Quality by design (QbD) approach-based development of optimized nanocarrier to achieve quality target product profile (QTPP)-targeted lymphatic delivery.

Background.Insulin, commonly used for diabetes treatment, needs better ways to improve its effectiveness and safety due to its challenges with poor permeability and stability. Various system has been developed for oral peptide delivery. The non-targeted system can prevent gastric and enzymatic degradation of peptides but cannot increase the bulk transport of peptides across the membrane. However, the non-selectivity is the limitation of the existing system. Numerous carbohydrate-binding receptors overexpressed on intestinal macrophage cells (M-cells) of gut-associated lymphoid tissue. It is the most desirable site for receptor-mediated endocytosis and lymphatic drug delivery of peptides.Objective. The prime objective of the study was to fabricate mannose ligand conjugated nanoparticles (MNPs) employing a quality-by-design approach to address permeability challenges after oral administration. Herein, the study's secondary objective of this study is to identify the influencing factor for producing quality products. Considering this objective, the Lymphatic uptake of NPs was selected as a quality target product profile (QTPP), and a systematic study was conducted to identify the critical formulation attributes (CFAs) and critical process parameters (CPP) influencing critical quality attributes (CQAs). Mannosylated Chitosan concentrations (MCs) and TPP concentrations were identified as CFAs, and stirring speed was identified as CPP.Methods. MNPs were prepared by the inotropic gelation method and filled into the enteric-coated capsule to protect from acidic environments. The effect of CFAs and CPP on responses like particle size (X) and entrapment (Y) was observed by Box-Behnken design (BBD). ANOVA statistically evaluated the result to confirm a significant level (p< 0.05). The optimal conditions of NPs were obtained by constructing an overlay plot and determining the desirability value. HPLC and zeta-seizer analysis characterized the lyophilized NPs. Cell-line studies were performed to confirm the safety and M-cell targeting of NPs to enhance Insulin oral bioavailability.Results. The morphology of NPs was revealed by SEM. The developed NPs showed a nearly oval shape with the average size, surface potential, and % drug entrapment were 245.52 ± 3.37 nm, 22.12 ± 2.13 mV, and 76.15 ± 1.3%, respectively. MTT assay result exhibited that MNPs safe and Confocal imaging inference that NPs selectively uptake by the M-cell.Conclusion. BBD experimental design enables the effective formulation of optimized NPs. The statistical analysis estimated a clear assessment of the significance of the process and formulation variable. Cell line study confirms that NPs are safe and effectively uptake by the cell.

The Role of Complement Component C3 in Protection Against Pseudomonas Pneumonia-Induced Lung Injury.

The complement system is a family of proteins that facilitate immune resistance by attacking microbes to decrease pathogen burden. As a result, deficiencies of certain complement proteins result in recurrent bacterial infections, and can also result in acute lung injury (ALI). We and others have shown that C3 is present in both immune and nonimmune cells, and modulates cellular functions such as metabolism, differentiation, cytokine production, and survival. Although the emerging roles of the complement system have implications for host responses to ALI, key questions remain vis-a-vis the lung epithelium. In this review, we summarize our recent article in which we reported that during Pseudomonas aeruginosa-induced ALI, lung epithelial cell-derived C3 operates independent of liver-derived C3. Specifically, we report the use of a combination of human cell culture systems and global as well as conditional knockout mouse models to demonstrate the centrality of lung epithelial cell-derived C3. We also summarize recent articles that have interrogated the role of intracellular and/or locally derived C3 in host defense. We propose that C3 is a highly attractive candidate for enhancing tissue resilience in lung injury as it facilitates the survival and function of the lung epithelium, a key cell type that promotes barrier function.

Theranostics: a multifaceted approach utilizing nano-biomaterials.

Biomaterials play a vital role in targeting therapeutics. Over the years, several biomaterials have gained wide attention in the treatment and diagnosis of diseases. Scientists are trying to make more personalized treatments for different diseases, as well as discovering novel single agents that can be used for prognosis, medication administration, and keeping track of how a treatment works. Theranostics based on nano-biomaterials have higher sensitivity and specificity for disease management than conventional techniques. This review provides a concise overview of various biomaterials, including carbon-based materials like fullerenes, graphene, carbon nanotubes (CNTs), and carbon nanofibers, and their involvement in theranostics of different diseases. In addition, the involvement of imaging techniques for theranostics applications was overviewed. Theranostics is an emerging strategy that has great potential for enhancing the accuracy and efficacy of medicinal interventions. Despite the presence of obstacles such as disease heterogeneity, toxicity, reproducibility, uniformity, upscaling production, and regulatory hurdles, the field of medical research and development has great promise due to its ability to provide patients with personalised care, facilitate early identification, and enable focused treatment.

