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1.
Phytochem Anal ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38659229

RESUMO

INTRODUCTION: Trillium govanianum Wall. ex D.Don is a folk medicinal herb rich in structurally diverse steroidal saponins. The annual demand for this herb in India is about 200-500 metric tons, highlighting the need for a thorough quality assessment. OBJECTIVE: The objective of this study is to develop an easy and reliable ultrahigh-performance liquid chromatography-evaporative light scattering detector (UHPLC-ELSD)-based quality assessment method with 14 specialised metabolites of T. govanianum and identify the potential targets of this herb using network pharmacology. MATERIAL AND METHODS: A UHPLC-ELSD method was developed and validated with 14 markers of T. govanianum. The developed method and natural deep eutectic solvent (NADES)-assisted extraction were utilised for the recovery enhancement study of targeted specialised metabolites from rhizome samples (collected from five geographically distinct areas). In addition, the network pharmacology approach was performed for these 14 markers to predict the plausible biological targets of T. govanianum. RESULT: The developed method showed good linearity (r2: 0.940-0.998), limit of detection (LOD) (2.4-9.0 µg), limit of quantification (LOQ) (7.92-29.7 µg), precision (intra-day relative standard deviations [RSDs] 0.77%-1.96% and inter-day RSDs 2.19-4.97%), and accuracy (83.24%-118.90%). NADES sample TG-1* showed the highest recovery (yield: 167.66 ± 4.39 mg/g of dry weight) of total saponin content (TSC) as compared to its hydroethanolic extract (yield: 103.95 ± 5.36 mg/g of dry weight). Sample TG-1* was the most favourable (yield: 167.66 ± 4.39 mg/g) in terms of TSC as compared to other analysed samples (32.68 ± 1.04-88.22 ± 6.79 mg/g). Govanoside D (yield: 3.43-28.06 mg/g), 22ß-hydroxyprotodioscin (yield: 3.22-114.79 mg/g), and dioscin (yield: 1.07-20.82 mg/g) were quantified as the major metabolites. Furthermore, network pharmacology analysis of targeted 14 markers indicated that these molecules could be possible therapeutic agents for managing neuralgia, diabetes mellitus, and hyperalgesia. CONCLUSION: The current study represents the first report for the simultaneous quantification and a network pharmacology-based analysis of 14 chemical marker compounds isolated from T. govanianum.

2.
J Proteome Res ; 23(5): 1801-1809, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38655769

RESUMO

Alcohol consumption perturbs the gut immune barrier and ultimately results in alcoholic liver diseases, but little is known about how immune-related cells in the gut are perturbed in this process. In this study, we employed laser capture microdissection and a label-free proteomics approach to investigate the consequences of alcohol exposure to the proteomes of crypts and villi in the proximal small intestine. Intestinal tissues from alcohol-fed and pair-fed mice were microdissected to selectively capture cells in the crypts and villi regions, followed by one-pot protein digestion and data-independent LC-MS/MS analysis. We successfully identified over 3000 proteins from each of the crypt or villi regions equivalent to ∼3000 cells. Analysis of alcohol-treated tissues indicated an enhanced alcohol metabolism and reduced levels of α-defensins in crypts, alongside increased lipid metabolism and apoptosis in villi. Immunofluorescence imaging further corroborated the proteomic findings. Our work provides a detailed profiling of the proteomic changes in the compartments of the mouse small intestine and aids in molecular-level understanding of alcohol-induced tissue damage.


