Previously, we demonstrated that galangin (3,5,7-trihydroxyflavone) protects human keratinocytes against ultraviolet B (UVB)-induced oxidative damage. In this study, we investigated the effect of galangin on induction of antioxidant enzymes involved in synthesis of reduced glutathione (GSH), and investigated the associated upstream signaling cascades. By activating nuclear factor-erythroid 2-related factor (Nrf2), galangin treatment significantly increased expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione synthetase (GSS). This activation of Nrf2 depended on extracellular signal-regulated kinases (ERKs) and protein kinase B (AKT) signaling. Inhibition of GSH in galangin-treated cells attenuated the protective effect of galangin against the deleterious effects of UVB. Our results reveal that galangin protects human keratinocytes by activating ERK/AKT-Nrf2, leading to elevated expression of GSH-synthesizing enzymes.
Catalytic Domain ; Extracellular Signal-Regulated MAP Kinases ; Glutamate-Cysteine Ligase ; Glutathione Synthase ; Glutathione* ; Humans* ; Keratinocytes* ; Proto-Oncogene Proteins c-akt

BACKGROUND: Exposure to ethanol abuse and severe oxidative stress are risk factors for hepatocarcinoma. The aim of this study was to evaluate the effects of S-adenosylmethionine (SAMe) and its combinations with taurine and/or betaine on the level of glutathione (GSH), a powerful antioxidant in the liver, in acute hepatotoxicity induced by ethanol. METHODS: To examine the effects of SAMe and its combinations with taurine and/or betaine on ethanol-induced hepatotoxicity, AML12 cells and C57BL/6 mice were pretreated with SAMe, taurine, and/or betaine, followed by ethanol challenge. Cell viability was detected with an MTT assay. GSH concentration and mRNA levels of GSH synthetic enzymes were measured using GSH reductase and quantitative real-time reverse transcriptase-PCR. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were measured with commercially available kits. RESULTS: Pretreatment of SAMe, with or without taurine and/or betaine, attenuated decreases in GSH levels and mRNA expression of the catalytic subunit of glutamate-cysteine ligase (GCL), the rate-limiting enzyme for GSH synthesis, in ethanol-treated cells and mice. mRNA levels of the modifier subunit of GCL and glutathione synthetase were increased in mice treated with SAMe combinations. SAMe, taurine, and/or betaine pretreatment restored serum ALT and AST levels to control levels in the ethanol-treated group. CONCLUSIONS: Combinations of SAMe with taurine and/or betaine have a hepatoprotective effect against ethanol-induced liver injury by maintaining GSH homeostasis.
Alanine Transaminase ; Animals ; Aspartate Aminotransferases ; Betaine* ; Catalytic Domain ; Cell Survival ; Ethanol ; Glutamate-Cysteine Ligase ; Glutathione Synthase ; Glutathione* ; Homeostasis* ; Liver ; Mice ; Oxidative Stress ; Oxidoreductases ; Risk Factors ; RNA, Messenger ; S-Adenosylmethionine* ; Taurine*

