Apocynin ameliorates cadmium-induced hypertension through elevation of endothelium nitric oxide synthase

Oxidant-induced disruption of vascular K+ channel function: implications for diabetic vasculopathy

Diabetes in humans a chronic metabolic disorder characterised by hyperglycaemia, it is associated with an increased risk of cardiovascular disease, disruptions to metabolism and vascular functions. It is also linked to oxidative stress and its complications. Its role in vascular dysfunctions is generally reported without detailed impact on the molecular mechanisms. Potassium ion channel (K+ channels) are key regulators of vascular tone, and as membrane proteins, are modifiable by oxidant stress associated with diabetes. This review manuscript examined the impact of oxidant stress on vascular K+ channel functions in diabetes, its implication in vascular complications and metabolic and cardiovascular diseases.

In vitro cadmium exposure induces structural damage and endothelial dysfunction in female rat aorta

Cadmium is a heavy metal that is widespread in the environment and has been described as a metalloestrogen and a cardiovascular risk factor. Experimental studies conducted in male animals have shown that cadmium exposure induces vascular dysfunction, which could lead to vasculopathies caused by this metal. However, it is necessary to investigate the vascular effects of cadmium in female rats to understand its potential sex-dependent impact on the cardiovascular system. While its effects on male rats have been studied, cadmium may act differently in females due to its potential as a metalloestrogen. In vitro studies conducted in a controlled environment allow for a direct assessment of cadmium's impact on vascular function, and the use of female rats ensures that sex-dependent effects are evaluated. Therefore, the aim of this study was to investigate the in vitro effects of Cadmium Chloride (CdCl2, 5 µM) exposure on vascular reactivity in the isolated aorta of female Wistar rats. Exposure to CdCl2 damaged the architecture of the vascular endothelium. CdCl2 incubation increased the production and release of O2•-, reduced the participation of potassium (K+) channels, and increased the participation of the angiotensin II pathway in response to phenylephrine. Moreover, estrogen receptors alpha (Erα) modulated vascular reactivity to phenylephrine in the presence of cadmium, supporting the hypothesis that cadmium could act as a metalloestrogen. Our results demonstrated that in vitro cadmium exposure induces damage to endothelial architecture and an increase in oxidative stress in the isolated aorta of female rats, which could precipitate vasculopathies. Graphical Abstract. Own source from Canva and Servier Medical Art servers.

Aortic dysfunction by chronic cadmium exposure is linked to multiple metabolic risk factors that converge in anion superoxide production

CONTEXT

The chronic exposure to Cadmium (Cd) constitute an risk to develop hypertension and cardiovascular diseases associated with the increase of oxidative stress.

OBJECTIVE

In this study, we investigate the role of metabolic changes produced by exposure to Cd on the endothelial dysfunction via oxidative stress.

METHODS

Male Wistar rats were exposed to Cd (32.5-ppm) for 2-months. The zoometry and blood pressure were evaluated, also glucose and lipids profiles in serum and vascular reactivity evaluated in isolated aorta rings.

RESULTS

Rats exposed to Cd showed an increase of blood pressure and biochemical parameters similar to metabolic syndrome. Additionally, rats exposed to Cd showed a reduced relaxation in aortic rings, which was reversed after the addition of SOD and apocynin an inhibitor of NADPH.

CONCLUSION

The Cd-exposition induced hypertension and endothelial injury by that modifying the vascular relaxation and develop oxidative stress via NADPH oxidase, superoxide and loss nitric oxide bioavailability.

Combined apocyanin and aspirin treatment activates the PI3K/Nrf2/HO-1 signaling pathway and ameliorates preeclampsia symptoms in rats

OBJECTIVE

Pre-eclampsia (PE) is a pregnancy-associated disease characterized by placental dysfunction and increased oxidative stress. Apocyanin is a potent antioxidant and anti-inflammatory which has shown beneficial effects on PE pathogenesis. Aspirin is recognized as the recommendable drug in PE prevention and therapy. Therefore, we aimed to investigate the effects of combining apocyanin and aspirin to treat PE on rat models induced by N-nitro-L-arginine methyl ester (L-NAME) from gestational day (GD) 6 to 16 and elucidate the potential mechanisms.

