Synthesis and characterization of carbonated hydroxyapatite and bioinspired polymer-calcium phosphate nanocomposites

Taking the inspiration from natural bone, where collagen provides sites for the nucleation and growth of carbonated hydroxyapatite, we have developed self-assembling calcium phosphate-block copolymer nanocomposites by using a bottom-up approach. In this regard, self-assembling thermo-reversibly gelling block copolymers based on the nonionic, zwitterionic, anionic, block copolymers conjugated to hydroxyapatite-nucleating peptides, and polylysine-polyleucine diblock copoly-peptides were employed as templates for the precipitation of nano-sized calcium phosphates from aqueous solutions. Calcium phosphate nanocrystals were formed at the polymer-inorganic interface presumably nucleated by the ionic interactions. Solid-state NMR, XRD, TEM, TGA, FTIR and X-ray scattering techniques were used to characterize the nanocomposites. NMR and scattering measurements of polymer-inorganic gel composites proved nanocomposite formation and templating by the polymer micelles. The inorganic fraction of the nanocomposites was found to vary between 30-55 wt%. TEM studies showed that the morphology and the size of the hydroxyapatite crystals in the nanocomposites were similar to the apatite in the bone. The findings in our studies provide information for developing guidelines for design of novel HAp-polymer nanocomposites and for the understanding of the mechanism of biomineralization. Moreover, this study may also offer routes for bioinspired bottom-up approaches for the development of a number of nanostructured composites including injectable nanocomposite biomaterials for potential orthopedic applications. As a part of the present study, the carbonate incorporation into the hydroxyapatite lattice under various pH conditions was also investigated. Crystalline sodium and carbonate containing calcium hydroxyapatite (NaCO3HAp) powders were prepared using an oxidative decomposition of calcium-EDTA chelates in the sodium phosphate solution with hydrogen peroxide. Depending on pH, spherical particles with approximately 3.5 ym in diameter or hexagonal prismatic particles measuring 3 to 9 ym long were obtained. The precipitated particles were a single-phase NaCO3HAp. The carbonate content and the lattice parameters of the hydroxyapatite were a function of solution pH. Maximum carbonate incorporated into the HAp lattice was at pH=10. Formation of HAp on PMMA polymer films was also studied by using the same chelate decomposition method. Evolution of HAp coating as a function of experimental variables including time was examined

Analgesic, antipyretic, anti-inflammatory, and hepatoprotective activities of Pulicaria crispa (Forssk.) Oliv. (Asteraceae)

Some plants of the genus Pulicaria have been used in traditional medicines for treating back pain and inflammation. They possess various bioactivities such as antipyretic, analgesic, and hepatoprotective. This study aimed to investigate the potential analgesic, antipyretic, anti- inflammatory, and hepatoprotective activities of Pulicaria crispa (P. crispa) extract (PCE). Analgesic activity was evaluated using the hot plate and acetic acid-induced writhing tests. Antipyretic and anti-inflammatory activities were evaluated using rectal temperature and carrageenan-induced hind paw edema methods, respectively. CCl4-intoxication was used for hepatoprotective activity. Also, liver histopathology was assessed. PCE, at 500 mg/kg, exhibited significant analgesic, antipyretic, and anti-inflammatory effects. The increased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and bilirubin of CCl4-exposed rats reflects their liver injury. PCE significantly decreased the elevated liver markers. The hepatoprotective effect of PCE was confirmed, as it successfully reversed the altered levels of total protein, malondialdehyde (MDA), and non-protein sulfhydryls (NP-SH) in the liver tissues of CCl4-exposed rats. Histopathological studies confirmed the hepatoprotective nature of PCE. Pretreatment of rats with PCE reduced the severity of CCl4-induced liver damage. These findings concluded that PCE possesses analgesic, antipyretic, anti-inflammatory, and hepatoprotective activities

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

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

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

COMPARATIVE ANTI-INFLAMMATORY AND HEPATOPROTECTIVE ACTIVITIES OF ASTRAGALUS GUMMIFER LABILL HERB AND ROOTS IN RATS

Background: The Astragalus gummifer (F. Fabaceae), herb and roots were studied for anti-inflammatory and hepatoprotective activities. Materials and method: The alcoholic extracts of Astragalus gummifer (F. Fabaceae), herb (AGHE), and roots (AGRE), were used for anti-inflammatory and hepatoprotective activities in Wister rats. The effects of AGHE and AGRE were compared with the standard drugs Phenylbutazone and silymarin, for anti-inflammatory and hepatoprotective activities respectively. Result: Both extracts showed significant anti-inflammatory activity (P< 0.001). AGRE showed comparatively more significant hepatoprotective activity (P< 0.001), than AGHE (P< 0.05); at doses of 250 and 500 mg/kg body weight as manifested by lowering the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and total bilirubin. The hepatoprotective activity was, also, supported by total protein (TP), malondialdehyde (MDA), nonprotein sulfhydryls (NP-SH), and histo-pathological studies of liver tissue. Discussion: To the best of our knowledge, this is the first report of the anti-inflammatory and hepatoprotective activities of Astragalus gummifer. The results of present studies indicated that both AGHE and AGRE can be used in inflammatory conditions, while investigation supports the use of AGRE in cases that hepatoprotection are required in the hepatotoxic conditions. More supportive studies are required before clinical recommendation

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