In Vitro Determination of Nitric Oxide Synthase Inhibition, Antioxidant Capacity and Phenolic Content of Various Natural Products (Bee and Herbal Products).

It is obvious that the oxidation process is an undeniable fact and when it comes to aging, one of the first solutions that come to mind is natural products. When it comes to natural products, both plants and bee products play an important, almost combative role against oxidation. For this purpose, natural products of both plant and animal origin were considered together in our study: Linden, green tea, aronia, wild grapes, myrtle, blueberries and basil, honey, pollen and propolis. Total phenolic content values of the extracts ranged between 49.28 and 3859.06 mg gallic acid equivalent/100 g, and propolis, green tea, chestnut flower and aronia samples were found to have the highest values. When looking at the NOS inhibition potential, it was determined that propolis, pollen and aronia samples had the highest percentage inhibition values of 98.11, 92.29, 83.44, respectively. Antioxidant activities of methanolic extracts were investigated using iron(III) reducing/antioxidant capacity (FRAP), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity test and NOS inhibition tests. The phenolic composition of methanolic extracts was tested using the RP-HPLC-UV (high-performance liquid chromatographic method with ultraviolet) method with 19 phenolic standards.

Drug-Loaded Zwitterion-Based Nanomotors for the Treatment of Spinal Cord Injury.

Spinal cord injury (SCI) treatment requires a nanosystem for drug delivery that can effectively penetrate the blood-spinal cord barrier (BSCB). Herein, we designed poly(2-methacryloyloxyethyl phosphorylgallylcholine) (PMPC)/l-arginine (PMPC/A)-based nanomotors that can release nitric oxide (NO). The nanomotors were loaded with the inducible NO synthase inhibitor 1400W and nerve growth factor (NGF). PMPC with a zwitterionic structure not only provided good biocompatibility for the nanomotors but also facilitated their passage through the BSCB owing to the assistance of a large number of choline transporters on the BSCB. Additionally, the l-arginine loaded on the nanomotors was able to react with reactive oxygen species in the microenvironment of the injured nerve to produce NO, thereby conferring the ability of autonomic movement to the nanomotors, which facilitated the uptake of drugs by cells in damaged areas and penetration in pathological tissues. Moreover, in vivo animal experiments indicated that the PMPC/A/1400W/NGF nanomotors could effectively pass through the BSCB and restore the motion function of a rat SCI model by regulating its internal environment as well as the release of therapeutic drugs. Thus, the drug delivery system based on nanomotor technology offers a promising strategy for treating central nervous system diseases.

Quercetin and resveratrol are associated with the downregulation of TNFalpha/NF-kB/inos axis-mediated acute liver injury in rats induced by paracetamol poisoning / La quercetina y el resveratrol están asociados con la regulación decreciente de la lesión hepática aguda mediada por el eje TNF-alfa/NF-kB/inos en ratas inducida por envenenamiento con paracetamol

SUMMARY: Paracetamol (known as acetaminophen, or APAP) poisoning causes acute liver damage that can lead to organ failure and death. We sought to determine that APAP overdose can augment tumor necrosis factor-alpha (TNF-α)/ nuclear factor kappa B (NF-kB)/induced nitic oxide synthase (iNOS) axis-mediated hepatotoxicity in rats, and the anti-inflammatory polyphenolic compounds, quercetin (QUR) plus resveratrol (RES) can ameliorate these parameters. Therefore, we induced acute hepatotoxicity in rats using APAP overdose (2 g/kg, orally) and the protective group of rats were treated with 50 mg/kg QUR plus 30 mg/kg RES for one week before APAP ingestion. Animals were killed at day 8. APAP poisoning caused the induction of hepatic tissue levels of TNF-α, NF-kB, and iNOS, which were significantly (p<0.05) decreased by QUR+RES. QUR+RES, also inhibited liver injury biomarkers, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Additionally, a link between liver injury and TNF-α /NF-kB / iNOS axis mediated hepatotoxicity was observed. Thus, the presented data backing the conclusion that intoxication by paracetamol increases TNF-α / NF-kB / iNOS axis -mediated hepatotoxicity, and is protected by a combination of quercetin and resveratrol.

