Design of inhibitor peptide sequences based on the interfacial knowledge of the protein G-IgG crystallographic complex and their binding studies with IgG.

Protein-protein interactions (PPI) have emerged as valuable targets in medicinal chemistry due to their key roles in important biological processes. The modulation of PPI by small peptides offers an excellent opportunity to develop drugs against human diseases. Here, we exploited the knowledge of the binding interface of the IgG-protein G complex (PDB:1FCC) for designing peptides that can inhibit these complexes. Herein, we have designed several closely related peptides, and the comparison of results from experiments and computational studies indicated that all the peptides bind close to the expected binding site on IgG and the complexes are stable. A minimal sequence consisting of 11 amino acids (P5) with binding constants in the range of 100 nM was identified. We propose that the main affinity differences across the series of peptides arose from the presence of polar amino acid residues. Further, the molecular dynamic studies helped to understand the dynamic properties of complexes in terms of flexibility of residues and structural stability at the interface. The ability of P5 to compete with the protein G in recognizing IgG can help in the detection and purification of antibodies. Further, it can serve as a versatile tool for a better understanding of protein-protein interactions.

High-throughput virtual screening of small-molecule inhibitors targeting immune cell checkpoints to discover new immunotherapeutics for human diseases.

Immunotherapy is widely used to treat various cancers, and the drugs used are called immune checkpoint (ICP) inhibitors. Overexpression of immune cell checkpoints is reported for other human diseases such as acute infections (malaria), chronic viral infection (HIV, hepatitis B virus, TB infections), allergy, asthma, neurodegeneration, and autoimmune diseases. Some mAbs (monoclonal antibodies) are available against ICPs, but they have side effects. Small molecule seems to be safer in comparison with mAbs. Three independent small-molecule inhibitor libraries consisting of 9466 compounds were screened against seven immune cell checkpoints by applying high-throughput virtual screening approach. A total of 13 ICP inhibitors were finalized based on docking, MM-GBSA scores, and ADME properties. Six compounds were selected for MD simulation, and then, rutin hydrate (targeting all seven immune cell checkpoints), amikacin hydrate (targeting six), and 6-hydroxyluteolin (targeting three) were found to be the best immune cell checkpoint inhibitors. These three potential inhibitors have shown the potential to activate human immune cells and thus may control the spread of human lifestyle or infectious diseases. Proposed inhibitors warrant the in vitro and in vivo validation to develop it as an immunotherapeutic.

Nanobody-peptide-conjugate (NPC) for passive immunotherapy against SARS-CoV-2 variants of concern (VoC): a prospective pan-coronavirus therapeutics.

The COVID-19 crisis, incited by the zoonotic SARS-CoV-2 virus, has quickly escalated into a catastrophic public health issue and a grave threat to humankind owing to the advent of mutant viruses. Multiple pharmaceutical therapies or biologics envision stopping the virus from spreading further; however, WHO has voiced concerns about the variants of concern (VoCs) inability to respond. Nanobodies are a new class of antibody mimics with binding affinity and specificity similar to classical mAbs, as well as the privileges of a small molecular weight, ease of entry into solid tissues, and binding cryptic epitopes of the antigen. Herein, we investigated multiple putative anti-SARS-CoV-2 nanobodies targeting the Receptor binding domain of the WHO-listed SARS-CoV-2 variants of concern using a comprehensive computational immunoinformatics methodology. With affinity maturation via alanine scanning mutagenesis, we remodeled an ultrapotent nanobody with substantial breadth and potency, exhibiting pico-molar binding affinities against all the VoCs. An antiviral peptide with specificity for ACE-2 receptors was affixed to make it multispecific and discourage viral entry. Collectively, we constructed a broad-spectrum therapeutic biparatopic nanobody-peptide conjugate (NPC) extending coverage to SARS-CoV-2 VoCs RBDs. We PEGylated the biparatopic construct with 20kD maleimide-terminated PEG (MAL-(PEG)n-OMe) to improve its clinical efficacy limiting rapid renal clearance, and performed in silico cloning to facilitate future experimental studies. Our findings suggest that combining biparatopic nanobody conjugate with standard treatment may be a promising bivariate tool for combating viral entry during COVID-19 illness.

Multi-pathogen based chimeric vaccine to fight against COVID-19 and concomitant coinfections.

