Assessment of antioxidant potential in seed extracts of Nyctanthes arbor-tristis L. and phytochemical profiling by Gas Chromatography-Mass Spectrometry system

Abstract The present study has been carried out with the seed extracts of Nyctanthes arbor-tristis L. (Parijat) and evaluates its antioxidant potential and profiling the phytochemical constituents by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. The antioxidant potential of the seed extracts was measured by four different in vitro assay like 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, superoxide anion free radical scavenging activity, ferric reducing antioxidant power (FRAP) and lipid peroxidation inhibition potential (LPIP) assay. The total phenol content (TPC) and total flavonoid content (TFC) were estimated. The ethyl acetate extract (EAE) of seeds showed potential DPPH free radical scavenging activity (EC50 129.49±3.55µg/ml), superoxide anion radical (EC50 969.94±8.03µg/ml) and LPIP (EC50 452.43±5.07 µg/ml) activities. The total phenol content was maximum in aqueous extract (AQE) which was 201.00±0.20 µg/mg gallic acid equivalent. The EAE was rich with total flavonoid and it was found to be 34.50±0.40 µg/mg rutin equivalent. The EAE was subjected for phytochemical-profiling using GC-MS system. The presence of different phytoconstituents supports the medicinal value of the seeds. The results suggest that EAE constitutes a promising new source of novel compounds. Further, it can be used for isolation and purification of specific compounds which have good antioxidant activities and possess useful biological activities.

Study of incidence and risk factors of surgical site infections in lower segment caesarean section cases of tertiary care hospital of north India.

OBJECTIVES: To determine the incidence density, risk factors and common pathogens associated with surgical site infections (SSI) following lower segment caesarean section (LSCS) surgeries. METHODS: In this Non-interventional prospective observational study, a total of 611 post caesarean emergency and elective cases were enrolled among the 1018 LSCS cases conducted for the period of May-August 2016. The demographic, risk factors and clinical data for appearance of signs and symptoms of SSI were recorded in a preformatted proforma. SSI's were classified as superficial, deep and organ space as per Centre for Disease Control (CDC), USA definitions. Pus specimens were processed and antimicrobial susceptibility results of the organisms were determined as standard microbiological techniques. RESULTS: The SSI rate was found to be 10.3 per 100 surgeries in our study with superficial SSI (66.7%) being most common. Inappropriate pre-surgical antibiotic prophylaxis, anaemia, previous LSCS as indication of LSCS, intra-operative blood transfusion and comorbid illness like heart disease, hypothyroidism, chronic liver and kidney disease were found to be significantly associated with SSI. Predominance of gram negative isolates (55.3%) was seen in comparison to gram positive isolates (44.7%) as cause of surgical site infections. CONCLUSIONS: SSIs rates observed are much higher than those observed in NHSN participating hospitals. Many of the risk factors identified are low hanging fruits and can be targeted to effectively reduce SSI rates.

Toxicity profiling and antioxidant activity of ethyl acetate extract of leaves of Premna integrifolia L. for its application as protective agent against xenobiotics.

Premna integrifoliaL. (Lamiaceae) is widely used in herbal formulation "Dashmoolarishta" which is useful in postnatal care. Ethyl acetate extract obtained from the leaves was evaluated for phenolic content and its antioxidant activity. Acute and subacute toxicity of the extract was studied in mice of both sexes to get an idea about LD50 value and assessed its safety profile before its application as a protective agent against different toxicities induced by xenobiotics. Phenol enriched extract (phenol content is 63.10 ± 1.26 mg/g of gallic acid equivalent and flavonoid content 75.33 ± 0.23 mg/g of rutin equivalent) showed good antioxidant activity. In acute toxicity studies it was observed that single different doses (300-5000 mg/kg b.wt.) of extract did not show any mortality of mice. Thus the LD50 of the extract was determined, and it was higher than 5000 mg/kg. There was no major change in behavioral and general appearance of mice. External morphology of liver, kidneys, lungs, spleen and heart did not show any effect of treatment. In subacute toxicity no statistically significant change in body weight, relative organ weight, food intake and water uptake, hematological, biochemical parameters were reported after comparison with control. Extract did not show significant effect in the level of antioxidant enzymes in the liver of mice of treated groups. No histopathological changes were observed in liver and kidney tissues. Thus, extract did not show any sign of toxic effects, when administered orally to male and female mice at dose level up to 1000 mg/kg. So, it can be utilized as protective agent against toxicity produced by different xenobiotics.