El envenenamiento por paracetamol (conocido como acetaminofeno o APAP) causa daño hepático agudo que puede provocar una insuficiencia orgánica y la muerte. El objetivo de este trabajo fue determinar si la sobredosis de APAP puede aumentar la hepatotoxicidad mediada por el eje del factor de necrosis tumoral alfa (TNF-α)/factor nuclear kappa B (NF-kB)/óxido nítico sintasa inducida (iNOS) en ratas, y si el polifenólico antiinflamatorio compuesto por quercetina (QUR) más resveratrol (RES) pueden mejorar estos parámetros. Por lo tanto, inducimos hepatotoxicidad aguda en ratas usando una sobredosis de APAP (2 g/kg, por vía oral). El grupo protector de ratas se trató con 50 mg/ kg de QUR más 30 mg/kg de RES durante una semana antes de la ingestión de APAP. Los animales se sacrificaron el día 8. El envenenamiento con APAP en el tejido hepático provocó la inducción de niveles de TNF-α, NF-kB e iNOS, que se redujeron significativamente (p<0,05) con QUR+RES. QUR+RES, también inhibió los biomarcadores de daño hepático, la alanina aminotransferasa (ALT) y el aspartato aminotransferasa (AST). Además, se observó una relación entre la lesión hepática y la hepatotoxicidad mediada por el eje TNF-α /NF-kB/iNOS. Por lo tanto, los datos presentados respaldan la conclusión de que la intoxicación por paracetamol aumenta la hepatotoxicidad mediada por el eje TNF-α /NF-kB / iNOS, y está protegida por una combinación de quercetina y resveratrol.

Anti-cancer effect of in vivo inhibition of nitric oxide synthase in a rat model of breast cancer.

Increased expression of nitric oxide synthase (NOS) is associated with different cancers such as cervical, breast, lung, brain, and spinal cord. Inhibition of NOS activity has been suggested as potential tool to prevent breast cancer. The anti-tumor therapeutic effect of L-nitro arginine methyl ester (L-NAME), NOS inhibitor, using in vivo models is currently under investigation. We hypothesized that L-NAME will show an anti-tumor effect by delaying a progression of breast cancer via a modulation of cell death and proliferation, and angiogenesis. We used a novel model of anti-cancer treatment by the administration of L-NAME (30 mg/kg in a day, intraperitoneal) injected every third day for five weeks to rat model of 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast tumor. Concentrations of nitrite anions, polyamines, malondialdehyde, NH4+ levels, and arginase activity in the blood were decreased in DMBA + L-NAME-treated rats compared with DMBA rats. The mortality rates, tumor number, weight, and volume, as well as the histopathological grade of breast cancer were also significantly reduced. In addition, L-NAME treatment showed a delay in tumor formation, and in body weight compared with rats administrated only with DMBA. In conclusion, our data show that L-NAME is a promising anti-cancer agent to treat breast cancer, which can lead to development of anti-tumor therapeutic tools in future.

Combination of NOS- and PDK-Inhibitory Activity: Possible Way to Enhance Antitumor Effects.

