Role of the intracerebroventricular injection of the visfatin and its interaction with neuropeptide Y and nitric systems on food intake in neonatal chicken.

Visfatin play an essential role in the central regulation of appetite in birds. This study aimed to determine role of intracerebroventricular (ICV) injection of the visfatin on food intake and its possible interaction with neuropeptide Y (NPY) and nitric oxide system in neonatal broiler chicken. In experiment 1, neonatal chicken received ICV injection visfatin (1, 2 and 4 µg). In experiment 2, chicken received ICV injection of B5063 (NPY1 receptor antagonist 1.25 µg), visfatin (4 µg) and co-injection of the B5063 + Visfatin. In experiments 3-6, SF22 (NPY2 receptor antagonist 1.25 µg), SML0891 (NPY5 receptor antagonist 1.25 µg), L-NAME (nitric oxide synthase inhibitor, 100 nmol) and L-arginine (Precursor of nitric oxide, 200 nmol) were injected instead of B5063. Then the amount of cumulative food was measured at 30, 60 and 120 min after injection. Obtained data showed, injection visfatin (2 and 4 µg) increased food intake compared to control group (P < 0.05). Co-injection of the B5063 + Visfatin decreased visfatin-induced hyperphagia compared to control group (P < 0.05). Co-injection of the L-NAME + Visfatin amplified visfatin-induced hyperphagia compared to control group (P < 0.05). The result showed that visfatin has hyperphagic role and this effect mediates via NPY1 and nitric oxide system in neonatal chicken.

Hypothermia Inhibits Dexmedetomidine-Induced Contractions in Isolated Rat Aortae.

Dexmedetomidine is widely used to induce sedation in the perioperative period. This study examined the effect of hypothermia (33 and 25 °C) on dexmedetomidine-induced contraction in an endothelium-intact aorta with or without the nitric oxide synthase inhibitor NW-nitro-L-arginine methyl ester (L-NAME). In addition, the effect of hypothermia on the contraction induced by dexmedetomidine in an endothelium-denuded aorta with or without a calcium-free Krebs solution was examined. The effects of hypothermia on the protein kinase C (PKC), myosin light chain (MLC20) phosphorylation, and Rho-kinase membrane translocation induced by dexmedetomidine were examined. Hypothermia inhibited dexmedetomidine-induced contraction in the endothelium-intact aorta with L-NAME or endothelium-denuded aorta. Hypothermia had almost no effect on the dexmedetomidine-induced contraction in the endothelium-denuded aorta with the calcium-free Krebs solution; however, the subsequent contraction induced by the addition of calcium was inhibited by hypothermia. Conversely, the transition from profound hypothermia back to normothermia reversed the hypothermia-induced inhibition of subsequent calcium-induced contractions. Hypothermia inhibited any contraction induced by KCl, PDBu, and NaF, as well as PKC and MLC20 phosphorylation and Rho-kinase membrane translocation induced by dexmedetomidine. These results suggest that hypothermia inhibits dexmedetomidine-induced contraction, which is mediated mainly by the impediment of calcium influx and partially by the attenuation of pathways involving PKC and Rho-kinase activation.

Microalbuminuria in Rats Treated with D-Nitroarginine Methyl Ether.

Microalbuminuria is an early symptom and prognostic marker of the progression of renal pathology. The analysis of the role of anionic components of the renal glomeruli in the albumin retention and the development of a model of minimal changes in the glomerular filter leading to the appearance of microalbuminuria are relevant. The effect of organic cations D-arginine methyl esters (D-AME) and D-nitroarginine (D-NAME) on the excretion of albumin by the kidneys in rats was studied. D-AME had no effect on urinary albumin excretion in rats. D-NAME caused microalbuminuria, which persisted for more than a day and sharply increased after injection of vasopressin. The number of anionic sites labeled with polyethyleneimine decreased in the structures of the glomerular filter. D-NAME-induced microalbuminuria can later serve as a model for studying nephroprotective or damaging factors.

Evaluation and estimation of diuretic activity of the linalyl acetate in the rats.

