Synthesis and characterization of ionic block copolymer templated calcium phosphate nanocomposites

Self-assembling thermo-reversibly gelling anionic and zwitterionic pentablock copolymers were used as templates for precipitation of calcium phosphate nanostructures, controlling their size and ordered structural arrangement. Calcium and phosphate ions were dissolved in a block-copolymer micellar dispersion at low temperatures. Aging at ambient temperature produced inorganic nanoparticles, presumably nucleated by ionic interactions. The self-assembled nanocomposites were characterized by small-angle X-ray and neutron scattering (SAXS/SANS), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). 1H-31P NMR with 1H spin diffusion from polymer to phosphate proved the formation of nanocomposites, with inorganic particle sizes from ∼2 nm, characterized by 1H-31P dipolar couplings, to \u3e 100 nm. TEM analysis showed polymer micelles surrounded by calcium phosphate. SAXS attested that a significant fraction of the calcium phosphate was templated by the polymer micelles. SANS data indicated that the order of the polymer was enhanced by the inorganic phase. The nanocomposite gels exhibited higher moduli than the neat polymer gels. The calcium phosphate was characterized by TGA, X-ray diffraction, high-resolution TEM, and various NMR techniques. An unusual crystalline phase with \u3e2 chemically and \u3e3 magnetically inequivalent HPO4 2- ions was observed with the zwitterionic copolymer, highlighting the influence of the polymer on the calcium phosphate crystallization. The inorganic fraction of the nanocomposite was around 30 wt % of the dried hydrogel. Thus, a significant fraction of calcium phosphate has been templated by the tailored self-assembling ionic block copolymers, providing a bottom-up approach to nanocomposite synthesis

Simultaneous determination of 6-shogaol and 6-gingerol in various ginger (Zingiber officinale Roscoe) extracts and commercial formulations using a green RP-HPTLC-densitometry method

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Various analytical methodologies have been reported for the determination of 6-shogaol (6-SHO) and 6-gingerol (6-GIN) in ginger extracts and commercial formulations. However, green analytical methods for the determination of 6-SHO and 6-GIN, either alone or in combination, have not yet been reported in literature. Hence, the present study was aimed to develop a rapid, simple, and cheaper green reversed phase high-performance thin-layer chromatography (RP-HPTLC) densitometry method for the simultaneous determination of 6-SHO and 6-GIN in the traditional and ultrasonication-assisted extracts of ginger rhizome, commercial ginger powder, commercial capsules, and commercial ginger teas. The simultaneous analysis of 6-SHO and 6-GIN was carried out via RP-18 silica gel 60 F254S HPTLC plates. The mixture of green solvents, i.e., ethanol:water (6.5:3.5 v/v) was utilized as a mobile phase for the simultaneous analysis of 6-SHO and 6-GIN. The analysis of 6-SHO and 6-GIN was performed at λmax = 200 nm for 6-SHO and 6-GIN. The densitograms of 6-SHO and 6-GIN from traditional and ultrasonication-assisted extracts of ginger rhizome, commercial ginger powder, commercial capsules, and commercial ginger teas were verified by obtaining their single band at Rf = 0.36 ± 0.01 for 6-SHO and Rf = 0.53 ± 0.01 for 6-GIN, compared to standard 6-SHO and 6-GIN. The green RP-HPTLC method was found to be linear, in the range of 100–700 ng/band with R2 = 0.9988 for 6-SHO and 50–600 ng/band with R2 = 0.9995 for 6-GIN. In addition, the method was recorded as “accurate, precise, robust and sensitive” for the simultaneous quantification of 6-SHO and 6-GIN in traditional and ultrasonication-assisted extracts of ginger rhizome, commercial ginger powder, commercial capsules, and commercial ginger teas. The amount of 6-SHO in traditional extracts of ginger rhizome, commercial ginger powder, commercial capsules, and commercial ginger teas was obtained as 12.1, 17.9, 10.5, and 9.6 mg/g of extract, respectively. However, the amount of 6-SHO in ultrasonication-assisted extracts of ginger rhizome, commercial ginger powder, commercial capsules, and commercial ginger teas were obtained as 14.6, 19.7, 11.6, and 10.7 mg/g of extract, respectively. The amount of 6-GIN in traditional extracts of ginger rhizome, commercial ginger powder, commercial capsules, and commercial ginger teas were found as 10.2, 15.1, 7.3, and 6.9 mg/g of extract, respectively. However, the amount of 6-GIN in ultrasonication-assisted extracts of ginger rhizome, commercial ginger powder, commercial capsules, and commercial ginger teas were obtained as 12.7, 17.8, 8.8, and 7.9 mg/g of extract, respectively. Overall, the results of this study indicated that the proposed analytical technique could be effectively used for the simultaneous quantification of 6-SHO and 6-GIN in a wide range of plant extracts and commercial formulations

Antioxidant and hepatoprotective effects of Astragalus echinops and Astragalus logopodioides ethanolic extracts on paracetamol-induced liver injury in rats

