This study aims to optimize the process for preparing chitosan-based ultrasound-coupled hydrogel pads and investigate their application potential in ultrasonography. Chitosan, 2-acrylamido-2-methylpropanesulfonic acid, and N-isopropylacrylamide were used as the main materials to prepare chitosan-based ultrasound-coupled hydrogel pads. The free-radical polymerization conditions were optimized by a three-factor, three-level orthogonal test with the tensile strength and ultrasound image quality of the hydrogel pads as evaluation indicators. The optimal prescription was selected by optimizing three factors of raw material ratio, polymerization temperature, and freeze-drying time. The structure and performance of the hydrogel pads were characterized by a scanning electron microscope, a universal testing machine, and an ultrasonic diagnostic instrument. The results showed that the optimal prescription was as follows: the chitosan: 2-acrylamide-2-methylpropanesulfonic acid: N-isopropylacrylamide ratio of 2:0.55:17.27, the polymerization temperature of 25 ℃, and the freeze-drying time of 48 h. The ultrasonically-coupled hydrogel pads prepared under these conditions were transparent, with a porous structure, good adhesion, and high tensile strength. The hydrogel pads had good swelling properties and the swelling degree decreased slowly on day 10. The quality of the ultrasound images obtained via chitosan-based hydrogel pads was not significantly different from that obtained via medical ultrasound coupling agent. In this study, we analyzed the effects of different preparation processes on the gel formation of chitosan-based ultrasound-coupled hydrogel pads. The hydrogel pads were transparent and mild and non-irritating to the human body, serving as an ultrasound transmission material for ultrasonography.
Chitosan/chemistry* ; Hydrogels/chemistry* ; Acrylamides/chemistry* ; Ultrasonography ; Polymerization ; Sulfonic Acids/chemistry* ; Alkanesulfonates/chemistry* ; Tensile Strength ; Freeze Drying ; Temperature

OBJECTIVETo identify the free radical scavenging activity of ethanolic extract of Evolvulus alsinoides.

METHODSThe free radical scavenging activity was evaluated by in vitro methods like reducing power assay, total antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) reduction, superoxide radical scavenging activity, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)) scavenging activity, hydroxyl radical scavenging assay, and nitric oxide radical scavenging assay, which were studied by using ascorbic acid as standard.

RESULTSThe extract showed significant activities in all antioxidant assays compared with the reference antioxidant ascorbic acid. The total antioxidant activity as well as the reducing power was also found to increase in a dose-dependent manner.

CONCLUSIONEvolvulus alsinoides may act as a chemopreventive agent, providing antioxidant properties and offering effective protection from free radicals.

Antioxidants ; chemistry ; Benzothiazoles ; chemistry ; Biphenyl Compounds ; chemistry ; Convolvulaceae ; chemistry ; Ethanol ; chemistry ; Free Radical Scavengers ; chemistry ; Hydroxyl Radical ; chemistry ; Nitric Oxide ; chemistry ; Oxidation-Reduction ; drug effects ; Picrates ; chemistry ; Plant Extracts ; chemistry ; Sulfonic Acids ; chemistry ; Superoxides ; chemistry

Tibetan medicinal plants have been used for more than 2 000 years. In order to find their differences in antioxidant activity, total phenolics and total flavonoids between "hot-nature" and "cold-nature" herbs, we investigated the antioxidant activities of 40 Tibetan herbs from Qinghai plateau, with 20 herbs in cold-nature and 20 herbs in hot-nature. Antioxidant capacities were evaluated by the following methods: scavenging ABTS•(+) (2, 2'azinobis-(3-ethylbenz-thiazoline-6-sulfonic acid), scavenging O2•(-), and Ferric-reducing antioxidant power (FRAP). The effects on inhibition of mitochondrion lipid peroxidation were determined by measuring the formation of TBARS (Thiobarbituric acid reactive substrates). Total phenolics and flavonoids were estimated by Folin-Ciocalteu and NaNO2-Al(NO3)3-NaOH colorimetric methods. Interestingly, the cold-nature herbs displayed higher antioxidant activities than the hot-nature ones, corresponding to nearly three-fold higher total phenolic contents in the cold-nature herbs. Moreover, the antioxidant activities correlated linearly with the levels of total phenolics for both cold-nature and hot-nature herbs, but only with the levels of total flavonoids for the hot-nature herbs. The results suggested that the phenolic compounds, but not the flavonoids, play the major role in antioxidant capacities of the cold-nature herbs. These findings could shed new lights on the study the theory of Tibetan medicine.
Antioxidants ; pharmacology ; Benzothiazoles ; metabolism ; Cold Temperature ; Flavonoids ; analysis ; pharmacology ; Hot Temperature ; Humans ; Lipid Peroxidation ; drug effects ; Magnoliopsida ; chemistry ; Medicine, East Asian Traditional ; Mitochondria ; metabolism ; Oxidation-Reduction ; Phenols ; analysis ; pharmacology ; Plant Extracts ; chemistry ; classification ; pharmacology ; Plants, Medicinal ; chemistry ; Sulfonic Acids ; metabolism ; Tibet

