible binding modes of the selected peptides. Furthermore, the selected peptides were characterized and their ADMET properties were explored in silico. RESULTS: Five peptides were identified as potential binders based on their robust reactivity to the bait protein. The selected peptides appeared to interact with the crucial residues that were notably exposed on the surface of E1-E2 trimeric structure. The explored in silico studies suggested their non-allergenicity, non-toxicity and likeliness to be antiviral. CONCLUSION: The potential binding peptides of CHIKV-rE2 protein were identified using phage display technology and characterized in silico. The selected peptides could be further used for the development of therapeutics against the CHIKV infection.>.

Synergistic antibacterial and anti-biofilm activity of nisin like bacteriocin with curcumin and cinnamaldehyde against ESBL and MBL producing clinical strains.

Bacteriocins are small peptides that can inhibit the growth of a diverse range of microbes. There is a need to identify bacteriocins that are effective against biofilms of resistant clinical strains. The present study focussed on the efficacy of purified nisin like bacteriocin-GAM217 against extended spectrum ß-lactamase (ESBL) and metallo-beta-lactamase (MBL) producing clinical strains. Bacteriocin-GAM217 when combined with curcumin and cinnamaldehyde, synergistically enhanced antibacterial activity against planktonic and biofilm cultures of Staphylococcus epidermidis and Escherichia coli. Bacteriocin-GAM217 and phytochemical combinations inhibited biofilm formation by >80%, and disrupted the biofilm for selected ESBL and MBL producing clinical strains. The anti-adhesion assay showed that these combinatorial compounds significantly lowered the attachment of bacteria to Vero cells and that they elicited membrane permeability and rapid killing as viewed by confocal microscopy. This study demonstrates that bacteriocin-GAM217 in combination with phytochemicals can be a potential anti-biofilm agent and thus has potential for biomedical applications.

Antiviral therapeutics for chikungunya virus.

Introduction: Chikungunya virus (CHIKV), a reemerging human arthropod borne virus, can causes global epidemic outbreaks and has become a serious health concern due to the unavailability of any antiviral therapy/vaccine. Extensive research has been conducted to target different proteins from CHIKV to curtail the spread of virus.Areas covered: This review provides an overview of the granted patents including the current status of antiviral strategies targeting CHIKV.Expert opinion: Under the current scenario, potential molecules and different approaches have been utilized to suppress CHIKV infection. MV-CHIKV and VRC-CHKVLP059-00-VP vaccine candidates have successfully completed phase I clinical trials and ribavirin (inhibitor) has shown significant inhibition of CHIKV replication and could be the most promising candidates. The drug resistance and toxicity can be modulated by using the inhibitors/drugs in combination. Moreover, nanoparticle formulations can improve the efficacy and bioavailability of drugs.

In silico study of chikungunya polymerase, a potential target for inhibitors.

Non-structural protein 4 (nsP4) polymerase of chikungunya virus (CHIKV) has a crucial role in genome replication and hence could act as a promising target for novel therapeutics. Though, nsP4 is important in viral life cycle, but it is less explored as therapeutic target. The catalytic core of nsP4 Polymerase includes conserved GDD motif which is present not only across different CHIKV strains but also across other Alphaviruses. This emphasizes the uniqueness and importance of this motif in the functioning of nsP4 polymerase and hence, we focused on GDD motif for docking of drug molecules. Herein, a model of nsP4 polymerase was developed using Swiss Model, validated by Ramachandran plot and molecular dynamic simulation. Molecular docking was performed using LeadIT FlexX flexible docking module with FDA approved drug molecule library. On the basis of flexX score, top 5 leads with flexX scores - 33.7588, - 30.2555, - 29.6043, - 28.916 and - 28.5042 were selected. The bonding pattern of these leads were analysed in discovery studio and were further screened on the basis of molecular dynamic simulation studies. Simulation analysis revealed that only the top lead, Mitoxantrone Hydrochloride which is an anticancer drug and is currently indicated in leukemias and lymphomas interacted favourably and stably with nsP4. Our findings suggest that Mitoxantrone Hydrochloride can be a potential novel inhibitor of CHIKV polymerase and should be further validated by in vitro assays.

Nanoemulsions of Green Tea Catechins and Other Natural Compounds for the Treatment of Urinary Tract Infection: Antibacterial Analysis.

