Membrane softening by nonsteroidal anti-inflammatory drugs investigated by neutron spin echo.

In spite of their well-known side effects, the nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed medications for their antipyretic and anti-inflammatory actions. Interaction of NSAIDs with the plasma membrane plays a vital role in their therapeutic actions and defines many of their side effects. In the present study, we investigate the effects of three NSAIDs, aspirin, ibuprofen, and indomethacin, on the structure and dynamics of a model plasma membrane using a combination of small angle neutron scattering (SANS) and neutron spin echo (NSE) techniques. The SANS and NSE measurements were carried out on a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membrane, with and without NSAIDs, at two different temperatures, 11 °C and 37 °C, where the DMPC membrane is in the gel and fluid phase, respectively. SANS data analysis shows that incorporation of NSAIDs leads to bilayer thinning of the membrane in both the phases. The dynamic properties of the membrane are represented by the intermediate scattering functions for NSE data, which are successfully described by the Zilman and Granek model. NSE data analysis shows that in both gel and fluid phases, addition of NSAIDs results in a decrease in the bending rigidity and compressibility modulus of the membrane, which is more prominent when the membrane is in the gel phase. The magnitude of the effect of NSAIDs on the bending rigidity and compressibility modulus of the membrane in the gel phase follows an order of ibuprofen > aspirin > indomethacin, whereas in the fluid phase, it is in the order of aspirin > ibuprofen > indomethacin. We find that the interaction between NSAIDs and phospholipid membranes is strongly dependent on the chemical structure of the drugs and physical state of the membrane. Mechanical properties of the membrane can be quantified by the membrane's bending rigidity. Hence, the present study reveals that incorporation of NSAIDs modulates the mechanical properties of the membrane, which may affect several physiological processes, particularly those linked to the membrane curvature.

Evaluating the Antibacterial Properties of Polyacetylene and Glucosinolate Compounds with Further Identification of Their Presence within Various Carrot (Daucus carota) and Broccoli (Brassica oleracea) Cultivars Using High-Performance Liquid Chromatography with a Diode Array Detector and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry Analyses.

Ongoing consumer concerns over using synthetic additives in foods has strongly influenced efforts worldwide to source suitable natural alternatives. In this study, the antibacterial efficacy of polyacetylene and glucosinolate compounds was evaluated against both Gram positive and Gram negative bacterial strains. Falcarinol [minimum inhibitory concentration (MIC) = 18.8-37.6 µg/mL] demonstrated the best overall antibacterial activity, while sinigrin (MIC = 46.9-62.5 µg/mL) was the most active glucosinolate compound. High-performance liquid chromatography with a diode array detector analysis showed falcarinol [85.13-244.85 µg/g of dry weight (DW)] to be the most abundant polyacetylene within six of the eight carrot (Daucus carota) cultivars investigated. Meanwhile, sinigrin (100.2-244.3 µg/g of DW) was the most abundant glucosinolate present within the majority of broccoli (Brassica oleracea) cultivars investigated using ultra performance liquid chromatography-tandem mass spectrometry analysis. The high abundance of both falcarinol and sinigrin within these respective species suggests that they could serve as potential sources of natural antibacterial agents for use as such in food products.

The chemical and antioxidant stability of isolated low molecular weight phlorotannins.

Due to their high anti-oxidant activity, phlorotannins represent potential natural alternatives to synthetic preservatives currently used within the food industry. However, their successful integration into food products requires research into their chemical integrity, particularly when selecting appropriate storage conditions. Subsequently, this study aims to investigate the stability of low molecular weight phlorotannin fractions from Fucus vesiculosus (L.). Powder and aqueous fractions were stored under five different conditions for 10weeks. Phlorotannin stability was determined using Q-ToF-MS and UPLC-TQD-MS/MS and a DPPH assay. After 10weeks of storage, fractions suspended in an aqueous matrix underwent oxidation when exposed to continuous atmospheric oxygen and thermal degradation when exposed to a constant temperature of 50°C, resulting in decreases in radical scavenging activity (p<0.001). Phlorotannins remained stable under all other storage conditions. This study highlights phlorotannins as highly stable polymers, under certain storage conditions, with an excellent capacity for scavenging radicals.

