Harpagophytum procumbens Extract Ameliorates Allodynia and Modulates Oxidative and Antioxidant Stress Pathways in a Rat Model of Spinal Cord Injury.

Spinal cord injury (SCI) is a deliberating disorder with impairments in locomotor deficits and incapacitating sensory abnormalities. Harpagophytum procumbens (Hp) is a botanical widely used for treating inflammation and pain related to various inflammatory and musculoskeletal conditions. Using a modified rodent contusion model of SCI, we explored the effects of this botanical on locomotor function and responses to mechanical stimuli, and examined possible neurochemical changes associated with SCI-induced allodynia. Following spinal cord contusion at T10 level, Hp (300 mg/kg, p.o.) or vehicle (water) was administered daily starting 24 h post-surgery, and behavioral measurements made every-other day until sacrifice (Day 21). Hp treatment markedly ameliorated the contusion-induced decrease in locomotor function and increased sensitivity to mechanical stimuli. Determination of Iba1 expression in spinal cord tissues indicated microglial infiltration starting 3 days post-injury. SCI results in increased levels of 4-hydroxynonenal, an oxidative stress product and proalgesic, which was diminished at 7 days by treatment with Hp. SCI also enhanced antioxidant heme oxygenase-1 (HO-1) expression. Concurrent studies of cultured murine BV-2 microglial cells revealed that Hp suppressed oxidative/nitrosative stress and inflammatory responses, including production of nitric oxide and reactive oxygen species, phosphorylation of cytosolic phospholipases A2, and upregulation of the antioxidative stress pathway involving the nuclear factor erythroid 2-related factor 2 and HO-1. These results support the use of Hp for management of allodynia by providing resilience against the neuroinflammation and pain associated with SCI and other neuropathological conditions.

Epigallocatechin 3-gallate attenuates arthritis by regulating Nrf2, HO-1, and cytokine levels in an experimental arthritis model.

Epigallocatechin 3-gallate (EGCG) is a polyphenol that has been shown to have antioxidant and anti-inflammatory effects. In this study, collagen-induced arthritis (CIA) model, in Wistar albino rats, was used to elucidate the effect of EGCG on pathogenetic pathways in inflammatory arthritis. The levels of serum TNF-α, IL-17, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx); the expression levels of tissue heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2); histopathologically, perisynovial inflammation and cartilage-bone destruction were examined. In the sham group, serum TNF-α, IL-17, and MDA levels increased, while SOD, CAT, GPx levels, and the expressions of Nrf2 and HO-1 decreased. On the other hand, in the EGCG administered groups, serum TNF-α, IL-17, and MDA levels improved, while SOD, CAT, GPx levels and the expressions of Nrf2 and HO-1 increased. Moreover, histopathological analysis has shown that perisynovial inflammation and cartilage-bone destruction decreased in the EGCG administered groups. These results suggest that EGCG has an antiarthritic effect by regulating the oxidative-antioxidant balance and cytokine levels in the CIA model, which is a surrogate experimental model of rheumatoid arthritis.

Olea europaea leaf extract up-regulates Nrf2/ARE/HO-1 signaling and attenuates cyclophosphamide-induced oxidative stress, inflammation and apoptosis in rat kidney.