METHODS

First, female pregnant rats were divided into five different groups: pregnant control, PE, PE + apocyanin, PE + aspirin, and PE + apocyanin + aspirin. Animals received apocyanin (16 mg/kg/day) orally or aspirin by gavage (1.5 mg/kg BM/day) from GD 4 to 16. Blood pressure and urine protein content were monitored every 4 days.

RESULTS

In the PE rat model, elevated systolic blood pressure and proteinuria were ameliorated by the combination of apocyanin and aspirin. Meanwhile, compared with single-dose apocyanin or aspirin, the combined treatment significantly corrected abnormal pregnancy outcomes, decreased sFlt-1 and PlGF, and alleviated oxidative stress both in blood and placental tissues. Moreover, the combined treatment upregulated PI3K, Akt, Nrf2, and HO-1 protein levels in the placental tissues from PE rats.Conclusion: Overall, our results suggested that combined treatment of apocyanin and aspirin ameliorates the PE symptoms compared with single-dose apocyanin or aspirin in a PE rat model. Also, we demonstrated that activating the PI3K/Nrf2/HO-1 pathway can be a valuable therapeutic target to improve the pregnancy outcomes of PE.

Cadmium-induced hypertension is associated with renal myosin light chain phosphatase inhibition via increased T697 phosphorylation and p44 mitogen-activated protein kinase levels

Dietary intake of the heavy metal cadmium (Cd²⁺) is implicated in hypertension, but potassium supplementation reportedly mitigates hypertension. This study aims to elucidate the hypertensive mechanism of Cd²⁺. Vascular reactivity and protein expression were assessed in Cd²⁺-exposed rats for 8 weeks to determine the calcium-handling effect of Cd²⁺ and the possible signaling pathways and mechanisms involved. Cd²⁺ induced hypertension in vivo by significantly (p < 0.001) elevating systolic blood pressure (160 ± 2 and 155 ± 1 vs 120 ± 1 mm Hg), diastolic blood pressure (119 ± 2 and 110 ± 1 vs 81 ± 1 mm Hg), and mean arterial pressure (133 ± 2 and 125 ± 1 vs 94 ± 1 mm Hg) (SBP, DBP, and MAP, respectively), while potassium supplementation protected against elevation of these parameters. The mechanism involved augmentation of the phosphorylation of renal myosin light chain phosphatase targeting subunit 1 (MYPT1) at threonine 697 (T697) (2.58 ± 0.36 vs 1 ± 0) and the expression of p44 mitogen-activated protein kinase (MAPK) (1.78 ± 0.20 vs 1 ± 0). While acetylcholine (ACh)-induced relaxation was unaffected, 5 mg/kg b.w. Cd²⁺ significantly (p < 0.001) attenuated phenylephrine (Phe)-induced contraction of the aorta, and 2.5 mg/kg b.w. Cd²⁺ significantly (p < 0.05) augmented sodium nitroprusside (SNP)-induced relaxation of the aorta. These results support the vital role of the kidney in regulating blood pressure changes after Cd²⁺ exposure, which may be a key drug target for hypertension management. Given the differential response to Cd²⁺, it is apparent that its hypertensive effects could be mediated by myosin light chain phosphatase (MLCP) inhibition via phosphorylation of renal MYPT1-T697 and p44 MAPK. Further investigation of small arteries and the Rho-kinase/MYPT1 interaction is recommended.

Addressing the Challenge of Potentially Hazardous Elements in the Reduction of Hypertension, Diabetes and Chronic Kidney Disease in the Caribbean

BACKGROUND

Environmental surveys have characterized trace elements such as lead (Pb), cadmium (Cd) and arsenic (As) as potential risk factors for non-communicable diseases. There have been few studies conducted in the Caribbean region to explore, define or clarify such findings locally. Furthermore, local pollution control efforts are often juxtaposed against more seemingly immediate economic concerns in poor communities.