Dynamical and Phase Behavior of a Phospholipid Membrane Altered by an Antimicrobial Peptide at Low Concentration.

The mechanism of action of antimicrobial peptides is traditionally attributed to the formation of pores in the lipid cell membranes of pathogens, which requires a substantial peptide to lipid ratio. However, using incoherent neutron scattering, we show that even at a concentration too low for pore formation, an archetypal antimicrobial peptide, melittin, disrupts the regular phase behavior of the microscopic dynamics in a phospholipid membrane, dimyristoylphosphatidylcholine (DMPC). At the same time, another antimicrobial peptide, alamethicin, does not exert a similar effect on the DMPC microscopic dynamics. The melittin-altered lateral motion of DMPC at physiological temperature no longer resembles the fluid-phase behavior characteristic of functional membranes of the living cells. The disruptive effect demonstrated by melittin even at low concentrations reveals a new mechanism of antimicrobial action relevant in more realistic scenarios, when peptide concentration is not as high as would be required for pore formation, which may facilitate treatment with antimicrobial peptides.

Polyacetylene levels in carrot juice, effect of pH and thermal processing.

This research focuses on the study of polyacetylenes in carrot juice and their response to pH, storage and thermal processing conditions. Falcarindiol-3-acetate (FaDOAc) and falcarinol (FaOH) were in fresh carrot juice at concentrations of 73 and 233 µg/L, respectively. Reducing the pH of the raw carrot juice from its natural pH 6.13 to pH 3.5 resulted in 2 and 5 fold better extraction of FaDOAc and FaOH respectively in comparison to a control sample (pH 6.13). Polyacetylenes were retained better in acidified juices and cold storage temperatures (4 °C) for first week of storage with respect to untreated juices. An increase in FaDOAc and FaOH of 10- and 16-fold, respectively, as compared to raw unprocessed samples was observed when processing samples at 90 °C for 1 min. This was assumed to be due to cell wall polysaccharides dissolution. However, negative correlation between total polyacetylenes and hexoses was confirmed by (1)H NMR spectroscopy, indicating some biological links between polyacetylenes and soluble sugars.

Quantitative investigations of aggregate systems.

Nanomaterials with disordered, ramified structure are increasingly being used for applications where low cost and enhanced performance are desired. A particular example is the use in printed electronics of inorganic conducting and semiconducting nanoparticles. The electrical, as well as other physical properties depend on the arrangement and connectivity of the particles in such aggregate systems. Quantification of aggregate structure and development of structure/property relationships is difficult and progress in the application of these materials in electronics has mainly been empirical. In this paper, a scaling model is used to parameterize the structure of printed electronic layers. This model has chiefly been applied to polymers but surprisingly it shows applicability to these nanolayers. Disordered structures of silicon nanoparticles forming aggregates are investigated using small angle x-ray scattering coupled with the scaling model. It is expected that predictions using these structural parameters can be made for electrical properties. The approach may have wide use in understanding and designing nano-aggregates for electronic devices.

Light-into-heat conversion in La2O3:Er(3+)-Yb3+ phosphor: an incandescent emission.

Low-power-threshold cw laser-induced incandescence (CWLII) has been observed in La(2)O(3):Er(3+)-Yb(3+) phosphor on excitation by a 976 nm IR laser. It is suggested that incandescence originates from the extensive heating induced by the nonradiative processes taking place following the laser excitation. Other mechanisms for similar observations have also been suggested in the literature and have been discussed with the present observations. The estimated temperature for the CWLII approaches around 2650 K, and this seems to provide an effective way to rapidly attain high temperature in nano/microvolumes of phosphor. The phosphor exhibited efficient upconversion, and the ratio of the (2)H(11/2)→(4)I(15/2) and (4)S(3/2)→(4)I(15/2) band intensities of Er(3+) permits measurement of the temperature rise, from a distance.

In-vitro carbofuran induced micronucleus formation in human blood lymphocytes.