Background: Paracetamol (PCM) has an adequate safety profile when taken in normal doses. However, it could produce oxidative stress with liver injury when taken in an overdose. Plants of Astragalus genus (F. Fabaceae) are of wide-spread applications. Astragalus echinops (A. echinops) and Astragalus logopodioides (A. logopodioides) were tested for their potential hepatoprotective activities against liver injury induced by PCM in rats.Material and Methods: Seven groups of rats were used for determination of hepatoprotective activities of the extracts. The normal and hepatotoxic control groups received the vehicle while other groups were treated with silymarin (100 mg/ kg), A. echinops (250 and 500 mg/kg) and A. logopodioides (250 and 500 mg/ kg), respectively for seven days. Liver injury was induced on the 5th day by oral dosing of PCM (2g/kg) to all rats except those in normal control group. Moreover, the in vitro antioxidant activities of A. echinops and A. logopodioides extracts were tested using 2,2- diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging.Results: Hepatic enzyme markers as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and glutamyl transferase and level of total bilirubin were significantly elevated, while total protein and albumin were declined significantly in PCM-exposed animals. The liver antioxidant markers like the activities of superoxide dismutase, catalase and glutathione peroxidase and the levels of reduced glutathione were significantly declined, while hepatic malondialdehyde levels were significantly increased in PCM alone-treated rats. Administration of A. echinops (250 and 500 mg/kg) and A. logopodioides (500 mg/ kg) extracts prior to PCM, significantly protected against the elevation in the serum activities of hepatic enzymes and bilirubin and reduced oxidative stress. The hepatoprotective effect of both extracts was further confirmed by histological findings in the liver tissue. In addition, both extracts displayed in vitro antioxidant activities in a concentration-dependent way.Conclusion: Our results suggest that both extracts protect the liver against oxidative damage and they could be used as effective hepatoprotectives against PCM induced liver injury.Keywords: Astragalus, Paracetamol, Hepatotoxicity, Hepatoprotective, DPPH, Antioxidan

Anti-inflammatory and hepatoprotective potentials of the aerial parts of Silene villosa Caryophyllaceae methanol extract in rats

Purpose: To explore the anti-inflammatory and hepatoprotective potentials of Silene villosa Caryophyllaceae methanol extract in rats.Methods: Toxicity of S. villosa extract was evaluated in rats. Inflammation was induced in rats by injection of 0.1 mL carrageenan (1 %) in the left hind paws. Carbon tetrachloride (CCl4) was used to induce liver damage. Five groups of rat were used. The 1st (normal control) and 2nd (hepatotoxic) groups received the vehicle. The 3rd, 4th, and 5th groups received silymarin, 250 and 500 mg/kg of S. villosa extract, respectively, for 7 days. Liver injury was induced on the 7th day by intraperitoneal administration of 1 mL/kg of CCl4 to rats in groups 2 - 5.Results: The results showed that S. villosa is safe. It significantly reduced carrageenan-induced edema compared to normal (p < 0.01) and standard (p < 0.01) groups. The extract protected (p < 0.01) rats against the deleterious effect of CCl4. It decreased (p < 0.01) the elevated serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transferase (γ-GT) and alkaline phosphatase (ALP) as well as elevated serum levels of bilirubin (BRN), compared to CCl4 control rats. Reduced activities of the antioxidant enzymes were significantly increased (p < 0.01) in rat liver, compared with CCl4 control group. The results were confirmed by histological findings in rat liver as the extract reduced necrosis and hydropic degeneration of hepatic tissue compared to CCl4 control group.Conclusion: The results suggest that S. villosa possesses anti-inflammatory and hepatoprotective activities in rats, and therefore, has therapeutic potentials in humans.Keywords: S. villosa, anti-inflammatory, carrageenan, CCl4, antioxidant, hepatotoxicity

Biomimetic self-assembling copolymer-hydroxyapatite nanocomposites with the nanocrystal size controlled by citrate

Citrate binds strongly to the surface of calcium phosphate (apatite) nanocrystals in bone and is thought to prevent crystal thickening. In this work, citrate added as a regulatory element enabled molecular control of the size and stability of hydroxyapatite (HAp) nanocrystals in synthetic nanocomposites, fabricated with self-assembling block copolymer templates. The decrease of the HAp crystal size within the polymer matrix with increasing citrate concentration was documented by solid-state nuclear magnetic resonance (NMR) techniques and wide-angle X-ray diffraction (XRD), while the shapes of HAp nanocrystals were determined by transmission electron microscopy (TEM). Advanced NMR techniques were used to characterize the interfacial species and reveal enhanced interactions between mineral and organic matrix, concomitant with the size effects. The surface-to-volume ratios determined by NMR spectroscopy and long-range 31P{1H} dipolar dephasing show that 2, 10, and 40 mM citrate changes the thicknesses of the HAp crystals from 4 nm without citrate to 2.9, 2.8, and 2.3 nm, respectively. With citrate concentrations comparable to those in body fluids, HAp nanocrystals of sizes and morphologies similar to those in avian and bovine bones have been produced