This study investigated the possible effects and molecular mechanisms of diallyl disulfide (DADS) against cyclophosphamide (CP)-induced hemorrhagic cystitis (HC) in rats. Inflammation response was assessed by histopathology and serum cytokines levels. We determined the protein expressions of nuclear transcription factor kappa-B (NF-kappaB), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumor necrosis factor-alpha (TNF-alpha), oxidative stress, urinary nitrite-nitrate, malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG). Finally, we studied the involvement of mitogen-activated protein kinases (MAPKs) signaling in the protective effects of DADS against CP-induced HC. CP treatment caused a HC which was evidenced by an increase in histopathological changes, proinflammatory cytokines levels, urinary nitrite-nitrate level, and the protein expression of NF-kappaB, COX-2, iNOS, TNF-alpha, p-c-Jun N-terminal kinase (JNK), and p-extracellular signal regulated kinase (ERK). The significant decreases in glutathione content and glutathione-S-transferase and glutathione reductase activities, and the significant increase in MDA content and urinary MDA and 8-OHdG levels indicated that CP-induced bladder injury was mediated through oxidative DNA damage. In contrast, DADS pretreatment attenuated CP-induced HC, including histopathological lesion, serum cytokines levels, oxidative damage, and urinary oxidative DNA damage. DADS also caused significantly decreased the protein expressions of NF-kappaB, COX-2, iNOS, TNF-alpha, p-JNK, and p-ERK. These results indicate that DADS prevents CP-induced HC and that the protective effects of DADS may be due to its ability to regulate proinflammatory cytokines production by inhibition of NF-kappaB and MAPKs expressions, and its potent anti-oxidative capability through reduction of oxidative DNA damage in the bladder.
Animals ; Cyclooxygenase 2 ; Cyclophosphamide ; Cystitis* ; Cytokines ; DNA Damage ; Glutathione ; Glutathione Reductase ; Inflammation ; Malondialdehyde ; Mitogen-Activated Protein Kinases ; NF-kappa B* ; Nitric Oxide Synthase Type II ; Oxidative Stress ; Phosphotransferases ; Rats* ; Transcription Factors ; Tumor Necrosis Factor-alpha ; Urinary Bladder

Acute Disease ; Adult ; Altitude Sickness ; blood ; enzymology ; Glutathione ; blood ; Glutathione Peroxidase ; blood ; Humans ; Lipid Peroxidation ; Male ; Military Personnel ; Nitric Oxide ; blood ; Nitric Oxide Synthase ; blood ; Oxidoreductases ; metabolism ; Superoxide Dismutase ; blood

This study investigated the role of nitric oxide on the oxidative damage in gastric mucosa of rats which received ischemia/reperfusion and its relation to mucus. Nitric oxide synthesis modulators such as L-arginine and NG-nitro-L-arginine methyl ester, and sodium nitroprusside, a nitric oxide donor, were injected intraperitoneally to the rats 30 min prior to ischemia/reperfusion which was induced by clamping the celiac artery and the superior mesenteric artery for 30 min and reperfusion for 1 h. Lipid peroxide production, the contents of glutathione and mucus, and glutathione peroxidase activities of gastric mucosa were determined. Histological observation of gastric mucosa was performed by using hematoxylin-eosin staining and scanning electron microscopy. The result showed that ischemia/reperfusion increased lipid peroxide production and decreased the contents of glutathione and mucus as well as glutathione peroxidase activities of gastric mucosa. Ischemia/reperfusion induced gastric erosion and gross epithelial disruption of gastric mucosa. Pretreatment of L-arginine, a substrate for nitric oxide synthase, and sodium nitroprusside prevented ischemia/reperfusion-induced alterations of gastric mucosa. However, NG-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, deteriorated oxidative damage induced by ischemia/reperfusion. In conclusion, nitric oxide has an antioxidant defensive role on gastric mucosa by maintaining mucus, glutathione, and glutathione peroxidase of gastric mucosa.
Animals ; Arginine ; Celiac Artery ; Constriction ; Gastric Mucosa ; Glutathione ; Glutathione Peroxidase ; Humans ; Mesenteric Artery, Superior ; Microscopy, Electron, Scanning ; Mucus* ; NG-Nitroarginine Methyl Ester ; Nitric Oxide Synthase ; Nitric Oxide* ; Nitroprusside ; Rats ; Reperfusion ; Tissue Donors