Assuntos
Etanol , Intestino Delgado , Proteômica , Animais , Intestino Delgado/metabolismo , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/patologia , Proteômica/métodos , Camundongos , Etanol/toxicidade , Espectrometria de Massas em Tandem , Proteoma/metabolismo , Proteoma/análise , Proteoma/efeitos dos fármacos , Microdissecção e Captura a Laser , Cromatografia Líquida , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Camundongos Endogâmicos C57BL , Masculino , Apoptose/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos
3.
STAR Protoc ; 5(1): 102870, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38329878

RESUMO

Atomic force microscope (AFM) is a powerful and versatile tool to determine the physical properties of cells. The force-distance curves obtained from AFM experiments can be used to determine the stiffness and viscoelastic properties of cells. Here, we present a protocol for the determination of viscoelasticity from live cells such as Drosophila hemocytes or mouse embryonic stem cells using AFM. This protocol has potential application in determining the physical properties of cells in healthy and diseased conditions. For complete details on the use and execution of this protocol, please refer to Mote et al. (2020),1 and Singh et al. (2023).2.


Assuntos
Fenômenos Mecânicos , Animais , Camundongos , Microscopia de Força Atômica/métodos
4.
Eur J Med Chem ; 260: 115748, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37666044

RESUMO

In the course of evolution, living organisms have become well equipped with diverse natural products that serve important functions, including defence from biotic and abiotic stress, growth regulation, reproduction, metabolism, and epigenetic regulation. It seems to be the organism's ecological niche that influences the natural product's structural and functional diversity. Indeed, natural products constitute the nuts and bolts of molecular co-evolution and ecological relationships among different life forms. Since natural products in the form of specialized secondary metabolites exhibit biological functions via interactions with specific target proteins, they can provide a simultaneous glimpse of both new therapeutics and therapeutic targets in humans as well. In this review, we have discussed the innate role of natural products in the ecosystem and how this intrinsic role provides a futuristic opportunity to identify new drugs and therapeutic targets rapidly.


Assuntos
Produtos Biológicos , Ecossistema , Humanos , Epigênese Genética , Produtos Biológicos/farmacologia
5.
Steroids ; 199: 109293, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37549778

RESUMO

Four previously undescribed steroidal saponins named govanosides C-F (1-4) and nine known compounds (5-13) were isolated from the rhizomes of Trillium govanianum Wall. ex D.Don. Govanosides C-E contained a rare sugar moiety i.e., 6-deoxy allose, while govanoside F has acetylated rhamnose moiety in its glycan part. Also, this is the first report on the isolation of feruloyl sucrose derivatives (11-12) and (E)-4-hydroxy-dodec-2-enedioic acid (13) from the Trillium genus. The structure of isolated compounds was deduced using 1D and 2D NMR, HRESIMS, LC-MS/MS, GC-MS, and saccharide linkage analysis. Steroidal scaffold isolates (1-10) were evaluated for their antagonistic effects on acetylcholinesterase inhibitory activity. Govanoside C (1) significantly inhibited acetylcholinesterase (IC50: 2.38 µM). Molecular docking experiments have also been performed to depict the molecule's interaction and binding free energy with acetylcholinesterase.


Assuntos
Saponinas , Trillium , Rizoma/química , Acetilcolinesterase , Trillium/química , Açúcares/análise , Cromatografia Líquida , Simulação de Acoplamento Molecular , Espectrometria de Massas em Tandem , Saponinas/química
6.
Soft Matter ; 19(23): 4188-4203, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37266565

RESUMO

The advent of atomic force microscopy, along with optical tweezers, ushered in a new field of single molecule force spectroscopy, wherein the response of a single protein or a macromolecule to external mechanical perturbations is measured. Controlled forces ranging from pN to nN are applied to measure the unfolding force distribution of a single protein domain. In a clamp type experiment, the folded protein is subjected to a constant force to measure the unfolding time distribution. Simultaneously, there were efforts to measure the elastic and viscous response of a single domain by applying sinusoidal forces and measuring the resulting deformations produced in a bid to quantify its viscoelasticity. The deformation's phase lag with respect to the applied force provides the elastic and viscous response of the protein, akin to oscillatory rheology. Despite numerous technical advances in AFM, an artefact-free measurement of a folded protein's viscoelasticity largely remains a challenge. In this perspective, we review efforts to measure the viscoelasticity of proteins using dynamic AFM, identifying pitfalls that make these measurements elusive. Finally, we discuss a new promising method, which reported viscoelasticity of a folded protein and its implications for our understanding of protein dynamics and structural flexibility.


