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1.
Gut ; 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38857990

ABSTRACT

OBJECTIVE: Epigenetic mechanisms, including DNA methylation (DNAm), have been proposed to play a key role in Crohn's disease (CD) pathogenesis. However, the specific cell types and pathways affected as well as their potential impact on disease phenotype and outcome remain unknown. We set out to investigate the role of intestinal epithelial DNAm in CD pathogenesis. DESIGN: We generated 312 intestinal epithelial organoids (IEOs) from mucosal biopsies of 168 patients with CD (n=72), UC (n=23) and healthy controls (n=73). We performed genome-wide molecular profiling including DNAm, bulk as well as single-cell RNA sequencing. Organoids were subjected to gene editing and the functional consequences of DNAm changes evaluated using an organoid-lymphocyte coculture and a nucleotide-binding oligomerisation domain, leucine-rich repeat and CARD domain containing 5 (NLRC5) dextran sulphate sodium (DSS) colitis knock-out mouse model. RESULTS: We identified highly stable, CD-associated loss of DNAm at major histocompatibility complex (MHC) class 1 loci including NLRC5 and cognate gene upregulation. Single-cell RNA sequencing of primary mucosal tissue and IEOs confirmed the role of NLRC5 as transcriptional transactivator in the intestinal epithelium. Increased mucosal MHC-I and NLRC5 expression in adult and paediatric patients with CD was validated in additional cohorts and the functional role of MHC-I highlighted by demonstrating a relative protection from DSS-mediated mucosal inflammation in NLRC5-deficient mice. MHC-I DNAm in IEOs showed a significant correlation with CD disease phenotype and outcomes. Application of machine learning approaches enabled the development of a disease prognostic epigenetic molecular signature. CONCLUSIONS: Our study has identified epigenetically regulated intestinal epithelial MHC-I as a novel mechanism in CD pathogenesis.

2.
EMBO Mol Med ; 2024 May 15.
Article in English | MEDLINE | ID: mdl-38750308

ABSTRACT

Necroptosis is a lytic form of regulated cell death reported to contribute to inflammatory diseases of the gut, skin and lung, as well as ischemic-reperfusion injuries of the kidney, heart and brain. However, precise identification of the cells and tissues that undergo necroptotic cell death in vivo has proven challenging in the absence of robust protocols for immunohistochemical detection. Here, we provide automated immunohistochemistry protocols to detect core necroptosis regulators - Caspase-8, RIPK1, RIPK3 and MLKL - in formalin-fixed mouse and human tissues. We observed surprising heterogeneity in protein expression within tissues, whereby short-lived immune barrier cells were replete with necroptotic effectors, whereas long-lived cells lacked RIPK3 or MLKL expression. Local changes in the expression of necroptotic effectors occurred in response to insults such as inflammation, dysbiosis or immune challenge, consistent with necroptosis being dysregulated in disease contexts. These methods will facilitate the precise localisation and evaluation of necroptotic signaling in vivo.

3.
Neuroradiol J ; 37(3): 323-331, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38195418

ABSTRACT

BACKGROUND AND PURPOSE: Deep learning (DL) accelerated MR techniques have emerged as a promising approach to accelerate routine MR exams. While prior studies explored DL acceleration for specific lumbar MRI sequences, a gap remains in comprehending the impact of a fully DL-based MRI protocol on scan time and diagnostic quality for routine lumbar spine MRI. To address this, we assessed the image quality and diagnostic performance of a DL-accelerated lumbar spine MRI protocol in comparison to a conventional protocol. METHODS: We prospectively evaluated 36 consecutive outpatients undergoing non-contrast enhanced lumbar spine MRIs. Both protocols included sagittal T1, T2, STIR, and axial T2-weighted images. Two blinded neuroradiologists independently reviewed images for foraminal stenosis, spinal canal stenosis, nerve root compression, and facet arthropathy. Grading comparison employed the Wilcoxon signed rank test. For the head-to-head comparison, a 5-point Likert scale to assess image quality, considering artifacts, signal-to-noise ratio (SNR), anatomical structure visualization, and overall diagnostic quality. We applied a 15% noninferiority margin to determine whether the DL-accelerated protocol was noninferior. RESULTS: No significant differences existed between protocols when evaluating foraminal and spinal canal stenosis, nerve compression, or facet arthropathy (all p > .05). The DL-spine protocol was noninferior for overall diagnostic quality and visualization of the cord, CSF, intervertebral disc, and nerve roots. However, it exhibited reduced SNR and increased artifact perception. Interobserver reproducibility ranged from moderate to substantial (κ = 0.50-0.76). CONCLUSION: Our study indicates that DL reconstruction in spine imaging effectively reduces acquisition times while maintaining comparable diagnostic quality to conventional MRI.