Development and validation of a high-performance thin-layer chromatographic method for the quantitative analysis of vitexin in Passiflora foetida herbal formulations

© 2019 Dehon et al. Introduction: Formative evaluations of clinical teaching for emergency medicine (EM) faculty are limited. The goal of this study was to develop a behaviorally-based tool for evaluating and providing feedback to EM faculty based on their clinical teaching skills during a shift. Methods: We used a three-phase structured development process. Phase 1 used the nominal group technique with a group of faculty first and then with residents to generate potential evaluation items. Phase 2 included separate focus groups and used a modified Delphi technique with faculty and residents, as well as a group of experts to evaluate the items generated in Phase 1. Following this, residents classified the items into novice, intermediate, and advanced educator skills. Once items were determined for inclusion and subsequently ranked they were built into the tool by the investigators (Phase 3). Results: The final instrument, the Faculty Shift Card, is a behaviorally-anchored evaluation and feedback tool used to facilitate feedback to EM faculty about their teaching skills during a shift. The tool has four domains: teaching clinical decision-making; teaching interpersonal skills; teaching procedural skills; and general teaching strategies. Each domain contains novice, intermediate, and advanced sections with 2-5 concrete examples for each level of performance. Conclusion: This structured process resulted in a well-grounded and systematically developed evaluation tool for EM faculty that can provide real-time actionable feedback to faculty and support improved clinical teaching

ANTIOXIDANT AND HEPATOPROTECTIVE EFFECTS OF ASTRAGALUS ECHINOPS AND ASTRAGALUS LOGOPODIOIDES ETHANOLIC EXTRACTS ON PARACETAMOL-INDUCED LIVER INJURY IN RATS

Background: Paracetamol (PCM) has an adequate safety profile when taken in normal doses. However, it could produce oxidative stress with liver injury when taken in an overdose. Plants of Astragalus genus (F. Fabaceae) are of wide-spread applications. Astragalus echinops (A. echinops) and Astragalus logopodioides (A. logopodioides) were tested for their potential hepatoprotective activities against liver injury induced by PCM in rats. Material and Methods: Seven groups of rats were used for determination of hepatoprotective activities of the extracts. The normal and hepatotoxic control groups received the vehicle while other groups were treated with silymarin (100 mg/ kg), A. echinops (250 and 500 mg/kg) and A. logopodioides (250 and 500 mg/ kg), respectively for seven days. Liver injury was induced on the 5th day by oral dosing of PCM (2g/kg) to all rats except those in normal control group. Moreover, the in vitro antioxidant activities of A. echinops and A. logopodioides extracts were tested using 2,2- diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging. Results: Hepatic enzyme markers as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and glutamyl transferase and level of total bilirubin were significantly elevated, while total protein and albumin were declined significantly in PCM-exposed animals. The liver antioxidant markers like the activities of superoxide dismutase, catalase and glutathione peroxidase and the levels of reduced glutathione were significantly declined, while hepatic malondialdehyde levels were significantly increased in PCM alone-treated rats. Administration of A. echinops (250 and 500 mg/kg) and A. logopodioides (500 mg/ kg) extracts prior to PCM, significantly protected against the elevation in the serum activities of hepatic enzymes and bilirubin and reduced oxidative stress. The hepatoprotective effect of both extracts was further confirmed by histological findings in the liver tissue. In addition, both extracts displayed in vitro antioxidant activities in a concentration-dependent way. Conclusion: Our results suggest that both extracts protect the liver against oxidative damage and they could be used as effective hepatoprotectives against PCM induced liver injury

Heavy metal accumulation in the leaves, stem and root of the invasive submerged macrophyte Myriophyllum spicatum L. (Haloragaceae): an example of Kadin Creek (Mugla, Turkey)

In this study, the existence of heavy metals such as chromium (Cr), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) their distribution in the organs of plant and their bioaccumulation rates in water samples and Myriophyllum spicatum which were collected from the Kadin Creek in seasonal periods between 2011 and 2012 were analyzed. Heavy metal concentrations in the mineralized plant and water samples were determined with Inductive coupled plasma with mass spectroscopy (ICP-MS). Results showed the maximum heavy metal concentrations, in the root and minimum heavy metal concentrations, except chromium, in the stem. The distribution of heavy metals As, Cd, Hg and Pb was in the form of root > leaf > stem; the distribution of Cr was in the root > stem > leaf. There was a strong negative correlation between the suspended solid matter and heavy metal concentrations in the plant tissues. Heavy metal accumulation showed increase generally in fall. Heavy metals in the water were sorted as Pb > Cr > As > Hg > Cd by their mean concentrations. According to the factor data of bioconcentration, the order of heavy metal accumulation in the plant was As > Cr > Pb > Hg > Cd