Assuntos
Fenômenos Mecânicos , Proteínas , Microscopia de Força Atômica/métodos , Proteínas/química
7.
Comput Biol Chem ; 104: 107826, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36848855

RESUMO

Malaria is a major global health issue due to the emergence of resistance to most of the available antimalarial drugs. There is an urgent need to discover new antimalarials to tackle the resistance issue. The present study aims to explore the antimalarial potential of chemical constituents reported from Cissampelos pareira L., a medicinal plant traditionally known for treating malaria. Phytochemically, benzylisoquinolines and bisbenzylisoquinolines are the major classes of alkaloids reported from this plant. In silico molecular docking revealed prominent interactions of bisbenzylisoquinolines such as hayatinine and curine with Pfdihydrofolate reductase (-6.983 Kcal/mol and -6.237 Kcal/mol), PfcGMP-dependent protein kinase (-6.652 Kcal/mol and -7.158 Kcal/mol), and Pfprolyl-tRNA synthetase (-7.569 Kcal/mol and -7.122 Kcal/mol). The binding affinity of hayatinine and curine with identified antimalarial targets was further evaluated using MD-simulation analysis. Among the identified antimalarial targets, the RMSD, RMSF, the radius of gyration, and PCA indicated the formation of stable complexes of hayatinine and curine with Pfprolyl-tRNA synthetase. The outcomes of in silico investigation putatively suggested that bisbenzylisoquinolines may act on the translation of the Plasmodium parasite to exhibit antimalarial potency.


Assuntos
Aminoacil-tRNA Sintetases , Antimaláricos , Benzilisoquinolinas , Cissampelos , Malária , Plantas Medicinais , Humanos , Antimaláricos/farmacologia , Antimaláricos/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Cissampelos/química , Malária/tratamento farmacológico
8.
J Biomol Struct Dyn ; 41(1): 55-66, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-34825633

RESUMO

Steroidal sapogenins (SS) are structural analogues of steroidal drugs, which are frequently used for the treatment of several diseases including reproductive, malignancies, neurological, and inflammation-related diseases. The glucocorticoid receptor (GR) is a nuclear receptor that regulates development, metabolism, and inflammation, in response to steroidal ligands. Therefore, GR is considered as a potential therapeutic target for steroidal agents to the treatment of inflammation-related diseases. We hypothesized that SS may act as an agonist for GR due to structural similarity with corticosteroids. In this study, we carried out in silico screening of various SS from the genus Trillium to check their potential as an agonist for GR. Our data suggest that out of 42 SS, only 7 molecules have interacted with GR. However, molecular mechanics with generalized Born and surface area (MM-GBSA) analysis revealed that only two SS (SS 38 and SS 39) molecules bind favorably to GR. Among these, SS 38 (docking score: -9.722 Kcal/mol and MM-GBSA ΔGbind: -50.192 Kcal/mol) and SS 39 (docking score: -11.20 Kcal/mol and MM-GBSA ΔGbind: -58.937 Kcal/mol) have best docking and MM-GBSA scores. Molecular dynamics (MD) simulation studies of SS 38, SS 39, and dexamethasone-GR complex revealed that both SS shows hydrogen bonding and hydrophobic interaction with GR over the 120 ns simulation with mild fluctuations. The current study suggests that SS 38 and SS 39 may be further explored as a potential agonist to treat several disease conditions mediated by GR.


