OBJECTIVETo evaluate the antioxidant activities of different chemical constituents from Astragalus mongholicus Bunge and their protection against xanthine (XA)/xanthine oxidase (XO)-induced toxicity in PC12 cells.

METHODSThe compounds of Astragalus mongholicus Bunge were isolated by chromatography and the structures were elucidated on the basis of spectral data interpretation. Their antioxidant activities were detected by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities in a cell-free system. Meanwhile, the effects against XA/XO-induced toxicity were assessed using MTT assay in PC12 cells.

RESULTSTen principal constituents were isolated and identified as formononetin (I), ononin (II), calycosin (III), calycosin-7-O-beta-D-glucoside (IV), 9,10-dimethoxypterocarpan-3-O-beta-D-glucoside (V), adenosine (VI), pinitol (VII), daucosterol (VIII), beta-sitoster (IX) and saccharose (X) from Astragalus mongholicus Bunge. The compounds I, III, and IV scavenged DPPH free radicals in vitro. Formononetin and calycosin were found to inhibit XA/XO-induced cell injury significantly, with an estimated EC50 of 50 ng/mL.

CONCLUSIONCompound II, VI, and VII are first reported in this plant. Calycosin exhibits the most potent antioxidant activity both in the cell-free system and in the cell system.

Animals ; Astragalus Plant ; chemistry ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Free Radical Scavengers ; chemistry ; pharmacology ; Free Radicals ; metabolism ; Isoflavones ; chemistry ; pharmacology ; PC12 Cells ; Rats ; Xanthine ; toxicity ; Xanthine Oxidase ; toxicity

OBJECTIVETo explore the effect of deltamethrin (DM) on production of free radical and transcription factor Nrf2 in rats' brain tissue.

METHODS8 male rats were randomly assigned to four groups and administered with 1% W/W tertiary butylhydroquinone (tBHQ) or olive oil for 3 days, prior to exposure to DM and then with 12.50 mg or 0mg DM/Kg BW for 5 days. The level of free radical in rats' hippocampus tissue was detected by electron spin resonance (ESR) spectroscopy. 18 male rats were randomly assigned to three groups and administered with i.p. (daily dose was respectively 0, 3.13, 12.50 mg/kg DM) for five days. After treatment, Nrf2 protein levels in the cytoplasmic and nuclear fractions of both cerebral cortex and hippocampus tissue were measured by western blot.

RESULTSThe level of free radical in hippocampus tissue of rats administered by DM and pretreatment with tBHQ prior to DM were increased to a 2.45-fold and 2.97-fold of values of control group, respectively (P < 0.05). Nrf2 protein levels in the cytoplasmic fractions of cerebral cortex of both low and high dose group were significantly increased, 1.68- fold and 1.34- fold of values of control group, respectively. Nrf2 protein levels in the nuclear fractions of cerebral cortex of both low and high dose group were increased in a dose- dependent model, 1.51-fold and 2.29-fold of values of control group, respectively (P < 0.01). Nrf2 protein levels in the cytoplasmic fractions of hippocampus tissue of both low and high dose group were increased in a dose- dependent model, 2.26-fold and 3.58-fold of values of control group, respectively. Nrf2 protein levels in the nuclear fractions of hippocampus tissue of both low and high dose group were increased, 2.42-fold and 2.45-fold of values of control group, respectively (P < 0.01).

CONCLUSIONThe studies in vivo demonstrate that DM treatment could induce free radical production and expression of Nrf2 protein in both cerebral cortex and hippocampus tissue and activate Nrf2.

Animals ; Brain ; drug effects ; metabolism ; Free Radicals ; metabolism ; Male ; NF-E2-Related Factor 2 ; metabolism ; Nitriles ; toxicity ; Pyrethrins ; toxicity ; Rats ; Rats, Sprague-Dawley