Beneficial effect of 5-HT1b/1d agonist on Parkinson's disease by modulating glutamate and reducing deposition of α-synuclein.

The given investigation examined the neuroprotection role of 5-HT1b/1d agonist in reserpine induced Parkinson's disease (PD) in male Wistar rats. PD was induced in rats by reserpine at 5 mg/kg ip for 3 days and thereafter the rats were provided with the following treatments for 4 days, zolmitriptan (ZLM) group (30 mg/kg ip); STD group (levodopa + carbidopa, 200 + 5 mg/kg ip); ZLM + GA group (zolmitriptan, 30 mg/kg ip and glutamic acid, 1.5 mg/kg); ZLM + DX group (zolmitriptan, 30 mg/kg ip and dextromethorphan, 20 mg/kg ip). All the groups were then assessed for cognitive and motor functions at the end of the protocol. Moreover, oxidative stress parameters and histopathological changes were observed in rats of all treatment groups. Deposition of α-synuclein in the brain tissue was observed by silver staining. Data of this investigation revealed that motor and cognitive functions were improved in the ZLM-treated group compared with the negative control group, which was observed to be reversed in ZLM + GA group. Treatment with ZLM ameliorated oxidative stress and histopathological changes in the brain tissue of PD rats. Further, ZLM reduced the deposition of α-synuclein in PD rats, which reversed in ZLM + GA-treated group. This study concludes by stating that 5-HT1b/1d agonist can prevent neurodegeneration and reduce oxidative stress in PD rats. The probable underlying mechanism of such an effect of 5-HT1b/1d agonist could be by regulating the deposition of α-synuclein and reducing the expression of NMDA receptor.

Geraniol reverses obesity by improving conversion of WAT to BAT in high fat diet induced obese rats by inhibiting HMGCoA reductase.

OBJECTIVES: Present report evaluates the protective effect of geraniol on high fat diet (HFD) induced obesity in rats and also determines the molecular mechanism of it. METHODS: Rats were induced with obesity with administration of HFD for four weeks and geraniol 200 and 400 mg/kg p.o. was administered for the next four week in the respective groups. Blood glucose and oral glucose tolerance test (OGTT), lipid profile was estimated in the geraniol treated HFD induced obesity in rats. Moreover, docking study was performed to determine the specific mechanism of geraniol by targeting HMG-CoE A reductase (in silico). RESULTS: There was significant increase in body weight and amelioration in altered serum glucose and lipid profile were observed in the geraniol treated group than negative control group. Weight of organs and adipose tissue isolated from different regions of the body was reduced in geraniol treated group than negative control. Moreover, geraniol interact with HMG-CoA reductase having binding energy -5.13. CONCLUSIONS: In conclusion, data of the report reveals that geraniol reduces obesity by promoting the conversion of white adipose tissue (WAT) to brown adipose tissue (BAT), as it interacts with HMG-CoA reductase in HFD induced obesity in rats.

Mycobacterium tuberculosis Rv2324 is a multifunctional feast/famine regulatory protein involved in growth, DNA replication and damage control.

Feast/famine regulatory proteins (FFRPs) are multifunctional regulators. We show that Mtb Rv2324 is important for growth, survival, and countering DNA damage in Mycobacterium tuberculosis (Mtb). DNA-relaxation activity against linear and supercoiled substrates suggest its involvement in transcription activation, while its high affinity for recombination, replication and repair substrates suggest a role there too. Small-Angle-X-ray scattering supports the adoption of an 'open' quaternary association in response to amino-acid binding. Size-exclusion-chromatography and glutaraldehyde cross-linking identify the adoption of diverse oligomers modulated by amino-acid binding, and DNA interactions. We tested G52A, G101T and D104A mutants which correspond to highly conserved residues, distal to the DNA-binding site, and are important for amino acids binding. G101T exhibits increased DNA affinity, while G52A and D104A exhibit weak DNA-binding thereby suggesting that they mediate effector-binding, and DNA binding activities. Gain and loss-of-function studies show that Rv2324 overexpression promotes growth-rate, while its knock-down leads to retarded growth. Rv2324 down-regulation lowers Mtb survival inside resting and IFN-ϒ-activated macrophages. Rv2324 protects the pathogen from DNA damage, as evidenced by the reduction in the knockdown strain's survival following treatment with H2O2 and UV light. Overall, we show that Rv2324 plays a crucial role in regulating survival and growth of Mtb.