Assuntos
Sapogeninas , Trillium , Humanos , Receptores de Glucocorticoides/química , Sapogeninas/farmacologia , Sapogeninas/metabolismo , Simulação de Acoplamento Molecular , Trillium/metabolismo , Simulação de Dinâmica Molecular , Inflamação , Ligantes
9.
J Phys Chem Lett ; 13(40): 9473-9479, 2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36198174

RESUMO

The nanomechanical response of a folded single protein, the natural nanomachine responsible for myriad biological processes, provides insight into its function. The conformational flexibility of a folded state, characterized by its viscoelasticity, allows proteins to adopt different shapes to perform their function. Despite efforts, its direct measurement has not been possible so far. We present a direct and simultaneous measurement of the stiffness and internal friction of the folded domains of the protein titin using a special interferometer based atomic force microscope. We analyzed the data by carefully separating different contributions affecting the response of the experimental probe to obtain the folded state's viscoelasticity. Above ∼95 pN of force, the individual immunoglobulins of titin transition from an elastic solid-like native state to a soft viscoelastic intermediate.


Assuntos
Imunoglobulinas , Proteínas Musculares , Conectina , Elasticidade , Fricção , Proteínas Musculares/fisiologia
10.
Methods Appl Fluoresc ; 10(4)2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-35961301

RESUMO

Fluorescence Correlation Spectroscopy, a commonly used technique for measuring diffusion of biomolecules and tracer dyes in different solvents, is employed to characterise the local transport properties in battery electrolytes. Diffusion of ions, a major limiting factor in battery capacity and charging rates, depends on the local interactions and structuredness of the electrolytic species. Structuredness in the electrolyte results from typical solvation behaviour of diffusing ions/molecules leading to long-range interactions. In this work, we have used FCS to measure tracer diffusion of Coumarin 343 in a mixture of Ethylene Carbonate (EC) and Dimethyl Carbonate (DMC), commonly used as electrolyte solvent in Li-ion batteries. The measured diffusion is found to depend on lithium-ion concentrations. It is found that the addition of LiPF6to an EC-DMC equimolar mixture slows down tracer diffusion significantly. Indeed, the bulk viscosity of the electrolyte added with LiPF6salt varies with salt concentration. However, the change in bulk viscosity (global behaviour) at high ion concentrations does not match the one inferred from applying Stoke-Einstein's relation to the diffusion data (local behaviour). This indicates that the homogeneity of the electrolyte does not extend spatially to molecular scales around the diffusing tracer molecule. Measurements made on coin cells prepared with different concentrations of LiPF6show battery performance limited at higher concentrations, characterized by specific capacity loss at faster charging cycles. This limitation is directly related to the local behaviour of the electrolyte as quantified by measurements of tracer diffusion, which slows down, which remarkably outweighs the advantage of high carrier densities.


Assuntos
Fontes de Energia Elétrica , Lítio , Eletrólitos/química , Íons/química , Lítio/química , Solventes , Análise Espectral
11.
Nanomaterials (Basel) ; 12(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35159871

RESUMO

We estimate the elasticity of single polymer chains using atomic force microscope (AFM)-based oscillatory experiments. An accurate estimate of elasticity using AFM is limited by assumptions in describing the dynamics of an oscillating cantilever. Here, we use a home-built fiber-interferometry-based detection system that allows a simple and universal point-mass description of cantilever oscillations. By oscillating the cantilever base and detecting changes in cantilever oscillations with an interferometer, we extracted stiffness versus extension profiles for polymers. For polyethylene glycol (PEG) in a good solvent, stiffness-extension data showed significant deviation from conventional force-extension curves (FECs) measured in constant velocity pulling experiments. Furthermore, modeling stiffness data with an entropic worm-like chain (WLC) model yielded a persistence length of (0.5 ± 0.2 nm) compared to anomaly low value (0.12 nm ± 0.01) in conventional pulling experiments. This value also matched well with equilibrium measurements performed using magnetic tweezers. In contrast, polystyrene (PS) in a poor solvent, like water, showed no deviation between the two experiments. However, the stiffness profile for PS in good solvent (8M Urea) showed significant deviation from conventional force-extension curves. We obtained a persistence length of (0.8 ± 0.2 nm) compared to (0.22 nm ± 0.01) in pulling experiments. Our unambiguous measurements using interferometer yield physically acceptable values of persistence length. It validates the WLC model in good solvents but suggests caution for its use in poor solvents.