This study aimed to explore the diuretic activity of linalyl acetate (LA). LA is an essential oil, it is an integral phyto-constituent of various plants. In this study, acute and chronic diuretic activities were explored by measuring the levels of different electrolytes and pH in the urine of experimental rats. Rats were divided into five groups. The control group was given 10 mg/kg normal saline, the treated group was given 10 mg/kg furosemide, and the remaining 3 groups received different doses of LA including 25, 50, and 75 mg/kg through intraperitoneal route, to determine its diuretic potential. Urine volume for acute diuretic activity was measured for 6 hours however for chronic diuretic activity was measured for 6 days. For a comparative study of LA with a control group and treated group with reference drug, diuretic index was used. Moreover, the underlying mechanism of the diuretic activity was also explored by comparing atropine, L-NAME, and indomethacin. The results of each group with 6 rats in each group were obtained by ± standard error of the mean of every group. Analysis of Variance (ANOVA) was used for statistical analysis. Results revealed that the LA 75 mg/kg dose showed comparable results as of furosemide. Moreover, this study revealed the involvement of muscarinic receptors to produce diuresis in comparison with atropine with very little involvement of prostanoids and no effect on NO pathway induced by indomethacin and L-NAME respectively. It is concluded that LA possess anti-diuretic potential. Muscarinic receptors might be involved in producing diuretic effects.

Protective Effects of Aspirin Supplemented With Quercetin in L-NAME-Induced Preeclampsia-Like Rats.

Aspirin supplemented with quercetin was reported to enhance the therapeutic effects of aspirin in a rat model of preeclampsia. In this study, the underlying mechanisms were further explored. Preeclampsia was induced by L-NAME (50 mg/kg/day) via oral gavage from gestation day (GD)14 to GD19. Aspirin (1.5 mg/kg/day) administration was performed using aspirin mixed with rodent dough from GD0 to GD19. The administration of quercetin (2 mg/kg/day) was performed by intraperitoneal infusion from GD0 to GD19. Protein levels were evaluated using ELISA or Western blot, and microRNA (miRNA) level was evaluated by RT-PCR. Aspirin supplemented with quercetin ameliorated the increase of systolic blood pressure (SBP), proteinuria, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels, and improved the pregnancy outcomes in preeclampsia rats. Aspirin supplemented with quercetin inhibited miR-155 expression in preeclampsia rats. The decreased miR-155 level in placenta further increased the protein level of SOCS1 and inhibited the phosphorylation of p65. In this study, we demonstrated that aspirin supplemented with quercetin enhanced the effects of aspirin for the treatment of preeclampsia.

Metabolic dysfunction induced by HFD + L-NAME preferentially affects hippocampal mitochondria, impacting spatial memory in rats.

High-fat diet-induced metabolic changes are not restricted to the onset of cardiovascular diseases, but also include effects on brain functions related to learning and memory. This study aimed to evaluate mitochondrial markers and function, as well as cognitive function, in a rat model of metabolic dysfunction. Eight-week-old male Wistar rats were subjected to either a control diet or a two-hit protocol combining a high fat diet (HFD) with the nitric oxide synthase inhibitor L-NAME in the drinking water. HFD plus L-NAME induced obesity, hypertension, and increased serum cholesterol. These rats exhibited bioenergetic dysfunction in the hippocampus, characterized by decreased oxygen (O2) consumption related to ATP production, with no changes in H2O2 production. Furthermore, OPA1 protein expression was upregulated in the hippocampus of HFD + L-NAME rats, with no alterations in other morphology-related proteins. Consistently, HFD + L-NAME rats showed disruption of performance in the Morris Water Maze Reference Memory test. The neocortex did not exhibit either bioenergetic changes or alterations in H2O2 production. Calcium uptake rate and retention capacity in the neocortex of HFD + L-NAME rats were not altered. Our results indicate that hippocampal mitochondrial bioenergetic function is disturbed in rats exposed to a HFD plus L-NAME, thus disrupting spatial learning, whereas neocortical function remains unaffected.

Vasorelaxant effects of ellagitannins isolated from Cuphea carthagenensis.