We have previously demonstrated a high antitumor potential of NOS inhibitor T1023 (1-isobutanoyl-2-isopropylisothiourea hydrobromide): antitumor antiangiogenic activity in several animal tumor models and its ability to synergistically enhance the antitumor effects of bevacizumab, cyclophosphamide and γ-radiation. At the same time, rather rapid adaptation of experimental neoplasias to T1023 treatment was often observed. We attempted to enhance the antitumor activity of this NOS inhibitor by supplementing its molecular structure with a PDK-inhibiting fragment, dichloroacetate (DCA), which is capable of hypoxia-oriented toxic effects. We synthesized compound T1084 (1-isobutanoyl-2-isopropylisothiourea dichloroacetate). Its toxic properties, NOS-inhibiting and PDK-inhibiting activity in vivo, and antitumor activity on the mouse Ehrlich carcinoma model (SEC) were investigated in compare with T1023 and Na-DCA. We found that the change of the salt-forming acid from HBr to DCA does not increase the toxicity of 1-isobutanoyl-2-isopropylisothiourea salts, but significantly expands the biochemical and anti-tumor activity. New compound T1084 realizes in vivo NOS-inhibiting and PDK-inhibiting activity, quantitatively, at the level of the previous compounds, T1023 and Na-DCA. In two independent experiments on SEC model, a pronounced synergistic antitumor effect of T1084 was observed in compare with T1023 and Na-DCA at equimolar doses. There were no signs of SEC adaptation to T1084 treatment, while experimental neoplasia rapidly desensitized to the separate treatment of both T1023 and Na-DCA. The totality of the data obtained indicates that the combination of antiangiogenic and hypoxia-oriented toxic effects (in this case, within the molecular structure of the active substance) can increase the antitumor effect and suppress the development of hypoxic resistance of neoplasias. In general, the proposed approach can be used for the design of new anticancer agents.

Nitric oxide impairs spatial learning and memory in a rat model of Alzheimer's disease via disturbance of glutamate response in the hippocampal dentate gyrus during spatial learning.

Nitric oxide (NO)-dependent pathways may play a significant role in the decline of synaptic and cognitive functions in Alzheimer's disease (AD). However, whether NO in the hippocampal dentate gyrus (DG) is involved in the spatial learning and memory impairments of AD by affecting the glutamate (Glu) response during these processes is not well-understood. Here, we prepared an AD rat model by long-term i.p. of D-galactose into ovariectomized rats, and then the effects of L-NMMA (a NO synthase inhibitor) on Glu concentration and amplitude of field excitatory postsynaptic potential (fEPSP) were measured in the DG region during the Morris water maze (MWM) test in freely-moving rats. During the MWM test, compared with the sham group, the escape latency was increased in the place navigation trial, and the percentage of time spent in target quadrant and the number of platform crossings were decreased in the spatial probe trial, in addition, the increase of fEPSP amplitude in the DG was significantly attenuated in AD group rats. L-NMMA significantly attenuated the spatial learning and memory impairment in AD rats, and reversed the inhibitory effect of AD on increase of fEPSP amplitude in the DG during the MWM test. In sham group rats, the Glu level in the DG increased significantly during the MWM test, and this response was markedly enhanced in AD rats. Furthermore, the response of Glu in the DG during spatial learning was recovered by microinjection of L-NMMA into the DG. Our results suggest that NO in the DG impairs spatial learning and memory and related synaptic plasticity in AD rats, by disturbing the Glu response during spatial learning.

Effects of nitric oxide modulators and antioxidants on endocrine and cellular markers of acute stress in rats.

The effects of nitric oxide modulators (NO-modulators) and antioxidants on acute (RSx1) restraint stress induced endocrine, cellular and oxidative/nitrosative stress markers was studied in Wistar rats. The results of our study revealed that exposure to RS(x1) enhanced malondialdehyde (MDA), heat shock protein (HSP-70), corticosterone, nuclear factor kappa B (NF-κB) levels and suppressed glutathione (GSH), superoxide dismutase (SOD) and total nitrites and nitrates (NOx) levels. NO precursor and NO synthase inhibitors were found to differentially modulate stress mechanisms, by altering NF-κB, HSP-70 and corticosterone levels. l-Ascorbic acid significantly suppressed acute stress induced elevation of NF-κB and HSP-70 levels depicting protective effects, as also evidenced by reversal of elevated plasma corticosterone levels. Therefore, modulation of oxidative and nitrosative pathways, offers an approach in modulating stress induced changes associated with various disorders.