12.
Langmuir ; 38(3): 1034-1044, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35007074

RESUMO

Diffusion of tracer dye molecules in water confined to the nanoscale is an important subject with a direct bearing on many technological applications. It is not yet clear, however, if the dynamics of water in hydrophilic as well as hydrophobic nanochannels remains bulk-like. Here, we present diffusion measurement of a fluorescent dye molecule in water confined to the nanoscale between two hydrophilic surfaces whose separation can be controlled with a precision of less than a nm. We observe that the fluorescence intensities correlate over fast (∼30 µs) and slow (∼1000 µs) time components. The slow time scale is due to adsorption of fluorophores to the confining walls, and it disappears in the presence of 1 M salt. The fast component is attributed to diffusion of dye molecules in the gap. It is found to be bulk-like for sub-10 nm separations and indicates that the viscosity of water under confinement remains unaltered up to a confinement gap as small as ∼5 nm. Our findings contradict some of the recent measurements of diffusion under nanoconfinement; however, they are consistent with many estimates of self-diffusion using molecular dynamics simulations and measurements using neutron scattering experiments.

13.
Nat Prod Res ; 36(1): 37-45, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32378425

RESUMO

Trillium govanianum, commonly known as Nag Chhatri and Teen Patra, is a popular herbal supplement traditionally used for curing different inflammatory and sexual disorders, infection and wound healing. Steroidal saponins are considered as active components of this species. The present study demonstrated the isolation of nine steroidal saponins, including one new compound named as govanoside B (9) and eight known, pregna-chacotrioside (1), pennogenin-triglycoside (2), borassoside E (3), pennogenin-tetraglycoside (4), protodioscin (5), clintonioside B (6), pennogenin-diglycoside (7) and borassoside D (8). This is the first report on the isolation of 1, 2, 4, 5, 6, 7 and 8 from rhizomes of T. govanianum. The extract, fractions and isolated compounds were further evaluated for their DPPH and ABTS radical scavenging activity.


Assuntos
Saponinas , Esteroides , Trillium , Rizoma/química , Saponinas/isolamento & purificação , Saponinas/farmacologia , Esteroides/isolamento & purificação , Esteroides/farmacologia , Trillium/química
14.
ACS Appl Mater Interfaces ; 13(45): 54133-54142, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34726370

RESUMO

High-performance nonvolatile resistive random access memories (ReRAMs) and their small stimuli control are of immense interest for high-speed computation and big-data processing in the emerging Internet of Things (IoT) arena. Here, we examine the resistive switching (RS) behavior in growth-controlled HfO2/La0.67Sr0.33MnO3 (LSMO) heterostructures and their tunability in a low magnetic field. It is demonstrated that oxygen-deficient HfO2 films show bipolar switching with a high on/off ratio, stable retention, as well as good endurance owing to the orthorhombic-rich phase constitution and charge (de)trapping-enabled Schottky-type conduction. Most importantly, we have demonstrated that RS can be tuned by a very low externally applied magnetic field (∼0-30 mT). Remarkably, application of a magnetic field of 30 mT causes RS to be fully quenched and frozen in the high resistive state (HRS) even after the removal of the magnetic field. However, the quenched state could be resurrected by applying a higher bias voltage than the one for initial switching. This is argued to be a consequence of the electronically and ionically "active" nature of the HfO2-x/LSMO interface on both sides and its susceptibility to the electric and low magnetic field effects. This result could pave the way for new designs of interface-engineered high-performance oxitronic ReRAM devices.

