Boswellic acids ameliorate neurodegeneration induced by AlCl3: the implication of Wnt/ß-catenin pathway.

Alzheimer's disease (AD) is a neurodegenerative disease (ND) that represents the principal cause of dementia. Effective treatment is still lacking. Without prevention, Alzheimer's disease (AD) incidence is expected to triple within 30 years. The risk increases in highly polluted areas and is positively linked to chronic aluminum (Al) exposure. Canonical Wingless-Int (Wnt)/ß-catenin pathway has been found to play a considerable role in ND pathogenesis. Resins of Boswellia serrata (frankincense) have been used traditionally for their psychoactive activity, in addition to their memory-boosting effects. Boswellic acids (BA) are pentacyclic triterpenes. They have antioxidant, anti-inflammatory, antinociceptive, and immunomodulatory activities. This study aimed to elucidate the role of the Wnt/ß-catenin pathway in BA protective activity against aluminum-induced Alzheimer's disease. For 6 weeks, rats were treated daily with AlCl3 (100 mg/kg/i.p.) either alone or with BA (125 or 250 mg/kg PO). Results indicated that BA significantly improved learning and memory impairments induced by AlCl3 treatment. Moreover, BA treatment significantly decreased acetylcholinesterase levels and reduced amyloid-beta (Aß) expression. In addition, BA ameliorated the increased expression of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß), inhibited lipid peroxidation, and increased total antioxidants in the brain. Indeed, BA significantly suppressed AlCl3-induced decrease of brain-derived neurotrophic factor, pGSK-3ß (Ser 9), and ß-catenin. BA (250 mg/kg) showed a significant protective effect compared to a lower dose. The results conclude that BA administration modulated the expression of Wnt/ß-catenin pathway-related parameters, contributing to BA's role against Al-induced Alzheimer's disease. Effect of Boswellic acids on AlCl3-induced neurodegenerative changes. ChE cholinesterase, Ach acetylcholine, BDNF brain-derived neurotrophic factor, IL-1ß interleukin-1ß, TNF-α tumor necrosis factor-α.

miR­101a­3p overexpression prevents acetylcholine­CaCl2­induced atrial fibrillation in rats via reduction of atrial tissue fibrosis, involving inhibition of EZH2.

Atrial fibrillation (AF), a clinically common heart arrhythmia, can result in left ventricular hypofunction, embolism and infarction. MicroRNA (miR)­101a­3p is lowly expressed in atrial tissues of patients with AF, but its role in AF remains unknown. In the present study, an AF model in rats was established via intravenous injection of acetylcholine (Ach)­CaCl2. The downregulation of miR­101a­3p and upregulation of enhancer of zeste 2 homolog 2 (EZH2) were observed in AF model rats, indicating the involvement of miR­101a­3p and EZH2 in AF development. To study the effect of miR­101a­3p on AF in vivo, AF model rats were intramyocardially injected with lentivirus expressing miR­101a­3p. Electrocardiogram analysis identified that miR­101a­3p overexpression restored disappeared P wave and R­R interphase changes in Ach­CaCl2­induced rats. Overexpression of miR­101a­3p also increased the atrial effective refractory period, reduced AF incidence and shortened duration of AF. Histological changes in atrial tissues were observed after H&E and Masson staining, which demonstrated that miR­101a­3p reduced atrial remodeling and fibrosis in AF model rats. Moreover, EZH2 expression was downregulated in atrial tissues by miR­101a­3p induction. Immunohistochemistry for collagen Ⅰ and collagen III revealed a reduction in atrial collagen synthesis following miR­101a­3p overexpression in AF model rats. Additionally, miR­101a­3p lowered the expression of pro­fibrotic biomarkers, including TGF­ß1, connective tissue growth factor, fibronectin and α­smooth muscle actin. The luciferase reporter assay results also indicated that EZH2 was a target gene of miR­101a­3p. Taken together, it was found that miR­101a­3p prevented AF in rats possibly via inhibition of collagen synthesis and atrial fibrosis by targeting EZH2, which provided a potential target for preventing AF.