Olive leaf extract (OLE) has potential health benefits and protects against cytotoxicity in different organs. However, nothing has yet been reported on its potential to prevent cyclophosphamide (CP)-induced nephrotoxicity. This study investigated the possible protective effect of OLE on CP-induced kidney injury in rats, focusing on oxidative stress, inflammation, apoptosis and Nrf2/ARE/HO-1 signaling. Rats received 100 or 200 mg/kg body weight OLE for 15 days and a single injection of 150 mg/kg CP at day 16. CP induced kidney injury evidenced by the significantly increased serum creatinine and urea, and histopathological alterations, including glomerular atrophy, interstitial hemorrhage, dilated urinary space and necrosis. CP-induced rats exhibited increased kidney lipid peroxidation, protein carbonyl, nitric oxide (NO) and pro-inflammatory cytokines, and up-regulated NF-κB, Bax, cytochrome c and caspase-3. OLE ameliorated kidney function markers and prevented CP-induced tissue damage. In addition, OLE significantly prevented oxidative stress, inflammation and apoptosis by enhancing the antioxidant defenses and Bcl-2 expression, and suppressing the pro-inflammatory and pro-apoptotic markers NF-κB, Bax, cytochrome c and caspase-3. OLE up-regulated Nrf2, HO-1 and NQO-1 expression in the kidney of CP-induced rats. In conclusion, OLE has a substantial protective role against CP-induced nephrotoxicity in rats by up-regulating the Nrf2/ARE/HO-1 signaling, enhancing the antioxidant activity and attenuating inflammation and apoptosis.

Sitagliptin improves renal function in diabetic nephropathy in male Sprague Dawley rats through upregulating heme oxygenase-1 expression.

PURPOSE: Oxidative stress is an important mechanism for diabetic nephropathy. Studies showed that hemo oxygenase-1 (HO-1) expression in renal tissue of patients with diabetic nephropathy has upregulated, while the HO-1 can protect the body through anti-oxidative stress. The study aimed to preliminarily explore the molecular mechanism by observing the effect of Sitagliptin on HO-1 expression in renal tissue of rats with diabetic nephropathy. METHODS: The diabetic nephropathy rat model was established by STZ injection followed by intraperitoneal injection of sitagliptin with different concentrations. The mRNA expressions of HO-1 were detected by real-time PCR and Western blot and HO-1 enzyme activity change was detected by colorimetry. Human renal mesangial cell (HRMC) were cultured in vitro with high glucose concentration (30 µmol/L), phosphatidylinositol-3-kinase (PI3K) level and nuclear factor erythroid-2-related factor (Nrf2) content in cytoplasm and cell nucleus were observed before and after treatment with sitagliptin, as well as the action of in meditating HO-1 expression. RESULTS: HO-1 mRNA, protein level, and HO-1 enzyme activity in renal tissue of rats with diabetic nephropathy were significantly increased after treatment with sitagliptin (P < 0.05). As comparison, the 24 h urinary microalbumin, creatinine, and boold urea nitrogen were all decreased after treatment of sitagliptin (P < 0.05). Similar results were observed after CoPP (an agonist of HO-1) treatment (P < 0.05). In contrast, ZnPP, an inhibitor of HO-1, significantly abrogated the inhibitory effect of sitagliptin (P < 0.05). Phosphorylation of PI3K and Nrf2 nuclear translocation under high-glucose concentration condition was induced by sitagliptin in HRMC. HO-1 expression was suppressed by pretreating HRMC with PI3K inhibitor or RNA interference. CONCLUSIONS: Sitagliptin may induce HO-1 expression via activation of PI3K and Nrf2 in rats with diabetic nephropathy; HO-1 can improve the oxidative stress of diabetic nephropathy, eventually protect from diabetic nephropathy.

ß-Caryophyllene Attenuates Focal Cerebral Ischemia-Reperfusion Injury by Nrf2/HO-1 Pathway in Rats.

