196 research outputs found
Isolation, characterization and hypolipidemic activity of ferulic acid in high-fat-diet-induced hyperlipidemia in laboratory rats
Prosopis cineraria (L.) Druce (Leguminosae) (syn. Prosopis spicigera L.) has antidiabetic and antioxidant potential. Earlier we reported its hypolipidemic activity obtained from ethanol extract (ET-PCF). Object of this work was to isolate ferulic acid (FA) from ET-PCF and evaluate hypolipidemic activity against high-fat diet (HFD)-induced hyperlipidemic laboratory rats. ET-PCF was subjected to flash column chromatography to isolate FA. The chemical structure of the isolated compound was elucidated by UV, IR, 1H NMR,13C NMR and LC-MS. Further, the antihyperlipidemic effect of FA (10, 20 and 40 mg/kg, p.o.) in HFD-induced hyperlipidemic rats was investigated. Hyperlipidemia was induced in male Sprague-Dawley rats by feeding with HFD for 60 days. Lipid parameters such as total cholesterol (TC), Low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) levels were measured in serum and hepatic tissue. Hepatic oxido-nitrosative stress (SOD, GSH, MDA and NO) were also determined. Histological evaluation of liver tissue was carried out. The structure of the isolated compound was characterized based on spectral data and confirmed as FA. HFD induced an alteration in serum, and hepatic lipid profile (triglyceride, cholesterol, HDL, and LDL) was significantly restored (p < 0.001) by administration of FA (20 and 40 mg/kg, p.o.). The elevated level of oxido-nitrosative stress in liver was significantly reduced (p < 0.001) by FA (20 and 40 mg/kg, p.o.). Histological aberration induced in the liver after HFD ingestion were restored by FA administration. Ferulic acid isolated from ET-PCF showed hypolipidemic effects in HFD-induced hyperlipidemic rats via modulation of elevated oxido-nitrosative stress
Standard Model with Cosmologically Broken Quantum Scale Invariance
We argue that scale invariance is not anomalous in quantum field theory,
provided it is broken cosmologically. We consider a locally scale invariant
extension of the Standard Model of particle physics and argue that it fits both
the particle and cosmological observations. The model is scale invariant both
classically and quantum mechanically. The scale invariance is broken
cosmologically producing all the dimensionful parameters. The cosmological
constant or dark energy is a prediction of the theory and can be calculated
systematically order by order in perturbation theory. It is expected to be
finite at all orders. The model does not suffer from the hierarchy problem due
to absence of scalar particles, including the Higgs, from the physical
spectrum.Comment: 13 pages, no figures significant revisions, no change in results or
conclusion
Alignments in quasar polarizations: pseudoscalar-photon mixing in the presence of correlated magnetic fields
We investigate the effects of pseudoscalar-photon mixing on electromagnetic
radiation in the presence of correlated extragalactic magnetic fields. We model
the Universe as a collection of magnetic domains and study the propagation of
radiation through them. This leads to correlations between Stokes parameters
over large scales and consistently explains the observed large-scale alignment
of quasar polarizations at different redshifts within the framework of the big
bang model.Comment: 12 pages, 5 figures, version published in PR
Search for Global Metric Anisotropy in Type Ia Supernova Data
We examine the Type 1a supernova data in order to determine if it shows any
signal of large scale anisotropy. The anisotropy is modelled by an extended
G\"{o}del metric, which incorporates expansion along with rotation. The model
is smoothly connected to the usual FRW type, while expressing anisotropic
metric effects depending on certain parameters. We find no significant signal
of anisotropy in the data. We obtain bounds on an anisotropic redshift versus
magnitude relationship, and accompanying parameters of the G\"{o}del-Obukhov
metric.Comment: 16 pages, 2 figures, minor changes, to be published in Modern Physics
Letters
Evaluation of the Antiasthmatic Activity of Methanolic Extract of Trigonella Foenum Graecum on Experimental Models of Bronchial Asthma
The present study deals with the phytochemical screening and evaluation of antiasthmatic activity of methanolic extract of Trigonella foenumgraecum on experimental models of bronchial asthma and anaphylaxis. The antiasthmatic activity was studied on histamine-induced bronchospasm in guinea pig (Dunkey-Hartley) for respiratory parameters such as maximum airflow, minimum airflow, tidal volume, respiratory rate, minute volume, specific airway resistance determination on double chambered whole body plethysmography on un-anesthetized guinea pigs, for mast cell degranulation by compound 48/80 (in vitro) was done using rat (Albino Wistar) peritoneal fluid. Trigonella foenum graecum treated result indicated significant protection against histamine-induced bronchospasm in guinea pigs at highest dose i.e. 400mg/kg. The bronchodilatory effect of Trigonella foenum graecum was found comparable to the protection offered by the standard drug Salbutamol on respiratory parameters in double chambered whole body plethysmography, Treatment with Trigonella foenum graecum at a dose of 400mg/kg showed a significant decrease in degranulation rate of actively and passively sensitized mast cells of sensitized rats when challenged with antigen. Trigonella foenum graecum. Possess significant anti-asthmatic activity due to its potential anti inflammatory, antioxidant and the antihistaminic activity, which reflects as anti-degranulating effect on mast cells and on respiratory parameters.
