The anti-oxidant and anti-apoptotic effects of nebivolol and zofenopril in a model of cerebral ischemia/reperfusion in rats

Ameliorative effect of nebivolol in doxorubicin-induced cardiotoxicity

This study aimed to investigate the potential of nebivolol in preventing doxorubicin-induced cardiotoxicity by targeting the inflammatory, oxidative, and apoptotic pathways. Twenty-eight male rats were randomly divided into four groups, each consisting of seven rats. The control group received standard diets and unrestricted access to water. The rats in the normal saline (N/S) group were administered a 0.9% normal saline solution for two weeks. The doxorubicin group (the "induced group") received doxorubicin at a dosage of 2.5 mg/kg three times per week for two weeks. The nebivolol group received an oral dose of 4 mg/kg of nebivolol for the same duration. The cardiac tissues of rats treated with doxorubicin exhibited increased levels of tumor necrosis factor, interleukin-1, malondialdehyde, and caspase-3 compared to the normal saline control group (p<0.05), along with decreased levels of total antioxidant capacity and Bcl-2. These results show that doxorubicin is harmful to the heart. The administration of nebivolol significantly reduced the cardiotoxic effects induced by doxorubicin, as indicated by a statistically significant decrease in the levels of inflammatory markers, specifically tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) (p<0.05). The nebivolol group exhibited a significant decrease in malondialdehyde levels, which serves as a signal of oxidation, in cardiac tissue compared to the doxorubicin-only group (p<0.05). Additionally, the nebivolol group showed a significant increase in overall antioxidant capacity. Nebivolol dramatically attenuated doxorubicin-induced cardiotoxicity in rats, likely by interfering with oxidative stress, the inflammatory response, and the apoptotic pathway.

Extemporaneous combination therapy with nebivolol/zofenopril in hypertensive patients: usage in Italy

OBJECTIVE

Clinically describing hypertensive patients initiating nebivolol/zofenopril extemporaneous combination (NZ-EXC) and estimating the number of patients currently receiving NZ-EXC and of those potentially eligible for the fixed-dose combination of the two molecules (NZ-FDC) in Italy.

METHODS

This retrospective observational study used data from IQVIA Italian Longitudinal Patient Database (LPD). Adult hypertensive patients firstly prescribed NZ-EXC between 1 July 2011 and 30 June 2020 were identified and their demographic and clinical characteristics were extracted. Treatment adherence was evaluated as proportion of days covered (PDC) and classified as low (PDC <40%), intermediate (PDC ≥40% and <80%) or high (PDC ≥80%). Two additional cohorts were identified in 2019 to provide the national-level yearly estimates of patients prescribed NZ-EXC and of patients eligible for NZ-FDC.

RESULTS

In total 1745 patients were prescribed NZ-EXC: 60% were women; mean age was 65 years. The most frequent comorbidities were dyslipidemia (19.0%), diabetes (15.5%) and thyroid diseases (13.1%); the most common co-prescribed treatments were antithrombotics (29.1%), lipid-lowering agents (28.8%), nonsteroidal anti-inflammatory drugs (26.1%) and antihyperglycemic agents (13.5%). Mean PDC was 39%, and 57% of the patients had a PDC < 40%. The yearly estimate of patients prescribed NZ-EXC in 2019 was 59,000, while potential users of NZ-FDC were estimated to be 29,000.

CONCLUSIONS

NZ-EXC in hypertensive patients is a common practice in Italy and the development of a NZ-FDC can be a viable treatment option for hypertensive patients who are already receiving nebivolol and zofenopril through the concomitant assumption of two distinct pills. As supported by scientific literature, FDCs of antihypertensive drugs could simplify treatment, improve adherence and potentially reduce health-care costs as related to a better control of blood pressure.