Cuphea carthagenensis (Jacq.) J. F. Macbr. is a popular plant in Brazilian folk medicine owing to its hypotensive and central nervous system depressant effects. This study aimed to validate the hypotensive effect of the plant's aqueous extract (AE) in rats and examine the vascular actions of three hydrolyzable tannins, oenothein B, woodfordin C, and eucalbanin B, isolated from AE. Systolic blood pressure in unanesthetized rats was determined using the non-invasive tail-cuff method. Oral treatment of normotensive rats with 0.5 and 1.0 g/kg/day AE induced a dose-related hypotensive effect after 1 week. In rat aortic rings pre-contracted with noradrenaline, all ellagitannins (20 - 180 µM) induced a concentration-related vasorelaxation. This effect was blocked by either removing the endothelium or pre-incubating with NG-nitro-l-arginine methyl ester (10 µM), an inhibitor of nitric oxide (NO) synthase. In KCl-depolarized rat portal vein preparations, the investigated compounds did not affect significantly the maximal contractile responses and pD2 values of the concentration-response curves to CaCl2. Our results demonstrated the hypotensive effect of C. carthagenensis AE in unanesthetized rats. All isolated ellagitannins induced vasorelaxation in vitro via activating NO synthesis/NO release from endothelial cells, without altering the Ca2+ influx in vascular smooth muscle preparations. Considering the low oral bioavailability of ellagitannins, the determined in vitro actions of these compounds are unlikely to account for the hypotensive effect of AE in vivo. It remains to be determined the role of the bioactive ellagitannin-derived metabolites in the hypotensive effect observed after oral treatment of unanesthetized rats with the plant extract.

Nitric Oxide Plays a Dual Role in Cardiorenal Syndrome in Vitro Model.

BACKGROUND/AIMS: Nitric oxide (NO) plays a dual role, acting as both an oxidant and a reducer, with various effects depending on its concentration and environment. Acute kidney injury's (AKI) pathogenesis observed in cardiorenal syndrome 3 (CRS 3) involves inflammatory responses and the production of reactive oxygen and nitrogen species. However, the role of NO on the development of CRS 3 is still not completely understood. The study aimed to mimic CRS 3 in vitro and investigate NO signaling and inflammatory molecules. METHODS: Thus, HEK293 cells were submitted to normoxia (NX) or hypoxia (HX) protocols for 16 h followed by 3 h of reoxygenation, treated or not with L-NAME. Conditionate medium by HEK293 was transferred to H9c2 for 24 h. Cellular viability was evaluated by MTT assay, real time PCR was used to analyze gene expression and NO content were evaluated in the intra and extracellular medium by amperimetry. RESULTS: Carbonic anhydrase 9 (CA9) expression increased 2.9-fold after hypoxia. Hypoxia reduced 18 % cell viability in HEK293 that was restored by L-NAME treatment. The sum of nitrite (NO2-) and S-nitrosothiol (S-NO) fractions in HEK293 cells showed a substantial decrease on NO intracellular content (38 %). Both IL-6 and IL-10 decreased in all groups compared to NX cells. Besides TNF-α and Bax/Bcl2 ratio increased in hypoxia (approximately 120-fold and 600-fold, respectively) and L-NAME restored this effect. Regarding H9c2 cells, the S-NO fractions showed a substantial decrease in extracellular content after HX (17%) that was not restored by L-NAME. IL-1ß decreases in cardiac cells treated with conditioned medium from HX/L-NAME. CONCLUSION: In conclusion this study highlights the complex interplay of NO and inflammatory factors in hypoxia-induced renal and cardiac cell responses, with potential implications for cardiorenal syndrome.

NO Deficiency Compromises Inter- and Intrahemispheric Blood Flow Adaptation to Unilateral Carotid Artery Occlusion.