Synthesis of Poly(2-Hydroxyethyl Methacrylate) (PHEMA)-Based Superparamagnetic Nanoparticles for Biomedical and Pharmaceutical Applications.

The performance of polymeric nanomaterials relies greatly upon their properties which are intimately related to the methods of fabrication of their materials. Among various synthetic polymers the polymers of 2-hydroxyethyl methacrylate (PHEMA) maintains a prime position in the biomedical field due to their useful physicochemical properties and suitability for controlled drug delivery applications. Furthermore, the addition of iron oxide to PHEMA nanoparticles imparts superparamagnetism to the nanoparticles and expands the range of their uses to include magnetic drug targeting applications. Here we focus on three methods for preparation of PHEMA nanoparticles, one by suspension polymerization, a second by emulsion polymerization without the use of any surfactants, and the final one with the incorporation of iron oxide into PHEMA nanoparticles.

Nano-silver hydroxyapatite based antibacterial 3D scaffolds of gelatin/alginate/poly (vinyl alcohol) for bone tissue engineering applications.

In the present study macroporous three dimensional spongy scaffolds composed of gelatin, alginate, and poly (vinyl alcohol) were prepared by cryogelation technique and silver hydroxyapatite was reinforced into the 3 D matrix. The polymer nanocomposite materials were characterized by analytical techniques such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and x-ray diffraction (XRD) analysis. The nanocomposite scaffolds were studied for their porous nature, water sorption capacity, and mechanical behavior. The suitability of scaffolds for bone tissue engineering applications was judged by evaluating their antibacterial and cytotoxic nature against gram positive and gram negative bacteria, and MC3T3-E1 preosteoblast cells, respectively. The scaffolds were also studied for release of silver ions and the influence of various experimental conditions on the release profiles of silver ions was investigated.

Proton Transfer Pathways of 2,2'-Bipyridine-3,3'-diol in pH Responsive Fatty Acid Self-Assemblies: Multiwavelength Fluorescence Lifetime Imaging in a Single Vesicle.

Fatty acids are known to form different supramolecular aggregates in aqueous solutions depending on the pH of the medium. The dynamics of the transformation of oleate micelles into oleic acid/oleate vesicles has been investigated using a pH-sensitive intramolecular proton transfer fluorophore, 2,2'-bipyridine-3,3'-diol [BP(OH)2]. Different prototropic forms of BP(OH)2 exist in different pH values of the system, and thus, the ground state and the excited state dynamics of BP(OH)2 have been modulated in these confined media. The formation of different tautomeric forms of BP(OH)2 in oleate micelles (at basic pH) is confirmed using time-resolved emission spectra and fluorescence anisotropy measurements. The hydrophobic environment provided by these assemblies reduces the water-assisted nonradiative decay channels and lengthens the fluorescence lifetime of BP(OH)2. The rotational relaxation time in the micellar assembly is higher than that in the vesicle, which may be due to the higher microviscosity sensed by the fluorophore in the micelle. Besides, we have shown for the first time that BP(OH)2 can be used as a membrane-bound fluorophore, using fluorescence lifetime imaging microscopy (FLIM). A broad distribution in the size of the vesicle is observed from the FLIM image. Further, we have used multiwavelength FLIM to collect the FLIM images of a single vesicle at different emission wavelengths, and the lifetime distribution obtained from the FLIM images at different emission wavelengths in a single vesicle correlates well with the lifetime values obtained from the ensemble average measurements in the bulk solution.