Review on Pharmacognostic, Phytochemical and Pharmacological Characteristics of Medicinal Plants which can be used to Design a Novel Ayurvedic Formulation to Treat Hypertension in Multidimensional Approaches.

BACKGROUND: Hypertension is a cardiovascular disorder that is an incurable clinical condition. It requires lifelong therapy for its management along with long terms application of synthetic drugs associated with severe toxicity in multiple organs. However, the therapeutic application of herbal medicines to treat hypertension has gained considerable attention. The limitations and hurdles associated with conventional plant extract medications are their safety, efficacy, dose, and unknown biological activity. OBJECTIVE: In the modern era, the active phytoconstituent-based formulation has come into trend. Various extraction techniques have been reported to extract and isolate active phytoconstituents. Pharmacognostic, physiochemical, phytochemical, and quantitative analytical methods were developed for their qualitative and quantitative analysis. The passage of time and changes in lifestyle also modulate the variable cause of hypertension. Single-drug-based approach therapy cannot efficiently control the cause of hypertension. Designing a potent herbal formulation with different active constituents and modes of action against hypertension is necessary to effectively manage hypertension. METHODS: This review comprises a selection of three different plants, Boerhavia diffusa, Rauwolfia Serpentina, and Elaeocarpus ganitrus exhibiting antihypertension activity. RESULTS: The objective behind selecting individual plants is their active constituents which have different mechanisms of action for the treatment of hypertension. This review comprises the various extraction methods of the active phytoconstituents and pharmacognostic, physiochemical, phytochemical, and quantitative analysis parameters, respectively. It also lists active phytoconstituents present in plants and the different pharmacological modes of action. Selected plant extracts have different antihypertensive mechanisms. Extract of Boerhavia diffusa consisting of Liriodendron & Syringaresnol mono ß-D-Glucosidase exhibit Ca2+ channel antagonistic activity; where Reserpine is a phytoconstituent of Rauwolfia serpentina, which depletes catecholamine, Ajmalin shows an antiarrhythmic effect by blocking the sodium channel and the aqueous extract of E. ganitrus seeds reduces mean arterial blood pressure by inhibiting the ACE enzyme. CONCLUSION: It has been revealed that poly-herbal formulation of respective phytoconstituent can be used as potent antihypertensive medicine to treat hypertension effectively.

Protective effect of vanillin on the management of cecal ligation and puncture induced sepsis rat model.

Present investigation evaluates the protective effect of vanillin against sepsis. Sepsis was induced by cecal ligation and puncture (CLP) in rat and vanillin was administered at dose of 100 and 200 mg/kg p.o. for five days after induction of sepsis. Effect of vanillin was observed on the percentage of survival, body weight and food intake were determined in CLP induced sepsis rats. Level of liver enzymes in the serum and organ weight was also observed in vanillin treated CLP induced rats. Moreover, histopathological changes were also observed in liver and lung tissue of hematoxylin and eosin (H&E) staining. There was significant improvement in bodyweight and food intake in vanillin treated group than negative control group after the sepsis induction. Moreover, vanillin improves the percentage of survival rate and reduces the level of liver enzymes and spleen weight in CLP induced sepsis rat. It also improves the level of glutathione (GSH) compared to negative control group. In conclusion, data of investigation reveals that vanillin ameliorates the survival rate and oxidative stress in CLP induced sepsis rat model.

Single-cell multimodal glioma analyses identify epigenetic regulators of cellular plasticity and environmental stress response.

Glioma intratumoral heterogeneity enables adaptation to challenging microenvironments and contributes to therapeutic resistance. We integrated 914 single-cell DNA methylomes, 55,284 single-cell transcriptomes and bulk multi-omic profiles across 11 adult IDH mutant or IDH wild-type gliomas to delineate sources of intratumoral heterogeneity. We showed that local DNA methylation disorder is associated with cell-cell DNA methylation differences, is elevated in more aggressive tumors, links with transcriptional disruption and is altered during the environmental stress response. Glioma cells under in vitro hypoxic and irradiation stress increased local DNA methylation disorder and shifted cell states. We identified a positive association between genetic and epigenetic instability that was supported in bulk longitudinally collected DNA methylation data. Increased DNA methylation disorder associated with accelerated disease progression and recurrently selected DNA methylation changes were enriched for environmental stress response pathways. Our work identified an epigenetically facilitated adaptive stress response process and highlights the importance of epigenetic heterogeneity in shaping therapeutic outcomes.

