Cytotoxic and genotoxic effects of Centella asiatica extract in the cultured human peripheral blood lymphocytes

Centella asiatica (CA) is a medicinal herb which has been valued in ayurvedic medicine for its different activities. In the present studies, CA methanolic extract was prepared by Soxhlet extraction and then evaluated for the cytotoxicity and genotoxicity in cultured human peripheral blood lymphocytes. Mitotic Index (MI) Cell Proliferation Kinetics (CPK) and Sister-chromatid exchanges (SCE) were scored to measure the cytotoxic and genotoxic effects of the CA extract in cultures set up from the three different healthy donors. The treatment of the cell culture was done employing two different CA methanolic extract concentrations (500 & 1000 µg/ml) and the control (did not receive any additive). Our present studies revealed that the MI, CPK and SCES for control are 4.28, 0.49 and 6.08 respectively where as the CA extracts has the MI, CPK and SCES for 500µg/ml are 4.07, 0.47 and 5.84 respectively and for 1000 µg/ml are 3.96, 0.46 and 5.52 respectively. From the results, we can conclude that the MI and frequency of SCES of CA methanolic extracts are almost similar to that of control which indicates that the CA plant extracts has no significant cytotoxicity and genotoxicity effects in cultured human peripheral blood lymphocytes

ZnBr2-SiO2 catalyzed green synthesis of tetrazoles: Molecular docking and antioxidant activity studies

A series of 5-substituted and 1,5-disubstituted tetrazoles were synthesized in high yields from various biologically active substituted nitriles with sodium azide under heterogeneous catalysed (ZnBr2-SiO2) [2+3] cycloaddition conditions. This reaction gave an excellent yield in the presence of catalytic amount of 0.2 g of ZnBr2-SiO2, glycerol solvent system under microwave irradiation conditions. All the prepared compounds were characterized by elemental analysis 1H NMR, 13C NMR, FT-IR, and mass spectral data. The newly synthesized compounds were investigated for their respective molecular target using molecular docking studies. The results reveal that compounds 5a, 5c, 5e and 3e have conferred with multi target property. The compounds 5a, 5c and 5e have shown the highest binding affinities of -10.1, -9.7 and -10.6 with reverse transcriptase, -8.5, -8.2 and -8.9 with Aurora B, respectively. The compounds 5a, 5e and 3e have shown -8.9, -8.5 and 8.4 with Aromatase, respectively. In addition, the antioxidant activity data reveals that all the compounds showed good antioxidant activity, particularly the compounds 3d, 5d, and 5e exhibited promising radical scavenging activity

Mycobacterium tuberculosis progresses through two phases of latent infection in humans

Little is known about the physiology of latent Mycobacterium tuberculosis infection. We studied the mutational rates of 24 index tuberculosis (TB) cases and their latently infected household contacts who developed active TB up to 5.25 years later, as an indication of bacterial physiological state and possible generation times during latent TB infection in humans. Here we report that the rate of new mutations in the M. tuberculosis genome decline dramatically after two years of latent infection (two-sided p < 0.001, assuming an 18 h generation time equal to log phase M. tuberculosis, with latency period modeled as a continuous variable). Alternatively, assuming a fixed mutation rate, the generation time increases over the latency duration. Mutations indicative of oxidative stress do not increase with increasing latency duration suggesting a lack of host or bacterial derived mutational stress. These results suggest that M. tuberculosis enters a quiescent state during latency, decreasing the risk for mutational drug resistance and increasing generation time, but potentially increasing bacterial tolerance to drugs that target actively growing bacteria.publishersversionpublishe

Space discontinuous Galerkin method for shallow water flows - kinetic and HLLC flux, and potential vorticity generation

In this paper, a second order space discontinuous Galerkin (DG) method is presented for the numerical solution of inviscid shallow water flows over varying bottom topography. Novel in the implementation is the use of HLLC and kinetic numerical fluxes in combination with a dissipation operator, applied only locally around discontinuities to limit spurious numerical oscillations. Numerical solutions over (non-)uniform meshes are verified against exact solutions; the numerical error in the $L_2$-norm and the convergence of the solution are computed. Bore-vortex interactions are studied analytically and numerically to validate the model; these include bores as "breaking waves'' in a channel and a bore traveling over a conical and Gaussian hump. In these complex numerical test cases, we correctly predict the generation of potential vorticity by non-uniform bores. Finally, we successfully validate the numerical model against measurements of steady oblique hydraulic jumps in a channel with a contraction. In the latter case, the kinetic flux is shown to be more robust

Horizontal patterns of water temperature and salinity in an estuarine tidal channel: Ria de Aveiro