Comparative study of sorption and solubility of heat-cure and self-cure acrylic resins in different solutions.

OBJECTIVE: The objective of this study was to compare the sorption and solubility of heat-cure and self-cure acrylic resins in different solutions. MATERIALS AND METHODS: One heat-cure acrylic resin (Trevalon) and one self-cure acrylic resin (Rapid Repair) were studied. Five groups of square-shaped specimens (20 mm × 20 mm × 2 mm) were prepared for each acrylic resin and then immersed in five solutions: distilled water, artificial saliva, denture cleansing solution, distilled water, and denture cleaning solution for 12 h alternatively, artificial saliva and denture cleaning solution for 12 h alternatively at 37 ± 2°C, and tested sorption and solubility by weight gain/loss method, respectively, after 1, 6, and 11 weeks. The data were analyzed by one-way analysis of variance followed by post hoc Tukey's test. RESULTS: Water sorption mean values varied from 17.5 ± 0.88 to 27.25 ± 1.04 µg/mm 3 for heat cure and from 12.75 ± 0.55 to 19.75 ± 1.04 µg/mm 3 for self-cure in the different solutions after different interval periods of 1, 6, and 11 weeks. These values were statistically significant (P< 0.001). Water solubility mean values varied from 0.25 ± 0.55 to 1.5 ± 0.55 µg/mm 3 for heat cure and from 1.5 ± 0.55 to 6.5 ± 0.55 µg/mm 3 for self-cure in the different solutions after different interval periods of 1, 6, and 11 weeks. These values were statistically not significant (P > 0.05). There was no linear correlation between sorption and solubility values. Overall, analysis of results showed the maximum sorption value in denture cleansing solution followed by alternative soaking in distilled water and artificial saliva. Least sorption was observed with artificial saliva followed by distilled water. CONCLUSION: Both heat-cure and self-cure acrylic resins showed varying water sorption and solubility. The results of both water sorption and solubility showed compliance with the International Standards Organization specification. No correlation was found between water sorption and solubility. Artificial saliva solution is a better storage medium than distilled water and denture cleansing solution for both heat-cure and self-cure acrylic resins.

Synthesis of poly (2-hydroxyethyl methacrylate) (PHEMA) based nanoparticles for biomedical and pharmaceutical applications.

The performance of polymeric nanomaterials relies greatly upon their properties which are intimately related to the methods of fabrication of the materials. Among various synthetic polymers, the polymers of 2-hydroxyetyhyl methacrylate (PHEMA) maintain a prime position in biomedical field due to their useful physicochemical properties and suitability for controlled drug delivery applications. Here we focus on three methods of preparation of PHEMA nanoparticles, by suspension polymerization, emulsion polymerization and dispersion polymerization without the use of any surfactants.

Designing of macroporous biocompatible cryogels of PVA-haemoglobin and their water sorption study.

Macroporous polymeric materials are three-dimensional porous architectures having enormous utility in the areas of biomedical, biotechnological and separation sciences. Thus realizing the crucial role of macroporous polymeric materials in tissue engineering and allied fields the present paper discusses synthesis, characterization, and blood compatibility study of macroporous cryogels of PVA and haemoglobin. Biocompatible spongy and porous hydrogels of polyvinyl alcohol-haemoglobin have been synthesized by repeated freezing-thawing method and characterized by Infrared (FTIR), and ESEM techniques. The FTIR analysis of prepared cryogels indicated that haemoglobin was introduced into the cryogel possibly via hydrogen bonds formed amongst hydroxyl groups and amino groups present in PVA and haemoglobin, respectively. The 'cryogels' were evaluated for their water uptake potentials and influence of various factors such as chemical architecture of the spongy hydrogels, pH and temperature of the swelling bath were investigated on the degree of water sorption by the cryogels. The hydrogels were also swollen in salt solutions and various simulated biological fluids. The effect of drying temperature on its water sorption capacity was also studied. The biocompatibility of the prepared cryogels was judged by in vitro methods of blood-clot formation, percent haemolysis and protein (BSA) adsorption.