BACKGROUND: Pulmonary damage resulting from lipid peroxidation is a principal effect of paraquat intoxication. The host-defense functions of surfactant are known to be mediated by the surfactant proteins A and D (SP-A and SP-D, respectively). The primary objective of this study was to evaluate the variations over time in levels of surfactant protein and lipid peroxidation (LPO) in lung tissue following free-radical-induced injury. METHODS: 42 adult, male, Sprague-Dawley rats were administered intraperitoneal injections of paraquat (35 mg/kg body weight). SP-A and SP-D levels were determined via Western blot. LPO in the left lung homogenate was measured via analyses of the levels of thiobarbituric acid-reactive substances. RESULTS: LPO levels peaked at 6 hours, with no associated histological changes. SP-D levels increased until hour 12 and declined until hour 48; SP-D levels subsequently began to increase again, peaking at hour 72. SP-A levels peaked at hour 6, declining thereafter. CONCLUSIONS: We suggest that in the early phase of paraquat injury, SP-D levels reflect alveolar damage and that de novo synthesis of SP-D takes 72 hours. Levels of SP-A, on the other hand, reflect abnormalities in the surfactant system in the late stage of paraquat intoxication. Surfactant proteins may play a role in protecting the lungs from reactive oxygen injury. A time-dependent variation has been observed in the levels of surfactant proteins A and D following paraquat injury, and it has been suggested that these proteins play a role in the protection of lung tissue against ROS-induced injuries.
Animals ; Free Radicals/*toxicity ; Herbicides/*toxicity ; *Lipid Peroxidation ; Lung/*drug effects ; Male ; Paraquat/*toxicity ; Pulmonary Surfactant-Associated Proteins/*analysis ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species/toxicity ; Respiratory Distress Syndrome, Adult/*chemically induced

OBJECTIVETo investigate the antioxidant and cytotoxic properties of five diarylheptanoids (1-5) isolated from the rhizomes of Zingiber officinale.

METHODVarious models such as scavenging superoxide anions and 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals, inhibiting lipid peroxidation, as well as protecting of rat pheochromocytoma (PC12) cells induced by hydrogen peroxide (H2O2) were employed to assay the antioxidative effects of the diarylheptanoids. The cytotoxicities of compounds 1-5 were measured with MTT assays.

RESULTThe test compounds (1-5) showed promising DPPH inhibitory activities, and compound 5 exhibited the strongest DPPH scavenging activity with an IC50 value of (22.6+/-2.4) micromol x L(-1). Compounds 1, 3 and 4 showed potential anti-peroxidative effects with inhibitory rates of (66.3+/-15.4)%, (68.7+/-15.8)% and (72.2+/-10.6)%, respectively, at 100 microg x mL(-1). It could be observed that compounds 1, 3 and 4 demonstrated significant neuroprotective activities in a dose-dependent manner. Moreover, compound 3 exhibited certain cytotoxicities against human chronic myelogenous leukemia cells (K562) and its adriamycin-resistant cells (K562/ADR) with IC50 values of (34.9+/-0.6), (50.6+/-23.5) micromol x L(-1), respectively.

CONCLUSIONIn vitro results demonstrated that five diarylheptanoids (1-5) isolated from the roots of Z. officinale were capable of scavenging radicals, inhibiting lipid peroxidation and protecting PC12 cells against the insult by H2O2. Additionally, compound 3 could inhibit the growth of K562 and K562/ADR cells.

Animals ; Antioxidants ; toxicity ; Cell Proliferation ; drug effects ; Cytotoxins ; toxicity ; Diarylheptanoids ; isolation & purification ; metabolism ; toxicity ; Free Radicals ; metabolism ; Ginger ; chemistry ; Humans ; Hydrogen Peroxide ; metabolism ; K562 Cells ; Oils, Volatile ; pharmacology ; PC12 Cells ; Rats ; Rats, Sprague-Dawley

BACKGROUNDRecent studies have revealed the important role of free radicals in renal damage induced by high-energy shock waves (HESW). This study aimed at investigating the effects of Astragalus membranaceus, a traditional Chinese medicinal herb, on free radical-mediated HESW-induced damage to renal tubules in a live rabbit model.

METHODSForty-five healthy male New Zealand white rabbits were randomly divided into three groups: control group (n = 15), sham group (n = 15), and herb-treated group (n = 15). Three days prior to HESW application, the controls received verapamil (0.4 mg/kg), the shams received physiological saline (20 ml), and the herb-treated animals received Astragalus membranaceus (2.4 g/kg) intravenously. HESW (1500 shocks, 18 kV) was applied to the right kidneys of all anesthetized rabbits. We measured superoxide dismutase (SOD) and malondialdehyde (MDA) levels before and after shock treatment in blood and kidney homogenates. Histopathological changes were also observed.

RESULTSMDA levels increased and SOD activity decreased significantly in the sham group (P < 0.05 for both) after shock treatment. MDA levels showed a much less increase in the controls (P < 0.05) and did not increase to statistically significant levels in the group receiving Astragalus membranaceus (P > 0.05). SOD values were significantly higher in the controls than in the shams (P < 0.05). By contrast, SOD levels recovered rapidly in the rabbits receiving Astragalus membranaceus, reaching a nadir within 24 hours, and returning to baseline more quickly than in control and sham rabbits (P < 0.05). Histopathological examinations showed that renal tubular damage in the controls was less severe than in the shams, while damage in the Astragalus membranaceus group was even more mild, with rapid recovery in comparison with the controls.

