BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to h...BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; Department of Physiology, Medical College, Datong University. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking University from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared between the model group and control group. RESULTS: The S and τc in the model group [0.738 4±0.003 5; (8.472±0.027)×10-10 s/circle] were obviously different from those in the control group [0.683 9±0.008 3; (7.945±0.082)×10-10 s/circle, t =5.731, 5.918, P < 0.05], which suggested that ischemia/reperfusion injury decreased the fluidity of brain cell membrane. After adding Chuanxiongqin hydrochloride, there were no obvious differences between the model group [0.688 5±0.030 5; (7.886±0.341)×10-10 s/circle] and control group (P > 0.05), indicating that Chuanxiongqin hydrochloride could recover the fluidity of brain cell membrane after ischemia/reperfusion injury close to the level in the normal control group. Chuanxiongqin hydrochloride could directly scavenge the O2 · and OH· free radicals, and the maximal clearance rates were 83.92% and 44.99% respectively. CONCLUSION: Chuanxiongqin hydrochloride increases the fluidity of membrane of ischemia-injured brain cell by scavenging both O2 ·and OH· free radicals.展开更多
In this work, Bioactive-functionalized interpenetrating network (IPNs) hydrogel (BIOF-INPs) were prepared and investigated in vitro for the free radical detection/defense, therapeutic release as well as shear bond str...In this work, Bioactive-functionalized interpenetrating network (IPNs) hydrogel (BIOF-INPs) were prepared and investigated in vitro for the free radical detection/defense, therapeutic release as well as shear bond strength to dentine, ability to re-mineralize surface of the dentin after application of these bio-inspired materials using a biologically inspired mineralization process in vitro as well as investigating antimicrobial properties of the BIOF-INPs against S. aureous. The aim of this investigation was to evaluate the suitability and flexibility of the designer materials to act as an “in vitro” probe to gain insights into molecular origin of TMD and associated disorders.展开更多
The present paper reviews new findings in redoxproperties of the active constituent of Chinese herbalmedicine(CHM),a kind of CHM or a compoundprescription as an antioxidant.Firstly,we have studiedtheir antioxidant and...The present paper reviews new findings in redoxproperties of the active constituent of Chinese herbalmedicine(CHM),a kind of CHM or a compoundprescription as an antioxidant.Firstly,we have studiedtheir antioxidant and prooxidant actions with electronspin resonance(ESR).The results show that the activecomponents from over 10 kinds of CHM are able toscavenge the oxygen free radicals but propyl gallate展开更多
Objective: To elucidate the anxiolytic and free radical scavenging effect of methanolic extract of Apium graveolens(A. graveolens) in adult C57BL/6 mice.Methods: Sixty male mice were divided into 6 groups: control, ve...Objective: To elucidate the anxiolytic and free radical scavenging effect of methanolic extract of Apium graveolens(A. graveolens) in adult C57BL/6 mice.Methods: Sixty male mice were divided into 6 groups: control, vehicle, positive control and A. graveolens(125, 250 and 500 mg/kg). Different behavioral models of elevated plus maze, open field, light/dark, hole-board and pentobarbital-induced sleep were used to assess anxiety-like behavior. Biochemical parameters including monoamine oxidase-A(MAO-A) activity, lipid peroxidation, % inhibition of superoxide anion and glutathione peroxidase activity were measured. Histologic studies were also examined.Results: Mice receiving various doses of A. graveolens(125, 250 and 500 mg/kg)showed an alleviation of anxiety-like behavior as evidenced by the battery of behavioral tests. Likewise, A. graveolens treatment was found to significantly decrease MAO-A activity, lipid peroxidation as well as cause a significant increase of % inhibition of superoxide anion and glutathione peroxidase activity in both cortex and striatum. The total number of survival neurons found in the frontal cortex and striatum was significantly higher than that of the vehicle-treated group.Conclusions: Taken together, we showed that A. graveolens improve the behavioral changes which might be related to the inhibition of free radicals and modulation of MAOA activity resulting in an increased number of survival neurons. Our findings suggest the therapeutic potential of A. graveolens in the treatment of anxiety.展开更多
