Humans ; Oxidative Stress ; drug effects ; Oxidoreductases ; metabolism ; physiology

OBJECTIVETo investigate the effect of high glucose on mitochondrial respiratory chain function in INS-1 cells.

METHODSThe pancreatic beta cell line INS-1 was divided into the normal control (NC), high glucose (HG), and N-acetyl-L-cysteine (NAC) pretreatment groups, which were cultured for 72 h in the presence of 5.5 mmol/L glucose, 16.7 mmol/L glucose, and 16.7 mmol/L glucose with 1.0 mmol/L NAC, respectively. The activities of the enzyme complexes I and III of the respiratory chain in the cells were assessed with spectrophotometry, the ATP levels were examined using a luciferinluciferase kit, and insulin levels detected by radioimmunoassay.

RESULTSThe activities of the respiratory chain enzyme complexes I and III were 1.53-/+0.24 and 1.08-/+0.22 micromol.mg(-1).min(-1) in high glucose group, respectively, significantly lower than those in the normal control group (2.31-/+0.33 and 1.92-/+0.39 micromol.mg(-1).min(-1), P<0.01). ATP and insulin levels also decreased significantly in high glucose group as compared with those in the normal control group (P<0.01). The addition of NAC partially inhibited high glucose-induced decreases in the enzyme complex activities, ATP levels and insulin secretion (P<0.05).

CONCLUSIONThe respiratory chain function is positively correlated to insulin secretion in INS-1 cells, and exposure to high glucose causes impairment of the two enzyme complexes activities through oxidative stress, resulting in the mitochondrial respiratory chain dysfunction. High glucose-induced damages of the mitochondrial respiratory chain function can be partially inhibited by NAC.

Cell Respiration ; drug effects ; Cells, Cultured ; Glucose ; pharmacology ; Humans ; Insulin-Secreting Cells ; cytology ; physiology ; Mitochondria ; physiology ; Oxidative Stress ; drug effects

Animals ; Antioxidants ; physiology ; Dehydroepiandrosterone ; physiology ; Lipid Metabolism ; physiology ; Male ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley

Alzheimer's disease (AD) has become one of the most important and most interesting focuses in the field of medical and scientific research. Up to now, the pathogenesis of AD has not been completely clarified. However, the high-density of amyloid β-protein (Aβ) in senile plaques of AD brain and the neurotoxicity of Aβ have been indisputable facts. The mechanisms underlying Aβ neurotoxicity are very complicated, involving calcium overload, inflammation, ion channel dysfunction, oxidative stress and so on. Among all of those, the mechanism of oxidative stress in Aβ neurotoxicity and the experimental progress of antioxidants in AD treatment have been widely reported in recent years. This review mainly discussed current research progresses on the oxidative stress of Aβ, so as to provide readers with some clues to the antioxidant therapy of AD.
Alzheimer Disease ; etiology ; metabolism ; physiopathology ; Amyloid beta-Peptides ; adverse effects ; metabolism ; Animals ; Antioxidants ; pharmacology ; Humans ; Oxidative Stress ; drug effects ; physiology

Animals ; Dose-Response Relationship, Drug ; Male ; Mice ; Mice, Inbred Strains ; Nickel ; toxicity ; Oxidative Stress ; physiology ; Testis ; drug effects ; metabolism

AIMTo investigate the effect of formaldehyde (FA) on testes and the protective effect of vitamin E (VE) against oxidative damage by FA in the testes of adult rats.

METHODSThirty rats were randomly divided into three groups: (1) control; (2) FA treatment group (FAt); and (3) FAt + VE group. FAt and FAt + VE groups were exposed to FA by inhalation at a concentration of 10 mg/m(3) for 2 weeks. In addition, FAt + VE group were orally administered VE during the 2-week FA treatment. After the treatment, the histopathological and biochemical changes in testes, as well as the quantity and quality of sperm, were observed.

RESULTSThe testicular weight, the quantity and quality of sperm, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and glutathione (GSH) were significantly decreased whereas the level of malondialdehyde (MDA) was significantly increased in testes of rats in FAt group compared with those in the control group. VE treatment restored these parameters in FAt + VE group. In addition, microscopy with hematoxylin-eosin (HE) staining showed that seminiferous tubules atrophied, seminiferous epithelial cells disintegrated and shed in rats in FAt group and VE treatment significantly improved the testicular structure in FAt + VE group.

CONCLUSIONFA destroys the testicular structure and function in adult rats by inducing oxidative stress, and this damage could be partially reversed by VE.

Animals ; Antioxidants ; pharmacology ; Epididymis ; drug effects ; pathology ; Formaldehyde ; toxicity ; Male ; Oxidative Stress ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley ; Sperm Count ; Testis ; drug effects ; pathology ; Vitamin E ; pharmacology

OBJECTIVETo investigate the effects of D-galactose (D-gal) on aging of rat marrow mesenchymal stem cells (MSCs) and its mechanism.

METHODSMSCs isolated from young (7 d) SD rats were randomly divided into four groups:control group, 1g/L, 10g/L and 50g/L D-gal treatment groups. In control group MSCs were cultured in DMEM containing 10% FBS for 48 h. In the D-gal treatment groups, MSCs were cultured in DMEM containing 10% FBS with 1g/L, 10g/L or 50g/L D-gal for 48 h. The senescence-associated changes were examined with SA-β-galactosidase (SA-β-gal) staining, the expressions of p53, p21 and p16 were detected by Western blot. The living and apoptotic cells were determined by AO/EB staining. Cell proliferation was detected by MTT assay. SOD activity was measured by xanthine oxidase method, and the MDA content was estimated with thiobarbituric acid (TBA) method.