Recent Advances in the Endogenous Brain Renin-Angiotensin System and Drugs Acting on It

The RAS (renin-angiotensin system) is the part of the endocrine system that plays a prime role in the control of essential hypertension. Since the discovery of brain RAS in the seventies, continuous efforts have been put by the scientific committee to explore it more. The brain has shown the presence of various components of brain RAS such as angiotensinogen (AGT), converting enzymes, angiotensin (Ang), and specific receptors (ATR). AGT acts as the precursor molecule for Ang peptides—I, II, III, and IV—while the enzymes such as prorenin, ACE, and aminopeptidases A and N synthesize it. AT1, AT2, AT4, and mitochondrial assembly receptor (MasR) are found to be plentiful in the brain. The brain RAS system exhibits pleiotropic properties such as neuroprotection and cognition along with regulation of blood pressure, CVS homeostasis, thirst and salt appetite, stress, depression, alcohol addiction, and pain modulation. The molecules acting through RAS predominantly ARBs and ACEI are found to be effective in various ongoing and completed clinical trials related to cognition, memory, Alzheimer's disease (AD), and pain. The review summarizes the recent advances in the brain RAS system highlighting its significance in pathophysiology and treatment of the central nervous system-related disorders.

Gastroprotective effects of nebivolol and simvastatin against cold restraint stress-induced gastric ulcer in rats

Gastric ulcer is one of the most serious diseases. Nebivolol (Neb), a β1-blocker, exhibits vasodilator and anti-oxidative properties, simvastatin (Sim) antihyperlipidemic drug, exhibits anti-oxidative, anti-inflammatory properties and promote endogenous nitric oxide (NO) production. The aim of this study was to evaluate the gastroprotective effects of Neb and Sim against cold restraint stress (CRS)-induced gastric ulcer in rats. Rats were restrained, and maintained at 4°C for 3 hours. Animals were divided into six groups; control group, CRS group, and four treatment groups received ranitidine (Ran), Neb, Sim and both Neb and Sim. Treatments were given orally on a daily basis for 7 days prior to CRS. The gastroprotective effects of Neb and Sim were assessed biochemically by measuring variations in prostaglandins E2, NO, reduced glutathione and malondialdehyde, and functionally by estimating force of contractions of isolated rat fundus in the studied groups in response to acetylecholine stimulation and morphologically using hematoxylin and eosin staining, periodic acid Schiff's reaction and immunohistochemistry for cyclooxygenase 2 in gastric mucosa. CRS caused significant ulcerogenic effect. Alternatively, pretreatment with Ran, Neb, and Sim significantly corrected biochemical findings, pharmacological and histological studies.

Incidence of hypoplastic posterior communicating artery and fetal posterior cerebral artery in Andhra population of India: a retrospective 3-Tesla magnetic resonance angiographic study

The posterior communicating arteries (PCoA) are important component of collateral circulation between the anterior and posterior part of circle of Willis (CW). The hypoplasia or aplasia of PCoA will reflect on prognosis of the neurological diseases. Precise studies of the incidence of hypoplastic PCoA in Andhra Pradesh population of India are hitherto unreported, since the present study was undertaken. Two hundred and thirty one magnetic resonance angiography (MRA) images were analyzed to identify the hypoplasia of PCoA and presence of fetal type of posterior cerebral artery (f-PCA) in patients with different neurological symptoms. All the patients underwent 3.0T MRI exposure. The results were statistically analysed. A total of 63 (27.3%) PCoA hypoplasia and 13 cases with f-PCA (5.6%) cases were identified. The hypoplastic PCoA was noted more in males than females (P<0.05) and right side hypoplasia was common than the left (P<0.04); bilateral hypoplasia of PCoA was seen in 37 cases out of 63 and is significant. The hypoplastic cases of the present study also were associated with variations of anterior cerebral arteries and one case was having vertebral artery hypoplasia. Incidence of PCoA as unilateral or bilateral with other associated anomalies of CW is more prone to develop stroke, migraine and cognitive dysfunction. Knowledge of these variations in the PCoA plays a pivotal role in diagnoses of neurological disorders and in neurovascular surgeries and angiographic point of view.