15.
Phytomedicine ; 91: 153663, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34358759

RESUMO

BACKGROUND: Diabetic Kidney Disease (DKD) is a common complication of diabetes and a leading cause of end-stage renal disease progression. Therefore, therapeutic strategies are desirable to mitigate the progression of disease into more severe consequences. Hypothesis/Purpose:Tinospora cordifolia is a traditionally known antidiabetic plant; however, its effect against DKD remains unexplored. Therefore, in the present study, we assessed the efficacy and mechanism of action of Tinospora cordifolia extract (TC) against DKD. METHODS: The molecular interaction of the various phytoconstituents of TC with PPARγ were analyzed in silico. The effect of TC was studied on the viability, cell cycle, and gene expressions (PPARγ, TGFß, and αSMA) in high glucose treated NRK-52E and SV40 MES13 cells. Further, streptozotocin-induced diabetic rats were treated with TC for eight weeks, and the effects on different biochemical, histological and molecular parameters were studied. RESULTS: In silico analysis revealed the integration of various phytoconstituents of TC with PPARγ. It further increased PPARγ and decreased TGFß and αSMA expressions in NRK-52E and SV40 MES13 cells. In diabetic rats, TC improved the fasting blood glucose, serum urea, and creatinine levels. It also lowered the urine microalbumin and advanced glycation end products (AGEs) levels. Histopathological studies revealed the preventive effect of TC on degenerative changes, mesangial proliferation and glomerular hypertrophy. Further, it reduced the inflammation and fibrotic changes in the kidney tissue estimated by various markers. The kidney tissue and gene expression analysis revealed the augmented levels of PPARγ after TC treatment. CONCLUSION: In conclusion, TC exerted the protective effect against DKD by inhibiting inflammation and fibrogenesis through the activation of PPARγ dependent pathways.


Assuntos
Nefropatias Diabéticas , PPAR gama/metabolismo , Extratos Vegetais , Tinospora , Animais , Linhagem Celular , Diabetes Mellitus Experimental/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Rim/efeitos dos fármacos , Rim/patologia , Glomérulos Renais/citologia , Túbulos Renais/citologia , Camundongos , Extratos Vegetais/farmacologia , Ratos , Tinospora/química
16.
Nanotechnology ; 32(40)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34144547

RESUMO

The quantitative measurement of viscoelasticity of nano-scale entities is an important goal of nanotechnology research and there is considerable progress with advent of dynamic atomic force microscopy. The hydrodynamics of cantilever, the force sensor in AFM measurements, plays a pivotal role in quantitative estimates of nano-scale viscoelasticity. The point-mass (PM) model, wherein the AFM cantilever is approximated as a point-mass with mass-less spring is widely used in dynamic AFM analysis and its validity, particularly in liquid environments, is debated. It is suggested that the cantilever must be treated as a continuous rectangular beam to obtain accurate estimates of nano-scale viscoelasticity of materials it is probing. Here, we derived equations, which relate stiffness and damping coefficient of the material under investigation to measured parameters, by approximating cantilever as a point-mass and also considering the full geometric details. These equations are derived for both tip-excited as well as base-excited cantilevers. We have performed off-resonance dynamic atomic force spectroscopy on a single protein molecule to investigate the validity of widely used PM model. We performed measurements with AFMs equipped with different cantilever excitation methods as well as detection schemes to measure cantilever response. The data was analyzed using both, continuous beam model and the PM model. We found that both models yield same results when the experiments are performed in truly off-resonance regime with small amplitudes and the cantilever stiffness is much higher than the interaction stiffness. Our findings suggest that a simple PM approximation based model is adequate to describe the dynamics, provided care is taken while performing experiments so that the approximations used in these models are valid.