Subject(s)
Deep Learning , Lumbar Vertebrae , Magnetic Resonance Imaging , Humans , Magnetic Resonance Imaging/methods , Male , Lumbar Vertebrae/diagnostic imaging , Female , Prospective Studies , Middle Aged , Aged , Signal-To-Noise Ratio , Spinal Stenosis/diagnostic imaging , Adult , Spinal Diseases/diagnostic imaging
5.
ACS Appl Mater Interfaces ; 16(4): 4803-4810, 2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38258417

ABSTRACT

Hybrid ultramicroporous materials (HUMs), metal-organic platforms that incorporate inorganic pillars, are a promising class of porous solids. A key area of interest for such materials is gas separation, where HUMs have already established benchmark performances. Thanks to their ready compositional modularity, we report the design and synthesis of a new HUM, GEFSIX-21-Cu, incorporating the ligand pypz (4-(3,5-dimethyl-1H-pyrazol-4-yl)pyridine, 21) and GeF62- pillaring anions. GEFSIX-21-Cu delivers on two fronts: first, it displays an exceptionally high C2H2 adsorption capacity (≥5 mmol g-1) which is paired with low uptake of CO2 (<2 mmol g-1), and, second, a low enthalpy of adsorption for C2H2 (ca. 32 kJ mol-1). This combination is rarely seen in the C2H2 selective physisorbents reported thus far, and not observed in related isostructural HUMs featuring pypz and other pillaring anions. Dynamic column breakthrough experiments for 1:1 and 2:1 C2H2/CO2 mixtures revealed GEFSIX-21-Cu to selectively separate C2H2 from CO2, yielding ≥99.99% CO2 effluent purities. Temperature-programmed desorption experiments revealed full sorbent regeneration in <35 min at 60 °C, reinforcing HUMs as potentially technologically relevant materials for strategic gas separations.

6.
Chem Sci ; 15(1): 195-203, 2023 Dec 20.
Article in English | MEDLINE | ID: mdl-38131086

ABSTRACT

The threat of antimicrobial resistance to antibiotics requires a continual effort to develop alternative treatments. Arylglycines (or phenylglycines) are one of the signature amino acids found in many natural peptide antibiotics, but their propensity for epimerization in solid-phase peptide synthesis (SPPS) has prevented their use in long peptide sequences. We have now identified an optimized protocol that allows the synthesis of challenging non-ribosomal peptides including precursors of the glycopeptide antibiotics and an analogue of feglymycin (1 analogue, 20%). We have exploited this protocol to synthesize analogues of the peptide antibiotic ramoplanin using native chemical ligation/desulfurization (1 analogue, 6.5%) and head-to-tail macrocyclization in excellent yield (6 analogues, 3-9%), with these compounds extensively characterized by NMR (U-shaped structure) and antimicrobial activity assays (two clinical isolates). This method significantly reduces synthesis time (6-9 days) when compared with total syntheses (2-3 months) and enables drug discovery programs to include arylglycines in structure-activity relationship studies and drug development.

7.
Nat Commun ; 14(1): 6046, 2023 09 28.
Article in English | MEDLINE | ID: mdl-37770424

ABSTRACT

Across the globe, 2-3% of humans carry the p.Ser132Pro single nucleotide polymorphism in MLKL, the terminal effector protein of the inflammatory form of programmed cell death, necroptosis. Here we show that this substitution confers a gain in necroptotic function in human cells, with more rapid accumulation of activated MLKLS132P in biological membranes and MLKLS132P overriding pharmacological and endogenous inhibition of MLKL. In mouse cells, the equivalent Mlkl S131P mutation confers a gene dosage dependent reduction in sensitivity to TNF-induced necroptosis in both hematopoietic and non-hematopoietic cells, but enhanced sensitivity to IFN-ß induced death in non-hematopoietic cells. In vivo, MlklS131P homozygosity reduces the capacity to clear Salmonella from major organs and retards recovery of hematopoietic stem cells. Thus, by dysregulating necroptosis, the S131P substitution impairs the return to homeostasis after systemic challenge. Present day carriers of the MLKL S132P polymorphism may be the key to understanding how MLKL and necroptosis modulate the progression of complex polygenic human disease.