Intrauterine L-NAME Exposure Weakens the Development of Sympathetic Innervation and Induces the Remodeling of Arterial Vessels in Two-Week-Old Rats.

Nitric oxide (NO) has been shown to stimulate differentiation and increase the survival of ganglionic sympathetic neurons. The proportion of neuronal NOS-immunoreactive sympathetic preganglionic neurons is particularly high in newborn rats and decreases with maturation. However, the role of NO in the development of vascular sympathetic innervation has never been studied before. We tested the hypothesis that intrauterine NO deficiency weakened the development of vascular sympathetic innervation and thereby changed the contractility of peripheral arteries and blood pressure level in two-week-old offspring. Pregnant rats consumed NOS inhibitor L-NAME (250 mg/L in drinking water) from gestational day 10 until delivery. Pups in the L-NAME group had a reduced body weight and blood level of NO metabolites at 1-2 postnatal days. Saphenous arteries from two-week-old L-NAME offspring demonstrated a lower density of sympathetic innervation, a smaller inner diameter, reduced maximal active force and decreased α-actin/ß-actin mRNA expression ratio compared to the controls. Importantly, pups in the L-NAME group exhibited decreased blood pressure levels before, but not after, ganglionic blockade with chlorisondamine. In conclusion, intrauterine L-NAME exposure is followed by the impaired development of the sympathetic nervous system in early postnatal life, which is accompanied by the structural and functional remodeling of arterial blood vessels.

Effect of Cholecystokinin-8 (CCK-8) on Blood Pressure and Blood Content of Calcitonin-Gene-Related Peptide (CGRP) in Rats with Hypertension Caused by Fructose or Inhibition of Nitric Oxide Synthesis.

We studied the effect of CCK-8 on BP and blood content of CGRP in rats with hypertension caused by fructose or inhibition of NO synthase with L-NAME. The decrease in the CGRP content was found during the development of fructose-induced hypertension, but not L-NAME-caused hypertension. Administration of CCK-8 to fructose-fed animals reduced BP and increased the content of CGRP. In rats with hypertension caused by NO deficit, CCK-8 lowered BP, but did not affect the content of CGRP. These findings suggest that CGRP mediates the hypotensive effect of CCK-8 in fructose-induced hypertension, but not in NO-deficient hypertension.

Renoprotection Induced by Aerobic Training Is Dependent on Nitric Oxide Bioavailability in Obese Zucker Rats.

Aerobic training (AT) promotes several health benefits that may attenuate the progression of obesity associated diabetes. Since AT is an important nitric oxide (NO-) inducer mediating kidney-healthy phenotype, the present study is aimed at investigating the effects of AT on metabolic parameters, morphological, redox balance, inflammatory profile, and vasoactive peptides in the kidney of obese-diabetic Zucker rats receiving L-NAME (N(omega)-nitro-L-arginine methyl ester). Forty male Zucker rats (6 wk old) were assigned into four groups (n = 10, each): sedentary lean rats (CTL-Lean), sedentary obese rats (CTL-Obese), AT trained obese rats without blocking nitric oxide synthase (NOS) (Obese+AT), and obese-trained with NOS block (Obese+AT+L-NAME). AT groups ran 60 min in the maximal lactate steady state (MLSS), five days/wk/8 wk. Obese+AT rats improved glycemic homeostasis, SBP, aerobic capacity, renal mitochondria integrity, redox balance, inflammatory profile (e.g., TNF-α, CRP, IL-10, IL-4, and IL-17a), and molecules related to renal NO- metabolism (klotho/FGF23 axis, vasoactive peptides, renal histology, and reduced proteinuria). However, none of these positive outcomes were observed in CTL-Obese and Obese+AT+L-NAME (p < 0.0001) groups. Although Obese+AT+L-NAME lowered BP (compared with CTL-Obese; p < 0.0001), renal damage was observed after AT intervention. Furthermore, AT training under conditions of low NO- concentration increased signaling pathways associated with ACE-2/ANG1-7/MASr. We conclude that AT represents an important nonpharmacological intervention to improve kidney function in obese Zucker rats. However, these renal and metabolic benefits promoted by AT are dependent on NO- bioavailability and its underlying regulatory mechanisms.