Carotid artery stenosis (CAS) affects approximately 5-7.5% of older adults and is recognized as a significant risk factor for vascular cognitive impairment (VCI). The impact of CAS on cerebral blood flow (CBF) within the ipsilateral hemisphere relies on the adaptive capabilities of the cerebral microcirculation. In this study, we aimed to test the hypothesis that the impaired availability of nitric oxide (NO) compromises CBF homeostasis after unilateral carotid artery occlusion (CAO). To investigate this, three mouse models exhibiting compromised production of NO were tested: NOS1 knockout, NOS1/3 double knockout, and mice treated with the NO synthesis inhibitor L-NAME. Regional CBF changes following CAO were evaluated using laser-speckle contrast imaging (LSCI). Our findings demonstrated that NOS1 knockout, NOS1/3 double knockout, and L-NAME-treated mice exhibited impaired CBF adaptation to CAO. Furthermore, genetic deficiency of one or two NO synthase isoforms increased the tortuosity of pial collaterals connecting the frontoparietal and temporal regions. In conclusion, our study highlights the significant contribution of NO production to the functional adaptation of cerebrocortical microcirculation to unilateral CAO. We propose that impaired bioavailability of NO contributes to the impaired CBF homeostasis by altering inter- and intrahemispheric blood flow redistribution after unilateral disruption of carotid artery flow.

Myoendothelial feedback in mouse mesenteric resistance arteries is similar between the sexes, dependent on nitric oxide synthase, and independent of TPRV4.

Myoendothelial feedback (MEF), the endothelium-dependent vasodilation following sympathetic vasoconstriction (mediated by smooth muscle to endothelium gap junction communication), has been well studied in resistance arteries of males, but not females. We hypothesized that MEF responses would be similar between the sexes, but different in the relative contribution of the underlying nitric oxide and hyperpolarization mechanisms, given that these mechanisms differ between the sexes in agonist-induced endothelium-dependent dilation. We measured MEF responses (diameter changes) of male and female first- to second-order mouse mesenteric arteries to phenylephrine (10 µM) over 30 min using isolated pressure myography ± blinded inhibition of nitric oxide synthase (NOS) using Nω-nitro-l-arginine methyl ester (l-NAME; 0.1-1.0 mM), hyperpolarization using 35 mM KCl, or transient receptor potential vanilloid 4 (TRPV4) channels using GSK219 (0.1-1.0 µM) or RN-1734 (30 µM). MEF was similar [%dilation (means ± SE): males = 26.7 ± 2.0 and females = 26.1 ± 1.9 at 15 min] and significantly inhibited by l-NAME (1.0 mM) at 15 min [%dilation (means ± SE): males = 8.2 ± 3.3, P < 0.01; females = 6.8 ± 1.9, P < 0.001] and over time (P < 0.01) in both sexes. l-NAME (0.1 mM) + 35 mM KCl nearly eliminated MEF in both sexes (P < 0.001-0.0001). Activation of TRPV4 with GSK101 (0.1-10 µM) induced similar dilation between the sexes. Inhibition of TRPV4, which is reportedly involved in the hyperpolarization mechanism, did not inhibit MEF in either sex. Similar expression of eNOS was found between the sexes with Western blot. Thus, MEF is prominent and similar in murine first- and second-order mesenteric resistance arteries of both sexes, and reliant primarily on NOS and secondarily on hyperpolarization, but not TRPV4.NEW & NOTEWORTHY We found that female mesenteric resistance arteries have similar postconstriction dilatory responses (i.e., myoendothelial feedback) to a sympathetic neurotransmitter analog as male arteries. Both sexes use nitric oxide synthase (NOS) and hyperpolarization, but not TRPV4, in this response. Moreover, the key protein involved in this pathway (eNOS) is similarly expressed in these arteries between the sexes. These similarities are surprising given that agonist-induced endothelium-dependent dilatory mechanisms differ in these arteries between the sexes.

Endothelium-Derived Dopamine and 6-Nitrodopamine in the Cardiovascular System.