This study aimed to identify the effect of ß-caryophyllene (BCP) pretreatment and elucidate the Nrf2/HO-1 signaling mechanism after focal cerebral ischemia-reperfusion (I-R) injury in rats. Adult male Sprague-Dawley rats were randomly assigned to the sham-operated group, I-R group and BCP pretreated I-R group. At 24 h after reperfusion, neurological deficits and infarct volume were evaluated. Pathological changes of neuron in hippocampuses were observed by Nissil staining and transmission electron microscopy (TEM). Oxidative stress was assessed by malondialdehyde (MDA) level, lipid peroxidation (LPO), nitric oxide (NO), superoxide dismutase (SOD) and Catalase (CAT) activity. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were analysed by Western blotting and real-time quantitative polymerase chain reaction (Q-PCR). The protein expression of Bcl-2 and Bax was determined by immunohistochemistry. Apoptotic cells were detected using TUNEL staining. In I-R group, neurological deficit scores, cerebral infarct volume, MDA levels, LPO content, NO level, expression of Bax and TUNEL-positive cells were found to be increased at 24 h after I-R injury, while SOD activity, CAT activity and expression of Bcl-2 were decreased. However, results in the BCP pretreatment groups were reversed. And the protein and mRNA expressions of Nrf2 and HO-1 were significantly up-regulated in the BCP pretreated I-R group. Results of Nissil staining and TEM scan manifested that BCP remarkablely improved neuronal injury after I-R in rats. All the above suggested that BCP pretreatment played a neuroprotective role in cerebral I-R injury, which might be exerted by upregulating the expression of Nrf2 and HO-1 to ameliorate oxidative damage and neuronal apoptosis.

Targeted mass spectrometry for the analysis of nutritive modulation of catalase and heme oxygenase-1 expression.

Comprehensive physiological food assessment requires recording of activity profiles. To elucidate the nutritive regulation of antioxidant enzymes, a generally applicable targeted MS method was established for the expression analysis of catalase and then adapted to heme oxygenase-1. Before tryptic digestion, target proteins were prefractionated by off-gel IEF of stimulated and control cell lysate. Targeted proteome analysis was achieved by LC coupled with scheduled selected reaction monitoring MS using 2 proteotypic peptides per protein and 3-4 transitions per peptide. Relative quantification was performed by stable isotope labeling by amino acids in cell culture (SILAC). The assay showed good correlation with results by Western blot. Linearity, precision, and sensitivity were even improved (LC/SRM vs. Western blot: 3 vs. 1 orders of magnitude, RSD 3.7-13.7% vs. 18.4%, LOD 0.2 vs. 1.6µg/mL). The developed method indicated that coffee does not modulate catalase expression in macrophages (T7cat 103±22%, T17cat 103±16%, p>0.05 vs. control), but leads to a highly significant increase of heme oxygenase-1 expression (T15Ho-1 420±24%, T22Ho-1 364±37%, p<0.001 vs. control, p>0.05 T15Ho-1 vs. T22Ho-1). In regard to multiplex options of the method, targeted proteome analysis can be a valuable tool for the comprehensive analysis of cellular effects of food components. BIOLOGICAL SIGNIFICANCE: In the present study, targeted mass spectrometry was applied to determine the influence of food components on the expression of antioxidative enzymes. The results implicate that targeted proteomics may develop into a valuable tool in food science and nutrition to determine the physiological effects of nutrients. In contrast to conventional methods for expression analysis, targeted proteome analysis can be applied to monitor the effects of a food component on a broad range of cellular targets in parallel. Additionally, proteins or protein modifications can be addressed which elude immunochemical methods.

Posttreatment with 11-Keto-ß-Boswellic Acid Ameliorates Cerebral Ischemia-Reperfusion Injury: Nrf2/HO-1 Pathway as a Potential Mechanism.

Oxidative stress is well known to play a pivotal role in cerebral ischemia-reperfusion injury. The nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway has been considered a potential target for neuroprotection in stroke. 11-Keto-ß-boswellic acid (KBA) is a triterpenoid compound from extracts of Boswellia serrata. The aim of the present study was to determine whether KBA, a novel Nrf2 activator, can protect against cerebral ischemic injury. Middle cerebral artery occlusion (MCAO) was operated on male Sprague-Dawley rats. KBA (25 mg/kg) applied 1 h after reperfusion significantly reduced infarct volumes and apoptotic cells as well as increased neurologic scores at 48 h after reperfusion. Meanwhile, posttreatment with KBA significantly decreased malondialdehyde (MDA) levels, restored the superoxide dismutase (SOD) activity, and increased the protein Nrf2 and HO-1 expression in brain tissues. In primary cultured astrocytes, KBA increased the Nrf2 and HO-1 expression, which provided protection against oxygen and glucose deprivation (OGD)-induced oxidative insult. But knockdown of Nrf2 or HO-1 attenuated the protective effect of KBA. In conclusion, these findings provide evidence that the neuroprotection of KBA against oxidative stress-induced ischemic injury involves the Nrf2/HO-1 pathway.