Bio-active components from Carthamus tinctorius were separated on the basis of antioxidant capacities in vitro. The antioxidant capacity was investigated on the basis of the ability to scavenge DPPH radical, ABTS radical and reduce Fe3+ of different polar fractions. Furthermore, the chemical compounds were isolated from bio-active fraction, and were evaluated for the antioxidative effects. Five major components were isolated and identified from water extract as 6-hydroxykaempferol 3,6,7-tri-O-β-D-glucoside(1), 6-hydroxykaempferol 3-O-β-rutinoside-6-O-β-D-glucoside (2), 6-hydroxykaempferol 3-O-β-D-glucoside (3), hydroxysafflor yellow A (4) and anhydrosafflor yellow B (5). By evaluating and comparing the antioxidative effects of different fractions and obtained compounds, the results showed that water extract displayed significantly high antioxidative activities and 6-hydroxykaempferol glycosides and quinochalcone C-glycosides were found as main contribution for antioxidant property.
Antioxidants ; isolation & purification ; metabolism ; pharmacology ; Benzothiazoles ; metabolism ; Biphenyl Compounds ; metabolism ; Carthamus tinctorius ; chemistry ; Chalcone ; analogs & derivatives ; isolation & purification ; metabolism ; pharmacology ; Ferric Compounds ; metabolism ; Free Radicals ; metabolism ; Kaempferols ; isolation & purification ; metabolism ; pharmacology ; Oxidation-Reduction ; drug effects ; Picrates ; metabolism ; Plant Extracts ; isolation & purification ; metabolism ; pharmacology ; Plants, Medicinal ; chemistry ; Quinones ; isolation & purification ; metabolism ; pharmacology ; Sulfonic Acids ; metabolism ; Water ; chemistry

AIM: The aqueous methanolic extracts of two plants from Algeria, Helichrysum stoechas subsp. rupestre and Phagnalon saxatile subsp. saxatile, were investigated for their antioxidant activity. METHOD: Total phenolics, flavonoids, and tannins were determined by spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined by spectrophotometric methods, through: Total antioxidant capacity, and radical scavenging effects by the DPPH and ABTS methods, reducing and chelating power, and blanching inhibition of the β-carotene. RESULTS: All of the extracts showed interesting antioxidant and radical scavenging activity. The highest contents in phenolics, tannins, and the highest total antioxidant capacity as gallic acid equivalents of 97.5 ± 0.33 mg GAE/g DW was obtained for the flowers of H. stoechas subsp. rupestre extract in the phosphomolybdenum assay. An extract of the leafy stems of P. saxatile subsp. saxatile revealed the highest content of flavonoids, and the highest antioxidant activity by the radical scavenging and β-carotene assays when compared with standards. The best activity was by the scavenging radical DPPH with an IC50 value of 5.65 ± 0.10 μg·mL(-1). CONCLUSION The studied medicinal plants could provide scientific evidence for some traditional uses in the treatment of diseases related to the production of reactive oxygen species (ROS) and oxidative stress.
Algeria ; Antioxidants ; analysis ; pharmacology ; Asteraceae ; chemistry ; Benzothiazoles ; metabolism ; Biphenyl Compounds ; metabolism ; Flavonoids ; analysis ; pharmacology ; Helichrysum ; chemistry ; Oxidative Stress ; drug effects ; Phenols ; analysis ; pharmacology ; Picrates ; metabolism ; Plant Extracts ; chemistry ; pharmacology ; Plant Structures ; chemistry ; Spectrophotometry ; methods ; Sulfonic Acids ; metabolism ; Tannins ; analysis ; pharmacology

SHG was sulfated by chlorosulfonic acid-pyridine method, and six samples which we got were prepared in different reaction conditions. There is a characteristic absorption peak near 260 nm in UV spectra and there are two characteristic absorption peaks near 1240 cm(-1) and 810 cm(-1) in the FT-IR. Degree of sulfation (DS) was calculated by elemental analysis and turbidimetry. Under the same conditions the absorption peaks become strong with the DS increase. The anticoagulant activity of SHG and sulfated modification samples was evaluated by the classic coagulant assays of prothrombin time (PT), activated partial thrombin time (APTT) live enzymes, and plasma thrombin time (TT). Results show that sulfated SHG has a good anticoagulant activity in vitro, and DS increased activity within a certain range.
Animals ; Anticoagulants ; chemistry ; isolation & purification ; pharmacology ; Blood Coagulation Tests ; Fabaceae ; chemistry ; Glucans ; chemistry ; isolation & purification ; pharmacology ; Partial Thromboplastin Time ; Plants, Medicinal ; chemistry ; Prothrombin Time ; Rabbits ; Spectrophotometry, Ultraviolet ; Spectroscopy, Fourier Transform Infrared ; Sulfonic Acids ; chemistry ; Thrombin Time

OBJECTIVETo evaluate the hemocompatibility of a small-caliber expanded polytetrafluoroethylene vessel with silk fibroin coating sulfonated by low temperature plasma treatment.

METHODSThe composite blood vessel was prepared by first coating the small-caliber expanded polytetrafluoroethylene vessel with silk fibroin followed by sulfonation by low temperature plasma treatment. After hemolysis test in vitro, dynamic coagulation time test, blood platelet adhesion test, and recalcification time test were performed to evaluate the hemocompatibility of the composite blood vessel.

RESULTSScanning electronic microscopy revealed obvious platelets adhesion on the conventional artificial (control) vessel, which seldom occurred on the composite vessel. The curve of absorbance-clotting time of the composite vessel declined more slowly than that of the control vessel. The recalcification time of the composite blood vessel averaged 603 s, significantly longer than that of the control vessel (480 s, P = 0.000).

CONCLUSIONThe composite blood vessel has good antithrombotic activity and hemocompatibility as a promising vascular prosthesis.

Blood Vessel Prosthesis ; Coated Materials, Biocompatible ; chemistry ; Cold Temperature ; Fibroins ; chemistry ; Humans ; Materials Testing ; Plasma Gases ; Polytetrafluoroethylene ; chemistry ; Sulfonic Acids ; chemistry