Oncogenic extrachromosomal DNA functions as mobile enhancers to globally amplify chromosomal transcription.

Extrachromosomal, circular DNA (ecDNA) is emerging as a prevalent yet less characterized oncogenic alteration in cancer genomes. We leverage ChIA-PET and ChIA-Drop chromatin interaction assays to characterize genome-wide ecDNA-mediated chromatin contacts that impact transcriptional programs in cancers. ecDNAs in glioblastoma patient-derived neurosphere and prostate cancer cell cultures are marked by widespread intra-ecDNA and genome-wide chromosomal interactions. ecDNA-chromatin contact foci are characterized by broad and high-level H3K27ac signals converging predominantly on chromosomal genes of increased expression levels. Prostate cancer cells harboring synthetic ecDNA circles composed of characterized enhancers result in the genome-wide activation of chromosomal gene transcription. Deciphering the chromosomal targets of ecDNAs at single-molecule resolution reveals an association with actively expressed oncogenes spatially clustered within ecDNA-directed interaction networks. Our results suggest that ecDNA can function as mobile transcriptional enhancers to promote tumor progression and manifest a potential synthetic aneuploidy mechanism of transcription control in cancer.

Reduced subgenomic RNA expression is a molecular indicator of asymptomatic SARS-CoV-2 infection.

Background: It is estimated that up to 80% of infections caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are asymptomatic and asymptomatic patients can still effectively transmit the virus and cause disease. While much of the effort has been placed on decoding single nucleotide variation in SARS-CoV-2 genomes, considerably less is known about their transcript variation and any correlation with clinical severity in human hosts, as defined here by the presence or absence of symptoms. Methods: To assess viral genomic signatures of disease severity, we conducted a systematic characterization of SARS-CoV-2 transcripts and genetic variants in 81 clinical specimens collected from symptomatic and asymptomatic individuals using multi-scale transcriptomic analyses including amplicon-seq, short-read metatranscriptome and long-read Iso-seq. Results: Here we show a highly coordinated and consistent pattern of sgRNA expression from individuals with robust SARS-CoV-2 symptomatic infection and their expression is significantly repressed in the asymptomatic infections. We also observe widespread inter- and intra-patient variants in viral RNAs, known as quasispecies frequently found in many RNA viruses. We identify unique sets of deletions preferentially found primarily in symptomatic individuals, with many likely to confer changes in SARS-CoV-2 virulence and host responses. Moreover, these frequently occurring structural variants in SARS-CoV-2 genomes serve as a mechanism to further induce SARS-CoV-2 proteome complexity. Conclusions: Our results indicate that differential sgRNA expression and structural mutational burden are highly correlated with the clinical severity of SARS-CoV-2 infection. Longitudinally monitoring sgRNA expression and structural diversity could further guide treatment responses, testing strategies, and vaccine development.

An overview on medicinal perspective of thiazolidine-2,4-dione: A remarkable scaffold in the treatment of type 2 diabetes.

Diabetes or diabetes mellitus is a complex or polygenic disorder, which is characterized by increased levels of glucose (hyperglycemia) and deficiency in insulin secretion or resistance to insulin over an elongated period in the liver and peripheral tissues. Thiazolidine-2,4-dione (TZD) is a privileged scaffold and an outstanding heterocyclic moiety in the field of drug discovery, which provides various opportunities in exploring this moiety as an antidiabetic agent. In the past few years, various novel synthetic approaches had been undertaken to synthesize different derivatives to explore them as more potent antidiabetic agents with devoid of side effects (i.e., edema, weight gain, and bladder cancer) of clinically used TZD (pioglitazone and rosiglitazone). In this review, an effort has been made to summarize the up to date research work of various synthetic strategies for TZD derivatives as well as their biological significance and clinical studies of TZDs in combination with other category as antidiabetic agents. This review also highlights the structure-activity relationships and the molecular docking studies to convey the interaction of various synthesized novel derivatives with its receptor site.

Rv1717 Is a Cell Wall - Associated ß-Galactosidase of Mycobacterium tuberculosis That Is Involved in Biofilm Dispersion.