The review deals with the release of endothelium-derived dopamine and 6-nitrodopamine (6-ND) and its effects on isolated vascular tissues and isolated hearts. Basal release of both dopamine and 6-ND is present in human isolated umbilical cord vessels, human popliteal vessels, nonhuman primate vessels, and reptilia aortas. The 6-ND basal release was significantly reduced when the tissues were treated with Nω-nitro-l-arginine methyl ester and virtually abolished when the endothelium was mechanically removed. 6-Nitrodopamine is a potent vasodilator, and the mechanism of action responsible for this effect is the antagonism of dopamine D2-like receptors. As a vasodilator, 6-ND constitutes a novel mechanism by which nitric oxide modulates vascular tone. The basal release of 6-ND was substantially decreased in endothelial nitric oxide synthase knockout (eNOS-/-) mice and not altered in neuronal nitric oxide synthase knockout (nNOS-/-) mice, indicating a nonneurogenic source for 6-ND in the heart. Indeed, in rat isolated right atrium, the release of 6-ND was not affected when the atria were treated with tetrodotoxin. In the rat isolated right atrium, 6-ND is the most potent endogenous positive chronotropic agent, and in Langendorff's heart preparation, it is the most potent endogenous positive inotropic agent. The positive chronotropic and inotropic effects of 6-ND are antagonized by ß1-adrenoceptor antagonists at concentrations that do not affect the effects induced by noradrenaline, adrenaline, and dopamine, indicating that blockade of the 6-ND receptor is the major modulator of heart chronotropism and inotropism. The review proposes that endothelium-derived catecholamines may constitute a major mechanism for control of vascular tone and heart functions, in contrast to the overrated role attributed to the autonomic nervous system.

Perinatal N(G)-Nitro-L-arginine methyl ester administration decreases anxiety- and depression-like behaviors in adult mice.

OBJECTIVE: We hypothesized that perinatal manipulations of the nitrergic system would affect adult animal behaviors. METHODS: We tested this hypothesis by perinatally administering N(G)-Nitro-L-arginine methyl ester (L-NAME), a non-specific antagonist of nitric oxide synthase for 15 days and assessed anxiety- and depression-like behaviors in adult mice. At 70 days of age, the mice were subjected to a battery of tests consisting of the open-field, light/dark box, forced swim, and tail-flick tests. The tests were performed at two-day intervals, and the order of the tests within the battery was determined according to the progressive invasiveness degree. RESULTS: L-NAME-treated animals exhibited decreased anxiety-like behavior in the light/dark box and open field tests, with no change in locomotor activity. Additionally, they demonstrated decreased depression-like behavior in the forced swim test and no change in pain perception in the tail-flick test. CONCLUSION: The nitrergic system is possibly involved in neural circuitry development that regulates behaviors since blocking perinatal nitric oxide production decreases anxiety- and depression-like behaviors in adult mice.

Potential Antihypertensive Activity of the Aqueous Extract of Ammi visnaga and its Effect on ACE-2 in Rats.

AIMS: This work aimed to investigate the antihypertensive activity of Ammi visnaga. BACKGROUND: The aqueous extract of Ammi visnaga has traditionally been used to treat hypertension in Morocco. OBJECTIVE: The objective of this investigation was to evaluate the effect of Ammi visnaga aqueous extract (AVAE) on arterial blood pressure, systolic blood pressure (SBP), mean blood pressure (MBP), diastolic blood pressure (DBP), and heart rate (HR) in normotensive and hypertensive rats. In addition, the effect of the aqueous extract of Ammi visnaga on vasodilatation was assessed in isolated rat aortic rings with functional endothelium pre-contracted with epinephrine EP or KCl. METHODS: AVAE was obtained, and its antihypertensive ability was pharmacologically investigated in L-NAME hypertensive and normotensive rats. The rats received oral AVAE at two selected doses of 70 and 140 mg/kg for six hours (acute experiment) and seven days (sub-chronic). Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. Moreover, the vasorelaxant activity of AESA was performed in thoracic aortic ring rats. In addition, the mechanisms of action involved in the vasorelaxant effect were studied. RESULTS: AVAE lowered blood pressure only in L-Name-induced hypertensive rats. Furthermore, AVAE (0.375-1.375 mg/ml) showed a vasodilator effect in isolated aortic rats. In addition, not all of the medications used in our study were responsible for the signaling pathway. As a result, additional pharmaceuticals are required to confirm the mechanism of this signaling pathway. CONCLUSION: The aqueous extract of Ammi visnaga exerts an interesting antihypertensive activity, which could be mediated through its vasorelaxant activity. The study supports its use as a medicinal plant against hypertension in Morocco.

Improvement in Clinical Features of L-NAME-Induced Preeclampsia-like Rats through Reduced SERPINA5 Expression.