Subject(s)
Apoptosis , Protein Kinases , Humans , Animals , Mice , Phosphorylation , Protein Kinases/genetics , Protein Kinases/metabolism , Cell Membrane/metabolism , Mutation , Transcription Factors/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism
8.
Cell Death Differ ; 30(4): 1059-1071, 2023 04.
Article in English | MEDLINE | ID: mdl-36755069

ABSTRACT

MLKL and RIPK3 are the core signaling proteins of the inflammatory cell death pathway, necroptosis, which is a known mediator and modifier of human disease. Necroptosis has been implicated in the progression of disease in almost every physiological system and recent reports suggest a role for necroptosis in aging. Here, we present the first comprehensive analysis of age-related histopathological and immunological phenotypes in a cohort of Mlkl-/- and Ripk3-/- mice on a congenic C57BL/6 J genetic background. We show that genetic deletion of Mlkl in female mice interrupts immune system aging, specifically delaying the age-related reduction of circulating lymphocytes. -Seventeen-month-old Mlkl-/- female mice were also protected against age-related chronic sterile inflammation in connective tissue and skeletal muscle relative to wild-type littermate controls, exhibiting a reduced number of immune cell infiltrates in these sites and fewer regenerating myocytes. These observations implicate MLKL in age-related sterile inflammation, suggesting a possible application for long-term anti-necroptotic therapy in humans.


Subject(s)
Inflammation , Protein Kinases , Mice , Humans , Female , Animals , Infant , Necrosis/metabolism , Protein Kinases/metabolism , Mice, Inbred C57BL , Inflammation/pathology , Cell Death , Transcription Factors/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism
9.
Chemosphere ; 307(Pt 4): 136003, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35987265

ABSTRACT

Herein, a simple hydrothermal approach was used to make multiplex heteroatoms doped carbon dots from Tinospora cordifolia miers plant extract. Their ability to the catalytic activity of dyes and anti-spurious applications was evaluated. The formation of NBCNDs and source of (T. cordifolia miers) study the optical properties, and functional groups are investigated using UV-Visible spectroscopy and FT-IR techniques. The synthesized NBCNDs structure and elemental compositions were examined via HR-TEM, XRD, and XPS, respectively. According to the HRTEM images, the average particle size of the NBCNDs was around 4.3± 1 nm, with d-spacing of 0.19 nm. The obtained NBCNDs were exposed under 395 nm UV light to emit bluish-green tuneable fluorescence with QY (quantum yield) of 23.7%. The prepared NBCNDs as a potential catalyst for the AYR and CV dye reduction process using freshly prepared NaBH4, with determined rate constant values at 0.1220 and 0.1521 min-1, respectively. Lastly, we constructed a quick response (QR) code security label for anti-spurious applications using stencil techniques. The "confidential info" was encrypted using a QR code digital system, and the decryption was read using a smartphone under 365 nm light irradiation.


Subject(s)
Carbon , Quantum Dots , Carbon/chemistry , Fluorescent Dyes/chemistry , Ions , Nitrogen/chemistry , Plant Extracts/chemistry , Quantum Dots/chemistry , Spectroscopy, Fourier Transform Infrared
10.
Cell Mol Gastroenterol Hepatol ; 14(6): 1295-1310, 2022.
Article in English | MEDLINE | ID: mdl-36038072