BACKGROUND: COVID-19 has proved to be a fatal disease of the year 2020, due to which thousands of people globally have lost their lives, and still, the infection cases are at a high rate. Experimental studies suggested that SARS-CoV-2 interacts with various microorganisms, and this coinfection is accountable for the augmentation of infection severity. METHODS AND RESULTS: In this study, we have designed a multi-pathogen vaccine by involving the immunogenic proteins from S. pneumonia, H. influenza, and M. tuberculosis, as they are dominantly associated with SARS-CoV-2. A total of 8 antigenic protein sequences were selected to predict B-cell, HTL, and CTL epitopes restricted to the most prevalent HLA alleles. The selected epitopes were antigenic, non-allergenic, and non-toxic and were linked with adjuvant and linkers to make the vaccine protein more immunogenic, stable, and flexible. The tertiary structure, Ramachandran plot, and discontinuous B-cell epitopes were predicted. Docking and MD simulation study has shown efficient binding of the chimeric vaccine with the TLR4 receptor. CONCLUSION: The in silico immune simulation analysis has shown a high level of cytokines and IgG after a three-dose injection. Hence, this strategy could be a better way to decrease the disease's severity and could be used as a weapon to prevent this pandemic.

Autophagy based cellular physiological strategies target oncogenic progression.

Evidence accumulated from past findings indicates that defective proteostasis may contribute to risk factors for cancer generation. Irregular assembly of abnormal proteins catalyzes the disturbance of cellular proteostasis and induces the ability of abnormal cellular proliferation. The autophagy mechanism plays a key role in the regular clearance of abnormal/poor lipids, proteins, and various cellular organelles. The results of functional and effective autophagy deliver normal cellular homeostasis, which establishes supportive metabolism and avoids unexpected tumorigenesis events. Still, the precise molecular mechanism of autophagy in tumor suppression has not been clear. How autophagy triggers selective or nonselective bulk degradation to dissipate tumor promotion under stress conditions is not clear. Under proteotoxic insults to knockdown the drive of tumorigenesis, it is critical for us to figure out the detailed molecular functions of autophagy in human cancers. The current article summarizes autophagy-based theragnostic strategies targeting various phases of tumorigenesis and suggests the preventive roles of autophagy against tumor progression. A better understanding of various molecular partners of autophagic flux will improve and innovate therapeutic approaches based on autophagic-susceptible effects against cellular oncogenic transformation.

Febrifugine dihydrochloride as a new oral chemotherapeutic agent against visceral leishmaniasis infection.

Visceral leishmaniasis (VL) is the deadliest form of leishmaniasis without a safer treatment option. This study implies drug repurposing to find a novel antileishmanial compound, namely febrifugine dihydrochloride (FFG) targeting Leishmania antioxidant system. Starting with virtual screening revealed the high binding affinity and lead likeness of FFG against the trypanothione reductase (TR) enzyme of Leishmania donovani, followed by experimental validation. The promastigotes inhibition assay gave the IC50 concentration of FFG and Miltefosine (positive control) as 7.16 ± 1.39 nM and 11.41 ± 0.29 µM, respectively. Their CC50 was found as 451 ± 12.73 nM and 135.9 ± 5.94 µM, respectively. FFG has been shown to increase the reactive oxygen species (ROS), leading to apoptosis-like cell death among L. donovani promastigotes. Spleen touch biopsy resulted in 62% and 55% decreased parasite load with FFG and miltefosine treatment, respectively. Cytokine profiling has shown an increased proinflammatory cytokine response post-FFG treatment. Moreover, FFG is safe on the liver toxicity parameter in mice post-treatment.

Cognizance of posttranslational modifications in vaccines: A way to enhanced immunogenicity.