OBJECTIVES

The present commentary is a call to action for the evaluation of potentially hazardous elements as potential risk indicators and/or factors of common noncommunicable diseases in the Caribbean.

DISCUSSION

Findings from Jamaican studies have identified exposure to potentially hazardous elements (PHE) via water, food, and other anthropogenic activities to the detriment of the resident population. Several attempts have been made to abate toxic metal exposure in children with relative success. However, high levels of PHE have been noted in vulnerable populations such as patients with hypertension, diabetes mellitus and chronic kidney disease. Currently, there is low priority towards infrastructure building within the Caribbean region that would promote and sustain long term monitoring and better inform environmental polices impacting chronic diseases.

CONCLUSIONS

Further investigations are needed to clarify the role that PHE play in increasing the risk or progression of non-communicable diseases, especially in vulnerable groups.

COMPETING INTERESTS

The authors declare no competing financial interests.

Apocynin inhibits placental TLR4/NF-κB signaling pathway and ameliorates preeclampsia-like symptoms in rats

OBJECTIVE

We aimed to investigate the potency of apocynin in ameliorating preeclampsia and explore the underlying mechanisms.

METHODS

Preeclampsia model was constructed in rats by administering 200 mg/kg/day L-NAME. Apocynin was given orally in drinking water. Systolic blood pressure and proteinuria were monitored during treatment. Survival rate rate of the pups and placental weight were assessed. Serum sFlt-1, PIGF, IL-6 and placental TLR4 levels were measured using ELISA or qRT-PCR.

RESULTS

Apocynin dose-dependently decreased systolic blood pressure and proteinuria during gestation. Survival rate of the pups and placental weight were improved by apocynin treatment. Apocynin ameliorated the imbalance of sFlt-1 and PIGF in serum and placenta of rats with preeclampsia. Apocynin attenuated serum inflammatory cytokine expression and placental inflammation most likely due to downregulation of the placental TLR4/NF-kB pathway in L-NAME treated rats.

CONCLUSIONS

Apocynin potently ameliorates the L-NAME-induced preeclampsia, which is achieved by re-balancing the sFlt-1 and PIGF levels, attenuating inflammation, and inhibiting TLR4/NF-κB p65 signaling.

The Role of Antioxidants in the Prevention of Cadmium-Induced Endothelial Dysfunction

Background:

Cadmium is a worldwide spread toxicant that accumulates in tissues and affects many organs, mainly through oxidative damage. Oxidative stress is often associated with cardiovascular diseases and, when it affects vessels, it induces endothelial dysfunction, which, in turn, could precipitate atherosclerosis and hypertension. Therefore, it is reasonable to suggest antioxidant supplementation as a therapy against cadmiuminduced endothelial dysfunction.

Objective:

This literature review aims to present the mechanisms involving oxidative stress in which cadmium induces endothelial dysfunction and the benefits of antioxidant supplementation as a therapeutic strategy against its harmful effects.

Methods:

On PubMed Central, articles that contemplated studies on cadmium intoxication and associated oxidative stress with endothelial dysfunction as well as articles that reported the use of antioxidant supplementation in an attempt to prevent or avoid endothelial dysfunction induced by cadmium exposure were selected.

Results:

Most of the studies that associated cadmium intoxication with endothelial dysfunction suggested oxidative stress as the major mechanism for this damage. Furthermore, experimental studies also revealed that the administration of substances with antioxidant properties, such as ascorbic acid and curcumin, has beneficial effects on the prevention of such dysfunction, reducing reactive oxygen species within the vessels, preventing a reduction in the amount of glutathione and the increase in blood pressure observed in animals exposed to cadmium.

Conclusion:

Antioxidant therapy demonstrated to be a potential treatment to reduce cardiovascular injuries provoked by cadmium, but more studies are needed to determine the best antioxidant substance and dose to treat or avoid this complication.