The farmers in general get exposed to different chemicals including pesticides. Many of these compounds are capable of inducing mutations in DNA and lead to several diseases including cancer. Carbofuran is a broad spectrum pesticide and frequently used in agricultural practices in India. In this study we intended to evaluate DNA damage inflicted by pesticide exposure in human blood lymphocytes under in vitro condition. The lymphocytes were exposed to varying concentrations of carbofuran (0—50μM) and analyzed by means of the micronucleus (MN) test. The results obtained showed significant increase in MN frequency after exposure to 5, 10, 25 and 50μM of carbofuran as compared to the control group. The frequencies of MN were observed to be in concentration dependent manner. As we further increase the concentration of carbofuran, we observed significant decrease in the mean percentage of binucleated cells (70—49%) and increase in the number of micronuclei formed per 1000 binucleated cells. Simultaneously, we also observed reduction in Cytokinesis—Block Proliferation index (CBPI) with increase in the carbofuran concentrations. The results indicate that this pesticide may exhibit genotoxic effect at higher concentrations. This study emphasizes the need to reinforce the good practices campaigns in order to enlighten those who work with pesticides and also to make them aware about the importance of using protective measures.

Annealing effects on capacitance-voltage characteristics of a-Si/SiN(x) multilayer prepared using hot-wire chemical vapour deposition.

Post-deposition annealing of a-Si/SiN(x) multilayer films at different temperature shows varying shift in high frequency (1 MHz) capacitance-voltage (HFCV) characteristics. Various a-Si/SiN(x) multilayer films were deposited using hot wire chemical vapor deposition (HWCVD) and annealed in the temperature range of 800 to 900 degrees C to precipitate Si quantum dots (Si-QD) in a-Si layers. HFCV measurements of the as-deposited and annealed films in metal-insulator-semiconductor (MIS) structures show hysterisis in C-V curves. The hysteresis in the as-deposited films and annealed films is attributed to charge trapping in Si-dangling bonds in a-Si layer and in Si-QD respectively. The charge trapping density in Si-QD increases with temperature while the interface defects density (D(it)) remains constant.

Role of aqueous extract of Cynodon dactylon in prevention of carbofuran- induced oxidative stress and acetylcholinesterase inhibition in rat brain.

The present study was designed to investigate the ameliorating effect of aqueous extract of C. dactylon on carbofuran induced oxidative stress (OS) and alterations in the activity of acetylcholinesterase (AChE) in the brain of rats. Vitamin C was used as a positive control. Wistar rats were administered with single sub-acute oral dose (1.6 mgkg-1 b.wt.) of carbofuran for 24 h. The OS parameters such as lipid peroxidation (LPO) and the activities of antioxidant enzymes including super oxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST), and that of AChE were studied in brain. Carbofuran treatment significantly increased the activities of SOD and CAT by 75 and 60%, respectively. It also induced the level of LPO by 113%. In contrast, the activities of GST and AChE were recorded to be diminished by 25 and 33%, respectively. Pretreatment of the rats with aqueous extract of C. dactylon (oral; 500mgkg-1) restored SOD activity completely but CAT activity only partially (7%). Carbofuran induced LPO was moderated by 95% in the brain of C. dactylon treated rats. The observed changes in OS parameters in C. dactylon treated group were comparable to that observed in vitamin C (200 mg-kg-1 b. wt.) treated group. Surprisingly, C. dactylon treatment significantly recovered the activity of AChE to a similar level as observed in the brain of control group. In contrast vitamin C treatment did not cause significant change in the activity of AChE in carbofuran treated group. There were no noticeable changes in the aforementioned study parameters in the brain of rats receiving C. dactylon and vitamin C, only. The results suggest that the study is extremely important in the context of development of new anticholinestesterase and antioxidant antidotes against carbofuran from C. dactylon.

Effect of Curcuma longa freeze dried rhizome powder with milk in STZ induced diabetic rats.

This study deals with the effects of freeze dried rhizome powder of Curcuma longa (C. longa) dissolved in milk on normal as well as diabetic models. Diabetes of type II and type I was within 3 days of a single administration of doses of 45 and 65 mg kg(-1) of streptozotocin respectively. Various parameters such as blood glucose levels, triglycerides, total cholesterol, high density lipoprotein, very low density lipoprotein, low density lipoprotein, serum glutamic oxaloacetic transaminase, serum glutamic pyruvate transaminase, alkaline phosphatase, creatinine, hemoglobin, urine protein and urine sugar in addition to body weight were taken in to consideration and were analyzed after administration of variable doses of rhizome powder. The dose of 200 mg kg(-1) was identified as the most effective dose as it increased HDL, Hb and bw (P<0.05) with significant decrease in the levels of blood glucose, lipid profile and hepatoprotective enzymes (P<0.001).