Metoprolol and Nebivolol Prevent the Decline of the Redox Status of Low-Molecular-Weight Aminothiols in Blood Plasma of Rats During Acute Cerebral Ischemia

Cerebral ischemia has previously been shown to cause a systemic decrease in levels of the reduced forms of low-molecular-weight aminothiols [cysteine (Cys), homocysteine (Hcy), and glutathione (GSH)] in blood plasma. In this study, we examined the effect of beta-adrenergic receptor (β-AR) antagonists metoprolol (Met) and nebivolol (Neb) on the redox status of these aminothiols during acute cerebral ischemia in rats. We used a model of global cerebral ischemia (bilateral occlusion of common carotid arteries with hypotension lasting for 10 minutes). The antagonists were injected 1 hour before surgery. Total and reduced Cys, Hcy, and GSH levels were measured 40 minutes after the start of reperfusion. Neb (0.4 and 4 mg/kg) and Met (8 and 40 mg/kg) treatment increased the levels of reduced aminothiols and the global methylation index in the hippocampus. The treatments also prevented any decrease in reduced aminothiol levels in blood plasma during ischemia. Although both of these drugs eliminated delayed postischemic hypoperfusion, only Neb reduced neuronal damage in the hippocampus. The results indicate an essential role of β1-AR blockage in the maintenance of redox homeostasis of aminothiols in the plasma and brain during acute cerebral ischemia.

Neuroprotective effects of the new Na channel blocker rs100642 in global ischemic brain injury

INTRODUCTION

RS100642, a mexiletine analogue, is a novel sodium channel blocker with neuroprotective and antioxidant activities. The protectivity of RS100642, which has been shown against focal cerebral ischemia, was investigated in global cerebral ischemia in this study.

MATERIAL AND METHODS

Global cerebral ischemia was induced for five minutes in adult male Wistar Albino rats via the 4-vessel occlusion method. Intravenous administration of 1 mg/kg RS100642 following reperfusion for 30 min (RS100642 group) was compared with a sham treatment group (ischemia group) and nonischemized group (control) histologically based on morphology and caspase-3 immunohistochemistry, and biochemically based both on measurement of oxidative stress including malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities and on assessment of apoptosis including caspase-3 and -8 activities and tumor necrosis factor α (TNF-α) levels at the end of 6 h.

RESULTS

While the RS100642 group had significantly lower MDA levels and higher SOD activities than the sham treatment group (p < 0.05), GPx and CAT activities of the RS100642 and sham treatment groups were similar (p > 0.05) and significantly lower than those of the controls (p < 0.05). Necrosis and caspase-3 activity and immunoreactivity in the RS100642 group were significantly lower than those in the sham treatment group (p < 0.05), while there was no significant difference between groups regarding caspase-8 and TNF-α (p > 0.05).

CONCLUSIONS

Na⁺ channel blockade by RS100642 has remarkable neuroprotective effects following global brain ischemia/reperfusion damage. Further research is required to determine the optimum dose and time of administration.

Protective Effects of the Third Generation Vasodilatory Βeta - Blocker Nebivolol against D-Galactosamine - Induced Hepatorenal Syndrome in Rats

BACKGROUND:

Renal dysfunction is very common in patients with advanced liver cirrhosis and portal hypertension. The development of renal failure in the absence of clinical, anatomical or pathological causes renal of failure is termed hepatorenal syndrome (HRS).

AIM:

The present study was constructed to investigate the possible protective effects of nebivolol (Nebi) against D-galactosamine (Gal)-induced HRS in rats.

MATERIAL AND METHODS:

Rats were treated with Nebi for ten successive days. On the 8th day of the experiment, they received a single dose of Gal. Serum levels of Cr, BUN, Na+ and K+ as well as AST, ALT, total bilirubin (TB), NH3 and endothelin-1 (ET-1) were determined following Gal administration. Moreover, renal and liver contents of MDA, GSH, F2-isoprostanes (F2-IPs), tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-B (NF-κB), total nitric oxide (NO), in addition to activities of caspase-3 (Cas-3), heme oxygenase-1 (HO-1), inducible and endothelial NO synthase (iNOS and eNOS) enzymes were also assessed. Finally, histopathological examination was performed.