PURPOSE: The aim of this study was to assess the effects of guava leaf extract (GLE) supplementation on antioxidant enzyme activity and expression of endothelial nitric oxide synthase (eNOS) mRNA in ovariectomized rats. METHODS: All animals were randomly assigned to four groups (n = 7 for each group): non-ovariectomized control (Sham), the ovariectomized control (OVX), ovariectomy + 150 mg/kg b.w. of GLE (OVX·GL), and ovariectomy + 300 mg/kg b.w. of GLE (OVX·GH). Treatment groups were administered GLE for 8 weeks every day. RESULTS: Body weight gain was significantly reduced in the OVX·GL group compared with the OVX group (p < 0.05). The level of serum 17β-estradiol (E2) was significantly lower in the OVX groups than the Sham group (p < 0.05). Serum triglyceride (TG) and HDL-cholesterol levels were not significantly different between all groups. However, serum total cholesterol (TC) level was significantly reduced in the OVX·GH group compared with the OVX group (p < 0.05). Serum free fatty acid (FFA) level and liver TG level were significantly reduced in both OVX·GL and OVX·GH groups compared with the OVX group (p < 0.05). Furthermore, serum glutathione peroxidase (GPx) activity was significantly elevated in the GLE groups (p < 0.05). The mRNA expression level of GPx was not affected by ovariectomy. However, administration of GLE resulted in significantly increased nuclear factor erythroid 2-related factor (Nrf2) and catalase (CAT) mRNA expression levels in the liver (p < 0.05). In addition, liver nitric oxide (NO) level was significantly reduced in the OVX·GH group compared with the OVX group (p < 0.05). Expression level of endothelial nitric oxide synthase (eNOS) was significantly elevated in the OVX·GH group compared with the OVX group (p < 0.05). CONCLUSION: These results suggest that GLE could have protective effects in OVX rats by stimulating eNOS expression and improving the antioxidant defense system.
Animals ; Body Weight ; Catalase ; Cholesterol ; Female ; Glutathione Peroxidase ; Liver ; Nitric Oxide ; Nitric Oxide Synthase Type III ; Ovariectomy ; Psidium* ; Rats* ; RNA, Messenger ; Triglycerides

Erectile dysfunction (ED) is a highly prevalent disorder that affects millions of men worldwide. ED is now considered an early manifestation of atherosclerosis, and consequently, a precursor of systemic vascular disease. This study was designed to investigate the effects of male silkworm pupa powder (SWP) on the levels of nitric oxide synthase (NOS) expression, nitrite, and glutathione (GSH); lipid peroxidation; libido; and erectile response of the corpus cavernosum of the rat penis. We induced ED in the study animals by oral administration of 20% ethanol over 8 weeks. The SWP-treated male rats were divided into 3 groups that were orally administered 200, 400, and 800 mg/kg. The libido of the SWP-administered male rats was higher than that of the ethanol control group. In addition, the erectile response of the corpus cavernosum was restored in males on SWP administration, to a level similar to that of the normal group without ED. The testosterone concentration did not increase significantly. The lipid peroxidation in the corpus cavernosum of the male rats administered SWP decreased significantly. In contrast, compared to the ethanol group, SWP-administered male rats showed increased GSH levels in the corpus cavernosum. The level of nitrite and NOS expression in the corpus cavernosum of SWP-administered male rats increased significantly. These results indicated that SWP effectively restored ethanol-induced ED in male rats.
Administration, Oral ; Animals ; Atherosclerosis ; Bombyx ; Erectile Dysfunction ; Ethanol ; Glutathione ; Humans ; Libido ; Lipid Peroxidation ; Male ; Nitric Oxide Synthase ; Penis ; Pupa ; Rats ; Testosterone ; Vascular Diseases

PURPOSE: We examined pregnancy outcomes and maternal plasma asymmetric dimethylarginine (ADMA) concentrations in the presence or absence of uterine artery notch, and analyzed their relationships to the expression of placental endothelial nitric oxide synthase (eNOS) and antioxidant enzymes, including manganese superoxide dismutase (MnSOD), glutathione peroxidase (GPX), and catalase. METHODS: We assessed uterine artery doppler waveforms in 30 women who had been hospitalized for delivery. Plasma concentrations of ADMA were also measured. Tissue samples of placentas were obtained from 15 patients with diastolic notch and 15 patients without diastolic notch, according to uterine Doppler velocimetry analysis. We evaluated the placental expression of eNOS, MnSOD, GPX and catalase with Western blot analysis and eNOS with immunohistochemistry. RESULTS: The maternal plasma ADMA concentration increased significantly in the group with bilateral Uterine artery notch compared with the group without uterine artery notch (P=0.04). The expression of eNOS in the placenta significantly increased and the expression of MnSOD and GPX decreased significantly in the group with uterine artery notch at the third trimester. CONCLUSION: Uterine artery diastolic notch in pregnant women is associated with high maternal plasma ADMA, increased placental eNOS, and decreased MnSOD and GPX.
Arginine ; Blotting, Western ; Catalase ; Female ; Glutathione Peroxidase ; Humans ; Nitric Oxide Synthase Type III ; Placenta ; Plasma ; Pregnancy ; Pregnancy Outcome ; Pregnancy Trimester, Third ; Pregnant Women ; Rheology ; Superoxide Dismutase ; Uterine Artery