Purpose: Nanoemulsions (NEs) of polyphenon 60 (P60) and cranberry (NE I) and P60 and curcumin (NE II) were prepared with the aim to enhance anti-bacterial potential and to understand the mechanism of anti-bacterial action of the encapsulated compounds. Methods: To evaluate the antibacterial potential of the developed NE, microtiter biofilm formation assay was performed. The cytotoxicity analysis was done to assess the toxicity profile of the NEs. Further antibacterial analysis against uropathogenic strains was performed to check the developed NEs were effective against these strains. Results: In microtiter dish biofilm formation assay, both NE formulations inhibited the growth more effectively (Av. % inhibition ~84%) as compared to corresponding aqueous solution (Av. % inhibition ~64%) and placebo (Av. % inhibition ~59%) at their respective minimum inhibitory concentration (MIC) values. Cytotoxicity analysis using 3-(4,5-Dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT assay) showed that the formulations were nontoxic to Vero cells. The antibacterial studies against uropathogenic resistant strains also showed that NEs effectively inhibited the growth of bacterial strains. Conclusion: From different studies it was concluded that both the NE's were able to inhibit bacterial strains and could be further used for the treatment of urinary tract infection (UTI). The antibacterial activity of developed NEs showed that these could be used as alternative therapies for the treatment of UTI.

Virtual screening of inhibitors against Envelope glycoprotein of Chikungunya Virus: a drug repositioning approach.

Chikungunya virus (CHIKV) a re-emerging mosquito-borne alpha virus causes significant distress which is further accentuated in the lack of specific therapeutics or a preventive vaccine, mandating accelerated research for anti-CHIKV therapeutics. In recent years, drug repositioning has gained recognition for the curative interventions for its cost and time efficacy. CHIKV envelope proteins are considered to be the promising targets for drug discovery because of their essential role in viral attachment and entry in the host cells. In the current study, we propose structure-based virtual screening of drug molecule on the crystal structure of mature Chikungunya envelope protein (PDB 3N41) using a library of FDA approved drug molecules. Several cephalosporin drugs docked successfully within two binding sites prepared at E1-E2 interface of CHIKV envelop protein complex with significantly low binding energies. Cefmenoxime, ceforanide, cefotetan, cefonicid sodium and cefpiramide were identified as top leads with a cumulative score of -67.67, -64.90, -63.78, -61.99, and - 61.77, forming electrostatic, hydrogen and hydrophobic bonds within both the binding sites. These shortlisted leads could be potential inhibitors of E1-E2 hetero dimer in CHIKV, hence might disrupt the integrity of envelope glycoprotein leading to loss of its ability to form mature viral particles and gain entry into the host.

Expression, purification and functional characterization of recombinant hypervariable region (HVR) of Chikungunya virus nsP3 protein.

One of the most important rapidly emerging mosquito-borne alphavirus is Chikungunya virus (CHIKV). There is a necessity to develop anti-CHIKV therapeutics, as neither antiviral drug nor vaccines have been licensed yet. Several CHIKV proteins are being studied worldwide, but non-structural protein 3 (nsP3) has been less explored. This protein consists of three domains: macrodomain, alphavirus unique domain (AUD) and hypervariable region (HVR). The proline-rich regions of HVR contain SRC homology 3 (SH3)-binding domain which is essential for its functionality. Interaction of these motifs with host amphiphysin protein is crucial for viral RNA replication. Restricting the interactions of HVR could lead to inhibition of viral life cycle. Therefore, the present study focuses on purification of HVR protein and its structural and functional assay for therapeutic intervention in future use. In order to obtain purified protein, HVR region was amplified from TOPO clones of nsP3 of IND-06-Guj strain and cloned into expression vector. Expression and solubilization of the protein were optimized at various conditions of salt, detergent and imidazole before purification. The soluble recombinant HVR (His-HVR) protein was purified using affinity chromatography. Purified protein was analyzed for structural studies and functional assays. Circular dichroism of His-HVR protein was performed for structural study, and it was observed that it consists of mostly random coils. For functional assay, co-pull down of His-HVR protein was performed with endogenous amphiphysin-I protein of N2a cells and was analyzed using Western blotting. This purified protein obtained could be used as a potential target reagent for novel therapeutic interventions in the future.

Nose-to-brain delivery of lamotrigine-loaded PLGA nanoparticles.