Pre-eclampsia (PE) is a severe pregnancy disorder that poses a significant health risk to both mother and fetus, with no preventive or therapeutic measures. Our previous research suggested an association between elevated SERPINA5 levels and PE features. This study investigated whether SERPINA5 could be a potential therapeutic target for PE. We established PE-like features in pregnant rats using L-NAME (75 mg/kg/d) treatment. Adenoviruses carrying overexpressed or suppressed SERPINA5 genes were intravenously injected into these PE rats on the fifth and seventh days of pregnancy. We evaluated the rats' systolic blood pressure, urine protein concentration, and placental and fetal metrics and histology. Placental gene expression following SERPINA5 overexpression was evaluated using mRNA sequencing. The L-NAME-induced PE rat model observed a significant increase in placental and peripheral SERPINA5 levels. The overexpression of SERPINA5 exacerbated L-NAME-induced hypertension and proteinuria in pregnant rats. A histology examination revealed a smaller placental junctional zone in L-NAME + overexpressing rats. Placental gene expression analysis in the L-NAME + overexpressing group indicated increased coagulation activation. L-NAME-induced hypertension and proteinuria were mitigated when SERPINA5 expression was suppressed. Additionally, placental development was improved in the SERPINA5-suppressed group. Our findings suggested that SERPINA5 may worsen L-NAME-induced PE-like features by promoting the activation of the coagulation cascade. Therefore, reducing SERPINA5 expression could potentially serve as a therapeutic strategy for PE.

Correlational Study of Aminopeptidase Activities between Left or Right Frontal Cortex versus the Hypothalamus, Pituitary, Adrenal Axis of Spontaneously Hypertensive Rats Treated with Hypotensive or Hypertensive Agents.

It has been suggested that the neuro-visceral integration works asymmetrically and that this asymmetry is dynamic and modifiable by physio-pathological influences. Aminopeptidases of the renin-angiotensin system (angiotensinases) have been shown to be modifiable under such conditions. This article analyzes the interactions of these angiotensinases between the left or right frontal cortex (FC) and the same enzymes in the hypothalamus (HT), pituitary (PT), adrenal (AD) axis (HPA) in control spontaneously hypertensive rats (SHR), in SHR treated with a hypotensive agent in the form of captopril (an angiotensin-converting enzyme inhibitor), and in SHR treated with a hypertensive agent in the form of the L-Arginine hypertensive analogue L-NG-Nitroarginine Methyl Ester (L-NAME). In the control SHR, there were significant negative correlations between the right FC with HPA and positive correlations between the left FC and HPA. In the captopril group, the predominance of negative correlations between the right FC and HPA and positive correlations between the HPA and left FC was maintained. In the L-NAME group, a radical change in all types of interactions was observed; particularly, there was an inversion in the predominance of negative correlations between the HPA and left FC. These results indicated a better balance of neuro-visceral interactions after captopril treatment and an increase in these interactions in the hypertensive animals, especially in those treated with L-NAME.

Participation of the nitric oxide pathway in lordosis induced by apelin-13 in female rats.

The present study investigated the participation of the nitric oxide pathway in facilitating lordosis behavior induced by intrahypothalamic administration of apelin-13 in ovariectomized rats primed with estradiol benzoate (EB). The experiments involved the administration of a nitric oxide synthase inhibitor (L-NAME) or a nitric oxide-dependent, soluble guanylyl cyclase inhibitor (ODQ), and an inhibitor of protein kinase G (KT5823) to the ventromedial hypothalamus (VMH) of EB-primed rats 30 min before infusion of apelin-13 (0.75 µg/µl). This dose of apelin-13 consistently induces lordosis behavior at 30 min, 120 min, and 240 min following infusion. Results showed that injections of either L-NAME or KT5823 significantly reduced the lordosis induced by apelin at 120 and 240 min. However, VMH infusion of ODQ 30 min before apelin-13 infusion reduced but did not significantly inhibit, the lordosis elicited by this peptide at the same time points. We conclude that the nitric oxide pathway in the VMH plays an important role in lordosis induced by apelin-13 in EB-primed rats.

Regulation of the Endogenous Opiate Signaling Pathway against Oxidative Stress and Inflammation: A Considerable Approach for Exploring Preclinical Treatment of Parkinson's Disease.