The Ability of the Nitric Oxide Synthases Inhibitor T1023 to Selectively Protect the Non-Malignant Tissues.

Previously, we showed that a nitric oxide synthase (NOS) inhibitor, compound T1023, induces transient hypoxia and prevents acute radiation syndrome (ARS) in mice. Significant efficacy (according to various tests, dose modifying factor (DMF)-1.6-1.9 against H-ARS/G-ARS) and safety in radioprotective doses (1/5-1/4 LD10) became the reason for testing its ability to prevent complications of tumor radiation therapy (RT). Research methods included studying T1023 effects on skin acute radiation reactions (RSR) in rats and mice without tumors and in tumor-bearing animals. The effects were evaluated using clinical, morphological and histological techniques as well as RTOG classification. T1023 administration prior to irradiation significantly limited the severity of acute RSR. This was due to a decrease in radiation alteration of the skin and underlying tissues, and the preservation of the functional activity of cell populations that are critical in the pathogenesis of radiation burn. The DMF values for T1023 for skin protection were 1.4-1.7. Moreover, its radioprotective effect was fully selective to normal tissues in RT models of solid tumors-T1023 reduced the severity of acute RSR and did not modify the antitumor effects of γ-radiation. The results indicate that T1023 can selectively protect the non-malignant tissues against γ-radiation due to hypoxic mechanism of action and potentiate opportunities of NOS inhibitors in RT complications prevention.

Nitric oxide synthase inhibition in healthy adults reduces regional and total cerebral macrovascular blood flow and microvascular perfusion.

The importance of nitric oxide (NO) in regulating cerebral blood flow (CBF) remains unresolved, due in part to methodological approaches, which lack a comprehensive assessment of both global and regional effects. Importantly, NO synthase (NOS) expression and activity appear greater in some anterior brain regions, suggesting region-specific NOS influence on CBF. We hypothesized that NO contributes to basal CBF in healthy adults, in a regionally distinct pattern that predominates in the anterior circulation. Fourteen healthy adults (7 females; 24 ± 5 years) underwent two magnetic resonance imaging (MRI) study visits with saline (placebo) or the NOS inhibitor, L-NMMA, administered in a randomized, single-blind approach. 4D flow MRI quantified total and regional macrovascular CBF, whereas arterial spin labelling (ASL) MRI quantified total and regional microvascular perfusion. L-NMMA (or volume-matched saline) was infused intravenously for 5 min prior to imaging. L-NMMA reduced CBF (L-NMMA: 722 ± 100 vs. placebo: 771 ± 121 ml/min, P = 0.01) with similar relative reductions (5-7%) in anterior and posterior cerebral circulations, due in part to the reduced cross-sectional area of 9 of 11 large cerebral arteries. Global microvascular perfusion (ASL) was reduced by L-NMMA (L-NMMA: 42 ± 7 vs. placebo: 47 ± 8 ml/100g/min, P = 0.02), with 7-11% reductions in both hemispheres of the frontal, parietal and temporal lobes, and in the left occipital lobe. We conclude that NO contributes to macrovascular and microvascular regulation including larger artery resting diameter. Contrary to our hypothesis, the influence of NO on cerebral perfusion appears regionally uniform in healthy young adults. KEY POINTS: Cerebral blood flow (CBF) is vital for brain health, but the signals that are key to regulating CBF remain unclear. Nitric oxide (NO) is produced in the brain, but its importance in regulating CBF remains controversial since prior studies have not studied all regions of the brain simultaneously. Using modern MRI approaches, a drug that inhibits the enzymes that make NO (L-NMMA) reduced CBF by up to 11% in different brain regions. NO helps maintain proper CBF in healthy adults. These data will help us understand whether the reductions in CBF that occur during ageing or cardiovascular disease are related to shifts in NO signalling.