The static O-H bond parameters including O-H bond length, O-H charge difference, O-H Mulliken population and O-H bond stretching force constant (k) for 17 phenols were calculated by ab initio method HF/6-31G**. In com...The static O-H bond parameters including O-H bond length, O-H charge difference, O-H Mulliken population and O-H bond stretching force constant (k) for 17 phenols were calculated by ab initio method HF/6-31G**. In combination with the O-H bond dissociation enthalpies (BDE) of the phenols determined by experiment, it was found that there were poor correlationships between the static O-H bond parameters and O-H BDE. Considering the good correlationship bt tween O-H BDE and logarithm of free radical scavenging rate constant for phenolic antioxidant, it is reasonable to believe that the ineffectiveness of static O-H bond parameters in characterizing antioxidant activity arises from the fact that they cannot measure the O-H BDE.展开更多
This paper describes the synthesis and free radical ring-opening polymerization of 2-methyl-and 2-methyl-9-n-butyl (-7-methylene-1, 4, 6-trioxaspiro (4, 4) nonane). The structures of the two polymers were verified by ...This paper describes the synthesis and free radical ring-opening polymerization of 2-methyl-and 2-methyl-9-n-butyl (-7-methylene-1, 4, 6-trioxaspiro (4, 4) nonane). The structures of the two polymers were verified by IR, 'H and ^(13)C NMR spectra. The substituent on 9-position of 7-methylene-trioxaspiro (4, 4) nonane affects the structure of polymer and polymerization activity. The polymerization mechanism is discussed.展开更多
[Objectives]To study the antioxidant and hypoglycemic effects of different parts of Ardisia gigantifolia Stapf.[Methods]The hydroxyl radical scavenging activity,DPPH radical scavenging activity and total antioxidant c...[Objectives]To study the antioxidant and hypoglycemic effects of different parts of Ardisia gigantifolia Stapf.[Methods]The hydroxyl radical scavenging activity,DPPH radical scavenging activity and total antioxidant capacity of ABTS of 75%ethanol extract of A.gigantifolia Stapf and the petroleum ether,ethyl acetate,n-butanol,chloroform and aqueous extract were measured with Vc as positive control.At the same time,acarbose was used as reference substance to determine the inhibitory effect of each polar site onα-glucosidase.[Results]All parts of A.gigantifolia Stapf had antioxidant activity,among which ethyl acetate had the strongest antioxidant activity,and the scavenging rate of hydroxyl radical and DPPH radical was higher than that of positive control.The results showed that petroleum ether,ethyl acetate and chloroform had a good inhibitory effect onα-glucosidase(better than acarbose).[Conclusions]The ethyl acetate part of A.gigantifolia Stapf had the best antioxidant activity and inhibitory effect onα-glucosidase.It provides a basis for further research and development of A.gigantifolia Stapf.展开更多
Effects of 4-(1,3-diphenyl-1H-pyrazol-5-yl)phenol(APP),4-(1,5-diphenyl-lH-pyrazol-3-yl)phenol(BPP) and 4-(3,5-diphenyl-1H-pyrazol-1-yl)phenol(CPP) on 2,2'-azobis-(2-amidinopropane hydrochloride)(AAPH)...Effects of 4-(1,3-diphenyl-1H-pyrazol-5-yl)phenol(APP),4-(1,5-diphenyl-lH-pyrazol-3-yl)phenol(BPP) and 4-(3,5-diphenyl-1H-pyrazol-1-yl)phenol(CPP) on 2,2'-azobis-(2-amidinopropane hydrochloride)(AAPH)-induced oxidation of DNA were measured in the presence of various concentrations of Triton X-100,cetyltrimethylammonium bromide(CTAB),or sodium dodecyl sulfate(SDS) in order to clarify the influence of neutral,cationic and anionic microenvironments on antioxidant capacities of APP,BPP and CPP.Although these surfactants can protect DNA against AAPH-induced oxidation,the pyrazoles in the presence of these surfactants functioned as prooxidants when the concentrations of Triton X-100 and CTAB increased.However,CPP exhibited antioxidant property with the increase of the concentration of CTAB.On the contrary,APP,BPP and CPP were antioxidants in the presence of various concentrations of SDS.The added surfactants resulted in the complication of the microenvironments around DNA,pyrazoles and peroxyl radical(ROO*) derived from AAPH.The anionic charge of SDS was beneficial to enhancing the antioxidant effectiveness of these pyrazoles.It can be concluded that the charge property of surfactants markedly influenced the behavior of an antioxidant in AAPH-induced oxidation of DNA.展开更多