Vaccination is a significant advancement or preventative strategy for controlling the spread of various severe infectious and noninfectious diseases. The purpose of vaccination is to stimulate or activate the immune system by injecting antigens, i.e., either whole microorganisms or using the pathogen's antigenic part or macromolecules. Over time, researchers have made tremendous efforts to reduce vaccine side effects or failure by developing different strategies combining with immunoinformatic and molecular biology. These newly designed vaccines are composed of single or several antigenic molecules derived from a pathogenic organism. Although, whole-cell vaccines are still in use against various diseases but due to their ineffectiveness, other vaccines like DNA-based, RNA-based, and protein-based vaccines, with the addition of immunostimulatory agents, are in the limelight. Despite this, many researchers escape the most common fundamental phenomenon of protein posttranslational modifications during the development of vaccines, which regulates protein functional behavior, evokes immunogenicity and stability, etc. The negligence about post translational modification (PTM) during vaccine development may affect the vaccine's efficacy and immune responses. Therefore, it becomes imperative to consider these modifications of macromolecules before finalizing the antigenic vaccine construct. Here, we have discussed different types of posttranslational/transcriptional modifications that are usually considered during vaccine construct designing: Glycosylation, Acetylation, Sulfation, Methylation, Amidation, SUMOylation, Ubiquitylation, Lipidation, Formylation, and Phosphorylation. Based on the available research information, we firmly believe that considering these modifications will generate a potential and highly immunogenic antigenic molecule against communicable and noncommunicable diseases compared to the unmodified macromolecules.

Interleukin-17-A multifaceted cytokine in viral infections.

Viral infections are a major threat to the human population due to the lack of selective therapeutic measures. The morbidity and mortality reported worldwide are very alarming against viral pathogens. The proinflammatory environment is required for viral inhibition by initiating the host immune response. The host immune response fights these pathogens by secreting different cytokines. Interleukin-17 (IL-17) a proinflammatory cytokine mainly produced by T helper type 17 cells, plays a vital role in the regulation of host immune response against various pathogens, including viruses. However, dysregulated production of IL-17 induces chronic inflammation, autoimmune disorders, and may lead to cancer. Recent studies suggest that IL-17 is not only involved in the antiviral immune response but also promotes virus-mediated illnesses. In this review, we discuss the protective and pathogenic role of IL-17 against various viral infections. A detailed understanding of IL-17 during viral infections could contribute to improve therapeutic measures and enable the development of an efficient and safe IL-17 based immunotherapy.

Ibuprofen-based advanced therapeutics: breaking the inflammatory link in cancer, neurodegeneration, and diseases.

Ibuprofen is a classical nonsteroidal anti-inflammatory drug (NSAID) highly prescribed to reduce acute pain and inflammation under an array of conditions, including rheumatoid arthritis, osteoarthritis, dysmenorrhea, and gout. Ibuprofen acts as a potential inhibitor for cyclooxygenase enzymes (COX-1 and COX-2). In the past few decades, research on this small molecule has led to identifying other possible therapeutic benefits. Anti-tumorigenic and neuroprotective functions of Ibuprofen are majorly recognized in recent literature and need further consideration. Additionally, several other roles of this anti-inflammatory molecule have been discovered and subjected to experimental assessment in various diseases. However, the major challenge faced by Ibuprofen and other drugs of similar classes is their side effects, and tendency to cause gastrointestinal injury, generate cardiovascular risks, modulate hepatic and acute kidney diseases. Future research should also be conducted to deduce new methods and approaches of suppressing the unwanted toxic changes mediated by these drugs and develop new therapeutic avenues so that these small molecules continue to serve the purposes. This article primarily aims to develop a comprehensive and better understanding of Ibuprofen, its pharmacological features, therapeutic benefits, and possible but less understood medicinal properties apart from major challenges in its future application.KEY POINTSIbuprofen, an NSAID, is a classical anti-inflammatory therapeutic agent.Pro-apoptotic roles of NSAIDs have been explored in detail in the past, holding the key in anti-cancer therapies.Excessive and continuous use of NSAIDs may have several side effects and multiple organ damage.Hyperactivated Inflammation initiates multifold detrimental changes in multiple pathological conditions.Targeting inflammatory pathways hold the key to several therapeutic strategies against many diseases, including cancer, microbial infections, multiple sclerosis, and many other brain diseases.

Critical evaluation of the utility of pre- and post-therapy immunophenotypes in assessment of measurable residual disease in B-ALL.