Flavonoids and saponins from Passiflora edulis f. edulis leaves (purple passion fruit) and its potential anti-inflammatory activity.

OBJECTIVES: The objective of this work was to evaluate the anti-inflammatory activity of the aqueous extract, fractions and major compounds, which are isolated and identified from Passiflora edulis f. edulis (purple passion fruit) leaves extract. METHODS: For the isolation of the major compounds, reversed-phase chromatography and normal phase countercurrent chromatography were used. The separation was followed by thin layer chromatography and HPLC-DAD-ELSD. One-dimensional and two-dimensional NMR and ESI-TOF-MS/MS were used for structural elucidation. The anti-inflammatory activity was evaluated on a TPA multiple dose model of skin chronic inflammation in mice. Additionally, myeloperoxidase (MPO) and nitric oxide synthase (NOS) activity assays were performed as possible mechanisms of action studies. KEY FINDINGS AND CONCLUSIONS: The study of the butanolic fraction mainly showed the presence of saponins and flavonoids. Three minor flavonoids were detected; and three known saponins, cyclopassiflosides IX, XI and III were isolated and identified. This is the first unequivocal report of the presence of these compounds in P. edulis f. edulis leaves. The most favourable results of anti-inflammatory activity were obtained for the flavonoid-rich fraction. All the fractions and isolated compounds evaluated, presented high percentages of inhibition of nitric oxide synthase activity.

The implications of nitric oxide metabolism in the treatment of glial tumors.

Glial tumors are the most common intracranial malignancies. Unfortunately, despite such a high prevalence, patients' prognosis is usually poor. It is related to the high invasiveness, tendency to relapse and the resistance of tumors to traditional methods of treatment. An important link in the aspect of these issues may be nitric oxide (NO) metabolism. It is a very complex mechanism with multidirectional effects on the neoplastic process. Depending on the concentration axis, it can both exert pro-tumor action as well as contribute to the inhibition of tumorigenesis. The latest observations show that the control of its metabolism can be very helpful in the development of new methods of treating gliomas, as well as in increasing the effectiveness of the agents currently used. The influence of nitric oxide and nitric oxide synthase (NOS) activity on glioma stem cells seem to be of particular importance. The use of specific inhibitors may allow the reduction of tumor growth and its tendency to relapse. Another important feature of GSCs is their conditioning of glioma resistance to traditional forms of treatment. Recent studies have shown that modulation of NO metabolism can suppress this effect, preventing the induction of radio and chemoresistance. Moreover, nitric oxide is involved in the regulation of a number of immune mechanisms. Adequate modulation of its metabolism may contribute to the induction of an anti-tumor response in the patients' immune system.

New dihydro-ß-agarofuran sesquiterpenoids from Tripterygium wilfordii and their anti-inflammatory activity.

Twenty seven dihydro-ß-agarofuran sesquiterpenoids, including fifteen new congeners, wilforsinines I-W (1-9, 12-13, 24-27), and twelve known compounds were isolated from the dried root of Tripterygium wilfordii. The structures of the new sesquiterpenoids, wilforsinines I-W, were elucidated by extensive spectroscopic data analysis. The anti-inflammatory activity of isolates 1-27 were evaluated by examining their inhibitory effects on nitric oxide (NO) production in LPS-induced RAW 264.7 macrophage cells. Among them, wilforsinine K (3) and angulatin M (16) exerted optimal inhibitory effects on the production of NO in LPS-induced RAW 264.7 cells. Moreover, Western blot results revealed that their anti-inflammatory activities were correlated with the suppression of the expression of nitric oxide synthase (iNOS) and down-regulation of the level of NF-κB p65 phosphorylation.

Carajurin: a anthocyanidin from Arrabidaea chica as a potential biological marker of antileishmanial activity.