RESULTS:

Nebi attenuated Gal-induced renal and hepatic dysfunction. It also decreased the Gal-induced oxidative stress and inflammatory recruitment.

CONCLUSION:

Results demonstrated both nephroprotective and hepatoprotective effects of Nebi against HRS and suggested a role of its antioxidant, anti-inflammatory, anti-apoptotic and NO-releasing properties.

Protective Effects of Vasodilatory Βeta-Blockers Carvedilol and Nebivolol against Glycerol Model of Rhabdomyolysis-Induced Acute Renal Failure in Rats

BACKGROUND

Rhabdomyolysis (RM)-induced acute renal failure (ARF) accounts for about 10-40% of all cases of ARF.

AIM

The present study investigated the possible protective effect of two nitric oxides (NO)-releasing third generation β-blockers, carvedilol (Carv) and nebivolol (Nebi), against RM-mimicking glycerol (Gly)-induced ARF in rats.

MATERIAL AND METHODS

After 24 h dehydration, rats received a single dose of 50% Gly (8 ml/kg, im). They were treated with vehicle, Carv (2.5 mg/kg/day, po) or Nebi (10 mg/kg, po) for 3 successive days starting from an hour prior to Gly injection. Evaluation of blood pressure and locomotor activity was performed during the experiment. 72 h following Gly administration, total protein in the urine, serum levels of creatinine, blood urea nitrogen, sodium and potassium as well as the renal contents of malondialdehyde, reduced glutathione and NO were assessed, together with a histopathological examination of renal tissues.

RESULTS

Carv and Nebi attenuated Gly-induced renal dysfunction and histopathological alterations. They decreased the Gly-induced oxidative stress and increased renal NO concentration. Restoration of normal blood pressure and improvement of locomotor activity were also observed.

CONCLUSION

The results clearly demonstrate protective effects of Carv and Nebi against renal damage involved in RM-induced ARF and suggest a role of their antioxidant and NO-releasing properties.

Protective Effects of Caffeic Acid Phenethyl Ester on Fluoxetine-Induced Hepatotoxicity: An Experimental Study

Background. The aim of the study was to analyse the effect of caffeic acid phenethyl ester (CAPE) on fluoxetine-induced hepatotoxicity in rats. Materials and Methods. Group I served as control. Group II received CAPE intraperitoneally. Group III received fluoxetine per orally. Group IV received fluoxetine and CAPE. The total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), and liver enzymes including paraoxonase-1 (PON-1), aspartate transaminase, and alanine transaminase levels were measured. Liver tissues were processed histopathologically for evaluation of liver injury and to validate the serum enzyme levels. Results. An increase in TOS and OSI and a decrease in TAC and PON-1 levels in serum and liver tissues of Group III were observed compared to Groups I and II. After treatment with CAPE, the level of TOS and OSI decreased while TAC and PON-1 increased in serum and liver in Group IV. Histopathological examination of the liver revealed hepatic injury after fluoxetine treatment and reduction of injury with CAPE treatment. Conclusion. Our results suggested that CAPE treatment provided protection against fluoxetine toxicity. Following CAPE treatment with fluoxetine-induced hepatotoxicity, TOS and OSI levels decreased, whereas PON-1 and TAC increased in the serum and liver.