Cadmium exposure activates NADPH oxidase, renin-angiotensin system and cyclooxygenase 2 pathways in arteries, inducing hypertension and vascular damage

Exposure to high concentrations of cadmium (Cd), widely used in many industries and found in air, food and contaminated water, is not uncommon. Cd damages the cardiovascular system, but the vascular mechanisms involved are not fully understood. This study investigated the mechanisms involved in cardiovascular damage after exposure to high Cd concentrations. Three-month-old male Wistar rats were treated intraperitoneally for 14 days with distilled water (Untreated group) or 1 mg/kg cadmium chloride (Cd group). We investigated the systolic blood pressure (SBP) and vascular reactivity of mesenteric resistance arteries (MRA) and the aorta by analysing contractile and relaxation responses in the absence and presence of the endothelium; we also evaluated pathways involved in vascular tone regulation. Superoxide anion production, COX-2 protein expression and in situ detection of COX-2, AT-1, and NOX-1 were evaluated. Oxidative status, creatinine level and angiotensin-converting enzyme (ACE) activity in plasma were also evaluated. Fourteen-day exposure to a high Cd concentration induced hypertension associated with vascular dysfunction in MRA and the aorta. In both vessels, there was increased participation of cyclooxygenase 2 (COX2), angiotensin II type 1 (AT1) receptor and NOX1. MRA also presented endothelial dysfunction, denoted by impaired acetylcholine-mediated relaxation. All vascular changes were accompanied by increased reactive oxygen species production and COX2, NOX1 and AT1 receptor expression in vascular tissue. Overall, high Cd concentrations induced cardiovascular damage: hypertension, endothelial dysfunction and vascular damage in conductance and resistance arteries, NADPH oxidase, renin-angiotensin system and COX2 pathway activation.

Vasodilator and hypotensive effects of pure compounds and hydroalcoholic extract of Xenophyllum poposum (Phil) V.A Funk (Compositae) on rats

BACKGROUND

Xenophyllum poposum is an endemic species of the Andes Cordillera, popularly known as Popusa. Popusa is widely used by mountain communities as a folk medicine to treat altitude sickness and hypertension.

PURPOSE

The aim of this study is to evaluate the hypotensive effects and vascular reactivity of Popusa extracts and its pure isolated compounds.

METHODS

Hydroalcoholic extract of Xenophyllum poposum (HAE X. poposum; 40 mg/kg dose) were administered to rats by gavage and mean arterial pressures were recorded. Organ bath studies were conducted in endothelium-intact and denuded rings, and the vascular reactivity of the HAE X. poposum extract and its isolated compounds were compared and analysed. Cytosolic Ca²⁺ was measured in vascular smooth muscle cell line A7r5 using Fura2-AM.

RESULTS

HAE X. poposum significantly reduced the mean arterial blood pressure and heart rate in normotensive rats chronically treated with the extract, as well as mice acutely treated with the extract. A negative chronotropic effect was observed in the isolated rat heart. HAE X. poposum induced endothelial vasodilation mediated by nitric oxide (NO), reduced the contractile response to PE, and decreased PE-induced intracellular Ca²⁺ influx in vascular smooth muscle cells. Pure compounds isolated from HAE X. poposum such as 4‑hydroxy‑3-(3-methyl-2-butenyl) acetophenone, 5-acetyl-6‑hydroxy‑2-isopropenyl-2, and 3-dihydrobenzofurane (dihydroeuparin) also triggered endothelium-dependent vasodilation.

CONCLUSION

HAE X. poposum decreases blood pressure, heart rate and vascular response. The vasodilation properties of HAE X. poposum extract and its isolated compounds may act through the endothelial nitric oxide synthase, as well as calcium channel blocker mechanisms. The results of the present study provide the first qualitative analysis that supports the use of X. poposum in traditional folk medicine for the treatment of altitude sickness and hypertension.