Understanding the function of conserved hypothetical protein (CHP)s expressed by a pathogen in the infected host can lead to better understanding of its pathogenesis. The present work describes the functional characterization of a CHP, Rv1717 of Mycobacterium tuberculosis (Mtb). Rv1717 has been previously reported to be upregulated in TB patient lungs. Rv1717 belongs to the cupin superfamily of functionally diverse proteins, several of them being carbohydrate handling proteins. Bioinformatic analysis of the amino acid sequence revealed similarity to glycosyl hydrolases. Enzymatic studies with recombinant Rv1717 purified from Escherichia coli showed that the protein is a ß-D-galactosidase specific for pyranose form rather than the furanose form. We expressed the protein in Mycobacterium smegmatis (Msm), which lacks its ortholog. In Msm Rv1717 , the protein was found to localize to the cell wall (CW) with a preference to the poles. Msm Rv1717 showed significant changes in colony morphology and cell surface properties. Most striking observation was its unusual Congo red colony morphotype, reduced ability to form biofilms, pellicles and autoagglutinate. Exogenous Rv1717 not only prevented biofilm formation in Msm, but also degraded preformed biofilms, suggesting that its substrate likely exists in the exopolysaccharides of the biofilm matrix. Presence of galactose in the extracellular polymeric substance (EPS) has not been reported before and hence we used the galactose-specific Wisteria floribunda lectin (WFL) to test the same. The lectin extensively bound to Msm and Mtb EPS, but not the bacterium per se. Purified Rv1717 also hydrolyzed exopolysaccharides extracted from Msm biofilm. Eventually, to decipher its role in Mtb, we downregulated its expression and demonstrate that the strain is unable to disperse from in vitro biofilms, unlike the wild type. Biofilms exposed to carbon starvation showed a sudden upregulation of Rv1717 transcripts supporting the potential role of Rv1717 in Mtb dispersing from a deteriorating biofilm.

An insight into the medicinal perspective of synthetic analogs of indole: A review.

Heterocycles occupy a salient place in chemistry due to their wide range of activity in the fields of drug design, photochemistry, agrochemicals, dyes, and so on. Amongst all, indole scaffold is considered as one of the most promising heterocycles found in natural and synthetic sources and has been shown to possess various biological activity, including anti-inflammatory, anti-HIV, antitubercular, antimalarial, anticonvulsant, antidiabetic, antihypertensive, analgesics, antidepressant, anticancer, antioxidant, antifungal, and antimicrobial, etc. All the reported indole molecules bind to multiple receptors with high affinity, thus expedite the research on the development of novel biologically active compounds through the various approach. In this review, we aimed to highlight synthetic and medicinal perspective on the development of indole-based analogs. In addition, structural activity relationship (SAR) study to correlate for their biological activity also discussed.

Effect of various drugs on differentially detectable persisters of Mycobacterium tuberculosis generated by long-term lipid diet.

Persisters of Mycobacterium tuberculosis (Mtb) that fail to form colonies on agar media when de-stressed are termed as differentially detectable (DD) persisters. Since in the host, Mtb primarily survives by utilizing lipids, we used a long-term lipid diet model to induce DD persisters of M. tuberculosis. Persisters were induced by replacing the dextrose-containing medium with one containing fatty acids instead of dextrose (FAM). After 2, 4 or 6 weeks, CFU and most probable number assays were performed; the difference between the two gave an estimate of DD persisters. Since rifampicin has been shown to induce formation of DD persisters in vitro, one set of FAM cultures were also given short-term rifampicin stress after 2, 4 or 6 weeks. Fraction of DD persisters increased with time and rifampicin treatment enhanced the effect of fatty acids, at 2 and 4 weeks. At six weeks, even in the absence of rifampicin, ∼95% population were DD persisters. The DD persisters were vulnerable to drugs interfering with bacterial respiration such as thioridazine, bedaquiline and clofazimine. The study indicates potential formation of DD persisters of Mtb in a lipid-rich microenvironment in the host even before antibiotic therapy.

Multiplex chromatin interactions with single-molecule precision.