Nebivolol Ameliorates Cisplatin-Induced Nephrotoxicity in Rats

Treatment with cisplatin is associated with dose-limiting side effects, mainly nephrotoxicity. On the other hand, nebivolol, a β1 -adrenoceptor antagonist, exhibits vasodilatory and antioxidative properties. This study aimed to determine whether nebivolol possesses a protective effect against cisplatin nephrotoxicity and explore many mechanisms underlying this potential effect. Nephrotoxicity was induced in Wistar rats by a single intraperitoneal injection of cisplatin (6 mg/kg) on day 2. Nebivolol (10 mg/kg) was administered orally for 7 consecutive days. Nebivolol showed a nephroprotective effect as demonstrated by the significant reduction in the elevated levels of serum creatinine and urea as well as renal levels of malondialdehyde, nitric oxide products (nitrite/nitrate), inducible nitric oxide synthase, tumour necrosis factor-alpha, caspase-3, angiotensin II and endothelin-1 with a concurrent increase in renal levels of reduced glutathione and endothelial nitric oxide synthase compared to untreated rats. Histopathological examination confirmed the nephroprotective effect of nebivolol. Pre-treatment with Nω -nitro-L-arginine methyl ester, the non-specific nitric oxide synthase inhibitor, partially altered the protection afforded by nebivolol. In conclusion, nebivolol protects rats against cisplatin-induced nephrotoxicity that is most likely through its antioxidant, anti-inflammatory and antiapoptotic effects as well as by abrogation of the augmented angiotensin II and endothelin-1 levels.

Neuroprotective Effect of Scutellarin on Ischemic Cerebral Injury by Down-Regulating the Expression of Angiotensin-Converting Enzyme and AT1 Receptor

Background and Purpose

Previous studies have demonstrated that angiotensin-converting enzyme (ACE) is involved in brain ischemic injury. In the present study, we investigated whether Scutellarin (Scu) exerts neuroprotective effects by down-regulating the Expression of Angiotensin-Converting Enzyme and AT1 receptor in a rat model of permanent focal cerebral ischemia.

Methods

Adult Sprague–Dawley rats were administrated with different dosages of Scu by oral gavage for 7 days and underwent permanent middle cerebral artery occlusion (pMCAO). Blood pressure was measured 7 days after Scu administration and 24 h after pMCAO surgery by using a noninvasive tail cuff method. Cerebral blood flow (CBF) was determined by Laser Doppler perfusion monitor and the neuronal dysfunction was evaluated by analysis of neurological deficits before being sacrificed at 24 h after pMCAO. Histopathological change, cell apoptosis and infarct area were respectively determined by hematoxylin–eosin staining, terminal deoxynucleotidyl transfer-mediated dUTP nick end labeling (TUNEL) analysis and 2,3,5-triphenyltetrazolium chloride staining. Tissue angiotensin II (Ang II) and ACE activity were detected by enzyme-linked immunosorbent assays. The expression levels of ACE, Ang II type 1 receptor (AT1R), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) were measured by Western blot and real-time PCR. ACE inhibitory activity of Scu in vitro was detected by the photometric determination.

Results

Scu treatment dose-dependently decreased neurological deficit score, infarct area, cell apoptosis and morphological changes induced by pMCAO, which were associated with reductions of ACE and AT1R expression and the levels of Ang II, TNF-α, IL-6, and IL-1β in ischemic brains. Scu has a potent ACE inhibiting activity.

Conclusion

Scu protects brain from acute ischemic injury probably through its inhibitory effect on the ACE/Ang II/AT1 axis, CBF preservation and proinflammation inhibition.

Nebivolol Ameliorates Hepatic Ischemia/Reperfusion Injury on Liver But Not on Distant Organs

INTRODUCTION

Hepatic ischemia/reperfusion injury may occur after large tumor resection and liver transplantation procedures. Nitric oxide was shown to have protective effects on ischemia/reperfusion injury. Nebivolol is a compound that has been reported to improve nitric oxide release. We evaluated the effects of nebivolol in a rat liver ischemia/reperfusion model.

METHODS

A total of 40 rats were randomly divided into four groups (n = 10 each). Group I underwent only laparotomy, Group II was administered nebivolol and then underwent laparotomy, Group III underwent laparotomy and hepatic ischemia/reperfusion, and Group IV was administered nebivolol and then underwent laparotomy and hepatic ischemia/reperfusion. Serum AST, ALT, urea, and creatinine levels, and TAS and TOS levels of liver, lung, and kidney tissues were determined. Histopathological determination was also performed.