17.
J Biol Phys ; 47(2): 191-204, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34075502

RESUMO

Titin is a giant elastic protein which is responsible for passive muscle stiffness when muscle sarcomeres are stretched. Chloramphenicol, besides being a broad-spectrum antibiotic, also acts as a muscle relaxant. Therefore, it is important to study the interaction between titin I27 and chloramphenicol. We investigated the interaction of chloramphenicol with octamer of titin I27 using single-molecule force spectroscopy and fluorescence spectroscopy. The fluorescence data indicated that binding of chloramphenicol with I27 results in fluorescence quenching. Furthermore, it is observed that chloramphenicol binds to I27 at a particular concentration ([Formula: see text] 40 µM). Single-molecule force spectroscopy shows that, in the presence of 40 µM chloramphenicol concentration, the I27 monomers become mechanically stable, resulting in an increment of the unfolding force. The stability was further confirmed by chemical denaturation experiments on monomers of I27, which corroborate the evidence for enhanced mechanical stability at 40 µM drug concentration. The free energy of stabilization for I27 (wild type) was found to be 1.95 ± 0.93 kcal/mole and I27 with 40 µM drug was 3.25 ± 0.63 kcal/mole. The results show a direct effect of the broad-spectrum antibiotic chloramphenicol on the passive elasticity of muscle protein titin. The I27 is stabilized both mechanically and chemically by chloramphenicol.


Assuntos
Cloranfenicol , Fenômenos Mecânicos , Cloranfenicol/farmacologia , Conectina , Estrutura Terciária de Proteína , Análise Espectral
18.
J Pharm Pharmacol ; 73(4): 487-495, 2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33793831

RESUMO

OBJECTIVE: To provide the scientific basis for the utility of rhizome of Trillium govanianum as nutraceutical supplements in managing physiological glycemic levels. METHODS: The in vitro enzyme inhibitory activity of the extract, fractions, and the isolated steroidal saponins from the rhizome part of T. govanianum was carried out against α-amylase, α-glucosidase, and dipeptidyl peptidase IV. The molecular interactions, binding score, and pharmacokinetic parameters (absorption, distribution metabolism, and excretion) of steroidal saponins were analyzed by the Schrodinger molecular docking software. KEY FINDINGS: Current study explained that the extract, fractions, and isolated steroidal saponins from T. govanianum possess good α-amylase and α-glucosidase inhibitory activity while moderate dipeptidyl peptidase IV inhibitory activity. Moreover, in vitro results revealed that borassoside E (IC50 7.15 ± 1.78 µM), protodioscin (IC50 6.72 ± 0.04 µM), and diosgenin (IC50 12.75 ± 2.70 µM) are most effective in inhibiting the activity of α-amylase, α-glucosidase, and dipeptidyl peptidase IV, respectively. Current in silico and in vitro studies established an association between the steroidal saponins from T. govanianum and their molecular interactions with α-amylase, α-glucosidase, and dipeptidyl peptidase IV. CONCLUSION: The results of this investigation suggest that fractions and steroidal saponins from T. govanianum exhibit good antidiabetic activity which could be used as nutraceutical supplements for the management of systemic glucose level.


Assuntos
Inibidores da Dipeptidil Peptidase IV/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Hipoglicemiantes , Saponinas/farmacologia , Trillium/química , alfa-Amilases/antagonistas & inibidores , Dipeptidil Peptidase 4/análise , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Técnicas In Vitro , Simulação de Acoplamento Molecular/métodos , Extratos Vegetais/farmacologia , Rizoma/química , alfa-Amilases/análise , alfa-Glucosidases/análise
19.
Langmuir ; 37(9): 2974-2984, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33645228