Magnesium taurate attenuates progression of hypertension and cardiotoxicity against cadmium chloride-induced hypertensive albino rats

The present study was designed to evaluate the antihypertensive activity and cardioprotective effects of magnesium taurate against cadmium chloride (CdCl₂)-intoxicated albino rats. Sprague Dawley male albino rats (120-150 g) were divided into five groups having six animals in each group. Hypertension and cardiotoxicity were induced in animals by administration of CdCl₂ (0.5 mg/kg/day, i.p.) for four weeks. Magnesium taurate (2 and 4 mg/kg/day) was administered orally after induction of hypertension (after two weeks) in their respective groups concurrently with CdCl₂ for next two weeks. Amlodipine (3 mg/kg/day, p.o.) was used as a standard and administered after induction of hypertension. Blood pressure was monitored biweekly by using non-invasive blood pressure system and biochemical parameters and histopathology of the heart were evaluated after four weeks of the experimental protocol. During the four weeks of the experimental protocol, the toxic control group showed significant elevation of systolic and diastolic blood pressure concomitant with augmentation of cardiotoxicity as indicated by reduction in myocardial antioxidants including glutathione peroxidase, catalase, superoxide dismutase, reduced glutathione and increased malondialdehyde level in heart as compared to the normal group. The oral administrations of magnesium taurate significantly restored the blood pressure, myocardial antioxidants and malondialdehyde level as compared to toxic control group. In addition, histopathological examination showed that magnesium taurate treatments substantially reduced the myocardial damages against CdCl₂ treatment. The results suggest that magnesium taurate has prominent antihypertensive and cardioprotective activity via its potent antioxidant activity and can be used as a nutrition supplement to improve the cardiovascular health.

Magnesium taurate prevents cataractogenesis via restoration of lenticular oxidative damage and ATPase function in cadmium chloride-induced hypertensive experimental animals

Previously we found that hypertension potentiates the risk the cataractogenesis. In the present study, we investigated the protective effects of magnesium taurate (MgT) on hypertension and associated lenticular damages against cadmium chloride (CdCl₂)-induced hypertensive animals. Male Sprague-Dawley albino rats (150-180g) were assigned to five experimental groups (n=6). Among the five groups, normal group received 0.3% carboxymethyl cellulose (10ml/kg/day, p.o.). Hypertension control group received CdCl₂ (0.5mg/kg/day, i.p.). Tests and standard groups received MgT (3 and 6mg/kg/day, p.o.) and amlodipine (3mg/kg/day, p.o.) concurrently with CdCl₂ respectively_, for six consecutive weeks. Blood pressure, heart rate, and eyes were examined biweekly, and pathophysiological parameters in serum and eye lenses were evaluated after six weeks of the experimental protocol. The chronic administration of MgT concurrently with CdCl₂ significantly restored the blood pressure, serum and lens antioxidants (CAT, SOD, GPx, and GSH), MDA level, and ions (Na⁺, K⁺, and Ca²⁺). Additionally, MgT treatment led to significant increase in the lens proteins (total and soluble), Ca²⁺ ATPase, and Na⁺K⁺ ATPase activity as compared to hypertension control group. Ophthalmoscope observations indicated that MgT treatments delayed the progression of cataract against the hypertensive state. The study shows that MgT prevents the progression of cataractogenesis via restoration of blood pressure, lenticular oxidative damages, and lens ATPase functions in the hypertensive state. The results suggest that MgT supplement may play a beneficial role to manage hypertension and associated cataractogenesis.

Treatment of Rats with Apocynin Has Considerable Inhibitory Effects on Arylamine N-Acetyltransferase Activity in the Liver

The effect of apocynin on the activity of arylamine N-acetyltransferases (NATs) in excised liver samples was examined using eighteen Sprague-Dawley rats. Three groups of six animals each were fed a normal diet alone or a treatment of 50 or 100 mg/kg/day of apocynin via gavages for eight (8) weeks. Chronic in vivo administration of apocynin led to significant (p < 0.001) reduction of in vitro liver NAT activity up to 93% as compared with untreated rats (18.80 ± 2.10 μmols p-anisidine/min/μg liver protein). In vitro exposure of untreated liver homogenates to apocynin led to a dose-dependent inhibition of NAT activity with IC₅₀ = 0.69 ± 0.02 mM. In silico modelling of apocynin tautomers and radical species into human NAT crystal structures supported the hypothesis that thiol functionalities in NAT enzymes may be crucial in apocynin binding. The involvement of human NAT enzymes in different pathological conditions, such as cancer, has encouraged the research for selective NAT inhibitors in both humans and animal models with possible chemopreventive properties.