Preparation and characterization of novel biocompatible cryogels of poly (vinyl alcohol) and egg-albumin and their water sorption study.

Polyvinyl alcohol (PVA) and egg albumin are water-soluble, biocompatible and biodegradable polymers and have been widely employed in biomedical fields. In this paper, novel physically cross-linked hydrogels composed of poly (vinyl alcohol) and egg albumin were prepared by cyclic freezing/thawing processes of aqueous solutions containing PVA and egg albumin. The FTIR analysis of prepared cryogels indicated that egg albumin was successfully introduced into the formed hydrogel possibly via hydrogen bonds among hydroxyl groups, amide groups and amino groups present in PVA and egg albumin. The gels were also characterized thermally and morphologically by DSC and SEM-techniques, respectively. The prepared so called 'cryogels' were evaluated for their water uptake potential and influence of various factors such as chemical architecture of the spongy hydrogels, pH and temperature of the swelling bath were investigated on the degree of water sorption by the cryogels. The effect of salt solution and various simulated biological fluids on the swelling of cryogel was also studied. The in vitro biocompatibility of the prepared cryogel was also judged by methods such as protein (BSA) adsorption, blood clot formation and percentage hemolysis measurements.

Macroscopic, neat, single-walled carbon nanotube fibers.

Well-aligned macroscopic fibers composed solely of single-walled carbon nanotubes (SWNTs) were produced by conventional spinning. Fuming sulfuric acid charges SWNTs and promotes their ordering into an aligned phase of individual mobile SWNTs surrounded by acid anions. This ordered dispersion was extruded via solution spinning into continuous lengths of macroscopic neat SWNT fibers. Such fibers possess interesting structural composition and physical properties.

Functionalization of carbon nanotubes by free radicals.

Free radicals generated by decomposition of benzoyl peroxide in the presence of alkyl iodides have been used to derivatize small-diameter single-wall carbon nanotubes (HiPco tubes). The degree of functionalization, estimated by thermal gravimetric analysis, is as high as 1 in approximately 5 carbons in the nanotube framework. The derivatized nanotubes exhibits remarkably improved solubility in organic solvents. The attached groups can be removed by heating in an atmosphere of argon. Derivatization was also accomplished by treating SWNTs with various sulfoxides employing Fenton's reagent. [reaction: see text]

Covalent sidewall functionalization of single wall carbon nanotubes.

Alkyllithium reagents may be used to attach alkyl groups to the sidewalls of fluoro nanotubes. Thermal gravimetric analysis combined with UV-vis-Nir spectroscopy has been used to provide a quantitative measure of the degree of functionalization. SWNTs prepared using the HiPco process exhibit a higher degree of alkylation than SWNTs from the laser-oven method, indicating that the smaller diameter fluoro tubes are alkylated more readily. The spectral signature of the pristine SWNTs can be regenerated when the alkylated SWNTs are heated in Ar at 500 degrees C, demonstrating that dealkylation occurs at this temperature. TGA-MS analysis using a sample of n-butylated h-SWNTs showed that 1-butene and n-butane are formed during thermolysis.

Thermal rearrangements of spiro[2.4]hepta-1,4,6-trienes.

Thermolysis of spiro[2.4]hepta-1,4,6-triene (1a) at 50 degrees C yielded bicyclo[3.2.0]hepta-1,3,6-triene (5), which dimerized in two different fashions to form cyclobutanes. The 1,2-dimethyl and 1-propyl derivatives of 1a also rearranged at 50 degrees C, but at a faster rate, each yielding a pair of cyclobutane dimers. The structures of these symmetrical dimers were investigated by 1D and 2D NMR and NOE difference spectroscopy. Ab initio calculations indicated that the two strained olefins 1a and 5 had comparable energies about 50 kcal/mol lower than norborna-1(7),2,5-triene, which was thus excluded as a reaction intermediate.