ABSTRACT

BACKGROUND & AIMS: Human intestinal epithelial organoids (IEOs) are a powerful tool to model major aspects of intestinal development, health, and diseases because patient-derived cultures retain many features found in vivo. A necessary aspect of the organoid model is the requirement to expand cultures in vitro through several rounds of passaging. This is of concern because the passaging of cells has been shown to affect cell morphology, ploidy, and function. METHODS: Here, we analyzed 173 human IEO lines derived from the small and large bowel and examined the effect of culture duration on DNA methylation (DNAm). Furthermore, we tested the potential impact of DNAm changes on gene expression and cellular function. RESULTS: Our analyses show a reproducible effect of culture duration on DNAm in a large discovery cohort as well as 2 publicly available validation cohorts generated in different laboratories. Although methylation changes were seen in only approximately 8% of tested cytosine-phosphate-guanine dinucleotides (CpGs) and global cellular function remained stable, a subset of methylation changes correlated with altered gene expression at baseline as well as in response to inflammatory cytokine exposure and withdrawal of Wnt agonists. Importantly, epigenetic changes were found to be enriched in genomic regions associated with colonic cancer and distant to the site of replication, indicating similarities to malignant transformation. CONCLUSIONS: Our study shows distinct culture-associated epigenetic changes in mucosa-derived human IEOs, some of which appear to impact gene transcriptomic and cellular function. These findings highlight the need for future studies in this area and the importance of considering passage number as a potentially confounding factor.


Subject(s)
DNA Methylation , Organoids , Humans , Intestines , Epigenesis, Genetic , Intestinal Mucosa
11.
Chem Asian J ; 17(6): e202200093, 2022 Mar 14.
Article in English | MEDLINE | ID: mdl-35139260

ABSTRACT

There is a concerted attempt to develop self-assembled metallo-cages of greater structural complexity, and heteroleptic PdII cages are emerging as prime candidates in these efforts. Most of these are dinuclear: few examples of higher nuclearity have been reported. We demonstrate here a robust method for the formation of tripalladium(II) cages from the 2 : 3 : 3 combination of a tritopic ligand, PdII , and a selection of ditopic ligands of the correct size and geometry.


Subject(s)
Palladium , Palladium/chemistry
12.
Int J Mol Sci ; 24(1)2022 Dec 30.
Article in English | MEDLINE | ID: mdl-36614133

ABSTRACT

Cancer is one of the leading cause of lethality worldwide, CRC being the third most common cancer reported worldwide, with 1.85 million cases and 850,000 deaths annually. As in all other cancers, kinases are one of the major enzymes that play an essential role in the incidence and progression of CRC. Thus, using multi-kinase inhibitors is one of the therapeutic strategies used to counter advanced-stage CRC. Regorafenib is an FDA-approved drug in the third-line therapy of refractory metastatic colorectal cancer. Acquired resistance to cancers and higher toxicity of these drugs are disadvantages to the patients. To counter this, combination therapy is used as a strategy where a minimal dose of drugs can be used to get a higher efficacy and reduce drug resistance development. Ruthenium-based compounds are observed to be a potential alternative to platinum-based drugs due to their significant safety and effectiveness. Formerly, our lab reported Ru-1, a ruthenium-based compound, for its anticancer activity against multiple cancer cells, such as HepG2, HCT116, and MCF7. This study evaluates Ru-1's activity against regorafenib-resistant HCT116 cells and as a combination therapeutic with regorafenib. Meanwhile, the mechanism of the effect of Ru-1 alone and with regorafenib as a combination is still unknown. In this study, we tested a drug combination (Ru-1 and regorafenib) against a panel of HT29, HCT116, and regorafenib-resistant HCT116 cells. The combination showed a synergistic inhibitory activity. Several mechanisms underlying these numerous synergistic activities, such as anti-proliferative efficacy, indicated that the combination exhibited potent cytotoxicity and enhanced apoptosis induction. Disruption of mitochondrial membrane potential increased intracellular ROS levels and decreased migratory cell properties were observed. The combination exhibited its activity by regulating PI3K/Akt and p38 MAP kinase signalling. This indicates that the combination of REG/Ru-1 targets cancer cells by modulating the PI3K/Akt and ERK signalling.


Subject(s)
Colorectal Neoplasms , Ruthenium , Humans , Proto-Oncogene Proteins c-akt/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Ruthenium/pharmacology , Ruthenium/therapeutic use , Apoptosis , Colorectal Neoplasms/pathology , Phenylurea Compounds/therapeutic use , Cell Line, Tumor
13.
Front Genet ; 12: 770350, 2021.
Article in English | MEDLINE | ID: mdl-34925456

