551 research outputs found
Elucidation of Danzhixiaoyao Wan and Its Constituent Herbs on Antioxidant Activity and Inhibition of Nitric Oxide Production
Danzhixiaoyao Wan (DW) is a common 10 herbs formulation in China for regulating several clinical conditions affecting women. This research tried to explain one of DW's functions, purging heat, using in vitro pharmacological analyses. The whole formulation and each single herb of DW were compared based on antioxidant activity with the oxygen radical absorbance capacity (ORAC) assay, and for their inhibitory effect (IE) on nitric oxide (NO) production by lipopolysaccharide (LPS)-activated RAW 264.7 macrophages with the Griess assay. The results showed that DW as a whole formulation had both antioxidant activity and an IE on NO production, while the individual herb component of DW varied in their ORAC values and inhibition of NO production. The ORAC value of the whole DW was 450 μmol TE g−1. The order of antioxidant (ORAC) activity of the single herbs was: Mentha haplocalyx (1352 μmol TE g−1) > Glycyrrhiza uralensis (1184 μmol TE g−1) > Gardenia jasminoides (1129 μmol TE g−1) > Paeonia suffruticosa (465 μmol TE g−1), with the contributions being additive rather than synergistic. The production of nitrite by stimulated RAW 264.7 murine macrophages (unstimulated: 0.5 ± 0.1 μM versus LPS: 38.9 ± 2.3 μM) was significantly inhibited (P < 0.05) by M. haplocalyx, G. jasminoides, Bupleurum chinense and Paeonia lactiflora. DW as a whole had an IE on NO production, but this was not significant. The single herb M. haplocalyx had the highest ORAC value and the highest IE on NO production, followed by G. jasminoides. Both of these herbs have the ‘purging heat’ property in the theory of traditional Chinese medicine and this property of the samples may be correlated with the antioxidant activity and IE on NO production
Antioxidant activity of 45 Chinese herbs and the relationship with their TCM characteristics
Here, 45 Chinese herbs that regulate blood circulation were analyzed for antioxidant activity using the oxygen radical absorbance capacity (ORAC) assay. A recent publication by Ou et al. identified a close relationship between in vitro antioxidant activity and classification of Chinese herbs as yin or yang. The 45 Chinese herbs in this study could be assigned the traditional characteristics of natures (cold, cool, hot and warm), flavors (pungent, sweet, sour, bitter and salty) and functions (arresting bleeding, promoting blood flow to relieve stasis, nourishing blood and clearing away heat from blood). These characteristics are generalized according to the theory of yin and yang. We identified a broad range, 40–1990 µmol Trolox Equivalent/g herbs, of antioxidant activity in water extracts. There was no significant correlation between ORAC values and natures or functions of the herbs. There was a significant relationship between flavors and ORAC values. Bitter and/or sour herbs had the highest ORAC values, pungent and/or sweet herbs the lowest. Other flavors had intermediate values. Flavors also correspond with the yin/yang relationship and our results are supportive of the earlier publication. We reported for the first time antioxidant properties of many Chinese herbs. High antioxidant herbs were identified as Spatholobus suberectus vine (1990 µmol TE/g), Sanguisorba officinalis root (1940 µmol TE/g), Agrimonia pilosa herb (1440 µmol TE/g), Artemisia anomala herb (1400 µmol TE/g), Salvia miltiorrhiza root (1320 µmol TE/g) and Nelembo nucifera leaf (1300 µmol TE/g). Antioxidant capacity appears to correlate with the flavors of herbs identified within the formal TCM classification system and may be a useful guide in describing their utility and biochemical mechanism of action
Caco-2 cell permeability of flavonoids and saponins from Gynostemma pentaphyllum : the immortal herb
Gynostemma pentaphyllum (the immortal herb) has been an important component of Chinese Traditional Medicine for millennia. Recent clinical studies have revealed that the plant exhibits numerous beneficial biological activities, making it of interest to the pharmaceutical industry. An extract of the herb contains over 200 individual secondary metabolites including flavonol glycosides and dammarane saponins. To focus attention on the compounds most likely to be responsible for the biological activities, this study predicts the potential oral bioavailability of nine dammarane saponins and five flavonol glycosides from G. pentaphyllum using the Caco-2 cell monolayer permeability model. Two flavonoids, 8 and 9, and four saponins, 10, 11, 12, and 14, exhibited high permeability across the monolayers. The results indicated that a higher degree of glycosylation-facilitated permeability, suggestive of active transport. This study demonstrates the utility of the Caco-2 permeability assay as a method of identifying possible bioavailable compounds from medicinal herbal extracts
Biologically active compounds isolated from Centipeda and their biological activity as antioxidant and antiinflammatory agents
Compounds having useful biological activity, particularly antioxidant and anti-inflammatory activity, derived from Centipeda cunninghamii, and biol. active derivatives thereof, pharmaceutical compns. comprising these compounds, and prophylactic and therapeutic use of the compounds
CRANKITE: a fast polypeptide backbone conformation sampler
Background: CRANKITE is a suite of programs for simulating backbone conformations of polypeptides and proteins. The core of the suite is an efficient Metropolis Monte Carlo sampler of backbone conformations in continuous three-dimensional space in atomic details.
Methods: In contrast to other programs relying on local Metropolis moves in the space of dihedral angles, our sampler utilizes local crankshaft rotations of rigid peptide bonds in Cartesian space.