CONCLUSIONThis study provides preliminary evidence indicating that Astragalus membranaceus has strong protective effects on free radical-mediated renal tubular damage induced by HESW and that these effects are superior to the effects of verapamil.

Animals ; Astragalus membranaceus ; Free Radicals ; toxicity ; High-Energy Shock Waves ; adverse effects ; Kidney Tubules ; drug effects ; pathology ; Male ; Malondialdehyde ; blood ; Phytotherapy ; Rabbits ; Superoxide Dismutase ; blood ; Verapamil ; pharmacology

AIMTo investigate the effects of injectio Salvia Miltiorrhiza (SM) on gentamicin (GM)-induced free radical formation in guinea pig cochlea, and to explore possible mechanisms on GM-induced ototoxicity.

METHODSBiochemical assays of superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in guinea pig cochlea, combined with auditory brainstem response (ABR) measurement and transmission electron microscopic observation were used in this investigation.

RESULTSSOD activity was significantly declined while MDA content was distinctly increased in cochlear tissues after GM injection (P < 0.01). Moreover, they were well correlated with auditory function damage (|r| > 0.7). Co-treatment with SM evidently enhanced SOD activity and decreased MDA content (P < 0.01, P < 0.05). Furthermore, auditory function was markedly ameliorated. Morphological changes of cochlea were consistent with those of hearing function.

CONCLUSIONLipid peroxidation elicited by free radical was involved in GM-induced cochleotoxicity. SM might enhance SOD activity and prevent lipid peroxidation. As the result it might alleviate GM ototoxicity, and improve auditory function.

Animals ; Cochlea ; drug effects ; metabolism ; Free Radicals ; metabolism ; Gentamicins ; toxicity ; Guinea Pigs ; Lipid Peroxidation ; Malondialdehyde ; analysis ; Salvia miltiorrhiza ; Superoxide Dismutase ; metabolism

OBJECTIVETo investigate protective effects of hHSS transfection against CCl4 or H2O2.

METHODScDNA coding for hHSS was constructed into eukaryotic vector of pcDNA3.1 and transfected into BEL-7402 hepatoma cells. The expression of hHSS was analyzed with Northern blot.

RESULTSThe growth of the hepatoma cells was remarkably enhanced 24 to 144h after hHSS gene transfection, which suggesting hHSS gene expression could stimulate cells activity. Meantime, incubation of both wild-type and vector-transfected as well as hHSS-transfected cells with CCl4 or H2O2 resulted in severe damage as marked by cell mortality and the rate of apoptosis. However, it appeared that the transfection of hHSS enabled the hepatoma cells to raise obvious resistance against CCl4 and H2O2 injury. Compared the vector cells to the vector-transfected cells, apoptosis ratio were (32.44+/-0.52)% and (25.60+/-0.66)% in which treated with CCl4, while (47.78+/-0.45)% and (37.40+/-0.69)% in which treated with H2O2, t value is 16.82 and 25.20, P<0.01. MAPK phosphorylation was also activated after HSS transfected.

CONCLUSIONThe function of hHSS gene expression could be related to proliferation of cell and protection against free radical damage.

Apoptosis ; drug effects ; Carbon Tetrachloride ; toxicity ; Cytoprotection ; Free Radicals ; Growth Substances ; genetics ; physiology ; Humans ; Hydrogen Peroxide ; toxicity ; Liver Neoplasms ; pathology ; Mitogen-Activated Protein Kinases ; metabolism ; Peptides ; genetics ; physiology ; Phosphorylation ; RNA, Messenger ; analysis ; Transfection

OBJECTIVETo investigate the toxicity of cigarette smoke extract (CSE) and nicotine on mouse brain mitochondria as well as the protective effect of vitamin C in vitro.

METHODMouse brain mitochondria in vitro was incubated with CSE or nicotine in the absence or presence of vitamin C for 60 minutes, and the changes of mitochondrial function and structure were measured.

RESULTSCSE inhibited mitochondrial ATPase and cytochrome C oxidase activities in a dose-dependent manner. However, no significant changes in the peroxidation indices were observed when mitochondrial respiratory enzymes activity was inhibited, and protection of mitochondria from CSE-induced injury by vitamin C was not displayed in vitro. The effect of CSE on mouse brain mitochondria swelling response to calcium stimulation was dependent on calcium concentrations. CSE inhibited swelling of mitochondria at 6.5 mumol/L Ca2+, but promoted swelling response at 250 mumol/L Ca2+. Nicotine, the major component of cigarette smoke, showed no significant damage in mouse brain mitochondria in vitro. The CSE treatment induced mitochondrial inner membrane damage and vacuolization of the matrix, whereas the outer mitochondrial membrane appeared to be preserved.