Herb pair of Ephedrae Herba-Armeniacae Semen Amarum alleviates airway injury in asthmatic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Ephedrae Herba (EH, Ephedra sinica Stapf.) and Armeniacae Semen Amarum (ASA, Prunus armeniaca L. var. ansu Maxim.) have been used to treat asthma, cold, fever, and cough in China for thousands of years. AIM OF THE STUDY: In this study, we aimed to investigate the optimal ratio of EH and ASA compatibility (EAC) to reduce airway injury in asthmatic rats and its possible mechanism. METHODS: Rats were sensitized with a mixture of acetylcholine chloride and histamine bisphosphate 1 h before sensitization by intragastric administration of EAC or dexamethasone or saline for 7 days. Subsequently, the ultrastructure of rat airway epithelial tissue changes, apoptosis of the airway epithelial cells, and the expression of mRNA and protein of EGRF and Bcl-2 were detected. RESULTS: Transmission electron microscope: EAC (groups C and E) had the most prominent effect on repairing airway epithelial cells' ultrastructural changes in asthmatic rats. TUNEL: dexamethasone and EAC (groups B、C、E and F) inhibited the apoptosis of airway epithelial cells in asthmatic rats (P < 0.05). In situ hybridization: EAC (group E) inhibited the overexpression of EGFR and Bcl-2 mRNA (P < 0.05).Western Blotting: EAC (groups A、B、C、E and F) inhibited the upregulation of airway epithelial EGFR and Bcl-2 protein expression (P < 0.01). CONCLUSIONS: Our findings indicate that EAC can inhibit abnormal changes in airway epithelial structure and apoptosis of airway epithelial cells, thereby alleviating airway injury. In this study, the best combination of EH and ASA to alleviate airway epithelial injury in asthmatic rats was group E (EH: ASA = 8: 4.5).

Impact of soman and acetylcholine on the effects of propofol in cultured cortical networks.

Patients intoxicated with organophosphorous compounds may need general anaesthesia to enable mechanical ventilation or for control of epileptiform seizures. It is well known that cholinergic overstimulation attenuates the efficacy of general anaesthetics to reduce spontaneous network activity in the cortex. However, it is not clear how propofol, the most frequently used intravenous anaesthetic today, is affected. Here, we investigated the effects of cholinergic overstimulation induced by soman and acetylcholine on the ability of propofol to depress spontaneous action potential activity in organotypic cortical slices measured by extracellular voltage recordings. Cholinergic overstimulation by co-application of soman and acetylcholine (10 µM each) did not reduce the relative inhibition of propofol (1.0 µM; mean normalized action potential firing rate 0.49 ± 0.06 of control condition, p < 0.001, Wilcoxon signed rank test) but clearly reduced its efficacy. Co-application of atropine (10 nM) did not improve the efficacy. Propofol preserved its relative inhibitory potential but did not produce a degree of neuronal depression which can be expected to assure hypnosis in humans. Since a combination with atropine did not improve its efficacy, an increase in dosage will probably be necessary when propofol is used in victims suffering from organophosphorous intoxication.

Effects of Angiotensin-(1-7) and Angiotensin II on Acetylcholine-Induced Vascular Relaxation in Spontaneously Hypertensive Rats.