RESULTSCompared to control group, the number of SA-β-gal positive cells and the expression of p53, p21 and p16 were significantly increased in the 10g/L and 50g/L D-gal treatment groups. The apoptosis rate in 50g/L D-gal group was significantly higher than that in control group (P<0.01). The proliferation of MSCs was decreased in the 10g/L and 50g/L D-gal groups compared to control group (P<0.05). After 10g/L and 50g/L D-gal treatment, SOD activity was significantly decreased (P<0.01), and MDA level was increased (P<0.01).

CONCLUSIONThe aging of MSCs can be induced by 10g/L and 50g/L D-gal, which may be associated with the elevated levels of oxidative stress.

Animals ; Apoptosis ; drug effects ; Cells, Cultured ; Cellular Senescence ; drug effects ; Galactose ; pharmacology ; Male ; Mesenchymal Stromal Cells ; drug effects ; physiology ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley

We studied the overproduction of catalase (CAT) by Bacillus sp.WSHDZ-01 by oxidative stress via the feeding of ethanol and the pulse addition of H2O2. By adding 2.0% (V/V) ethanol to the culture broth, the intracellular CAT activity reached 11 151 U/mL, which was 2.5 times than that of the control (4 450 U/mL in flask). By adding 0.3% (V/V) H2O2, more extracellular CAT secreted to the culture broth, and the ratio of extracellular CAT to the total CAT increased to 27%. Based on these results, an oxidative stress strategy combining the ethanol feeding and the pulse addition of H2O2 was developed. With this strategy, the ratio of extracellular CAT to the total CAT reached 82.5%, increased by 18.6% than that of the control (without ethanol and H2O2 addition). CAT production increased to 28 990 U/mL, which was 95.5% higher than the control (14 830 U/mL in 3 L fermentor). The fermentation time decreased to 42 h, which was much shorter than that of adding ethanol or H2O2, and CAT productivity reached 470 U/(mL x h) while the control achieved 396.4 U/(mL x h).
Bacillus subtilis ; drug effects ; enzymology ; physiology ; Catalase ; biosynthesis ; Culture Media ; pharmacology ; Ethanol ; pharmacology ; Hydrogen Peroxide ; pharmacology ; Oxidative Stress

AIMTo evaluate the effect of oxidative stress on the spermatogenesis and lactate dehydrogenase-X (LDH-X) activity in mouse testis.

METHODSFor creating different levels of oxidative stress in mice, three selenium (Se) level diets were fed in separate groups for 8 weeks. Group 1 animals were fed yeast-based Se-deficient (0.02 ppm) diet. Group 2 and Group 3 animals were fed with the same diet supplemented with 0.2 ppm and 1 ppm Se as sodium selenite, respectively. After 8 weeks, biochemical and histopathological observations of the testis were carried out. LDH-X levels in the testis were analyzed by western immunoblot and ELISA.

RESULTSA significant decrease in testis Se level was observed in Group 1 animals, whereas it was enhanced in Group 3 as compared to Group 2. The glutathione peroxidase (GSH-Px) activity was significantly reduced in both the liver and testis in Group 1, but not in Group 2 and 3. A significant increase in the testis glutathione-S-transferase (GST) activity was observed in Group 1, whereas no significant change was seen in Groups 2 and 3. Histological analysis of testis revealed a normal structure in Group 2. A significant decrease in the germ cell population in Group 1 was observed as compared to Group 2 with the spermatids and mature sperm affected the most. Decrease in the lumen size was also observed. In the Se-excess group (Group 3), displacement of germ cell population was observed. Further, a decrease in the LDH-X level in testis was observed in Group 1.

CONCLUSIONExcessive oxidative stress in the Se deficient group, as indicated by changes in the GSH-Px/GST activity, affects the spermatogenic process with a reduction in mature sperm and in turn the LDH-X level.

Animals ; Diet ; Glutathione Transferase ; metabolism ; Isoenzymes ; drug effects ; metabolism ; L-Lactate Dehydrogenase ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; drug effects ; physiology ; Selenium ; deficiency ; pharmacokinetics ; pharmacology ; Spermatogenesis ; physiology ; Testis ; drug effects ; enzymology ; pathology ; physiology

Oxidative stress plays a pivotal role in the pathogenesis of varied nervous system diseases. Recent studies have demonstrated that hydrogen has selective antioxidative effect. It selectively reduces the hydroxyl radical (*OH) and peroxynitrite (ONOO(-)), the most cytotoxic of reactive oxygen species (ROS); however, it does not affect other ROS, which play important physiological roles at low concentrations. A large body of experimental studies has proved that hydrogen, through anti-oxidation, anti-inflammatory and inhibiting apoptosis, has a significant therapeutic effect in various neurological diseases, such as ischemia, hypoxia, degeneration and spinal cord contusion. It provides us with a new clinical method for the prevention and treatment of neurological diseases.
Antioxidants ; pharmacology ; Humans ; Hydrogen ; pharmacology ; Hydroxyl Radical ; metabolism ; Nervous System ; drug effects ; metabolism ; Nervous System Diseases ; drug therapy ; metabolism ; Oxidative Stress ; drug effects ; physiology ; Peroxynitrous Acid ; metabolism