文摘BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; Department of Physiology, Medical College, Datong University. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking University from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared between the model group and control group. RESULTS: The S and τc in the model group [0.738 4±0.003 5; (8.472±0.027)×10-10 s/circle] were obviously different from those in the control group [0.683 9±0.008 3; (7.945±0.082)×10-10 s/circle, t =5.731, 5.918, P < 0.05], which suggested that ischemia/reperfusion injury decreased the fluidity of brain cell membrane. After adding Chuanxiongqin hydrochloride, there were no obvious differences between the model group [0.688 5±0.030 5; (7.886±0.341)×10-10 s/circle] and control group (P > 0.05), indicating that Chuanxiongqin hydrochloride could recover the fluidity of brain cell membrane after ischemia/reperfusion injury close to the level in the normal control group. Chuanxiongqin hydrochloride could directly scavenge the O2 · and OH· free radicals, and the maximal clearance rates were 83.92% and 44.99% respectively. CONCLUSION: Chuanxiongqin hydrochloride increases the fluidity of membrane of ischemia-injured brain cell by scavenging both O2 ·and OH· free radicals.
文摘In this work, Bioactive-functionalized interpenetrating network (IPNs) hydrogel (BIOF-INPs) were prepared and investigated in vitro for the free radical detection/defense, therapeutic release as well as shear bond strength to dentine, ability to re-mineralize surface of the dentin after application of these bio-inspired materials using a biologically inspired mineralization process in vitro as well as investigating antimicrobial properties of the BIOF-INPs against S. aureous. The aim of this investigation was to evaluate the suitability and flexibility of the designer materials to act as an “in vitro” probe to gain insights into molecular origin of TMD and associated disorders.
文摘The present paper reviews new findings in redoxproperties of the active constituent of Chinese herbalmedicine(CHM),a kind of CHM or a compoundprescription as an antioxidant.Firstly,we have studiedtheir antioxidant and prooxidant actions with electronspin resonance(ESR).The results show that the activecomponents from over 10 kinds of CHM are able toscavenge the oxygen free radicals but propyl gallate
基金Supported by grant from the General Project and Invention of Prince of Songkla University(SCI570371S)BRAND's Brain Research Centre,Bangkok,Thailand
文摘Objective: To elucidate the anxiolytic and free radical scavenging effect of methanolic extract of Apium graveolens(A. graveolens) in adult C57BL/6 mice.Methods: Sixty male mice were divided into 6 groups: control, vehicle, positive control and A. graveolens(125, 250 and 500 mg/kg). Different behavioral models of elevated plus maze, open field, light/dark, hole-board and pentobarbital-induced sleep were used to assess anxiety-like behavior. Biochemical parameters including monoamine oxidase-A(MAO-A) activity, lipid peroxidation, % inhibition of superoxide anion and glutathione peroxidase activity were measured. Histologic studies were also examined.Results: Mice receiving various doses of A. graveolens(125, 250 and 500 mg/kg)showed an alleviation of anxiety-like behavior as evidenced by the battery of behavioral tests. Likewise, A. graveolens treatment was found to significantly decrease MAO-A activity, lipid peroxidation as well as cause a significant increase of % inhibition of superoxide anion and glutathione peroxidase activity in both cortex and striatum. The total number of survival neurons found in the frontal cortex and striatum was significantly higher than that of the vehicle-treated group.Conclusions: Taken together, we showed that A. graveolens improve the behavioral changes which might be related to the inhibition of free radicals and modulation of MAOA activity resulting in an increased number of survival neurons. Our findings suggest the therapeutic potential of A. graveolens in the treatment of anxiety.