Measurable residual disease (MRD) is an important parameter to predict outcome in B-cell acute lymphoblastic leukemia (B-ALL). Two different approaches have been used for the assessment of MRD by multiparametric flow cytometry that include the "Leukemia Associated Aberrant Immunophenotype (LAIP)" and "Difference from Normal (DFN)" approach. In this retrospective study, we analyzed 539 samples obtained from 281 patients of which 258 were paired samples and the remaining 23 samples were from post-induction time point only, to explore the utility of baseline immunophenotype (IPT) for MRD assessment. Single-tube 10-color panel was used both at diagnosis and MRD time points. Out of 281 patients, 31.67% (n = 89) were positive and 68.32% (n = 192) were negative for MRD. Among 258 paired diagnostic and follow-up samples, baseline IPT was required in only 9.31% (24/258) cases which included cases with hematogone pattern and isolated dim to negative CD10 expression patterns. Comparison of baseline IPT with post-induction MRD positive samples showed a change in expression of at least one antigen in 94.04% cases. Although the immunophenotypic change in expression of various antigens is frequent in post-induction samples of B-ALL, it does not adversely impact the MRD assessment. In conclusion, the baseline IPT is required in less than 10% of B-ALL, specifically those with hematogone pattern and/or dim to negative expression of CD10. Hence, a combination of DFN and LAIP approach is recommended for reliable MRD assessment.

LRSAM1 E3 ubiquitin ligase: molecular neurobiological perspectives linked with brain diseases.

Cellular protein quality control (PQC) plays a significant role in the maintenance of cellular homeostasis. Failure of PQC mechanism may lead to various neurodegenerative diseases due to accumulation of aberrant proteins. To avoid such fatal neuronal conditions PQC employs autophagy and ubiquitin proteasome system (UPS) to degrade misfolded proteins. Few quality control (QC) E3 ubiquitin ligases interplay an important role to specifically recognize misfolded proteins for their intracellular degradation. Leucine-rich repeat and sterile alpha motif-containing 1 (LRSAM1) is a really interesting new gene (RING) class protein that possesses E3 ubiquitin ligase activity with promising applications in PQC. LRSAM1 is also known as RING finger leucine repeat rich (RIFLE) or TSG 101-associated ligase (TAL). LRSAM1 has various cellular functions as it modulates the protein aggregation, endosomal sorting machinery and virus egress from the cells. Thus, this makes LRSAM1 interesting to study not only in protein conformational disorders such as neurodegeneration but also in immunological and other cancerous disorders. Furthermore, LRSAM1 interacts with both cellular protein degradation machineries and hence it can participate in maintenance of overall cellular proteostasis. Still, more research work on the quality control molecular functions of LRSAM1 is needed to comprehend its roles in various protein aggregatory diseases. Earlier findings suggest that in a mouse model of Charcot-Marie-Tooth (CMT) disease, lack of LRSAM1 functions sensitizes peripheral axons to degeneration. It has been observed that in CMT the patients retain dominant and recessive mutations of LRSAM1 gene, which encodes most likely a defective protein. However, still the comprehensive molecular pathomechanism of LRSAM1 in neuronal functions and neurodegenerative diseases is not known. The current article systematically represents the molecular functions, nature and detailed characterization of LRSAM1 E3 ubiquitin ligase. Here, we review emerging molecular mechanisms of LRSAM1 linked with neurobiological functions, with a clear focus on the mechanism of neurodegeneration and also on other diseases. Better understanding of LRSAM1 neurobiological and intracellular functions may contribute to develop promising novel therapeutic approaches, which can also propose new lines of molecular beneficial targets for various neurodegenerative diseases.

Contriving multiepitope subunit vaccine by exploiting structural and nonstructural viral proteins to prevent Epstein-Barr virus-associated malignancy.

Cancer is one of the common lifestyle diseases and is considered to be the leading cause of death worldwide. Epstein-Barr virus (EBV)-infected individuals remain asymptomatic; but under certain stress conditions, EBV may lead to the development of cancers such as Burkitt's and Hodgkin's lymphoma and nasopharyngeal carcinoma. EBV-associated cancers result in a large number of deaths in Asian and African population, and no effective cure has still been developed. We, therefore, tried to devise a subunit vaccine with the help of immunoinformatic approaches that can be used for the prevention of EBV-associated malignancies. The epitopes were predicted through B-cell, cytotoxic T lymphocytes (CTL), and helper T lymphocytes (HTL) from the different oncogenic proteins of EBV. A vaccine was designed by combining the B-cell and T-cell (HTL and CTL) epitopes through linkers, and for the enhancement of immunogenicity, an adjuvant was added at the N-terminal. Further, homology modeling was performed to generate the 3D structure of the designed vaccine. Moreover, molecular docking was performed between the designed vaccine and immune receptor (TLR-3) to determine the interaction between the final vaccine construct and the immune receptor complex. In addition, molecular dynamics was performed to analyze the stable interactions between the ligand final vaccine model and receptor TLR-3 molecule. Lastly, to check the expression of our vaccine construct, we performed in silico cloning. This study needed experimental validation to ensure its effectiveness and potency to control malignancy.