Hyperbaric oxygen preconditioning protects lung against hyperoxic acute lung injury in rats via heme oxygenase-1 induction.

Hyperoxic acute lung injury (HALI) is a clinical syndrome as a result of prolonged supplement of high concentrations of oxygen. Previous studies have shown hyperbaric oxygen preconditioning (HBO-PC) had a protective effect on oxidative injury. In the present study, we investigated the effect of HBO-PC on HALI in rats. The results demonstrated that HBO-PC ameliorated the lung biochemical and histological alterations induced by hyperoxia, decreased oxidative products but increased antioxidant enzymes. Furthermore, HBO-PC up-regulated heme oxygenase-1 (HO-1) mRNA and activity in lung tissues. The administration of HO-1 inhibitor, Zinc protoporphyrin IX, abolished its protective effects. The data showed that HBO-PC could protect rats against HALI and the anti-oxidative effect may be related to the up-regulation of HO-1.

Celastrol protects ischaemic myocardium through a heat shock response with up-regulation of haeme oxygenase-1.

BACKGROUND AND PURPOSE: Celastrol, a triterpene from plants, has been used in traditional oriental medicine to treat various diseases. Here, we investigated the cardioprotective effects of celastrol against ischaemia. EXPERIMENTAL APPROACH: Protective pathways induced by celastrol were investigated in hypoxic cultures of H9c2 rat cardiomyoblasts and in a rat model of myocardial infarction, assessed with echocardiographic and histological analysis. KEY RESULTS: In H9c2 cells, celastrol triggered reactive oxygen species (ROS) formation within minutes, induced nuclear translocation of the transcription factor heat shock factor 1 (HSF1) resulting in a heat shock response (HSR) leading to increased expression of heat shock proteins (HSPs). ROS scavenger N-acetylcysteine reduced expression of HSP70 and HSP32 (haeme oxygenase-1, HO-1). Celastrol improved H9c2 survival under hypoxic stress, and functional analysis revealed HSF1 and HO-1 as key effectors of the HSR, induced by celastrol, in promoting cytoprotection. In the rat ischaemic myocardium, celastrol treatment improved cardiac function and reduced adverse left ventricular remodelling at 14 days. Celastrol triggered expression of cardioprotective HO-1 and inhibited fibrosis and infarct size. In the peri-infarct area, celastrol reduced myofibroblast and macrophage infiltration, while attenuating up-regulation of TGF-ß and collagen genes. CONCLUSIONS AND IMPLICATIONS: Celastrol treatment induced an HSR through activation of HSF1 with up-regulation of HO-1 as the key effector, promoting cardiomyocyte survival, reduction of injury and adverse remodelling with preservation of cardiac function. Celastrol may represent a novel potent pharmacological cardioprotective agent mimicking ischaemic conditioning that could have a valuable impact in the treatment of myocardial infarction.

2-methoxycinnamaldehyde from Cinnamomum cassia reduces rat myocardial ischemia and reperfusion injury in vivo due to HO-1 induction.