ABSTRACT

Muscular Dystrophies (MDs) are a group of inherited diseases and heterogeneous in nature. To date, 40 different genes have been reported for the occurrence and/or progression of MDs. This study was conducted to demonstrate the application of next-generation sequencing (NGS) in developing a time-saving and cost-effective diagnostic method to detect single nucleotide variants (SNVs) and copy number variants (CNVs) in a single test. A total of 123 cases clinically suspected of MD were enrolled in this study. Amplicon panel-based diagnosis was carried out for 102 (DMD/BMD) cases and the results were further screened using multiplex ligation-dependent probe amplification (MLPA). Whilst in the case of LGMD (N = 19) and UMD (N = 2), only NGS panel-based analysis was carried out. We identified the large deletions in 74.50% (76/102) of the cases screened with query DMD or BMD. Further, the large deletion in CAPN3 gene (N = 3) and known SNV mutations (N = 4) were identified in LGMD patients. Together, the total diagnosis rate for this amplicon panel was 70.73% (87/123) which demonstrated the utility of panel-based diagnosis for high throughput, affordable, and time-saving diagnostic strategy. Collectively, present study demonstrates that the panel based NGS sequencing could be superior over to MLPA.

14.
Chem ; 7(11): 3085-3098, 2021 Nov 11.
Article in English | MEDLINE | ID: mdl-34825106

ABSTRACT

The trade-off between selectivity and adsorption capacity with porous materials is a major roadblock to reducing the energy footprint of gas separation technologies. To address this matter, we report herein a systematic crystal engineering study of C2H2 removal from CO2 in a family of hybrid ultramicroporous materials (HUMs). The HUMs are composed of the same organic linker ligand, 4-(3,5-dimethyl-1H-pyrazol-4-yl)pyridine, pypz, three inorganic pillar ligands, and two metal cations, thereby affording six isostructural pcu topology HUMs. All six HUMs exhibited strong binding sites for C2H2 and weaker affinity for CO2. The tuning of pore size and chemistry enabled by crystal engineering resulted in benchmark C2H2/CO2 separation performance. Fixed-bed dynamic column breakthrough experiments for an equimolar (v/v = 1:1) C2H2/CO2 binary gas mixture revealed that one sorbent, SIFSIX-21-Ni, was the first C2H2 selective sorbent that combines exceptional separation selectivity (27.7) with high adsorption capacity (4 mmol·g-1).

15.
Indian J Pharmacol ; 53(2): 125-131, 2021.
Article in English | MEDLINE | ID: mdl-34100396

ABSTRACT

OBJECTIVE: The present investigation was undertaken to develop a psoriatic-like skin inflammation rat model using imiquimod (IMQ) as an inducing agent. MATERIALS AND METHODS: The hairs of the back dorsal portion of the Wistar rats were removed and 80, 100, and 120 mg of IMQ cream (5% w/w) for 10 consecutive days was applied to different groups of rats. Further, psoriasis area severity index was used for calculating the psoriatic score, which included scoring of erythema, scaling, and thickening. Various biochemical parameters, pro-inflammatory cytokines, vascular endothelial growth factor (VEGF), and histopathological examination were also performed. RESULTS: The results demonstrated signs of erythema, scaling, and thickening on group applied with 120 mg and 100 mg of IMQ along with ear thickening. Biochemical evaluation revealed a significant increase in the granulation tissue weight followed by significant decrease in the levels of collagen and hexosamine. The antioxidant parameters superoxide dismutase and catalase were found to decline, while nitric oxide and lipid peroxidation were significantly elevated in skin lesions, also supported by increased pro-inflammatory cytokines expression, i.e., interleukin (IL)-1 ß, IL-6, IL-17, tumor necrosis factor-α, and VEGF. Histopathological studies revealed a disturbed natural structure along with increased epidermal proliferation, abnormal differentiation with increased number of keratinocytes in the psoriatic skin tissue. CONCLUSION: From the overall study, we have successfully developed a psoriatic-like skin inflammation rat model for the first time on Wistar strain using IMQ as an inducing agent.