Role of Quercetin in Cardiovascular Diseases

Cardiovascular disease constitutes a major public health concern in industrialized nations. Over recent decades; a large body of evidence has accumulated indicating that oxidative stress induced free radicals play a critical role in cellular processes implicated in atherosclerosis and many other heart diseases. However a diet high in antioxidants is associated with a reduced risk of cardiovascular disease. The compound quercetin is a dietary antioxidant with a polyphenolic structure that is present in many foods; such as onion; apples; wine and tea. An increased intake of quercetin has been correlated with a decrease in the risk of cardiovascular diseases. Quercetin has been reported to exhibit a wide range of biological and pharmacological effects in animals and man besides its antioxidative and free radical scavenging actions. This paper reviews various steps of oxidative stress mediated atherogenesis and their signaling pathways and also emphasizes the role of quercetin in controlling oxidative stress and reducing the incidence of cardiovascular diseases

Ab-initio and density functional study of L- and D-forms of alanine and serine in gas phase and bulk aqueous medium.

The molecular geometry of L and D-forms of alanine and serine in gas phase have been studied by using ab-initio quantum chemical calculations at the restricted Hartree-Fock (RHF) level by employing 6-31G and 6-311++G** basis sets. Subsequently, for considering the electron correlations, Density functional Calculations at the Becke3LYP (B3LYP) and Moller-Plesset second order (MP2) level of calculations have been carried out with the same basis sets for these optimized geometries. Effect of solvation in water on the optimized geometries was studied using the polarized continuum model of the self-consistent reaction field (SCRF) theory. The dipole moment, energy, polarizabilities and vibrational frequencies have been calculated in all cases. Frequency analysis was carried out to ensure that optimized geometry corresponds to a total energy minimum.

Enhancement of luminescence properties in Er3+ doped TeO2-Na2O-PbX (X=O and F) ternary glasses.

An enhancement of luminescence properties in Er3+ doped ternary glasses is observed on the addition of PbO/PbF2. The infrared to visible upconversion emission bands are observed at 410, 525, 550 and 658 nm, due to the 2H9/2-->4I15/2, 2H11/2-->4I15/2, 4S3/2-->4I15/2, 4F9/2-->4I15/2 transitions respectively, on excitation with 797 nm laser line. A detailed study reveals that the 2H9/2-->4I15/2 transition arises due to three step upconversion process while other transitions arise due to two step absorption. On excitation with 532 nm radiation, ultraviolet and violet upconversion bands centered at 380, 404, 410 and 475 nm wavelengths are observed along with one photon luminescence bands at 525, 550, 658 and 843 nm wavelengths. These bands are found due to the 4G11/2-->4I15/2, 2P3/2-->4I13/2, 2H9/2-->4I15/2, 2P3/2-->4I11/2, 2H11/2-->4I15/2, 4S3/2-->4I15/2, 4F9/2-->4I15/2 and 4S3/2-->4I13/2 transitions, respectively. Though incorporation of PbO and PbF2 both enhances fluorescence intensities however, PbF2 content has an important influence on upconversion luminescence emission. The incorporation of PbF2 enhances the red emission (658 nm) intensity by 1.5 times and the violet emission (410 nm) intensity by 2.0 times. A concentration dependence study of fluorescence reveals the rapid increase in the red (4F9/2-->4I15/2) emission intensity relative to the green (4S3/2-->4I15/2) emission with increase in the Er3+ ion concentration. This behaviour has been explained in terms of an energy transfer by relaxation between excited ions.

Vibrational assignment of the normal modes of 2-phenyl-4-(4-methoxy benzylidene)-2-oxazolin-5-one via FTIR and Raman spectra, and ab inito calculations.