RESULTS

Nebivolol significantly reduced liver function tests in group IV, but it did not improve renal functions. Oxidative stress and abnormal histopathological findings were found to be reduced in liver tissue in group IV. Although the oxidative stress was increased after hepatic ischemia/reperfusion, nebivolol could not reduce the oxidative stress in kidney tissue. There were no significant differences between group III and group IV in terms of the histopathological changes in kidney tissue. There were no significant differences in lung tissue between the groups.

CONCLUSIONS

The results of this study suggest that nebivolol has protective effects on liver but not on distant organs in a hepatic ischemia/reperfusion injury model. These experimental findings indicate that nebivolol may be useful in the treatment of hepatic ischemia/reperfusion injury.

The role of nitric oxide and oxidative stress in intestinal damage induced by selenium deficiency in chickens

Nitric oxide (NO) is an essential messenger molecule and is associated with inflammation and oxidative stress. Although NO has important biological functions in mammals, its role in the mechanism that occurs after intestinal injuries in chickens remains unknown. The objective of the present study was to investigate the real role of NO and oxidative stress in the intestinal injuries of chickens induced by selenium (Se) deficiency. A total 150 chickens were randomly divided into the following two groups: a low-Se group (L group, fed a Se-deficient diet containing 0.020 mg/kg Se) and a control group (C group, fed a commercial diet containing 0.2 mg/kg Se). The activities and mRNA levels of glutathione peroxidase (GSH-Px), the production of glutathione (GSH) and NO, and the protein and mRNA levels of inducible nitric oxide synthase (iNOS) were examined in the intestinal tissues (duodenum, jejunum, and rectum) at 15, 25, 35, 45, and 55 days. Methane dicarboxylic aldehyde (MDA) levels were also detected by assay kits. Then, the morphologies of the tissues were observed under the microscope after hematoxylin and eosin staining (H&E staining). The results showed that Se deficiency induced higher inflammatory damage and MDA levels (P < 0.05), which were accompanied by higher levels of iNOS and NO but lower levels of GSH and GSH-Px (P < 0.05). Our results indicated that Se deficiency induced oxidative damage in the intestinal tracts of chickens and that low levels of GSH-Px and high contents of NO may exert a major role in the injury of the intestinal tract induced by Se deficiency.

Evidence for negative effects of elevated intra-abdominal pressure on pulmonary mechanics and oxidative stress

OBJECTIVE

To compare the effects of pneumoperitoneum on lung mechanics, end-tidal CO2 (ETCO2), arterial blood gases (ABG), and oxidative stress markers in blood and bronchoalveolar lavage fluid (BALF) during laparoscopic cholecystectomy (LC) by using lung-protective ventilation strategy.

MATERIALS AND METHODS

Forty-six patients undergoing LC and abdominal wall hernia (AWH) surgery were assigned into 2 groups. Measurements and blood samples were obtained before, during pneumoperitoneum, and at the end of surgery. BALF samples were obtained after anesthesia induction and at the end of surgery.

RESULTS

Peak inspiratory pressure, ETCO2, and pCO2 values at the 30th minute were significantly increased, while there was a significant decrease in dynamic lung compliance, pH, and pO2 values in LC group. In BALF samples, total oxidant status (TOS), arylesterase, paraoxonase, and malondialdehyde levels were significantly increased; the glutathione peroxidase levels were significantly decreased in LC group. The serum levels of TOS and paraoxonase were significantly higher at the end of surgery in LC group. In addition, arylesterase level in the 30th minute was increased compared to baseline. Serum paraoxonase level at the end of surgery was significantly increased when compared to AWH group.

CONCLUSIONS

Our study showed negative effects of pneumoperitoneum in both lung and systemic levels despite lung-protective ventilation strategy.

Cardioprotective effects of curcumin and nebivolol against doxorubicin-induced cardiac toxicity in rats

Doxorubicin (DOX) is used in the treatment of cancer. However, cardiotoxicity is its major dose-limiting factor. Mechanism of DOX–cardiac toxicity is not completely elucidated. The aim of the current study was to explore whether the addition of subeffective dose of curcumin (100 mg/kg) to nebivolol would produce a better impact in treating DOX-induced cardiac toxicity in comparison with monotherapy.