Discovery of GSK2795039, a Novel Small Molecule NADPH Oxidase 2 Inhibitor

AIMS

The NADPH oxidase (NOX) family of enzymes catalyzes the formation of reactive oxygen species (ROS). NOX enzymes not only have a key role in a variety of physiological processes but also contribute to oxidative stress in certain disease states. To date, while numerous small molecule inhibitors have been reported (in particular for NOX2), none have demonstrated inhibitory activity in vivo. As such, there is a need for the identification of improved NOX inhibitors to enable further evaluation of the biological functions of NOX enzymes in vivo as well as the therapeutic potential of NOX inhibition. In this study, both the in vitro and in vivo pharmacological profiles of GSK2795039, a novel NOX2 inhibitor, were characterized in comparison with other published NOX inhibitors.

RESULTS

GSK2795039 inhibited both the formation of ROS and the utilization of the enzyme substrates, NADPH and oxygen, in a variety of semirecombinant cell-free and cell-based NOX2 assays. It inhibited NOX2 in an NADPH competitive manner and was selective over other NOX isoforms, xanthine oxidase, and endothelial nitric oxide synthase enzymes. Following systemic administration in mice, GSK2795039 abolished the production of ROS by activated NOX2 enzyme in a paw inflammation model. Furthermore, GSK2795039 showed activity in a murine model of acute pancreatitis, reducing the levels of serum amylase triggered by systemic injection of cerulein.

INNOVATION AND CONCLUSIONS

GSK2795039 is a novel NOX2 inhibitor that is the first small molecule to demonstrate inhibition of the NOX2 enzyme in vivo.

Apocynin attenuates testicular ischemia-reperfusion injury in rats

OBJECTIVE

This study was designed to examine the possible protective effect of apocynin, a NADPH oxidase inhibitor, against torsion/detorsion (T/D) induced ischemia/reperfusion (I/R) injury in testis.

METHODS

Male Wistar albino rats were divided into sham-operated control, and either vehicle, apocynin 20mg/kg- or apocynin 50mg/kg-treated T/D groups. In order to induce I/R injury, left testis was rotated 720° clockwise for 4 hours (torsion) and then allowed reperfusion (detorsion) for 4 hours. Left orchiectomy was done for the measurement of tissue malondialdehyde (MDA), glutathione (GSH) levels, myeloperoxidase (MPO) activity, and luminol, lucigenin, nitric oxide (NO) and peroxynitrite chemiluminescences (CL). Testicular morphology was examined by light microscopy.

RESULTS

I/R caused significant increases in tissue luminol, lucigenin, nitric oxide and peroxynitrite CL demonstrating increased reactive oxygen and nitrogen metabolites. As a result of increased oxidative stress tissue MPO activity, MDA levels were increased and antioxidant GSH was decreased. On the other hand, apocynin treatment reversed all these biochemical indices, as well as histopathological alterations that were induced by I/R. According to data, although lower dose of apocynin tended to reverse the biochemical parameters, high dose of apocynin provides better protection since values were closer to the control levels.

CONCLUSION

Findings of the present study suggest that NADPH oxidase inhibitor apocynin by inhibiting free radical generation and increasing antioxidant defense exerts protective effects on testicular tissues against I/R. The protection with apocynin was more pronounced with high dose.

Tetrahydrocurcumin protects against cadmium-induced hypertension, raised arterial stiffness and vascular remodeling in mice

Background

Cadmium (Cd) is a nonessential heavy metal, causing oxidative damage to various tissues and associated with hypertension. Tetrahydrocurcumin (THU), a major metabolite of curcumin, has been demonstrated to be an antioxidant, anti-diabetic, anti-hypertensive and anti-inflammatory agent. In this study, we investigated the protective effect of THU against Cd-induced hypertension, raised arterial stiffness and vascular remodeling in mice.