Subject(s)
Disease Models, Animal , Imiquimod/toxicity , Psoriasis/chemically induced , Animals , Psoriasis/metabolism , Psoriasis/pathology , Rats , Rats, Wistar
16.
Cureus ; 13(5): e14855, 2021 May 05.
Article in English | MEDLINE | ID: mdl-34104597

ABSTRACT

As the prevalence of hyperuricemia (elevated uric acid levels in the blood) increases, the relationship between serum uric acid levels and cardiovascular risk has garnered increased interest. Several studies have highlighted that elevated uric acid levels are likely tied to increased cardiovascular disease risk. Specifically, the presence of hyperuricemia is well-established to contribute to the onset of gout (an inflammatory condition characterized by painful/swollen joints). Several studies have shown that the risk of developing gout is strongly associated with the degree of hyperuricemia. In this review, we will provide insight into the association between gout and cardiovascular disease risk. It is also important to gain insight into the pathophysiology of gout to understand the contributions to cardiovascular disease risk as well as improve diagnosis and target treatment more effectively. An interdisciplinary approach for gout management and areas for further investigation will be discussed in this review.

17.
Cureus ; 13(3): e14011, 2021 Mar 20.
Article in English | MEDLINE | ID: mdl-33884252

ABSTRACT

Syphilitic myelitis, also known as tabes dorsalis, is a disease affecting the posterior columns of the spinal cord and dorsal roots and presents as sensory ataxia and neuropathic pain and less commonly as paresthesia and gastrointestinal disturbance. Tabes dorsalis is the clinical manifestation of a previous infection with syphilis, and the average latency period from initial infection to presentation of symptoms is approximately 25 years. This is a rarely encountered manifestation of syphilis since the widespread usage of antibiotics. Penicillin G is the mainstay therapy of neurosyphilis and has been shown to improve and resolve spinal cord lesions associated with tertiary syphilis. We present a case of tabes dorsalis in a 56-year-old female with a history of extensive autoimmune disease who initially presented with neck pain and numbness of the right lower extremity. The unique nature of this case lies in the patient's clinical course, as her symptoms were initially attributed to her history of autoimmune disease. A reactive CSF-VDRL (cerebrospinal fluid Venereal Disease Research Laboratory) test and MRI findings led clinicians to suspect neurosyphilis and begin penicillin G. The patient began to show significant clinical improvement after penicillin G therapy was begun and was discharged to a rehabilitation facility to continue antibiotics and begin aggressive physical therapy.

18.
Cell Death Differ ; 28(7): 2126-2144, 2021 07.
Article in English | MEDLINE | ID: mdl-33589776

ABSTRACT

Necroptosis is a lytic, inflammatory cell death pathway that is dysregulated in many human pathologies. The pathway is executed by a core machinery comprising the RIPK1 and RIPK3 kinases, which assemble into necrosomes in the cytoplasm, and the terminal effector pseudokinase, MLKL. RIPK3-mediated phosphorylation of MLKL induces oligomerization and translocation to the plasma membrane where MLKL accumulates as hotspots and perturbs the lipid bilayer to cause death. The precise choreography of events in the pathway, where they occur within cells, and pathway differences between species, are of immense interest. However, they have been poorly characterized due to a dearth of validated antibodies for microscopy studies. Here, we describe a toolbox of antibodies for immunofluorescent detection of the core necroptosis effectors, RIPK1, RIPK3, and MLKL, and their phosphorylated forms, in human and mouse cells. By comparing reactivity with endogenous proteins in wild-type cells and knockout controls in basal and necroptosis-inducing conditions, we characterise the specificity of frequently-used commercial and recently-developed antibodies for detection of necroptosis signaling events. Importantly, our findings demonstrate that not all frequently-used antibodies are suitable for monitoring necroptosis by immunofluorescence microscopy, and methanol- is preferable to paraformaldehyde-fixation for robust detection of specific RIPK1, RIPK3, and MLKL signals.


Subject(s)
Protein Kinases/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism , Animals , Cell Membrane/metabolism , HT29 Cells , Humans , Mice , Necroptosis , Phosphorylation
19.
Microb Pathog ; 149: 104582, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33086104