Emerging role of circulating microRNA in the diagnosis of human infectious diseases.

The endogenic microRNAs (miRNA) are evolutionary, conserved, and belong to a group of small noncoding RNAs with a stretch of 19-24 nucleotides. The miRNAs play an indispensable role in gene modulation at the posttranscriptional level, inclusive of stem-cell differentiation, embryogenesis, hematopoiesis, metabolism, immune responses, or infections. The miRNAs secreted from the cells and their presence in the biological fluids signifies the regulatory role of circulating miRNAs in the pathogenesis. The phenomenal expression levels of circulating miRNAs in serum or plasma during infection makes them the potential therapeutic biomarkers for the diagnosis of assorted human infectious diseases. In this article, we have accentuated the methods for the profiling of circulating miRNA as well as the importance of miRNA as biomarkers for the diagnosis of human infectious diseases. To date, numerous biomarkers have been identified for the diagnostic or prognostic purpose; for instance, miR-182, miR-486, and miR15a in sepsis; miR-320 and miR505 in inflammatory bowel disease; miR-155 and miR-1260 in influenza; miR-12, miRVP-3p, and miR-184 in arboviruses; and miR-29b and miR-125 in hepatitis infection. Nevertheless, the noninvasive diagnostic approach, with the aid of biomarkers, currently plays a decisive role in the untimely diagnosis of human infections. So, in the near future, the exploitation of circulating miRNAs as therapeutic biomarkers for the diagnosis of human infections will help us to cure the associated diseases promptly and effectively.

Exploring sand fly salivary proteins to design multiepitope subunit vaccine to fight against visceral leishmaniasis.

Visceral leishmaniasis (VL) is caused by the parasites of Leishmania donovani complex, leads to the death of 20 000 to 40 000 people from 56 affected countries, worldwide. Till date, there is not a single available vaccine candidate to prevent the VL infection, and treatment only relies upon expensive and toxic chemotherapeutic options. Consequently, immunoinformatics approach was applied to design a multiepitope-based subunit vaccine to enhance the humoral as well as cell-mediated immunity. Constructed vaccine candidate was further subjected to evaluation on allergenicity and antigenicity and physiochemical parameters. Later on, disulfide engineering was performed to increase the stability of vaccine construct. Also, molecular docking and molecular dynamics simulation study were performed to check the binding affinity and stability of toll-like receptor-4 to vaccine construct complex. Finally, codon optimization and in silico cloning were performed to ensure the expression of proposed vaccine construct in a microbial expression system.

Proteasome-mediated proteostasis: Novel medicinal and pharmacological strategies for diseases.

Proteins actively participate in a wide range of cellular physiological functions. But aggregation of proteins results in cytotoxicity, and unwanted aggregation of misfolded proteins often causes many diseases. During abnormal protein aggregation events, cells try to cope against such deleterious consequences because of the remarkable functional attempts of two distinct proteolytic mechanisms. These tightly regulative and signaling mechanisms are autophagy pathway and ubiquitin proteasome system. Proteasome complex system holds the elimination capacity of intracellular aberrant protein aggregation. Despite the considerable progress that has been achieved, which elucidates wide function and diverse roles of proteasome system, still several crucial problems remain unanswered. For example, how the complex proteasomes assembly and their interactive pathways determine the precise sense of several proteotoxic insults, which can severely affect the cell survival and homeostasis? The specific degradation of various aberrant proteins that can disturb cellular homeostasis is achieved by proper proteasome functionality, which is yet another unclear and critical challenge. Therefore, a better understanding of the various cellular signaling mechanisms composing the proteasome machinery carries broad therapeutic implications linked with proteopathies. This article signifies the urgent need, which is now crucial for us to improve our understanding of the proteasome architecture, structure, and functions that span multiple level strategies from the molecular level to the cellular level. This systematic in-depth information of proteasome may be helpful in the near future to design a new molecular framework based on intrinsic and extrinsic cellular mechanisms that drive the assembly of proteasome to induce cellular survival against proteostasis imbalance and disease conditions.