OBJECTIVETo study the effect of acute phosgene inhalation on the antioxidant enzymes, nitric oxide (NO) and nitric oxide synthase (NOS) in rats.

METHODSPhosgene was produced by decomposing bis (trichdomethyl) carbonate in the presence of N,N-dimethyl formamide. SD rats were randomly divided into two groups: control and phosgene exposure groups. In a special experimental device with equipment modulating the gas flow, phosgene exposed rats inhaled phosgene quantitatively for five minutes. Two hours later, all the rats were sacrificed and the ratio of wet weight to dried weight of lung (WW/DW) was calculated. Peripheral blood, serum and liver were collected to examine the activities of antioxidant enzymes including glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), NOS, and NO level. The total content of proteins were also determined.

RESULTSThe WW/DW ratio of lung in phosgene exposure group was much higher than that in control group (P < 0.01). The activities of GST in serum and liver of phosgene exposure group increased significantly (P < 0.05). The activities of SOD, CAT, GSHPx and NOS in serum or blood and liver of phosgene exposure group were also increased significantly (P < 0.05). But the content of NO was significantly decreased (P < 0.01).

CONCLUSIONAcute phosgene inhalation may cause a dramatically changes of several antioxidant enzyme activities, and acute injury of liver to some extent in rats. The latter is related to reactive oxygen species. But the elevation of antioxidant enzyme activities suggests that antioxidative treatment for acute phosgene poisoning should not be considered first.

Animals ; Antioxidants ; metabolism ; Chemical Warfare Agents ; poisoning ; Glutathione Peroxidase ; metabolism ; Male ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Phosgene ; poisoning ; Poisoning ; enzymology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

Esophageal reflux of gastric contents causes esophageal mucosal damage and inflammation. Recent studies show that oxygen-derived free radicals mediate mucosal damage in reflux esophagitis (RE). Chlorogenic acid (CGA), an ester of caffeic acid and quinic acid, is one of the most abundant polyphenols in the human diet and possesses anti-inflammatory, antibacterial and anti-oxidant activities. In this context, we investigated the effects of CGA against experimental RE in rats. RE was produced by ligating the transitional region between the forestomach and the glandular portion and covering the duodenum near the pylorus ring with a small piece of catheter. CGA (10, 30 and 100 mg/kg) and omeprazole (positive control, 10 mg/kg) were administered orally 48 h after the RE operation for 12 days. CGA reduced the severity of esophageal lesions, and this beneficial effect was confirmed by histopathological observations. CGA reduced esophageal lipid peroxidation and increased the reduced glutathione/oxidized glutathione ratio. CGA attenuated increases in the serum level of tumor necrosis factor-alpha, and expressions of inducible nitric oxide synthase and cyclooxygenase-2 protein. CGA alleviates RE-induced mucosal injury, and this protection is associated with reduced oxidative stress and the anti-inflammatory properties of CGA.
Animals ; Catheters ; Chlorogenic Acid* ; Cyclooxygenase 2 ; Diet ; Duodenum ; Esophagitis, Peptic* ; Free Radicals ; Gastroesophageal Reflux ; Glutathione ; Humans ; Inflammation ; Lipid Peroxidation ; Nitric Oxide Synthase Type II ; Omeprazole ; Oxidative Stress ; Polyphenols ; Pylorus ; Quinic Acid ; Rats* ; Tumor Necrosis Factor-alpha