Direct nose-to-brain delivery of drugs and faster onset of action have made intra-nasal route a much sought-after alternative to conventional routes of drug delivery to the brain. Lamotrigine is used for the treatment and management of neuropathic pain, and in the present work, lamotrigine (LTG)-PLGA nanoparticles were developed for intra-nasal delivery. The LTG-PLGA nanoparticles were prepared using modified nanoprecipitation method via high-speed homogenization and ultra-sonication techniques. Entrapment efficiency (EE%) of developed LTG-PLGA-NPs was found to be 84.87 ± 1.2% with drug loading of 10.21 ± 0.89%. The particle size of developed nanoparticles was found to be 184.6 nm with PDI value of 0.082 and zeta potential of - 18.8 mV. Dissolution profiles were studied in PBS (pH 7.4), simulated nasal fluid, and simulated cerebrospinal fluid where almost complete release was observed within 5 h in CSF. In vitro, cytotoxicity was analyzed using MTT assay where dose-dependent cytotoxicity was observed for developed LTG-PLGA-NPs. In vitro cytokine analysis showed positive effects of LTG-PLGA-NPs as pro-inflammatory cytokine suppressors. Further, in vivo studies were performed for radiolabeled formulation and drug (99mTc-LTG-PLGA-NPs and 99mTc-LTG-aqueous) using Sprague Dawley rats where with the help of gamma scintigraphy studies, various routes of administration viz. oral, intra-nasal, and intra-venous were compared. Various pharmacokinetic parameters were evaluated using biodistribution studies to estimate the drug levels in blood and brain. For 99mTc-LTG-PLGA-NPs via intra-nasal route, drug targeting efficiency (DTE%) was found to be 129.81% and drug target organ transport (DTP%) to be 22.81% in brain with Cmax of 3.82%/g within Tmax 1.5 h. Thus, the developed PLGA nanoparticles for intra-nasal delivery provide a possible alternative for existing available drug formulation for neuropathic pain management.

Baclofen-Loaded Poly (D,L-Lactide-Co-Glycolic Acid) Nanoparticles for Neuropathic Pain Management: In Vitro and In Vivo Evaluation.

In this work, poly (D,L-lactide-co-glycolic acid) (PLGA) nanoparticles of baclofen (Bcf-PLGA-NPs) were developed and optimized using nanoprecipitation method. The average particle size of the Bcf-PLGA-NP was found to be 124.8 nm, polydispersity index of 0.225, and zeta potential was found to be in the range of -20.4 mV. In vitro dissolution studies showed that Bcf was released from PLGA NPs in a sustained manner from 50% release in 2.5 hours to 80%-85% in 24 hours. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on Neuro-2a neuroblastoma cell line showed comparably low cytotoxicity of Bcf-PLGA-NPs as compared with aqueous solution of Bcf at reported Cmax values of the drug. To explore the nose-to-brain pathway, in vivo studies were carried out in Sprague-Dawley rats by radiolabeling of Bcf with technetium-99m (99mTc). Gamma scintigraphy images of the rats that were administered through intranasal (i.n.) route showed the maximum uptake of radiolabeled NPs from nose to brain at 3 hours as compared with the rats administered with NPs intravenously and orally. To assess the Bcf concentration in brain and blood, biodistribution studies were performed and following i.n. route the NPs were dispersed in brain (3.5%/g) and blood (3%/g) at 3 hours, and these observations were in agreement with the gamma scintigrams. Hence, from the results it was suggested that the developed PLGA NPs could serve as a potential carrier for the Bcf in the treatment of neuropathic pain.

Antibacterial Activity, Cytotoxicity, and the Mechanism of Action of Bacteriocin from Bacillus subtilis GAS101.

OBJECTIVE: The aim of this study was to purify and characterize bacteriocin from the soil isolate Bacillus subtilis GAS101, and to determine its antimicrobial as well as antibiofilm potential. The purified bacteriocin was further analyzed and evaluated for mammalian cell cytotoxicity and the possible mode of action. MATERIAL AND METHODS: Bacteriocin from B. subtilis GAS101 (an animal husbandry soil isolate) was partially purified and checked for antimicrobial and antibiofilm activity against gram-positive and gram-negative bacteria. The molecular weight of bacteriocin was determined using tricine SDS-PAGE gel. The stability of bacteriocin was investigated at various temperatures and pH levels, and its sensitivity towards 8 enzymes and 6 chemicals was determined. Cytotoxicity analysis was performed on a Vero cell line by a tetrazolium dye-based assay. Scanning electron microscopy (SEM) of bacteriocin-treated bacteria was carried out to determine the possible mode of action. RESULTS: Bacteriocin from B. subtilis GAS101 was a potential inhibitor of both the indicator organisms (Staphylococcus epidermidis and Escherichia coli), and had a molecular weight of approximately 6.5 kDa. An in situ gel assay showed a zone of inhibition corresponding to the estimated protein band size. Bacteriocin was stable and showed antibacterial activity in broad ranges of temperature (30-121°C) and pH (2-12). It was sensitive to 4 proteolytic enzymes, which indicated its proteinaceous nature. Bacteriocin showed > 70% cell viability on the mammalian Vero cell line. SEM depicted that the bacteriocin was able to disrupt the bacterial cell membrane as its probable mode of action. CONCLUSION: Thermostable and pH-tolerant bacteriocin from B. subtilis GAS101, of about 6.5 kDa, showed broad-spectrum antimicrobial and antibiofilm activity.