Encapsulation and Systemic Delivery of 5-Fluorouracil Conjugated with Silkworm Pupa Derived Protein Nanoparticles for Experimental Lymphoma Cancer.

Protein-based drug delivery systems have an edge over conventional drug delivery systems due to their biodegradability, non-antigenicity, and excellent biocompatibility to improve the therapeutic properties of anticancer drugs. This study describes the increased anticancer efficacy of 5-fluorouracil (5-FU) conjugated with silkworm Bombyx mori pupal biowaste derived nanoparticles. Here, we have checked the toxicity of pupa-protein nanoparticles (PpNps) and their potential as a carrier for anticancer drugs. PpNps were prepared by a desolvation method which resulted in a uniform particle size of 162.7 ± 2.9 nm. The 5-FU loaded PpNps were formulated and characterized. The drug content of the developed 5-FU conjugated nanoparticles was evaluated by HPLC analysis. The entrapment efficiency and loading capacity of 5-FU were analyzed by HPLC and determined to be 93% and 88.6%, respectively. The release studies showed the biphasic release of 5-FU at pH 7.4 where rapid drug release was achieved for first 30 min, followed by a sustained release of 5-FU from the developed Nps achieved for the next 8 h. Mice with developed ascites tumors were intraperitoneally treated with 5-FU-PpNps and sacrificed. There was a significant increase in total red blood cells and hemoglobulin in 5-FU-PpNps treated mice, whereas a significant decrease in white blood cells which indicated the reduced inflammation of cancer. Subsequently, 5-FU-PpNps decreased the tumor volume and tumor cell viability, which proved its cytotoxic property to cancer cells. This study presents a novel approach to derive B. mori pupal protein nanoparticles, which can be safely used for cancer drug delivery.

Anti-infective activities of 11 plants species used in traditional medicine in Malaysia.

Treatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts were tested for their toxicity against MRC-5 cells and Leishmania donovani by MTT, and chloroquine-resistant Plasmodium falciparum K1 strain by Histidine-Rich Protein II ELISA assays. None of the extract tested was cytotoxic to MRC-5 cells. Extracts of Uvaria grandiflora, Chilocarpus costatus, Tabernaemontana peduncularis, and Leuconotis eugenifolius had good activities against L. donovani with IC50 < 50 µg/mL. Extracts of U. grandiflora, C. costatus, T. peduncularis, L. eugenifolius, A. subulatum, and C. aeruginosa had good activities against P. falciparum K1 with IC50 < 10 µg/mL. Pinoresinol isolated from C. costatus was inactive against L. donovani and P. falciparum. C. costatus extract and pinoresinol increased the sensitivity of Staphylococcus epidermidis to cefotaxime. Pinoresinol demonstrated moderate activity against influenza virus (IC50 = 30.4 ±â€¯11 µg/mL) and was active against Coxsackie virus B3 (IC50 = 7.1 ±â€¯3.0 µg/mL). ß-Amyrin from L. eugenifolius inhibited L. donovani with IC50 value of 15.4 ±â€¯0.01 µM. Furanodienone from C. aeruginosa inhibited L. donovani and P. falciparum K1 with IC50 value of 39.5 ±â€¯0.2 and 17.0 ±â€¯0.05 µM, respectively. Furanodienone also inhibited the replication of influenza and Coxsackie virus B3 with IC50 value of 4.0 ±â€¯0.5 and 7.2 ±â€¯1.4 µg/mL (Ribavirin: IC50: 15.6 ±â€¯2.0 µg/mL), respectively. Our study provides evidence that medicinal plants in Malaysia have potentials as a source of chemotypes for the development of anti-infective leads.

Emerging Role of Circular RNAs as Potential Biomarkers for the Diagnosis of Human Diseases.