Endothelial dysfunction of small arteries occurs in patients with hypertension and in various hypertensive models. Endothelial function is usually evaluated by the degree of acetylcholine- (ACh-) induced vascular relaxation. Our previous study has found that compared to Wistar-Kyoto rats (WKY), ACh-induced vasodilatation was attenuated significantly in the mesenteric artery (MA), coronary artery (CA), and pulmonary artery (PA) of spontaneously hypertensive rats (SHR). This study investigated the influence of angiotensin- (Ang-) (1-7) and Ang II on blood pressure and ACh-induced vascular relaxation, as well as their interactive roles and downstream signal pathways in SHR and WKY. Intravenous injection of Ang II significantly increased, while Ang-(1-7) decreased the mean arterial pressure (MAP) in SHR. Ang-(1-7) improved ACh-induced relaxation in the MA, CA, and PA of SHR, while Ang II further attenuated it, which were inhibited by pretreatment with Mas receptor antagonist A-779 or AT1 receptor antagonist losartan, respectively. Ang-(1-7) decreased the basal arterial tension, and Ang II induced great vasoconstriction in SHR. Pretreatment with Ang-(1-7) inhibited the Ang II-induced pressor response, vasoconstriction, and the effects on ACh-induced relaxation in SHR. AT1 receptor expression was higher, while nitric oxide (NO), cGMP, and protein kinase G (PKG) levels of arteries were lower in SHR than in WKY. Ang II decreased, while Ang-(1-7) increased, the levels of NO, cGMP, and PKG of arteries. In addition, pretreatment with Ang-(1-7) inhibited the Ang II-induced reduction of NO, cGMP, and PKG in SHR. These results indicate that the activation of the Mas receptor by Ang-(1-7) can improve endothelial function and decrease MAP in SHR and inhibit the deteriorative effect of Ang II on endothelial function through the NO-cGMP-PKG pathway.

Preserved cardiovascular homeostasis despite blunted acetylcholine-induced dilation in mice with endothelial muscarinic M3 receptor deletion.

AIM: Muscarinic acetylcholine receptors (AChMR1-5) are fundamental for cellular responses upon release of the neurotransmitter acetylcholine (ACh) from parasympathetic nerve fibers. ACh is the prototypical agonist stimulating endothelium-dependent dilation, but most blood vessels lack parasympathetic innervation, raising the question as to the physiologic function of endothelial AChMR in vivo. Global deletion of AChM3R revealed a role in ACh-induced vasodilation in vitro and food uptake, but overall cardiovascular homeostasis has not been examined thoroughly. METHODS: To characterize the function of endothelial AChM3R in vivo, we deleted AChM3R specifically in endothelial cells with an inducible or a non-inducible Cre-loxP system, driven by the endothelium-specific promoters VE-cadherin (indEC-M3R-/- ) or TIE2 (tek2; EC-M3R-/- ) and examined arteriolar dilation in the cremaster microcirculation, arterial pressure and cardiac function in these mice in vivo. RESULTS: In both EC-M3R-/- , ACh-induced dilation was strongly impaired in arterioles in vivo, while responses to other dilators were mostly preserved. However, arterial pressure (indEC-M3R-/- ) and arteriolar tone as a surrogate for peripheral vascular resistance did not differ between EC-M3R-/- and control mice. Aged EC-M3R-/- mice (74-78 weeks) did not differ in body weight, heart weight, cardiac structure or contractile function from controls. CONCLUSION: We conclude that AChM3R elicits the endothelium-dependent dilation upon ACh also in arterioles in vivo. Despite this prominent role, the endothelial deletion of AChM3R does not affect overall cardiovascular homeostasis. Thus, their physiologic function in endothelial cells remains obscure.

Herbicidal Ionic Liquids Containing the Acetylcholine Cation.

This study presents a new group of herbicidal ionic liquids (HILs) based on a cation occurs commonly in nature-acetylcholine. The HILs were obtained with a high yield through ion exchange between acetylcholine chloride and potassium or sodium salts of selected acids with herbicidal activity. The results of the herbicidal activity measurement against common oilseed rape (Brassica napus L.) exceeded those of the commercial products. Spray solutions of the synthesized HILs revealed high surface activity and wetting properties which further manifested as higher herbicidal activity. The reduction of surface tension and low contact angles together with the specific action of acetylcholine allowed for better penetration of synthesized HILs into plant tissues. In addition, OECD 301F tests confirmed high mineralization of the HILs. The simple transformation of commercial herbicides into acetylcholine HILs proved to be a very effective method of increasing their activity, and constitutes an interesting solution to the problem of weed infestation with the use of a substance commonly found in nature.