Keywords: Trigonella foenum graecum; asthma; mast cell; compound 48/80; histamin
A Comprehensive Review on Plant derived Natural products for Diabetes and its complication as nephropathy
Diabetic nephropathy is one of the most severe microangiopathies of diabetes taking heavy toll on human lives. Diabetic nephropathy is characterized by the accumulation of extracelluar matrix protein leading to irreversible decline in renal function and end stage renal disease. Incomplete knowledge about molecular mechanism underlying nephropathy limit the use of modern medicines to treat this clinical entity. Moreover, current standard of therapy for diabetic nephropathy mainly focus on reduction in hyperglycemia and hypertension. These therapies have limited effect on delaying nephropathy progression. A pressing need for novel therapies initiated studies targeting various molecular pathways involved in nephropathic changes. Herbal medicines with beneficial phytochemicals are reported to delay the progression of nephropathic changes in diabetes in various experimental studies. This review try to summarize various phytoconstituents proved to be effective in management of diabetic nephropathy. The goal is to identify promising phytoconstituents that can be translated into beneficial therapeutic options.
Keywords: Diabetic complications, Medicinal plants, Phytoconstituents, Oxidative stress
Model Independent Foreground Power Spectrum Estimation using WMAP 5-year Data
In this paper, we propose & implement on WMAP 5-year data, a model
independent approach of foreground power spectrum estimation for multifrequency
observations of CMB experiments. Recently a model independent approach of CMB
power spectrum estimation was proposed by Saha et al. 2006. This methodology
demonstrates that CMB power spectrum can be reliably estimated solely from WMAP
data without assuming any template models for the foreground components. In the
current paper, we extend this work to estimate the galactic foreground power
spectrum using the WMAP 5 year maps following a self contained analysis. We
apply the model independent method in harmonic basis to estimate the foreground
power spectrum and frequency dependence of combined foregrounds. We also study
the behaviour of synchrotron spectral index variation over different regions of
the sky. We compare our results with those obtained from MEM foreground maps
which are formed in pixel space. We find that relative to our model independent
estimates MEM maps overestimates the foreground power close to galactic plane
and underestimates it at high latitudes.Comment: 12 pages, 4 figure
Dynamical Gauge Symmetry Breaking in Extension of the Standard Model
We study the extension of the Standard model with a
strong U(1) coupling. We argue that current experiments limit this coupling to
be relatively large. The model is dynamically broken to the Standard model at the scale of a few TeV with all the extra gauge bosons
and the exotic quarks acquiring masses much larger than the scale of
electroweak symmetry breaking. Furthermore we find that the model leads to
large dynamical mass of the top quark and hence also breaks the electroweak
gauge symmetry. It therefore leads to large dynamical effects within the
Standard model and can partially replace the Higgs interactions.Comment: 4 pages, revtex, no figures; revised version predicting realistic
mass spectru
Cosmological Implications of a Scale Invariant Standard Model
We generalize the standard model of particle physics such it displays global
scale invariance. The gravitational action is also suitably modified such that
it respects this symmetry. This model is interesting since the cosmological
constant term is absent in the action. We find that the scale symmetry is
broken by the recently introduced cosmological symmetry breaking mechanism.
This simultaneously generates all the dimensionful parameters such as the
Newton's gravitational constant, the particle masses and the vacuum or dark
energy. We find that in its simplest version the model predicts the Higgs mass
to be very small, which is ruled out experimentally. We further generalize the
model such that it displays local scale invariance. In this case the Higgs
particle disappears from the particle spectrum and instead we find a very
massive vector boson. Hence the model gives a consistent description of
particle physics phenomenology as well as fits the cosmological dark energy.Comment: 12 pages, no figure
Constraints on the Cosmological Constant due to Scale Invariance
We consider the standard model with local scale invariance. The theory shows
exact scale invariance of dimensionally regulated action. We show that massless
gauge fields, which may be abelian or non-abelian, lead to vanishing
contribution to the cosmological constant in this theory. This result follows
in the quantum theory, to all orders in the gauge couplings. However we have
not considered contributions higher orders in the gravitational coupling.
Similarly we also find that massless fermion fields yield null contribution to
the cosmological constant. The effective cosmological constant in this theory
is non-zero due to the phenomenon of cosmological symmetry breaking, which also
gives masses to all the massive fields, besides generating the Planck mass. We
find a simple relationship between the curvature scalar and the vacuum value of
the Higgs field in the limit when we ignore all other contributions to the
energy density besides the vacuum energy.Comment: 17 pages, no figures, revised version, no change in results or
conclusion
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