ETHNOPHARMACOLOGICAL RELEVANCE: Cinnamomum cassia Blume has been used as a traditional Chinese herbal medicine for alleviation of fever, inflammation, chronic bronchitis, and to improve blood circulation. AIM OF THE STUDY: We addressed whether 2-methoxycinnamaldehyde (2-MCA), one of active ingredients of Cinnamomum cassia, reduces vascular cell adhesion molecule-1 (VCAM-1) expression in tumor necrosis factor-alpha (TNF-α)-activated endothelial cells and protects ischemia/reperfusion (I/R)-injury due to heme oxygenase (HO)-1 induction. MATERIALS AND METHODS: Adult male rats were subjected to 30 min of ischemia by occlusion of the left anterior descending coronary artery followed by 24h of reperfusion. Rats were randomized to receive vehicle or 2-MCA (i.v.) 10 min before reperfusion. RESULTS: Administration of 2-MCA significantly improved I/R-induced myocardial dysfunction by increasing the values of the first derivative (±dp/dt) of left ventricular pressure and decreased infarct size. In addition, 2-MCA reduced the expression of high mobility group box 1 (HMGB1), an activator of the inflammatory cascade when released into the extracellular space, and VCAM-1 in I/R myocardium along with increase of HO-1 induction. The reduced injury was accompanied by significantly reduction of neutrophils infiltration and increased SOD activity in ischemic tissues and reduced serum level of cardiac troponin I (cTnI). Furthermore, 2-MCA significantly increased HO-1 induction by translocation of Nrf-2 from cytosol to nucleus in endothelial cells. Inhibition of VCAM-1 expression by 2-MCA was reversed both by SnPPIX, a HO-1 inhibitor and siHO-1 RNA trasfection in TNF-α-activated cells. In addition, 2-MCA significantly inhibited NF-κB luciferase activity in TNF-α-activated endothelial cells. As expected, 2-MCA significantly inhibited monocyte (U937) adhesion to endothelial cells. CONCLUSION: We concluded that 2-MCA protects of myocardial I/R-injury due to antioxidant and anti-inflammatory action possibly by HO-1 induction which can be explained why Cinnamomum cassia has been used in inflammatory disorders.

Anti-inflammatory effect of ethyl acetate extract from Cissus quadrangularis Linn may be involved with induction of heme oxygenase-1 and suppression of NF-κB activation.

AIM OF THE STUDY: Cissus quadrangularis (family: Vitaceae) has been widely used in traditional herbal medicine for the treatment of hemorrhoids, gastric ulcers and bone healing. In the present study, we determined the anti-inflammatory activity and the molecular mechanism of the ethyl acetate extract of Cissus quadrangularis stem (CQE) in LPS-stimulated RAW 264.7 macrophage cells. MATERIALS AND METHODS: The inhibitory effect of CQE on LPS-induced nitric oxide (NO) production was evaluated in conditioned media. Cell viability was monitored by MTT assay. Protein and mRNA expressions were determined by RT-PCR and Western blotting analysis, respectively. RESULTS: CQE potently inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophage cells in a dose-dependent manner. The mRNA and protein expressions of inducible nitric oxide synthase (iNOS) were suppressed also by CQE as was p65 NF-κB nuclear translocation. Further study demonstrated that CQE by itself induced heme oxygenase-1 (HO-1) gene expression at the protein and mRNA levels in dose- and time-dependent manner. In addition, the inhibitory effects of CQE on NO production were abrogated by a HO-1 inhibitor, zinc protoporphyrin IX (ZnPP). CONCLUSIONS: Collectively, these results suggest that CQE exerts an anti-inflammatory effect in macrophages, at least in part, through the induction of HO-1 expression. These findings provide the scientific rationale for anti-inflammatory therapeutic use of Cissus quadrangularis stem.

Boschniakia rossica prevents the carbon tetrachloride-induced hepatotoxicity in rat.