Analysis of the main constituents of Changshu tablet and its spasmolysis effect against contraction induced by acetylcholine in the rat-isolated intestinal smooth muscle.

The Changshu tablet (CST), one kind of Chinese patent medicine with astringent to the intestine and relieving diarrhea, was made by the root of Rose odorata Sweet var. gigantean (Coll.et Hemsl.) Rehd.et Wils. Although CST has a long history of clinical application, but the research of its chemical composition is less. So the objective of this study was to investigate the main constituents and preliminarily research its effect of the contraction of isolated intestine in vitro. The contents of total polyphenols (126.23mg/g) and total triterpenoids (132.75mg/g) in CST were determined by ultraviolet spectrophotometry. Procyanidin B3, epigallo catechin, catechin, epicatechin, (-)-fisetinidol-(4α, 8)-(-)-catechin, (4α, 8)-(-)-fisetinidol-(-)-epicatechins and (+)-guibourtinidol-(4ß, 8)-epicatechin were identified and determined by high performance liquid chromatography and their contents were distributed from 0.04mg/g to 1.46 mg/g. CST showed significant inhibitory effect against acetylcholine-induced contraction on the rat-isolated intestinal smooth muscle with a dose-dependent manner from 0.06 to 0.6mg/mL. The maxim inhibition rates of CST on duodenum, jejunum, ileum and colon were 65.70±3.47%, 79.74±1.27%, 58.90±1.87% and 45.75±2.21% respectively. These results indicated that CST has a spasmolytic role in gastrointestinal motility which was probably mediated through inhibition of muscarinic receptors. All these findings promote the improvement of the quality control standard of CST and provide pharmacological foundation for clinical application of CST in gastrointestinal tract.

Taurine Reverses Atrial Structural Remodeling in Ach-Cacl2 Induced Atrial Fibrillation Rats.

Taurine has been reported to have anti-arrhythmia effects, but the anti-atrial fibrillation (AF) effects and its mechanism remain incompletely understood. In the present study, the therapy effects and partly mechanisms were investigated. AF animal model was established by intravenous administered with the mixture of acetylcholine (Ach) and CaCl2 (66 µg/mL + 10 mg/mL) (i.v.) for 7 days. The actions of taurine (99 mg/kg∙d, introgastric administration) on the levels of Hs-CRP, IL-6, TNF-α, MMP-9, AngII, the extent of the fibrosis and ultrastructural changes in left atrial were studied. The data showed that the serum levels of TNF-α, IL-6, AngII and the plasma levels of Hs-CRP and MMP-9 were significantly elevated in automatic recovery group relative to the control group (p < 0.01), which were all decreased by taurine administration (p < 0.01) similar to Verapamil treatment. Masson's trichrome staining of the left atrial tissue showed an obvious interstitial fibrosis in rats of automatic recovery group. The alteration could be reversed by additional taurine. Electron microscopy revealed that taurine administration could significantly alleviate the ultrastructural damage of atrial cells, and the effects were similar to the Verapamil treatment. In conclusion, the results suggested that taurine could inhibit the structural remodeling of AF in rats partly by decreasing the levels of inflammatory factors and profibrotic molecules, attenuating the extent of myocardial fibrosis and protecting the integrity of myocardial ultrastructure.

Taurine Prevents the Electrical Remodeling in Ach-CaCl2 Induced Atrial Fibrillation in Rats.