This work presents results from two complementary and interconnected approaches to study water temperature and salinity patterns in an estuarine tidal channel. This channel is one of the four main branches of the Ria de Aveiro, a shallow lagoon located in the Northwest coast of the Iberian Peninsula. Longitudinal and cross-sectional fields of water temperature and salinity were determined by spatial interpolation of field measurements. A numerical model (Mohid) was used in a 2D depth-integrated mode in order to compute water temperature and salinity patterns. The main purpose of this work was to determine the horizontal patterns of water temperature and salinity in the study area, evaluating the effects of the main forcing factors. The field results were depth-integrated and compared to numerical model results. These results obtained using extreme tidal and river runoff forcing, are also presented. The field results reveal that, when the river flow is weak, the tidal intrusion is the main forcing mechanism, generating saline and thermal fronts which migrate with the neap/spring tidal cycle. When the river flow increases, the influence of the freshwater extends almost as far as the mouth of the lagoon and vertical stratification is established. Results of numerical modelling reveal that the implemented model reproduces quite well the observed horizontal patterns. The model was also used to study the hydrology of the study area under extreme forcing conditions. When the model is forced with a low river flow (1 m3 s−1) the results confirm that the hydrology is tidally dominated. When the model is forced with a high river flow (1,000 m3 s−1) the hydrology is dominated by freshwater, as would be expected in such an area

Numerical study of thin-film flows and open-channel flows

A numerical procedure is developed capable of simulating gravity-driven film flows in two-dimensions. The moving boundary problem is handled through the ALE formulation. In the case of turbulent fluid flows, the two-equations $k-\epsilon$ closure model is used to model the turbulence. A Chorin-type projection scheme is utilized to decouple the velocity and pressure fields, and the spatial discretization is done using the Finite Element Method. Thin liquid films draining down vertical or inclined planes are susceptible to long wavelength disturbances. An extensive numerical study of the surface wave instability in isothermal thin film flows is done by solving the full-scale nonlinear system. Temporal stability analysis of a spatially periodic disturbance reveals interesting wave dynamics. The transition from nearly sinusoidal supercritical waves to broad-banded solitary waves is found to go through a quasi-periodic regime. In this quasi-periodic state, the fundamental mode and several of its harmonics are in an oscillatory state, with continuous exchange of energy. An extensive parametric search has been done to obtain the phase boundary delineating the quasi-periodic regime. Complex wave interactions such as wave-splitting and wave-merging are discussed. Spatial stability analysis akin to the usual experimental studies is done and comparisons are made with the experiments. For the development of successful theories capable of predicting the formation of bedforms, it is essential to understand the turbulent fluid flow on top of the bed. To this end, mean flow and turbulence characteristics for flow over artificial stream-wise periodic bedforms are obtained. Due to the local accelerations associated with stream-line bending, very large velocities and stresses are found to exist at the tip of the dune The separation wake turbulence is found to completely dominate the wall-generated turbulence, and the maximum turbulence intensity levels occur at a distance, approximately equal to the dune height, away from the bed. The accuracy of the rigid-lid approximation is determined by computing the flow field with and without the rigid-lid approximation. The rigid-lid approximation is found to over-predict the shear at the dune crest. Lastly, the mean flow and turbulence characteristics in hydraulic jump are obtained. In the case of flow with inlet supercritical Froude number 2.0, a small recirculation zone is found to exist at the foot of the jump. The mixing layer turbulence associated with the surface roller and the recirculation zone are found to dominate the wall-generated turbulence

Two-dimensional modeling of flow and sedimentation

A two-dimensional (vertical) flow model is developed to simulate open channel flow. The governing equations are solved without any depth averaging. Free surface movement is handled with the help of Arbitrary Lagrangian Eulerian Method. $k - \epsilon$ closure is employed to determine the turbulent eddy viscosity. Spatial discretization is done using linear 3-noded triangular elements. Galerkin method of weighted residuals is used to obtain weak form formulation. Navier-Stokes equations are solved by marching in time using Fractional Step Scheme. Continuity equation is replaced with a pressure Poisson equation. Supercritical flow and hydraulic jump are simulated to validate the flow code. Suspended sediment transport is modeled using an advection-diffusion transport equation for sediment concentration. Bed load transport is determined with the help of empirical correlations. The boundary condition at the bed is specified as a reference concentration. Sample problem involving bed erosion and deposition is solved

Non-intrusive characterization of properties of hydrogels:

Besides biological and chemical cues, cellular behavior has been found to be affected by mechanical cues such as traction forces, surface topology and in particular mechanical properties of the substrate. In previous studies involving hydrogel substrates, mechanical characterization was performed assuming Poisson’s ratio to be equal to one-half. However, this might not be true in all cases and might alter the calculation of stiffness of hydrogels. The present study mainly focuses on characterizing the Young's modulus (E), shear modulus (G) and Poisson's ratio (v) of soft hydrogels using a non-intrusive technique. For this purpose, an apparatus referred to as the "four magnet setup", which allows the determination of local gel elastic properties, was developed. Closed form equations involving E, G and v of the hydrogel were derived and finite element analysis was employed to validate the equations. Linear elastic properties of bis-gels and DNA gels were obtained using the apparatus and verified using rheometry and bead experiments. This is the first report in literature in which the mechanical properties consisting of E, G and v were simultaneously obtained for soft hydrogels. A DNA gel design space involving parameters such as crosslinker concentration, side-chain concentration and lengths of DNA strands was systematically developed and the mechanical properties were evaluated using bead experiments. It was found that stiffness of DNA gels can be modulated over a wide range by modifying the various design parameters. Addition of DNA crosslinks generates force and alters the mechanical properties, which has implications for cell and tissue culture substrate design. Two techniques have been developed to characterize the force actuating potential of DNA gels. It was found that the force generated was proportional to the elastic modulus of the gel. Also, at higher temperatures the stiffness of the gels decreased and the amount of force generated also decreased. A comparison of the force generated in both methods showed that either method can be successfully employed. The force was found to be in the range of values reported in the literature for axonal growth in spinal cord neurons.Ph.D.Includes bibliographical referencesby Uday Chippad

Influence of Boiling, Steaming and Frying of Selected Leafy Vegetables on the In Vitro Anti-inflammation Associated Biological Activities

The aim of the present study was to evaluate the effect of cooking (boiling, steaming, and frying) on anti-inflammation associated properties in vitro of six popularly consumed green leafy vegetables in Sri Lanka, namely: Centella asiatica, Cassia auriculata, Gymnema lactiferum, Olax zeylanica, Sesbania grnadiflora, and Passiflora edulis. The anti-inflammation associated properties of methanolic extracts of cooked leaves were evaluated using four in vitro biological assays, namely, hemolysis inhibition, proteinase inhibition, protein denaturation inhibition, and lipoxygenase inhibition. Results revealed that the frying of all the tested leafy vegetables had reduced the inhibition abilities of protein denaturation, hemolysis, proteinase, and lipoxygenase activities when compared with other food preparation methods. Steaming significantly increased the protein denaturation and hemolysis inhibition in O. zeylanica and P. edulis. Steaming of leaves increased inhibition activity of protein denaturation in G. lactiferum (by 44.8%) and P. edulis (by 44%); hemolysis in C. asiatica, C. auriculata, and S. grandiflora; lipoxygenase inhibition ability in P. edulis (by 50%), C. asiatica (by 400%), and C. auriculata leaves (by 250%); proteinase inhibition in C. auriculata (100%) when compared with that of raw leaves. In general, steaming and boiling in contrast to frying protect the health-promoting properties of the leafy vegetables

Antidiabetic effects of Setaria italica seeds aqueous extract in STZ induced diabetic rats. A Histopathological study

&lt;p&gt;Background: Setaria italica is commonly known as Foxtail millet. In India it is chiefly cultivated in Andhra Pradesh, Telangana and Tamil Nādu. It can be taken as sweet or savoury food in all ways that rice is used. Due to the presence of high fibre content, it is suggested as a food for diabetic patients. Objectives: To evaluate the protective effects of SISAE on STZ induced diabetic rats. Materials and Methods: Histopathology of pancreas, liver, and kidney tissues of the STZ induced diabetic rats after treatment with SISAE for 30 days was studied. &nbsp;Results: In histopathological examination, Stained sections of pancreas of diabetic untreated rats showed destruction of beta cells with lymphocytic infiltrations and atrophy was appeared. But treatment with SISAE showed regenerative changes in the pancreas tissue architecture. Stained sections of the diabetic untreated rats showed degenerative liver with severe congestion of central vein, haemorrhage in the sinusoidal spaces with hazy nucleus. But, treatment with SISAE in diabetic rats showed improvement in histological structure of liver sections of diabetic rats with normal appearance of the liver lobules. And kidney sections of diabetic untreated rats showed tubular damage and haemorrhage. But after treatment with SISAE damage of the kidney tissue was controlled. &nbsp;Conclusion: The results from this study confirms that SISAE successfully ameliorated the degenerative changes in the histology of the pancreas, liver and kidney tissues of the STZ induced diabetic rats.&lt;/p&gt