INTRODUCTION: Oxidative stress and inflammation are major factors contributing to the progressive death of dopaminergic neurons in Parkinson's disease (PD). Recent studies have demonstrated that morphine's biosynthetic pathway, coupled with nitric oxide (NO) release, is evolutionarily conserved throughout animals and humans. Moreover, dopamine is a key precursor for morphine biosynthesis. METHOD: The present study evaluated a series of preclinical experiments to evaluate the effects of low-level morphine treatment upon neuro-immune tissues exposed to rotenone and 6-OHDA as models of PD, followed by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assay and cell/tissue computer-assisted imaging analyses to assess cell/neuronal viability. RESULTS: Morphine at normal physiological concentrations (i.e., 10-6 M and 10-7 M) provided neuroprotection, as it significantly inhibited rotenone and 6-OHDA dopaminergic insults; thereby, reducing and/or forestalling cell death in invertebrate ganglia and human nerve cells. To ensure that morphine caused this neuroprotective effect, naloxone, a potent opiate receptor antagonist, was employed and the results showed that it blocked morphine's neuroprotective effects. Additionally, co-incubation of NO synthase inhibitor L-NAME also blocked morphine's neuroprotective effects against rotenone and 6-OHDA insults. CONCLUSIONS: Taken together, the present preclinical study showed that while morphine can attenuate lipopolysaccharide-induced inflammation and cell death, both naloxone and L-NAME can abolish this effect. Preincubation of morphine precursors (i.e., L-3,4-dihydroxyphenylalanine, reticuline, and trihexyphenidyl [THP] at physiological concentrations) mimics the observed morphine effect. However, high concentrations of THP, a precursor of the morphine biosynthetic pathway, induced cell death, indicating the physiological importance of morphine biosynthesis in neural tissues. Thus, understanding the morphine biosynthetic pathway coupled with a NO signaling mechanism as a molecular target for neuroprotection against oxidative stress and inflammation in other preclinical models of PD is warranted.

Assessment of In Vitro Airway Smooth Muscle Relaxant Activity of Rhus coriaria L. Fruit Ethanolic Extract and Its Possible Mechanisms.

Rhus coriaria L. (Anacardiaceae), also known as Sumac, is commonly used as a spice, flavoring agent, and as a traditional medicinal herb. This includes also the traditional use for treating asthma, catarrh, and common colds. The accumulating evidence supports its cardioprotective, antidiabetic, neuroprotective, anticancer, gastroprotective, antibacterial, anti-inflammatory, antiviral, antioxidant, and respiratory effects. However, there are no previous studies that have shown its effects and mechanism in the airway smooth muscle tone, and therefore, the aim of our study was to investigate the in vitro pharmacological action of R. coriaria L. extract (RCE) on the rat isolated tracheal and bronchial preparations by exploring its relaxant activity and mechanism of action. The direct relaxant effect of RCE (0.1-0.7 mg/mL) was tested in the rat bronchi and trachea rings precontracted by carbachol (CCh). In addition, the pretreatment with RCE (1 mg/mL) was tested on the bronchial and tracheal reactivity induced by CCh, potassium chloride (KCl), or CaCl2. In addition, the cyclooxygenase inhibitor indomethacin and the nitric oxide synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME), respectively, were used for exploring the mechanisms of RCE-induced relaxation and reduction of reactivity. Our findings demonstrated that RCE induced a concentration-dependent relaxation and a significant reduction of reactivity, significantly reduced with either indomethacin or L-NAME. In addition, RCE decreased the responsiveness to KCl and affected the extracellular Ca2+-induced contraction in the tissues with added CCh or KCl in Ca2+-free Krebs-Henseleit solution. In summary, we have shown that RCE displayed relaxant activities in the in vitro airway smooth muscles, and the possible mechanisms seems to involve the prostaglandin, nitric oxide, and Ca2+ pathways. Taken together, our findings indicate the potential role of RCE in the treatment of respiratory diseases with limited airflow, or obstructive respiratory diseases, and could justify its traditional use in the respiratory diseases.