OBJECTIVE: To study the preventive actions and mechanism of taurine on the electrical remodeling in atrial fibrillation (AF) rats. METHODS: Male Wistar rats were injected with the mixture of acetylcholine (Ach) (66 µg/mL)-CaCl2 (10 mg/mL) (i.v.) for 7 days to establish AF model. Taurine was administered in drinking water 1 week before or at the same time of AF model establishment. The duration of AF was monitored by recording ECG of rats during the model establishment. At the end of the experiment, left atrial appendages were cut down to measure the effective refractory period (ERP) by S1-S2 double stimulation method; atrial tissues were collected in order to detect the concentration of K+ and taurine by flame atomic absorption spectrometry and ELISA respectively; total RNA were extracted from the atrium, gene expressions of Kv1.5, Kv4.3, Kir2.1, Kir3.4 were detected by semi-quantitative RT-PCR. RESULTS: Taurine administration effectively shortened the AF duration of rats and prolonged atrial ERP than the model and taurine depleted rats. In addition, atrial K+ level in taurine treated groups was significantly reduced nearly to the normal level. Moreover, the mRNA expression levels of Kir3.4 and Kv1.5 were significantly increased in the taurine preventive treated groups. CONCLUSIONS: Taurine can prevent the atrial electrical remodeling and decrease the duration of AF in rats by reducing the atrial K+ concentration and up-regulating mRNA expression levels of Kir3.4 and Kv1.5.

Inhibition of p53 Mutant Peptide Aggregation In Vitro by Cationic Osmolyte Acetylcholine Chloride.

Mutations of tumor suppressor protein p53 are present in almost about 50% of all cancers. It has been reported that the p53 mutations cause aggregation and subsequent loss of p53 function, leading to cancer progression. Here in this study we focus on the inhibitory effects of cationic osmolyte molecules acetylcholine chloride, and choline on an aggregation prone 10 amino acid p53 mutant peptide WRPILTIITL, and the corresponding wildtype peptide RRPILTIITL in vitro. The characterization tools used for this study include Thioflavin- T (ThT) induced fluorescence, transmission electron microscopy (TEM), congo red binding, turbidity, dynamic light scattering (DLS), and cell viability assays. The results show that acetylcholine chloride in micromolar concentrations significantly inhibit p53 mutant peptide aggregation in vitro, and could be promising candidate for p53 mutant/ misfolded protein aggregation inhibition.

IRAP inhibition using HFI419 prevents moderate to severe acetylcholine mediated vasoconstriction in a rabbit model.

Coronary artery vasospasm (constriction) caused by reduced nitric oxide bioavailability leads to myocardial infarction. Reduced endothelial release of nitric oxide by the neurotransmitter acetylcholine, leads to paradoxical vasoconstriction as it binds to smooth muscle cell M3 receptors. Thus, inhibition of coronary artery vasospasm will improve clinical outcomes. Inhibition of insulin regulated aminopeptidase has been shown to improve vessel function, thus we tested the hypothesis that HFI419, an inhibitor of insulin regulated aminopeptidase, could reduce blood vessel constriction to acetylcholine. The abdominal aorta was excised from New Zealand white rabbits (n=15) and incubated with 3mM Hcy to induce vascular dysfunction in vitro for 1h. HFI419 was added 5min prior to assessment of vascular function by cumulative doses of acetylcholine. In some rings, vasoconstriction to acetylcholine was observed in aortic rings after pre-incubation with 3mM homocysteine. Incubation with HFI419 inhibited the vasoconstrictive response to acetylcholine, thus improving, but not normalizing, vascular function (11.5±8.9% relaxation vs 79.2±37% constriction, p<0.05). Similarly, in another group with mild vasoconstriction, HFI419 inhibited this effect (34.9±4.6% relaxation vs 11.1±5.2%, constriction, p<0.05). HFI419 had no effect on control aorta or aorta with mild aortic dysfunction. The present study shows that HFI419 prevents acetylcholine mediated vasoconstriction in dysfunctional blood vessels. HFI419 had no effect on normal vasodilation. Our results indicate a therapeutic potential of HFI419 in reducing coronary artery vasospasm.