Male rats were used and subdivided into seven groups. Cardiac toxicity was induced in 6 groups by intraperitoneal injection of DOX over 23 days; of the six groups, five groups were treated with curcumin (100 and 200 mg/kg), nebivolol (1 and 2 mg/kg), and their combination; the sixth group was the control group used for comparison.

Oral administration of curcumin and/or nebivolol attenuated DOX cardiotoxicity as manifested by increasing survival rate, improvement in body weight, heart index, and ECG parameters, increase in ventricular isoprenaline responses, and improvement in cardiac enzymes, oxidative stress, apoptosis, and histopathological picture. The addition of the current low subeffective dose of curcumin to nebivolol ameliorated DOX cardiac toxicity to a much greater extent than monotherapy showing better antioxidant and antiapoptotic effects versus the per se effect of nebivolol. Therefore, the current study encourages adding low dose of curcumin to potentiate the effect of nebivolol in the clinical management of cardiac toxicity improving the patients’ quality of life if proper clinical safety data are available.

Protective effect of Sheng-Nao-Kang decoction on focal cerebral ischemia-reperfusion injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sheng-Nao-Kang decoction (SNK), a modified traditional Chinese medicine (TCM), has been used clinically for the treatment of acute and chronic cerebrovascular related diseases. To evaluate the protective effect of SNK on focal cerebral ischemia-reperfusion (I/R) injury in rats and investigate the underlying mechanisms.

MATERIALS AND METHODS

Focal cerebral I/R injury in rats was induced by middle cerebral artery occlusion (MCAO) for 2h followed by reperfusion for 24h. Adult male Sprague-Dawley (SD) rats were randomly divided into six kinds of groups: Sham group; I/R group; SNK-treated groups at doses of 0.7 g/kg, 1.4 g/kg and 2.8 g/kg; and nimodipine (NMP)-treated group. The recoveries of neurological function in rats were estimated by neurological defect scoring and 2,3,5-triphenyltetrazolium chloride (TTC) staining after 24h reperfusion. Various biochemical indexes in serum were assayed by colorimetry, including malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), inducible nitric oxide synthase (iNOS) and total nitric oxide synthase (TNOS). Histological structures of the brain in rats were observed by hematoxylin and eosin (H&E) staining. Immunohistochemistry was performed to detect the caspase-3 protein content in rats.

RESULTS

SNK administration significantly reduced the neurological defect scores and lessened the cerebral infarction volume. The treatment of SNK lowered MDA content, up-regulated SOD and GSH-Px levels, down-regulated iNOS and TNOS levels in serum. Furthermore, histological examination indicated that dense neuropil and largely surviving neurons were seen in SNK-treated rats. SNK administration restrained the expression of caspase-3 positive protein significantly.

CONCLUSION

The results suggest that SNK demonstrates a strong and ameliorative effect on cerebral I/R damage in rats. The protective mechanisms of SNK are associated with its properties of anti-apoptosis and anti-oxidation as well as regulation of iNOS and TNOS.

Role of N-Nitro-L-Arginine-Methylester as anti-oxidant in transient cerebral ischemia and reperfusion in rats

Background

Previous reports assessing the neuroprotective role of nonselective Nitric Oxide synthase (NOS) inhibitor N-nitro-L-arginine-methylester (L-NAME) following cerebral ischemia/reperfusion are contradictory. The aim of this work was to examine the potential benefits of L-NAME on rats subjected to transient focal cerebral ischemia/reperfusion.

Methods

The study involved 30 adult male Wistar rats divided into three groups 10 rats in each: First group was sham-operated and served as a control, a ischemia/reperfusion (I/R) group of rats infused with 0.9% normal saline intraperitoneally 15 minutes prior to 30 minutes of left common carotid artery (CCA) occlusion and a test group infused with L-NAME intraperitoneally 15 minutes prior to ischemia. Neurobehavioral assessments were evaluated and quantitative assessment of malondialdehyde (MDA), Nitric oxide (NO) metabolites and total antioxidant capacity (TAC) in both serum and the affected cerebral hemisphere were achieved.