Raman and FTIR spectra of 2-phenyl-4-(4-methoxy benzylidene)-2-oxazolin-5-one were recorded in the regions, 100-3300 and 400-4000 cm(-1), respectively. Vibrational frequencies and intensities of the fundamental modes of this hetrocyclic organic molecule were computed using ab initio as well as AM1 semiempirical molecular orbital methods. Ab initio calculations were carried out with basis set up to RHF/6-311G. Conformational studies regarding the effect of moving the methoxy group in the 2-phenyl-4-(4-methoxy benzylidene)-2-oxazolin-5-one molecule to a different position on the ring was also carried out. Observed vibrational wavenumbers were found to be mostly consistent with ab initio values. The most intense mode of vibration observed at 1250 cm(-1) in Raman spectra, also observed as a strong band in FTIR, was assigned as C-O stretching vibration in the methoxy group. Asymmetric stretching vibrations between CC and CN bonds was predicted as most intense mode by our ab initio calculation.

Upconversion in Er3+-doped Bi2O3-Li2O-BaO-PbO tertiary glass.

Radiative properties of Er3+-doped tertiary bismuth glass has been analyzed by the Judd-Ofelt theory. NIR to visible upconversion in the Er3+-doped glass has been reported. The mechanism for the upconversion is explained on the basis of quadratic dependence on excitation power and on the energy-matching scheme. Energy transfer is noted as the dominant process including the long-lived 4I11/2 level as the intermediate state for the green and red upconversion emissions. The effect of temperature on the fluorescence intensity of the two bands due to 2H11/2-->4I15/2 and 4S3/2-->4I15/2 transitions as well as on the transitions due to Stark components of the 4S3/2 level have been monitored and it is concluded that their intensity ratio may serve as better temperature sensing device.

Quercetin: a Versatile Flavonoid

Associative evidence from observational and intervention studies in human subjects shows that a diet including plant foods (particularly fruit and vegetables rich in antioxidants) conveys health benefits. There is no evidence that any particular nutrient or class of bioactive substances makes a special contribution to these benefits. Flavonoids occur naturally in fruits; vegetables and beverages such as tea and wine. Quercetin is the major flavonoid which belongs to the class called flavonols. Quercetin is found in many common foods including apples; tea; onions; nuts; berries; cauliflower; cabbage and many other foods. Quercetin provides many health promoting benefits; including improvement of cardiovascular health; eye diseases; allergic disorders; arthritis; reducing risk for cancers and many more. The main aim of this review is to obtain a further understanding of the reported beneficial health effects of Quercetin; its pharmacological effects; clinical application and also to evaluate its safety

Spectroscopic properties of Pr(3+) doped in tellurite glass.

The absorption and fluorescence spectra of Pr(3+) doped in tellurite glass has been recorded and analyzed in terms of Judd-Ofelt theory. The lifetime of (3)P(0) and (3)P(1) levels has been measured. Fluorescence quenching has been observed for higher concentrations of Pr(3+) ion. The temperature dependence of the fluorescence intensity and the lifetime of the (3)P(0) level has been investigated and found that they decrease with the increase of the temperature.

Optical properties of Sm3+ doped calibo glass with addition of lead oxide.

Optical absorption and fluorescence spectra of Sm3+ doped calibo glasses and the effects on these on addition of lead oxide have been recorded. The concentration of lead oxide has been varied from 0 to 30 mol%. The Judd-Ofelt intensity parameters Omegalambda (lambda=2, 4, 6) for f-f transitions in Sm3+ ions trapped in these glasses are calculated and their variation with increase in proportion of lead oxide has been discussed. It is observed from the fluorescence spectra that the intensity of fluorescence reaches a maximum when 20% of PbO is present. Stimulated emission cross-section is calculated and compared with its value for other lattices.

Overtone spectra of aniline derivatives.

Overtone spectra of 2-ethylaniline, N-methylaniline, N-ethylaniline, N,N-dimethylaniline and N,N-diethylaniline have been studied in 2500-15000 cm(-1) region. Vibrational frequency and anharmonicity constants for aryl/alkyl C-H stretch and N-H stretch vibrations have been determined. The effect of substitution of C(2)H(5) group on the ortho position in the ring and CH(3)/C(2)H(5) at the positions of the H-atom in NH(2) group has been studied in these molecules. It is noted that the aryl C-H stretching frequency and the N-H stretching frequency is appreciably increased due to the replacement of H in NH(2) group by CH(3)/C(2)H(5). These experimental observations are well supported by theoretical calculations for charge density on N-atom using molecular orbital AM(1) method.