ABSTRACT

The main objective of the present investigation was to mechanistically evaluate the potency of the root extract (EEC), its bioactive chloroform fraction (CEC) and eriosematin E (ECM) isolated from Eriosema chinense against Shigella flexneri-induced sub-chronic model of infectious diarrhoea using in vitro, in vivo, and in silico methods. The in vitro antibacterial activity against pathogenic strain of S. flexneri demonstrated maximum effect of ECM followed by CEC and EEC in inhibiting growth of bacteria. Further, for in vivo evaluation, was carried out by inducing diarrhoea to the rats by administering oral suspension of S. flexneri to the animals, which was followed by treatment for a period of 6 days. EEC at 200, CEC at 100 and ECM at 10 mg/kg, p.o. showed promising effect, where EEC and ECM were found to be more effective showing maximum % protection on 6th day. Results also demonstrated a significant restoration of altered antioxidants, pro-inflammatory cytokines (IL-1ß and TNF-α) expression, electrolyte balance, Na+/K+-ATPase activity and was also supported by histopathological examinations. Molecular docking study revealed that, eriosematin E inactivated the protease activity of SepA, a protein secreted by Shigella, which is responsible for disruption of epithelial barrier integrity. Thus, the overall observation confirmed the role of eriosematin E from E. chinense in treatment of Shigella flexneri-induced infectious diarrhoea.


Subject(s)
Antidiarrheals , Fabaceae , Animals , Antidiarrheals/pharmacology , Antidiarrheals/therapeutic use , Diarrhea/drug therapy , Molecular Docking Simulation , Rats , Shigella flexneri
20.
J Ethnopharmacol ; 251: 112561, 2020 Apr 06.
Article in English | MEDLINE | ID: mdl-31926988

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: The plant Psidium guajava L. (Myrtaceae), commonly used as an edible fruit is traditionally used worldwide in treatment of various gastrointestinal problems including diarrhoea. The leaves of the plant have also been evaluated for antidiarrhoeal activity in various chemical induced diarrhoea models. OBJECTIVE: The main objective of the present study was to evaluate the potency of P. guajava leaves and its major biomarker quercetin against enteropathogenic Escherichia coli (EPEC) induced infectious diarrhoea using preclinical and computational model. MATERIAL AND METHODS: P. guajava alcoholic leaf extract (PGE) was initially standardized using HPLC taking quercetin as a biomarker and was then subjected to antidiarrhoeal evaluation on rats in an EPEC induced diarrhoea rat model. The study included assessment of various behavioral parameters, initially for 6 h and then for up to 24 h of induction which was followed by estimation of stool water content, density of EPEC in stools and blood parameters evaluation. The colonic and small intestinal tissues of the treated animals were subjected to various biochemical estimations, in vivo antioxidant evaluation, estimation of ion concentration, Na+/K+-ATPase activity, assessment of pro-inflammatory cytokines and histopathological studies. Further, the major biomarker off PGE, quercetin was subjected to molecular docking studies with Na+/K+-ATPase and EPEC. RESULTS: The results demonstrated a significant antidiarrhoeal activity of quercetin (50 mg/kg), PGE at 200 and 400 mg/kg, p.o., where quercetin and PFGE at 200 mg/kg, p.o. were found to be more prominent, as confirmed through higher % protection, water content of stools and density of EPEC in stools. PGE and its biomarker quercetin also significantly recovered the WBC, Hb, platelets loss and also revealed a significant restoration of altered antioxidants level, pro-inflammatory cytokines (IL-1ß and TNF-α) expression and had positive influence on Na+/K+-ATPase activity. The docking studies of quercetin with Na+/K+-ATPase showed favourable interactions and residues Glu 327, Ser 775, Asn 776, Glu 779 and Asp 804 of Na+/K+-ATPase were adequately similar to quercetin for donating ligands for binding, while quercetin was also found to terminate the linkage between mammalian cells and EPEC thus, preventing further infection from EPEC. CONCLUSION: Inhibition in intestinal secretion, reduced nitric oxide production and inflammatory expression along with reactivation of Na+/K-ATPase activity could be attributed to the observed antidiarrhoeal potential of PGE against infectious diarrhoea, where quercetin was confirmed to be the main contributing factor.


Subject(s)
Antidiarrheals/therapeutic use , Diarrhea/drug therapy , Enteropathogenic Escherichia coli , Escherichia coli Infections/drug therapy , Plant Extracts/therapeutic use , Psidium , Quercetin/therapeutic use , Animals , Antidiarrheals/pharmacology , Colon/drug effects , Colon/pathology , Escherichia coli Infections/metabolism , Escherichia coli Infections/pathology , Female , Intestine, Small/drug effects , Intestine, Small/metabolism , Male , Molecular Docking Simulation , Nitric Oxide/metabolism , Plant Extracts/pharmacology , Plant Leaves , Quercetin/pharmacology , Rats, Wistar , Sodium-Potassium-Exchanging ATPase/metabolism
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