Leishmaniasis is a group of neglected tropical diseases whose treatment with antimonials bears limitations and has changed little in over 80 years. Medicinal plants have been evaluated as a therapeutic alternative for leishmaniasis. Arrabidaea chica is popularly used as a wound healing and antiparasitic agent, especially as leishmanicidal agent. This study examined the leishmanicidal activity of a crude extract (ACCE), an anthocyanidin-rich fraction (ACAF), and three isolated anthocyanidins from A. chica: carajurin, 3'-hydroxy-carajurone, and carajurone. We evaluated the antileishmanial activity against promastigote and intracellular amastigote forms of Leishmania amazonensis and determined cytotoxicity in BALB/c peritoneal macrophages, as well as nitrite quantification, using the Griess method. Molecular docking was carried out to evaluate interactions of carajurin at the nitric oxide synthase enzyme. All compounds were active against promastigotes after 72 h, with IC50 values of 101.5 ± 0.06 µg/mL for ACCE and 4.976 ± 1.09 µg/mL for ACAF. Anthocyanidins carajurin, 3'-hydroxy-carajurone, and carajurone had IC50 values of 3.66 ± 1.16, 22.70 ± 1.20, and 28.28 ± 0.07 µg/mL, respectively. The cytotoxicity assay after 72 h showed results ranging from 9.640 to 66.74 µg/mL for anthocyanidins. ACAF and carajurin showed selectivity against intracellular amastigote forms (SI> 10), with low cytotoxicity within 24 h, a statistically significant reduction in all infection parameters, and induced nitrite production. Molecular docking studies were developed to understand a possible mechanism of activation of the nitric oxide synthase enzyme, which leads to an increase in the production of nitric oxide observed in the other experiments reported. These results encourage us to suggest carajurin as a biological marker of A. chica.

Cyclooxygenase-dependent mechanisms mediate in part the anti-dilatory effects of perivascular adipose tissue in uterine arteries from pregnant rats.

Uterine perivascular adipose tissue (PVAT) contributes to uterine blood flow regulation in pregnancy, at least in part, due to its effects on uterine artery reactivity. We tested the hypothesis that uterine PVAT modulates the balance between the contribution of nitric oxide synthase (NOS)- and cyclooxygenase (COX)-dependent pathways to acetylcholine (ACh)-induced relaxation in isolated uterine arteries. Concentration-response curves to ACh (1 nM - 30 µM) were performed on uterine arteries from pregnant and non-pregnant rats. Arteries were exposed to Krebs-Henseleit solution (control) or PVAT-conditioned media (PVATmedia) in the presence of the following inhibitors: L-NAME (NOS inhibitor), indomethacin (COX inhibitor), SC560 (COX-1 inhibitor), NS398 (COX-2 inhibitor), SQ 29,548 (thromboxane receptor (TP) inhibitor). In arteries incubated with PVATmedia, the presence of indomethacin increased ACh-induced relaxation, reversing the anti-dilatory effect of PVATmedia. NOS inhibition reduced ACh-induced relaxation in uterine arteries from pregnant rats, and exposure to PVATmedia did not change this effect. Selective inhibition of COX-1 but not COX-2 suppressed relaxation responses to ACh in control arteries. The presence of PVATmedia abolished the effect of COX-1 inhibition. Incubation of uterine arteries from pregnant rats with PVATmedia increased production of thromboxane B2 (TxB2, p = 0.01) but thromboxane receptor (TP) inhibition did not affect the anti-dilatory properties of PVATmedia. In conclusion, inhibition of COX signaling suppressed the anti-dilatory effects of PVATmedia, while PVATmedia had no effect on the contribution of the NOS/NO pathway to ACh-induced relaxation in uterine arteries from pregnant rats, indicating that the anti-dilatory effects of uterine PVAT are mediated in part by COX-dependent mechanisms.

Phenolic composition, antioxidant capacity and physical characterization of ten blackcurrant (Ribes nigrum) cultivars, their juices, and the inhibition of type 2 diabetes and inflammation biochemical markers.