Methods

Male ICR mice received CdCl₂ (100 mg/l) via drinking water for 8 weeks. THU was administered intragastrically at dose of 50 or 100 mg/kg/day concurrently with Cd treatment.

Results

Administration of CdCl₂ significantly increased arterial blood pressure, blunted vascular responses to vasoactive agents, increased aortic stiffness, and induced hypertrophic aortic wall remodeling by increasing number of smooth muscle cells and collagen deposition, decreasing elastin, and increasing matrix metalloproteinase (MMP)-2 and MMP-9 levels in the aortic medial wall. Supplementation with THU significantly decreased blood pressure, improved vascular responsiveness, and reversed the structural and mechanical alterations of the aortas, including collagen and elastin deposition. The reduction on the adverse response of Cd treatment was associated with upregulated eNOS and downregulated iNOS protein expressions, increased nitrate/nitrite level, alleviated oxidative stress and enhanced antioxidant glutathione. Moreover, THU also reduced the accumulation of Cd in the blood and tissues.

Conclusions

Our results suggest that THU ameliorates cadmium-induced hypertension, vascular dysfunction, and arterial stiffness in mice through enhancing NO bioavailability, attenuating oxidative stress, improving vascular remodeling and decreasing Cd accumulation in other tissues. THU has a beneficial effect in moderating the vascular alterations associated with Cd exposure.

Juvenile antioxidant treatment prevents adult deficits in a developmental model of schizophrenia

Abnormal development can lead to deficits in adult brain function, a trajectory likely underlying adolescent-onset psychiatric conditions such as schizophrenia. Developmental manipulations yielding adult deficits in rodents provide an opportunity to explore mechanisms involved in a delayed emergence of anomalies driven by developmental alterations. Here we assessed whether oxidative stress during presymptomatic stages causes adult anomalies in rats with a neonatal ventral hippocampal lesion, a developmental rodent model useful for schizophrenia research. Juvenile and adolescent treatment with the antioxidant N-acetyl cysteine prevented the reduction of prefrontal parvalbumin interneuron activity observed in this model, as well as electrophysiological and behavioral deficits relevant to schizophrenia. Adolescent treatment with the glutathione peroxidase mimic ebselen also reversed behavioral deficits in this animal model. These findings suggest that presymptomatic oxidative stress yields abnormal adult brain function in a developmentally compromised brain, and highlight redox modulation as a potential target for early intervention.

Curcumin protects against cadmium-induced vascular dysfunction, hypertension and tissue cadmium accumulation in mice

Curcumin from turmeric is commonly used worldwide as a spice and has been demonstrated to possess various biological activities. This study investigated the protective effect of curcumin on a mouse model of cadmium (Cd)—induced hypertension, vascular dysfunction and oxidative stress. Male ICR mice were exposed to Cd (100 mg/L) in drinking water for eight weeks. Curcumin (50 or 100 mg/kg) was intragastrically administered in mice every other day concurrently with Cd. Cd induced hypertension and impaired vascular responses to phenylephrine, acetylcholine and sodium nitroprusside. Curcumin reduced the toxic effects of Cd and protected vascular dysfunction by increasing vascular responsiveness and normalizing the blood pressure levels. The vascular protective effect of curcumin in Cd exposed mice is associated with up-regulation of endothelial nitric oxide synthase (eNOS) protein, restoration of glutathione redox ratio and alleviation of oxidative stress as indicated by decreasing superoxide production in the aortic tissues and reducing plasma malondialdehyde, plasma protein carbonyls, and urinary nitrate/nitrite levels. Curcumin also decreased Cd accumulation in the blood and various organs of Cd-intoxicated mice. These findings suggest that curcumin, due to its antioxidant and chelating properties, is a promising protective agent against hypertension and vascular dysfunction induced by Cd.