RESUMO

Surface coatings play an important role in improving the performance of biomedical implants. Polydimethylsiloxane (PDMS) is a commonly used material for biomedical implants, and surface-coated PDMS implants frequently face problems such as delamination or cracking of the coating. In this work, we have measured the performance of nano-coatings of the biocompatible protein polymer silk fibroin (SF) on pristine as well as modified PDMS surfaces. The PDMS surfaces have been modified using oxygen plasma treatment and 3-amino-propyl-triethoxy-silane (APTES) treatment. Although these techniques of PDMS modification have been known, their effects on adhesion of SF nano-coatings have not been studied. Interestingly, testing of the coated samples using a bulk technique such as tensile and bending deformation showed that the SF nano-coating exhibits improved crack resistance when the PDMS surface has been modified using APTES treatment as compared to an oxygen plasma treatment. These results were validated at the microscopic and mesoscopic length scales through nano-scratch and nano-indentation measurements. Further, we developed a unique method using modified atomic force microscopy to measure the adhesive energy between treated PDMS surfaces and SF molecules. These measurements indicated that the adhesive strength of PDMS-APTES-SF is 10 times more compared to PDMS-O2-SF due to the higher number of molecular linkages formed in this nanoscale contact. This lower number of molecular linkages in the PDMS-O2 indicates that only fewer numbers of surface hydroxyl groups interact with the SF protein through secondary interactions such as hydrogen bonding. On the other hand, a larger number of amine groups present on PDMS-APTES surface hydrogen bond with the polar amino acids present on the silk fibroin protein chain, resulting in better adhesion. Thus, APTES modification to the PDMS substrate results in improved adhesion of nano-coating to the substrate and enhances the delamination and crack resistance of the nano-coatings.

20.
J Ethnopharmacol ; 274: 113850, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-33485976

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Cissampelos pareira, a well-known medicinal climber-plant of the Menispermaceae family, has been extensively used in the traditional medicinal system since the ancient time for the treatment of numerous diseases such as ulcer, wound, rheumatism, fever, asthma, cholera, diarrhoea, inflammation, snakebite, malaria, rabies, and also recommended for blood purification. AIM OF THE REVIEW: The main purpose of this review is to provide updated information on ethnopharmacology, phytochemistry, chromatographic and spectroscopic analysis, pharmacology, and toxicology of C. pareira along with the possible future research. This information will help to provide a foundation for plant-based drug discovery in the near future. MATERIAL AND METHODS: The online databases such as Scifinder, Web of Science, PubMed, and Google Scholar were used to collect electronically available literature data on C. pareira. Ayurveda text is searched for the traditional uses of this plant in India. The published books are also searched for the information on this plant. Our search was based on traditional uses, botany, phytochemistry, and pharmacological potential by using "Cissampelos pareira" as the keyword. RESULTS: To date, approximately 54 phytomolecules have been isolated and characterized from C. pareira including mainly isoquinoline alkaloids along with few flavonoids, flavonoid glycosides, and fatty acids. The crude extracts of C. pareira have shown various pharmacological activities such as antipyretic, anti-inflammatory, antiarthritic, antiulcer, antidiabetic, anticancer, antifertility, antimicrobial, antioxidant, antivenom, antimalarial, and immunomodulatory, etc. The chemical fingerprinting of C. pareira carried out using HPTLC, HPLC, UPLC, LC-MS, and GC-MS, revealed the presence of alkaloids (isoquinoline alkaloids), fatty acids, and flavonoid glycosides. Moreover, the toxicological assessment of C. pareira has been moderately investigated, which requires further comprehensive studies. CONCLUSION: Comprehensive literature survey reveals that till date, remarkable growth has been made on phytochemistry and pharmacology of C. pareira reflecting the great medicinal potential of this plant. Although some of the traditional uses have been well clarified and documented by modern pharmacological analysis, the correlation between its pharmacological activities and particular phytoconstituents still needs to be validated. Furthermore, there is partial data available on most of the pharmacological studies, along with incomplete toxicological screening. Future research needs to pay more attention to pharmacological studies of C. pareira via pre-clinical and clinical trials. Additionally, scientific validation of traditional knowledge of C. pareira is vital for ensuring safety, efficacy, and mechanism of action before clinical uses.


Assuntos
Cissampelos/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Animais , Bases de Dados Factuais , Humanos , Ayurveda , Compostos Fitoquímicos/química , Compostos Fitoquímicos/toxicidade , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Plantas Medicinais/química , Plantas Medicinais/toxicidade
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