RESUMEN
BACKGROUND: Colon cancer is the most aggressive form of cancers, that causes 0.5 million deaths per year around the globe. Targeting colon cancer by conventional therapeutic options elicits toxicity. Traditional medicines take a lead to alleviate the existing clinical challenges. OBJECTIVE: To investigate antibacterial activity against Helicobacter Pylori and in vitro anti-colon cancer activity by Acacia nilotica extract (ACE) and its active constituent pyrogallol. METHODS: Pyrogallol isolated from A. nilotica by column chromatography and HPLC and structure was elucidated by spectral analysis. Antibacterial activity was done by flow cytometry. Cytotoxicity was measured by MTT assay. Apoptotic morphology and nuclear fragmentation were assessed with AO/ethidium bromide and DAPI staining. DNA fragmentation was done by electrophoresis. Western blot used to analyze the molecular mechanism of apoptosis. Cell cycle arrest was determined using flow cytometry of propidium iodide stained cells. Cell migration was determined by wound healing assay. RESULTS: ACE (20 µg/ml) and pyrogallol (10 µg/ml) treatment reduced the survival of H.pylori at 61% and 62%, respectively. MTT results show that HT-29 cells are more sensitive to pyrogallol with an IC50 value of 35µg/ml compared to ACE. Pyrogallol treated HT-29 cells reached dead state i.e. late apoptotic state with severe nuclear fragmentation. Pyrogallol elicits dose dependent DNA fragmentation in HT-29 cells. Pyrogallol induced apoptosis by simultaneous down-regulation of Bcl-2 and up-regulation of BAX and cytochrome c. Pyrogallol arrested HT-29 cells in S and G2/M phase of cell cycle. Further pyrogallol exhibited marked antimetastatic potential by inhibiting the migration of HT-29 cells dose dependently. CONCLUSION: Both ACE and pyrogallol repressed the growth of H.pylori and as significant anti-colon cancer agent.
Asunto(s)
Antibacterianos/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Neoplasias del Colon/tratamiento farmacológico , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Helicobacter pylori/efectos de los fármacos , Pirogalol/farmacología , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Neoplasias del Colon/patología , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Citometría de Flujo , Células HT29 , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Pirogalol/química , Pirogalol/aislamiento & purificación , Relación Estructura-Actividad , Cicatrización de Heridas/efectos de los fármacosRESUMEN
The instability of the flow of a viscous fluid past a soft, two-layered gel is probed using experiments, and the observations are compared with results from a linear stability analysis. The experimental system consists of the rotating top plate of a rheometer and its stationary bottom plate on which the two-layer gel is placed. When the flow between the top plate and the two-layer gel is viscometric (i.e., laminar), the viscosity obtained from the rheometer is a measure of the material property of the fluid. However, after a critical shear stress, there is a sudden increase in apparent viscosity, indicating that the flow has undergone an instability due to the deformable nature of the two-layer gel. Experiments are carried out to quantify how the critical value of fluid shear stress required to destabilize the flow varies as a function of ratio of solid to fluid layer thickness, and the ratio of the shear moduli of the two gels. A linear stability analysis is carried out for plane Couette flow of a Newtonian fluid past the two-layered gel, by assuming the two solid layers to be elastic neo-Hookean materials. In order to compare the experimental and theoretical results, the effective shear modulus (Geff, defined by H/Geff=H1/G1+H2/G2) of the two-layer gel is found to be useful, where H=H1+H2. Here, Hi and Gi (i=1,2), respectively, denote the thickness and shear modulus of each layer. Results for the nondimensional parameter Γeff=ηV/(dGeff) (V is the velocity of the top plate; η is fluid viscosity, d is the fluid thickness) as a function of solid to fluid thickness H/d obtained from the stability analysis agree well with experimental observations, without any fitting parameters. In general, we find that the flow is more unstable if the softer gel is adjacent to the fluid flow compared to the case when it is not. This suggests that the instability is more interfacial in nature and is crucially dependent on the relative placement of the two layers, and not just on the effective modulus of the two-layer gel. We further show that the theoretical and experimental data for two-layer gels can be suitably collapsed onto the results obtained for a single-gel layer.
Asunto(s)
Geles , Sustancias Viscoelásticas , Resinas Acrílicas , Dimetilpolisiloxanos , Fluidoterapia , Modelos Teóricos , Siliconas , Viscosidad , AguaRESUMEN
Histone deacetylase (HDAC) enzymes have been demonstrated as critical components in maintaining chromatin homeostasis, CNS development, and normal brain function. Evidence in mouse models links HDAC expression to learning, memory, and mood-related behaviors; small molecule HDAC inhibitor tool compounds have been used to demonstrate the importance of specific HDAC subtypes in modulating CNS-disease-related behaviors in rodents. So far, no direct evidence exists to understand the quantitative changes in HDAC target engagement that are necessary to alter biochemistry and behavior in a living animal. Understanding the relationship between target engagement and in vivo effect is essential in refining new ways to alleviate disease. We describe here, using positron emission tomography (PET) imaging of rat brain, the in vivo target engagement of a subset of class I/IIb HDAC enzymes implicated in CNS-disease (HDAC subtypes 1, 2, 3, and 6). We found marked differences in the brain penetrance of tool compounds from the hydroxamate and benzamide HDAC inhibitor classes and resolved a novel, highly brain penetrant benzamide, CN147, chronic treatment with which resulted in an antidepressant-like effect in a rat behavioral test. Our work highlights a new translational path for understanding the molecular and behavioral consequences of HDAC target engagement.