Ikarisoside A inhibits acetylcholine-induced catecholamine secretion and synthesis by suppressing nicotinic acetylcholine receptor-ion channels in cultured bovine adrenal medullary cells.

Ikarisoside A is a natural flavonol glycoside derived from plants of the genus Epimedium, which have been used in Traditional Chinese Medicine as tonics, antirheumatics, and aphrodisiacs. Here, we report the effects of ikarisoside A and three other flavonol glycosides on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells. We found that ikarisoside A (1-100 µM), but not icariin, epimedin C, or epimedoside A, concentration-dependently inhibited the secretion of catecholamines induced by acetylcholine, a physiological secretagogue and agonist of nicotinic acetylcholine receptors. Ikarisoside A had little effect on catecholamine secretion induced by veratridine and 56 mM K(+). Ikarisoside A (1-100 µM) also inhibited (22)Na(+) influx and (45)Ca(2+) influx induced by acetylcholine in a concentration-dependent manner similar to that of catecholamine secretion. In Xenopus oocytes expressing α3ß4 nicotinic acetylcholine receptors, ikarisoside A (0.1-100 µM) directly inhibited the current evoked by acetylcholine. It also suppressed (14)C-catecholamine synthesis and tyrosine hydroxylase activity induced by acetylcholine at 1-100 µM and 10-100 µM, respectively. The present findings suggest that ikarisoside A inhibits acetylcholine-induced catecholamine secretion and synthesis by suppression of nicotinic acetylcholine receptor-ion channels in bovine adrenal medullary cells.

Qingfei Xiaoyan Wan alleviates asthma through multi-target network regulation.

BACKGROUND: Qingfei Xiaoyan Wan (QFXY), a traditional Chinese formula, is widely used for relieving cough, asthma, upper respiratory tract infection, bronchitis, pneumonia, and etc. in clinic. Comparing with other anti-asthma drugs, it is characterised with moderate and persistent efficacy as well as few side effects, however, the underlying action mechanism still remains elusive. This study aimed to identify QFXY multi-target network regulation as an asthma controller. METHODS: This study established asthma model induced by histamine phosphate and acetylcholine chloride (His&Ach) in guinea pigs, which then were administered orally with QFXY. Hematoxylin-Eosin staining sections were applied for evaluating QFXY effect. In both Model and QFXY groups, customized microarrays and 2D electrophoresis were adopted to detect differentially expressed genes (diff genes) and proteins (diff proteins) respectively, and some diff proteins were identified with MALDI-TOF/MS. The checked diff genes and proteins underwent Cluster, GO and KEGG analysis. Based on GAD and HPRD databases, QFXY-asthma target regulation network was constructed. RESULTS: His&Ach-induced asthma model of guinea pigs was established. HE sections presented anti-inflammation and anti-remodelling effects of QFXY. Comparing with the Model group, 55 diff genes and 6 diff proteins were identified in QFXY group. Validation by qPCR and Western blot showed the microarray and 2D data reliable. Furthermore, QFXY-asthma target regulation network was achieved. CONCLUSIONS: A primarily combined genomic and proteomic screening of QFXY targets displayed a series of candidate genes and proteins, which indicated that the effect of QFXY relied on the combined mechanism, anti-inflammation and anti-remodelling, as well as influencing signal transduction in vivo.

Effects of acute administration of ethanol on experimental arrhythmia.