The genomes of multicellular organisms are extensively folded into 3D chromosome territories within the nucleus1. Advanced 3D genome-mapping methods that combine proximity ligation and high-throughput sequencing (such as chromosome conformation capture, Hi-C)2, and chromatin immunoprecipitation techniques (such as chromatin interaction analysis by paired-end tag sequencing, ChIA-PET)3, have revealed topologically associating domains4 with frequent chromatin contacts, and have identified chromatin loops mediated by specific protein factors for insulation and regulation of transcription5-7. However, these methods rely on pairwise proximity ligation and reflect population-level views, and thus cannot reveal the detailed nature of chromatin interactions. Although single-cell Hi-C8 potentially overcomes this issue, this method may be limited by the sparsity of data that is inherent to current single-cell assays. Recent advances in microfluidics have opened opportunities for droplet-based genomic analysis9 but this approach has not yet been adapted for chromatin interaction analysis. Here we describe a strategy for multiplex chromatin-interaction analysis via droplet-based and barcode-linked sequencing, which we name ChIA-Drop. We demonstrate the robustness of ChIA-Drop in capturing complex chromatin interactions with single-molecule precision, which has not been possible using methods based on population-level pairwise contacts. By applying ChIA-Drop to Drosophila cells, we show that chromatin topological structures predominantly consist of multiplex chromatin interactions with high heterogeneity; ChIA-Drop also reveals promoter-centred multivalent interactions, which provide topological insights into transcription.

Linked-read Sequencing Analysis Reveals Tumor-specific Genome Variation Landscapes in Neurofibromatosis Type 2 (NF2) Patients.

HYPOTHESIS: We hypothesize that genomic variants including deletions, insertions, inversions, and tandem duplications beyond the changes in tumor suppressor NF2 gene affect gene expression of tumor-specific pathways in vestibular schwannomas (VS) patients with Neurofibromatosis type 2 (NF2), thus contributing to their clinical behavior. BACKGROUND: Genomic variation could reconfigure transcription in NF2 transformation process. Therefore, genome-wide high-resolution characterization of structural variants (SV) landscapes in NF2 tumors can expand our understanding of the genes regulating the clinical phenotypes in NF2-associated VS. METHODS: We performed whole-genome haplotype-specific structural variation analysis using synthetic linked reads generated through microfluidics-based barcoding of high molecular weight DNA followed by high-coverage Illumina paired-end whole-genome sequencing from 10 patients' tumors of different growth rates and their matching blood samples. RESULTS: NF2 tumor-specific deletions and large SVs were detected and can be classified based on their association with tumor growth rates. Through detailed annotation of these mutations, we uncover common alleles affected by these deletions and large SVs that can be associated with signaling pathways implicated in cell proliferation and tumorigenesis. CONCLUSION: The genomic variation landscape of NF2-related VS was investigated through whole-genome linked-read sequencing. Large SVs, in addition to deletions, were identified and may serve as modulators of clinical behavior.

Triacylglycerols: Fuelling the Hibernating Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb) has the remarkable ability to persist with a modified metabolic status and phenotypic drug tolerance for long periods in the host without producing symptoms of active tuberculosis. These persisters may reactivate to cause active disease when the immune system becomes disrupted or compromised. Thus, the infected hosts with the persisters serve as natural reservoir of the deadly pathogen. Understanding the host and bacterial factors contributing to Mtb persistence is important to devise strategies to tackle the Mtb persisters. Host lipids act as the major source of carbon and energy for Mtb. Fatty acids derived from the host cells are converted to triacylglycerols (triglycerides or TAG) and stored in the bacterial cytoplasm. TAG serves as a dependable, long-term energy source of lesser molecular mass than other storage molecules like glycogen. TAG are found in substantial amounts in the mycobacterial cell wall. This review discusses the production, accumulation and possible roles of TAG in mycobacteria, pointing out the aspects that remain to be explored. Finally, the essentiality of TAG synthesis for Mtb is discussed with implications for identification of intervention strategies.

Antileishmanial Activity of Pyrazolopyridine Derivatives and Their Potential as an Adjunct Therapy with Miltefosine.

A series of pyrazolo(dihydro)pyridines was synthesized and evaluated for antileishmanial efficacy against experimental visceral leishmaniasis (VL). Among all compounds, 6d and 6j exhibited better activity than miltefosine against intracellular amastigotes. Compound 6j (50 mg/kg/day) was further studied against Leishmania donovani/BALB/c mice via the intraperitoneal route for 5 days and displayed >91 and >93% clearance of splenic and liver parasitic burden, respectively. Combination treatment of 6j with a subcurative dose of miltefosine (5 mg/kg) in BALB/c mice almost completely ameliorated the disease (>97% inhibition) by augmenting nitric oxide generation and shifting the immune response toward Th1. Furthermore, investigating the effect of 6j on Leishmania promastigotes revealed that it induced molecular events, such as a loss in mitochondrial membrane potential, externalization of phosphatidylserine, and DNA fragmentation, that ultimately resulted in the programmed cell death of the parasite. These results along with pharmacokinetic studies suggest that 6j could be a promising lead for treating VL as an adjunct therapy with miltefosine.