文摘The static O-H bond parameters including O-H bond length, O-H charge difference, O-H Mulliken population and O-H bond stretching force constant (k) for 17 phenols were calculated by ab initio method HF/6-31G**. In combination with the O-H bond dissociation enthalpies (BDE) of the phenols determined by experiment, it was found that there were poor correlationships between the static O-H bond parameters and O-H BDE. Considering the good correlationship bt tween O-H BDE and logarithm of free radical scavenging rate constant for phenolic antioxidant, it is reasonable to believe that the ineffectiveness of static O-H bond parameters in characterizing antioxidant activity arises from the fact that they cannot measure the O-H BDE.
基金Supported by National Natural Science Foundation of China
文摘This paper describes the synthesis and free radical ring-opening polymerization of 2-methyl-and 2-methyl-9-n-butyl (-7-methylene-1, 4, 6-trioxaspiro (4, 4) nonane). The structures of the two polymers were verified by IR, 'H and ^(13)C NMR spectra. The substituent on 9-position of 7-methylene-trioxaspiro (4, 4) nonane affects the structure of polymer and polymerization activity. The polymerization mechanism is discussed.
基金Supported by Guilin Scientific Research and Technology Development Plan Project(2020011203-2)Guangxi Science and Technology Major Project(GuiKe AA22096020)+2 种基金Guilin Scientific Research and Technology Development Plan Project(20220104-4,20210202-1,2020011203-1)Open Project of Guangxi Key Laboratory of Cancer Immunology and Microenvironment Regulation(2022KF005)Central Fund for Guiding Local Science and Technology Development(ZY20230102).
文摘[Objectives]To study the antioxidant and hypoglycemic effects of different parts of Ardisia gigantifolia Stapf.[Methods]The hydroxyl radical scavenging activity,DPPH radical scavenging activity and total antioxidant capacity of ABTS of 75%ethanol extract of A.gigantifolia Stapf and the petroleum ether,ethyl acetate,n-butanol,chloroform and aqueous extract were measured with Vc as positive control.At the same time,acarbose was used as reference substance to determine the inhibitory effect of each polar site onα-glucosidase.[Results]All parts of A.gigantifolia Stapf had antioxidant activity,among which ethyl acetate had the strongest antioxidant activity,and the scavenging rate of hydroxyl radical and DPPH radical was higher than that of positive control.The results showed that petroleum ether,ethyl acetate and chloroform had a good inhibitory effect onα-glucosidase(better than acarbose).[Conclusions]The ethyl acetate part of A.gigantifolia Stapf had the best antioxidant activity and inhibitory effect onα-glucosidase.It provides a basis for further research and development of A.gigantifolia Stapf.
文摘Effects of 4-(1,3-diphenyl-1H-pyrazol-5-yl)phenol(APP),4-(1,5-diphenyl-lH-pyrazol-3-yl)phenol(BPP) and 4-(3,5-diphenyl-1H-pyrazol-1-yl)phenol(CPP) on 2,2'-azobis-(2-amidinopropane hydrochloride)(AAPH)-induced oxidation of DNA were measured in the presence of various concentrations of Triton X-100,cetyltrimethylammonium bromide(CTAB),or sodium dodecyl sulfate(SDS) in order to clarify the influence of neutral,cationic and anionic microenvironments on antioxidant capacities of APP,BPP and CPP.Although these surfactants can protect DNA against AAPH-induced oxidation,the pyrazoles in the presence of these surfactants functioned as prooxidants when the concentrations of Triton X-100 and CTAB increased.However,CPP exhibited antioxidant property with the increase of the concentration of CTAB.On the contrary,APP,BPP and CPP were antioxidants in the presence of various concentrations of SDS.The added surfactants resulted in the complication of the microenvironments around DNA,pyrazoles and peroxyl radical(ROO*) derived from AAPH.The anionic charge of SDS was beneficial to enhancing the antioxidant effectiveness of these pyrazoles.It can be concluded that the charge property of surfactants markedly influenced the behavior of an antioxidant in AAPH-induced oxidation of DNA.