The present study was undertaken to investigate the hepatoprotective effect of Boschniakia rossica extract (BRE), rich in phenylpropanoid glycoside and iridoid glucoside, on CCl(4)-induced liver damage. Male Wistar rats were randomly divided into six groups of ten each. While the first group was maintained as normal control, groups II-VI were administered 0.5 ml/kg CCl(4) (model), 100mg/kg BRE plus CCl(4), 200mg/kg BRE plus CCl(4), 50mg/kg silymarin plus CCl(4) and 200mg/kg BRE, respectively. CCl(4) challenge not only elevated the serum marker enzyme activities and reduced albumin (ALB) level but also increased liver oxidative stress, as evidenced by elevated lipid hydroperoxide (LOOH) and malondialdehyde (MDA) concentrations, combined with suppressed potential of hepatic antioxidative defense system including superoxide dismutase (SOD), glutathione peroxidase (GPx) activities and reduced glutathione (GSH) content. Furthermore, serum tumor necrosis factor-α (TNF-α), hepatic nitrite level, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein contents were elevated while cytochrome P450 2E1 (CYP2E1) expression and function were inhibited. Preadministration of BRE not only reversed the significant changes in serum toxicity markers, hepatic oxidative stress, xenobiotic metabolizing enzymes and proinflammatory mediators induced by CCl(4) but also restored liver CYP2E1 level and function. Interestingly, the protein expression of heme oxygenase-1 (HO-1) was further elevated by BRE treatment, which was markedly increased after CCl(4) challenge. These results demonstrate that BRE exhibits protective effect on CCl(4)-induced acute hepatic injury via, at least in part, reduced oxidative stress, suppressed inflammatory responses and induced HO-1 protein expression combined with improved CYP2E1 level and function in liver.

Inhibition of heme oxygenase activity in newborn mice by azalanstat.

Inhibition of heme oxygenase (HO), the rate-limiting enzyme in heme catabolism, may be an ideal strategy for preventing neonatal jaundice. Although natural and synthetic heme analogs, called metalloporphyrins (Mps), have been extensively investigated for this purpose, some Mps are phototoxic, affect the activity of other enzymes, or induce HO-1 transcription-properties that may limit their clinical use. Another class of compounds, imidazole-dioxolanes, has been shown to selectively inhibit the inducible isozyme HO-1. Therefore, we investigated the efficacy of azalanstat (AZA), an imidazole-dioxolane, towards inhibiting HO activity in 7-day-old mice. We found that a single dose of AZA at 500 micromol.kg(-1) body mass (BM) administered i.p. significantly inhibited HO activity and reduced in vivo bilirubin production. In the spleen, HO inhibition (>50%) was observed within 0.25-3 h after administration. After 24 h, however, spleen HO activity, HO-1 protein, and HO-1 mRNA levels significantly increased 1.2-, 2.4-, and 4.0-fold, respectively. We conclude that AZA effectively inhibits in vivo HO activity only at a high dose and that it also induces spleen HO-1 gene transcription. Therefore, other imidazole-dioxolanes should be evaluated to determine whether they are more potent than AZA for use in treating neonatal jaundice.

Induction of heme oxygenase-1 by plant extract KIOM-79 via Akt pathway and NF-E2 related factor 2 in pancreatic beta-cells.

The objective of the present study was to determine the mechanism by which KIOM-79 induced heme oxygenase-1 (HO-1) in rat pancreatic beta-cells (RINm5F). A mixture of plant extracts (KIOM-79) was obtained from Magnolia officinalis, Pueraria lobata, Glycyrrhiza uralensis, and Euphorbia pekinensis. HO-1, an antioxidant phase 2 enzyme, was previously reported to possess cytoprotective properties in pancreatic beta-cells. KIOM-79 induced heme oxygenase-1 (HO-1) expression at the mRNA and protein levels, leading to increased HO-1 activity. The transcription factor, NF-E2 related factor 2 (Nrf2), regulates the antioxidant response element (ARE) of the phase 2 detoxifying and antioxidant enzymes, resulting in modulation of HO-1 expression. KIOM-79 increased nuclear translocation, ARE binding, and transcriptional activity of Nrf2. Furthermore, KIOM-79 also elicited activation of Akt (protein kinase B) and LY294004 (inhibitor of Akt)-suppressed KIOM-79-induced activation of Nrf2, which subsequently decreased HO-1 protein levels. Taken together, these data suggest that KIOM-79 augments the cellular antioxidant defense capacity through induction of HO-1 via the Akt-Nrf2-ARE signaling pathway, thereby protecting cells from streptozotocin-induced oxidative stress.