CONCLUSIONThe toxic effect of CSE on brain mitochondria may be due to its direct action on enzymatic activity rather than through oxygen free radical injury. Nicotine is not the responsible component for the toxicity of CSE to brain mitochondria.

Adenosine Triphosphatases ; pharmacology ; Animals ; Antioxidants ; pharmacology ; Ascorbic Acid ; pharmacology ; Brain ; pathology ; Electron Transport Complex IV ; pharmacology ; Free Radicals ; Ganglionic Stimulants ; toxicity ; Mice ; Mitochondria ; pathology ; Nicotine ; toxicity ; Smoke ; adverse effects ; Tobacco

OBJECTIVEGlucocorticoid is considered as an effective drug for prevention and treatment of brain edema and reducing the blood-brain barrier (BBB) permeability. Intravenous immunoglobulin (IVIG) is frequently used to treat neurological diseases with immune abnormality, its function and potential mechanism on brain edema have not been reported. In this study, the roles of the total hydrosulfide group (TSH), non-protein hydrosulfide group (NPSH) and malondialdehyde (MDA) in etiology of the endotoxin brain edema in infant rats and the interfering effects of dexamethasone (DEX) and IVIG were investigated.

METHODSIn 35 infant rats, 10 mg/kg lipopolysaccharide (LPS) was intraperitoneally injected. The same volume of normal saline was injected to 24 control rats. Ten mg/kg DEX and 400 mg/kg IVIG were intravenously injected respectively to 36 and 24 infant rats instantly following LPS injection. The TSH, NPSH and MDA concentrations and the brain Evans blue contents were detected at different time in the brain tissue. The brain water content was measured by drying method.

RESULTSThe brain water, EB and MDA contents after endotoxin injection were significantly higher than those of control group, while the brain TSH, NPSH content were significantly lower than those of control group (P < 0.05 or P < 0.01); After treatment with DEX or IVIG, the brain EB, MDA and water content significantly decreased with the peak at 6 h (P < 0.05 or P < 0.01), TSH and NPSH significantly increased compared with LPS group. However, the NPSH content in IVIG treatment group did not change significantly (P > 0.05).

CONCLUSIONFree radicals play a role in the brain edema induced by LPS in infant rats. The primary results suggested that DEX and IVIG have therapeutic effect for the endotoxin-induced brain edema by affecting the free radicals.

Animals ; Blood-Brain Barrier ; drug effects ; metabolism ; Brain Edema ; chemically induced ; drug therapy ; metabolism ; Dexamethasone ; therapeutic use ; Endotoxins ; toxicity ; Free Radicals ; analysis ; Glucocorticoids ; therapeutic use ; Immunoglobulins, Intravenous ; administration & dosage ; therapeutic use ; Malondialdehyde ; analysis ; Rats ; Rats, Wistar ; Sulfides ; analysis

OBJECTIVETo evaluate the antagonism effects of green tea (GT) against microcystin LR (MC-LR) induced hepatotoxicity and nephrotoxicity in mice.

METHODSAll 40 male mice were randomly divided into four groups. Mice in group III and IV were pretreated with green tea for free drink at doses of 2 g/L and 12 g/L prior to MC-LR intoxication, for consecutively 18 days. The toxin treatment mice were administered continually intraperitoneal injections of MC-LR at a dose of 10 microg x kg(-1) x d(-1) bw from day 6th till sacrifice, continually 13 days. Mice were sacrificed and immediately subjected to necropsy, and the body weight, relative organ weight, serum biochemical parameters, antioxidant enzyme levels (SOD and GSH), lipid peroxidation products (MDA) and histopathology were systematically evaluated.

RESULTSMC-LR exposure led to increase the oxidative stress and organ injury was significantly observed through biochemical parameters and microscopic evaluation. However, high dose of GT pretreatment caused a significant elevation in serum GSH and SOD levels, and a decrease of serum MDA level as compared with MC-LR control. The mean values of GSH and SOD activities were separately 467.29 mg/L and 139.22 U/ml in group IV. Subsequently, GT pretreatment obviously diminished the serum ALT, AST and Cr activities. Those pathological damages in liver and kidney, were to a certain extent, lessened in GT pretreatment mice in correlation with the biochemical parameters.

CONCLUSIONGT might elevate antioxidant defense system, clean up free radicals, lessen oxidative damages and protect liver and kidney against MC-LR induced toxicity.

Animals ; Antioxidants ; pharmacology ; Chemical and Drug Induced Liver Injury ; Free Radicals ; metabolism ; Kidney Diseases ; chemically induced ; metabolism ; pathology ; Liver Diseases ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred Strains ; Microcystins ; toxicity ; Oxidative Stress ; Tea