Results: The sampler allows fast simulation and analysis of secondary structure formation and conformational changes for proteins of average length
(3R,4S,5S,8S,10R,13R)-3-Hydroxykaura-9(11),16-dien-18-oic acid
The title compound, C20H28O3, was isolated during our investigation into the chemical composition and pharmacological activity of Centipeda cunninghamii (DC.) A. Braun & Asch. (Asteraceae). The enantiopure compound, a diterpene with a carbon skeleton, is composed of three six- and one five-membered rings in chair, twist-boat, half-chair and envelope conformations, respectively. Each molecule makes one intra- and one intermolecular O—H⋯O hydrogen bond in the crystal lattice, forming hydrogen-bonded chains along [010]. The absolute configuration of the compound was assigned on the basis of optical rotation measurements
Synergistic inhibition of pro-inflammatory pathways by ginger and turmeric extracts in RAW 264.7 cells
Synergy plays a prominent role in herbal medicines to increase potency and widen the therapeutic windows. The mechanism of synergy in herbal medicines is often associated with multi-targeted behavior and complex signaling pathways which are challenging to elucidate. This study aims to investigate the synergistic mechanism of a combination (GT) of ginger (G) and turmeric (T) extracts by exploring the modulatory activity in lipopolysaccharides (LPS)-induced inflammatory pathways and key molecular targets. A Bioplex ProTM mouse cytokine 23-plex assay was utilized to assess the broad anti-cytokine activity of GT in LPS and interferon (IFN)-gamma (both at 50 ng/mL)-activated RAW 264.7 cells. The inhibitory effects of individual and combined G and T on major proinflammatory mediators including nitric oxide (NO), tumor necrosis factor (TNF) and interleukin (IL)-6 were tested using Griess reagents and ELISA assays, respectively. Immunofluorescent staining and Western blot were used to investigate the modulatory effect of GT on key proteins in the LPS/TLR4 signaling transduction. The regulation of murine microRNA miR-155-5p was tested using real-time PCR. The IC50 value and combination index (CI) values were used to demonstrate potency and synergistic interaction, respectively. GT synergistically attenuated a range of pro-inflammatory mediators including inducible NO, major cytokines (TNF and IL-6) and secondary inflammatory cytokines (GM-CSF and MCP-1). GT significantly inhibited LPS-induced NF-kB p65 translocation, the activation of TLR4, TRAF6, and phosphorylation of JNK and c-JUN. Moreover, the suppressive effect of GT on each of the protein targets in this axis was stronger than that of the individual components. Real-time PCR analysis showed that GT suppressed miR-155-5p to a greater extent than G or T alone in LPS-stimulated cells. Our study demonstrates the synergistic mechanism of GT in downregulating LPS-induced proinflammatory pathways at the miRNA and protein levels. Our results establish a scientific basis for the combined application of G and T as an advanced therapeutic candidate in inflammatory diseases with broad and synergistic anti-inflammatory activity and multi-targeted mechanisms
Observational constraints on the spectral index of the cosmological curvature perturbation
We evaluate the observational constraints on the spectral index , in the
context of the CDM hypothesis which represents the simplest viable
cosmology. We first take to be practically scale-independent. Ignoring
reionization, we find at a nominal 2- level . If
we make the more realisitic assumption that reionization occurs when a fraction
to 1 of the matter has collapsed, the 2- lower bound is
unchanged while the 1- bound rises slightly. These constraints are
compared with the prediction of various inflation models. Then we investigate
the two-parameter scale-dependent spectral index, predicted by running-mass
inflation models, and find that present data allow significant scale-dependence
of , which occurs in a physically reasonable regime of parameter space.Comment: ReVTeX, 15 pages, 5 figures and 3 tables, uses epsf.sty Improved
treatment of reionization and small bug fixed in the constant n case; more
convenient parameterization and better treatment of the n dependence in the
CMB anisotropy for the running mass case; conclusions basically unchanged;
references adde
Evaluation of machine-learning methods for ligand-based virtual screening
Machine-learning methods can be used for virtual screening by analysing the structural characteristics of molecules of known (in)activity, and we here discuss the use of kernel discrimination and naive Bayesian classifier (NBC) methods for this purpose. We report a kernel method that allows the processing of molecules represented by binary, integer and real-valued descriptors, and show that it is little different in screening performance from a previously described kernel that had been developed specifically for the analysis of binary fingerprint representations of molecular structure. We then evaluate the performance of an NBC when the training-set contains only a very few active molecules. In such cases, a simpler approach based on group fusion would appear to provide superior screening performance, especially when structurally heterogeneous datasets are to be processed
Inflation Dynamics and Reheating
We review the theory of inflation with single and multiple fields paying
particular attention to the dynamics of adiabatic and entropy/isocurvature
perturbations which provide the primary means of testing inflationary models.
We review the theory and phenomenology of reheating and preheating after
inflation providing a unified discussion of both the gravitational and
nongravitational features of multi-field inflation. In addition we cover
inflation in theories with extra dimensions and models such as the curvaton
scenario and modulated reheating which provide alternative ways of generating
large-scale density perturbations. Finally we discuss the interesting
observational implications that can result from adiabatic-isocurvature
correlations and non-Gaussianity.Comment: 51 pages, latex, 16 figures, version to appear in Reviews of Modern
Physic
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