Results

Rats’ neurological deficit and TAC were significantly decreased while NO and MDA were significantly increased in the I/R compared with the control group (P < 0.001). Alternatively in the L-NAME group, neurological deficit and TAC were significantly improved while NO and MDA were significantly decreased compared to I/R group (P < 0.001).

Conclusions

L-NAME pretreatment for rats undergoing cerebral ischemia/reperfusion significantly improves neurological deficit while reducing oxidative stress biomarkers in the affected cerebral hemisphere.

The protective effects of dexmedetomidine on the liver and remote organs against hepatic ischemia reperfusion injury in rats

AIM

To investigate the protective effects of dexmedetomidine against hepatic ischemia/reperfusion (IR) injury and hepatic IR induced remote organ injury.

METHODS

Forty Wistar albino rats were divided into the following four groups: sham, dexmedetomidine, IR, and IR + dexmedetomidine. Hepatic ischemia was created by the Pringle maneuver for 30 min followed by a 30 min reperfusion period in the IR and IR + dexmedetomidine groups. The dexmedetomidine and IR + dexmedetomidine groups were administered dexmedetomidine (100 μg/kg, single dose) intraperitoneally after the anesthesia insult. Blood samples and hepatic, renal, and lung tissue specimens were obtained to measure serum and tissue total oxidative activity (TOA), total antioxidant capacity (TAC), paraoxonase (PON-1), and oxidative stress index (OSI) after 60 min in all groups.

RESULTS

According to the biochemical analyses of the samples taken from the serum and the liver, lung, and kidney tissues, when comparing the sham group and the IR group, TOA and OSI values were higher in the IR group, while TAC and PON-1 values were lower (p < 0.05). It was observed that TOA and OSI values were significantly lower, while TAC and PON-1 values increased with dexmedetomidine treatment (p < 0.05). In addition, dexmedetomidine ameliorated hepatic histopathological changes inducing IR, but there were no significant histopathological changes in the remote organs.

CONCLUSION

This study demonstrated that dexmedetomidine markedly reduced the oxidative stress in serum, liver, and remote organs induced by hepatic IR injury, and ameliorated the histopathological damage in the liver.

By improving regional cortical blood flow, attenuating mitochondrial dysfunction and sequential apoptosis galangin acts as a potential neuroprotective agent after acute ischemic stroke

Ischemic stroke is a devastating disease with a complex pathophysiology. Galangin is a natural flavonoid isolated from the rhizome of Alpina officinarum Hance, which has been widely used as an antioxidant agent. However, its effects against ischemic stroke have not been reported and its related neuroprotective mechanism has not really been explored. In this study, neurological behavior, cerebral infarct volumes and the improvement of the regional cortical blood flow (rCBF) were used to evaluate the therapeutic effect of galangin in rats impaired by middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia. Furthermore, the determination of mitochondrial function and Western blot of apoptosis-related proteins were performed to interpret the neuroprotective mechanism of galangin. The results showed that galangin alleviated the neurologic impairments, reduced cerebral infarct at 24 h after MCAO and exerted a protective effect on the mitochondria with decreased production of mitochondrial reactive oxygen species (ROS). These effects were consistent with improvements in the membrane potential level (Dym), membrane fluidity, and degree of mitochondrial swelling in a dose-dependent manner. Moreover, galangin significantly improved the reduced rCBF after MCAO. Western blot analysis revealed that galangin also inhibited apoptosis in a dose-dependent manner concomitant with the up-regulation of Bcl-2 expression, down-regulation of Bax expression and the Bax/Bcl-2 ratio, a reduction in cytochrome c release from the mitochondria to the cytosol, the reduced expression of activated caspase-3 and the cleavage of poly(ADP-ribose) polymerase (PARP). All these data in this study demonstrated that galangin might have therapeutic potential for ischemic stroke and play its protective role through the improvement in rCBF, mitochondrial protection and inhibiting caspase-dependent mitochondrial cell death pathway for the first time.