The objective was to analyze the phenolic composition, antioxidant capacity, and physical characteristics of 10 blackcurrant cultivars, their juices, and the enzymatic inhibition of dipeptidyl peptidase-IV, α-amylase, α-glucosidase, nitric oxide synthase, and cyclooxygenase-2. Fruit masses ranged from 0.47 to 1.22 g and diameters from 7.42 to 14.42 mm. For the juices, pH ranged from 2.80 to 2.96, soluble solids from 11.33% to 17.5%, total acidity from 3.17 to 4.26 g/100 mL, and viscosity from 1.28 to 273.83 mPa·s. Total anthocyanins (TA) ranged from 1.81 to 5.48 mg eq cyanidin 3-O-glucoside/100 g, total polyphenols (TP) from 7.67 to 39.70 mg eq gallic acid/100 g, total condensed tannins from 3.24 to 7.76 g eq catechin/100 g, and antioxidant capacity from 219.24 to 499.26 µmol eq Trolox/100 g. Juices of the cultivars Coronet and Consort contained the highest levels of TA, TP, and antioxidants. Whistler cultivar contained high concentrations of major anthocyanins. Juices from all cultivars favorably inhibited the activities of enzymes used as surrogate biochemical markers for T2 diabetes and inflammation.

Cardiovascular effects of farnesol and its ß-cyclodextrin complex in normotensive and hypertensive rats.

Farnesol (FAR) is a sesquiterpene alcohol with a range of reported biological effects including cardioprotective, antioxidant and antiarrhythmic properties. However, due to its volatility, the use of drug incorporation systems, such as cyclodextrins, have been proposed to improve its pharmacological properties. Thus, the aim of this study was to evaluate and characterize the cardiovascular effects of FAR alone, and to investigate the antihypertensive effects of FAR complexed with ß-cyclodextrin (ßCD) in rats. Mean arterial pressure (MAP) and heart rate (HR) were measured before and after intravenous administration of FAR (0,5; 2,5; 5 and 7,5 mg/kg) in normotensive rats, and after oral acute administration (200 mg/kg) of FAR and FAR/ßCD complex in NG-nitro-L-arginine-methyl-ester (L-NAME) hypertensive rats. In normotensive animals, FAR induced dose-dependent hypotension associated with bradycardia. These effects were not affected by pre-treatment with L-NAME or indomethacin (INDO), but were partially attenuated by atropine. Pre-treatment with hexamethonium (HEXA) only affected hypotension. In the hypertensive rats, FAR/ßCD potentialized the antihypertensive effect when compared to FAR alone. Molecular docking experiments demonstrated for the first time that FAR has affinity to bind to the M3 and M2 muscarinic, and nicotinic receptors through hydrogen bonds in the same residues as known ligands. In conclusion, our results demonstrated that FAR induced hypotension associated with bradycardia, possibly through the muscarinic and nicotinic receptors. The inclusion complex with ßCD improved the antihypertensive effects of FAR, which can be relevant to improve current cardiovascular therapy using volatile natural components.

L-NAME, a nitric oxide synthase inhibitor, increases the protein expression of both executioner and inhibitor of apoptosis in the placental bed of mid-to-late pregnant rats.

The involvement of nitric oxide (NO) signaling in apoptosis was examined in the placental bed of mid-to-late pregnant rats. Pregnant rats were treated with l-NAME, a nitric oxide synthase inhibitor, by subcutaneous infusion for 48 hours before the examination at day 13.5, 17.5, or 21.5. l-NAME induced apoptosis in the placental bed to a limited extent at days 13.5 and 17.5, but not at day 21.5. When the placental bed was examined at day 17.5, the protein expression of both executioner (C-Cas3) and inhibitor (XIAP) of apoptosis was increased by l-NAME, but they did not co-localized with apoptosis. It was presumed that placental bed apoptosis induced by l-NAME is regulated through the expression of both executioner and inhibitor, possibly involving protein S-nitrosylation.