Kaempferol protects against cardiovascular abnormalities induced by nitric oxide deficiency in rats by suppressing the TNF-α pathway.

Kaempferol is a natural flavonoid compound that exhibits various pharmacological actions. However, there are few reports regarding the role of kaempferol in cardiovascular abnormalities. This study aimed to assess whether kaempferol could prevent cardiovascular malfunction and hypertrophy provoked by chronic inhibition of nitric oxide (NO) formation in rats. Rats (180-200 g) were treated daily with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) (40 mg/kg, in drinking water) for five weeks concomitant with kaempferol (oral administration) at a dose of 20 mg/kg or 40 mg/kg or lisinopril (5 mg/kg). Kaempferol partially prevented the progression of hypertension provoked by NO inhibition (p < 0.05). Left ventricular malfunction and hypertrophy present in hypertensive rats were alleviated by concurrent administration of kaempferol (p < 0.05). Furthermore, L-NAME rats had increased sympathetic nerve-mediated vasoconstriction and decreased acetylcholine-induced vasorelaxation and aortic wall thickening, which were resolved by kaempferol treatment (p < 0.05). Kaempferol restored tissue superoxide formation, malondialdehyde, catalase activity, plasma nitric oxide metabolites, tumor necrosis factor-alpha (TNF-α) and interleukin-6 in L-NAME rats (p < 0.05). Overexpression of tumor necrosis factor receptor 2 (TNFR2), phosphatidylinositol 3-kinases (PI3K), AKT serine/threonine kinase 1 (Akt1) and smad2/3 in heart tissue and upregulation of tumor necrosis factor receptor 1 (TNFR1), phosphorylated nuclear factor-kappaB (p-NF-κB) and transforming growth factor beta 1 (TGF-ß1) in vascular tissue were suppressed by kaempferol (p < 0.05). In conclusion, kaempferol exerts antihypertensive, cardioprotective, antioxidant, and anti-inflammatory effects in NO-dependent hypertensive rats. The underlying mechanisms of kaempferol in preventing cardiovascular changes induced by L-NAME were due to the suppression of the TNF-α pathway.

Quercetin supplementation attenuates airway hyperreactivity and restores airway relaxation in rat pups exposed to hyperoxia.

Hyperoxia exposure of immature lungs contributes to lung injury and airway hyperreactivity. Up to now, treatments of airway hyperreactivity induced by hyperoxia exposure have been ineffective. The aim of this study was to investigate the effects of quercetin on hyperoxia-induced airway hyperreactivity, impaired relaxation, and lung inflammation. Newborn rats were exposed to hyperoxia (FiO2 > 95%) or ambient air (AA) for seven days. Subgroups were injected with quercetin (10 mg·kg-1·day-1). After exposures, tracheal cylinders were prepared for in vitro wire myography. Contraction to methacholine was measured in the presence or absence of organ bath quercetin and/or Nω-nitro-L-arginine methyl ester (L-NAME). Relaxation responses were evoked in preconstricted tissues using electrical field stimulation (EFS). Lung tumor necrosis factor-alpha (TNF-α) and interleukin-1ß (IL-1ß) levels were measured by enzyme-linked immunosorbent assay (ELISA). A P < 0.05 was considered statistically significant. Contractile responses of tracheal smooth muscle (TSM) of hyperoxic animals were significantly increased compared with AA animals (P < 0.001). Treatment with quercetin significantly reduced contraction in hyperoxic groups compared with hyperoxic control (P < 0.01), but did not have any effect in AA groups. In hyperoxic animals, relaxation of TSM was significantly reduced compared with AA animals (P < 0.001), while supplementation of quercetin restored the lost relaxation in hyperoxic groups. Incubation of preparations in L-NAME significantly reduced the quercetin effects on both contraction and relaxation (P < 0.01). Treatment of hyperoxic animals with quercetin significantly decreased the expression of TNF-α and IL-1ß compared with hyperoxic controls (P < 0.001 and P < 0.01, respectively).The findings of this study demonstrate the protective effect of quercetin on airway hyperreactivity and suggest that quercetin might serve as a novel therapy to prevent and treat neonatal hyperoxia-induced airway hyperreactivity and inflammation.