In the eukaryotic transcriptome, the evolutionary conserved circular RNAs naturally occur from the family of noncoding RNAs. Circular RNAs possess a unique feature to interact with nucleic acids and ribonucleoproteins and are establishing themselves as an obligatory composition for the regulatory messages which are encoded by the genome. The back-splicing mechanism leads to the formation of circularized RNA, and because of this they become resistant to exonuclease-mediated degradation. The differential and aberrant expression of circular RNAs can be detected with the help of various profiling methods by using serum, plasma, and tissue samples. In this chapter, we have highlighted the role of circular RNAs as putative biomarker for the detection of various human diseases along with its profiling methods. Here we have discussed the differentially expressed circular RNAs in neurological disorders and infectious diseases along with cancer diseases. For instance, in case of pulmonary tuberculosis, hsa_circRNA_001937 was upregulated, while hsa_circRNA_102101 got downregulated; Hsa_circ_000178 was depicted to get upregulated in breast cancer which is associated with disease progression. Furthermore, it has been observed that circRNAs are abundantly present within the mammalian brain tissues. In epileptic condition, Circ-EFCAB2 was observed to get notably upregulated within patients. Taking the above conditions into consideration, circular RNAs have proven themselves as promising noninvasive biomarker for the detection of human diseases.

Structure-based virtual screening, molecular docking, ADMET and molecular simulations to develop benzoxaborole analogs as potential inhibitor against Leishmania donovani trypanothione reductase.

Visceral leishmaniasis (VL) is the most fatal form of leishmaniasis and it affects 70 countries worldwide. Increasing drug resistant for antileishmanial drugs such as miltefosine, sodium stibogluconate and pentamidine has been reported in the VL endemic region. Amphotericin B has shown potential antileishmanial activity in different formulations but its cost of treatment and associated nephrotoxicity have limited its use by affected people living in the endemic zone. To control the VL infection in the affected countries, it is necessary to develop new antileishmanial compounds with high efficacy and negligible toxicity. Computer aided programs such as binding free energy estimation; ADMET prediction and molecular dynamics simulation can be used to investigate novel antileishmanial molecules in shorter duration. To develop antileishmanial lead molecule, we performed standard precision (SP) docking for 1160 benzoxaborole analogs along with reference inhibitors against trypanothione reductase of Leishmania parasite. Furthermore, extra precision (XP) docking, ADMET prediction, prime MM-GBSA was conducted over 115 ligands, showing better docking score than reference inhibitors to get potential antileishmanial compounds. Simultaneously, area under the curve (AUC) was estimated using ROC plot to validate the SP and XP docking protocol. Later on, two benzoxaborole analogs with best MM-GBSA ΔG-bind were subjected to molecular simulation and docking confirmation to ensure the ligand interaction with TR. The presented drug discovery based on computational study confirms that BOB27 can be used as a potential drug candidate and warrants further experimental investigation to fight against VL in endemic areas.

Nanonization increases the antileishmanial efficacy of amphotericin B: an ex vivo approach.

With widespread resistance to pentavalent antimonial in the endemic eastern terai belt of Nepal and Bihar, India, Amphotericin B deoxycholate is now the first-line antileishmanial drug for the treatment of visceral leishmaniasis (VL). However, universal occurrence of infusion-related fever and rigors with amphotericin B (AmB), occasional serious life-threatening toxicities like cardiotoxicity, anaphylaxis, hypokalemia, and nephrotoxicity are major barriers to its use in areas with limited medical facilities. Liposomal amphotericins, however, are devoid of adverse effects, high cost makes it unaffordable. We had formulated nanoparticles (10-20 nm) from amphotericin B deoxycholate (1-2 µm) applying high pressure (150 atm) milling homogenization in argon atmosphere and tested its ex vivo efficacy in Leishmania infected J774A cell line and peritoneal macrophage. The ex vivo ED50 for intracellular amastigotes in peritoneal macrophage by nano-amphotericin was 0.0027 ± 0.001 µg/mL which was significantly less (p = 0.0029) than the required dose of amphotericin B (0.0426 ± 0.003 µg/mL). Similarly, in J774A cell line, 50 % of intracellular amastigotes were cleared by 0.0038 ± 0.001 µg/mL of nano-amphotericin while the dose was a bit more for AmB (0.0196 ± 0.001 µg/mL) illustrating the significant difference (p value, 0.0122). The nanoformulation has also shown high efficacy (ED50, 0.0028-0.0035 µg/mL) in inhibition of infected macrophage count. The new formulation accumulated to spleen, the targeted organ, 7 days after inoculation of drug to the infected hamster as traced in vivo by TEM convincing it as potential drug. Given a favorable safety profile and very low cost of production contemplated, it may prove to be a feasible alternative for conventional amphotericin B.