[Correlation of HO-2 expression in the corpus cavernosum with erectile disfunction in rats with chronic renal failure].

OBJECTIVE: To detect the expression of HO-2 in the corpus cavernosum of rats with chronic renal failure (CRF) , and investigate the role of HO-2 in penile erection and its association with testosterone. METHODS: Fifteen 10-week-old SD rats underwent 5/6 kidney removal for the establishment of CRF models, and another 15 included as controls. Twelve weeks later, both the two groups of animals were subjected to electrostimulation of the cavernous nerve for the detection of intracavernosal pressure (ICP) and mean arterial pressure (MAP), and the protein contents of HO-2, nNOS and eNOS in the penile tissues were determined by Western blot and immunohistochemical analysis. RESULTS: The ICPmax/MAP after 3 V and 5 V stimulation of the cavernous nerve was (0.121 +/- 0.084) and (0.135 +/- 0.088), the serum testosterone level was (1.190 +/- 0.946) nmol/L, and the expression of HO-2 was (0.510 +/- 0.397) in the CRF group, all significantly lower than in the control rats, which were (0.263 +/- 0.147 and 0.244 +/- 0.089), (7.800 +/- 5.001) nmol/L (P<0.01) and (2.672 +/- 1.720, P<0.01), respectively. There was a correlation between the decrease of HO-2 expression and the reduction of serum testosterone (r = 0.902, P < 0.01). CONCLUSION: The lowered level of serum testosterone and decreased contents of HO-2, eNOS and nNOS may play a role in CRF-induced ED.

Induction of heme oxygenase-1 by traditional Chinese medicine formulation ISF-1 and its ingredients as a cytoprotective mechanism against oxidative stress.

Traditional medicines are clinically used to treat post-stroke disorders in China. In search of alternative medicines for post-stroke rehabilitation, we recently identified the heme oxygenase-1 (HO-1) pathway as a key mechanism underlying the biological activities of the ischemic stroke formulation ISF-1. This study was designed to further investigate ISF-1 for HO-1 induction in cultured human cells and corresponding cytoprotective effects against oxidative injury. A rat stroke model induced by middle cerebral artery occlusion was employed to verify the activity of ISF-1 in vivo. It was found that HO-1 expression was induced by ISF-1 in a dose- and time-dependent manner. Four ingredients from ISF-1 were identified to be responsible for HO-1 induction. The appropriate combinations of these active ingredients or purified compounds resulted in synergistic induction of HO-1 expression. A minimal HO-1-inducing formulation was prepared and showed significant cytoprotection against H2O2-induced oxidative stress. Collectively, the herbal formulation ISF-1 was capable of inducing HO-1 expression, in vitro and in vivo, offering a potential mechanism for post-stroke rehabilitation. This study may shed light on the development of mechanism-defined therapies based on traditional herbal remedies.

Inchinkoto, a herbal medicine, and its ingredients dually exert Mrp2/MRP2-mediated choleresis and Nrf2-mediated antioxidative action in rat livers.

Inchinkoto (ICKT), a herbal medicine, has been recognized in Japan and China as a "magic bullet" for jaundice. To explore potent therapeutic agents for cholestasis, the effects of ICKT or its ingredients on multidrug resistance-associated protein 2 (Mrp2/ MRP2)-mediated choleretic activity, as well as on antioxidative action, were investigated using rats and chimeric mice with livers that were almost completely repopulated with human hepatocytes. Biliary excretion of Mrp2 substrates and the protein mass, subcellular localization, and mRNA level of Mrp2 were assessed in rats after 1-wk oral administration of ICKT or genipin, a major ingredient of ICKT. Administration of ICKT or genipin to rats for 7 days increased bile flow and biliary excretion of bilirubin conjugates. Mrp2 protein and mRNA levels and Mrp2 membrane densities in the bile canaliculi and renal proximal tubules were significantly increased in ICKT- or genipin-treated rat livers and kidneys. ICKT and genipin, thereby, accelerated the disposal of intravenously infused bilirubin. The treatment also increased hepatic levels of heme oxygenase-1 and GSH by a nuclear factor-E2-related factor (Nrf2)-dependent mechanism. Similar effects of ICKT on MRP2 expression levels were observed in humanized livers of chimeric mice. In conclusion, these findings provide the rationale for therapeutic options of ICKT and its ingredients that should potentiate bilirubin disposal in vivo by enhancing Mrp2/MRP2-mediated secretory capacities in both livers and kidneys as well as Nrf2-mediated antioxidative actions in the treatment of cholestatic liver diseases associated with jaundice.

Regulation and expression of heme oxygenase enzymes in aged-rat brain: age related depression in HO-1 and HO-2 expression and altered stress-response.

The heme oxygenase isozymes, HO-1 and HO-2, oxidatively cleave the heme molecule to produce biliverdin and the gaseous messenger, CO. The cleavage results in the release of iron, a regulator of transferrin, ferritin, and nitric oxide (NO) synthase gene expression. Biliverdin reductase (BVR) then catalyzes the reduction of biliverdin, generating the potent intracellular antioxidant, bilirubin. We report an age-related decrease in HO-1 and HO-2 expression present in select brain regions including the hippocampus and the substantia nigra, that are involved in the high order cognitive processes of learning and memory. The age-related loss of monoxide-producing potential in select regions of the brain was not specific to the HO system but was also observed in neuronal NO-generating system. Furthermore, compared to 2-month old rats, the ability of aged brain tissue to respond to hypoxic/hyperthermia was compromised at both the protein and the transcription levels as judged by attenuated induction of HO-1 immunoreactive protein and its 1.8 Kb transcript. Neotrofin (AIT), a cognitive-enhancing and neuroprotective drug, caused a robust increase in HO-1 immunoreactive protein in select neuronal regions and increased the expression of HO-2 transcripts. The potential interplay between regulation of HO-2 gene expression and the serum levels of the adrenal steroids is discussed. We suggest the search for therapeutic agents that reverse the decline and aberrant stress response of HO enzymes may lead to effective treatment regimens for age-associated neuronal deficits.

Heme oxygenase-1 (Hsp32) is involved in the protection of small intestine by whole body mild hyperthermia from ischemia/reperfusion injury in rat.

AIM: The aim of the present study was to explore whether heme oxygenase-1 (HO-1) is involved in the hyperthermia-provided protection of the small intestine from ischemia/reperfusion injury in rats. METHODS: Intestinal damage was induced in male Sprague-Dawley rats by clamping both the superior mesenteric artery and the celiac trunk for 30 min, followed by reperfusion. Whole-body hyperthermia was induced in anesthetized rats by placement in a temperature-controlled water bath. Whole-body hyperthermia to a core temperature of 42-43 degrees C for 15 min was followed by passive cooling. We started the hyperthermic treatment 6 h before the vascular clamping. The severity of the mucosal injury was evaluated by several biochemical markers and histological findings. Hyperthermia-induced heat-shock proteins were detected by Western blotting. We also investigated the effect of zinc protoporphyrin IX (an HO-1 inhibitor) on the protective effect of hyperthermia. RESULTS: The rats, which were killed after ischemia/reperfusion, had severe intestinal inflammation. Hyperthermia significantly induced the production of Hsp70 and HO-1 in intestinal mucosa and significantly reduced ischemia/reperfusion-induced mucosal injury. The combination of zinc protoporphyrin IX with hyperthermia extinguished the protective effects of hyperthermia on ischemia/reperfusion injury. CONCLUSION: Hyperthermia protects against ischemia/reperfusion injury in rat small intestine through the expression of heat-shock proteins, especially HO-1.