Many studies have shown that the relationship between alcohol consumption and most cardiovascular diseases is U-shaped, with nondrinkers and heavier drinkers having higher risks than moderate drinkers. However, the association between cardiac arrhythmias and acute alcohol consumption is not well understood. We set up several experimental arrhythmia animal models to examine the effects of acute administration of ethanol on arrhythmia. The results showed 0.4, 0.8 and 1.6 g/kg ethanol consumption obviously delayed the onset time of atrial fibrillation (AF) (P < 0.05 or P < 0.01) and increased the survival rates on acetylcholine-CaCl2-induced AF in mice. Ethanol (0.4, 0.8 and 1.6 g/kg) consumption significantly delayed the onset time of ventricular tachycardia (VT), ventricular fibrillation (VF) and cardiac arrest (CA) (P < 0.01), and 0.4 and 0.8 g/kg ethanol consumption increased the survival rates on CaCl2-induced arrhythmia in rats. Ethanol (0.4 g/kg) essentially increased the cumulative dosage of aconitine required to CA (P < 0.05), and 0.8 g/kg, 1.6 g/kg ethanol reduced the cumulative aconitine dosage to induce VT, VF and CA (P < 0.05 or P < 0.01) on aconitine-induced arrhythmia in rats. Ethanol (0.4, 0.8 and 1.6 g/kg) consumption remarkably increased the cumulative dosage of deslanoside to induce ventricualr premature contraction (P < 0.01) on deslanoside-induced arrhythmia in guinea pigs. Collectively, our results indicate that low concentrations of ethanol had anti-arrhythmic effect on experimental arrhythmia, and high concentrations of ethanol may aggravated the occurrence of experimental arrhythmia.

A novel toxic alkaloid from poison hemlock (Conium maculatum L., Apiaceae): identification, synthesis and antinociceptive activity.

2-Pentylpiperidine, named conmaculatin, a novel volatile alkaloid related to coniine was identified from the renowned toxic weed Conium maculatum L. (Apiaceae). The structure of conmaculatin was corroborated by synthesis (8 steps starting from cyclohexanol, overall yield 12%). Conmaculatin's strong peripheral and central antinociceptive activity in mice was observed in a narrow dose range (10-20mg/kg). It was found to be lethal in doses higher than 20mg/kg.

Diagnóstico de intoxicação por organofosforados baseado em quadro clínico / Organophosphate intoxication diagnosis based on clinical present

Os organofosforados são compostos agrotóxicos, de ampla comercialização no Brasil, que inibem a enzima acetilcolinesterase, levando a sintomas muscarínicos e nicotínicos, além de possíveis manifestações do sistema nervoso central (SNC). Na rotina de atendimento em Toxicologia, preconiza-se a identificação do agente para tomada de medidas específicas. Contudo, em casos de intoxicações por organofosforados, a peculiaridade do quadro clínico pode ser suficiente para o diagnóstico correto.Apresentamos revisão bibliográfica e relato de caso como ilustração do quadro clínico e levantamento dos casos atendidos no Ceatox-79 (Centro de Atendimento Toxicológico de Marília/SP) no ano de 2007.No caso atendido foi possível realizar o diagnóstico com base no quadro clínico da paciente, que se iniciou com sinais inespecíficos e evoluiu com a apresentação de sinais nicotínicos, possibilitando a conduta adequada. As intoxicações por agrotóxicos, principalmente por anticolinesterásicos, como os organofosforados, apresentam alta incidência. Apesar disso, ainda é escassa a quantidade de referências bibliográficas sobre o assunto, que também não é enfatizado em níveis acadêmico e profissional.

Cardiovascular effects of acetylcholine microinjection into the ventrolateral and dorsal periaqueductal gray of rats.

In the present study, we describe the cardiovascular effects of local acetylcholine (Ach) microinjection into both the ventrolateral (vlPAG) and dorsal (dPAG) periaqueductal gray areas of anesthetized rats and the possible local receptors involved with these responses. Microinjection of Ach (9, 27, 45 or 81 nmol/50 nL) into the vlPAG caused dose-related depressor responses. These hypotensive responses were blocked by local pretreatment with increasing doses of the nonselective muscarinic antagonist atropine (1, 3 or 9 nmol/50 nL)(.) The microinjection of Ach into the dPAG caused no significant cardiovascular responses in anesthetized rats. In conclusion, the present findings suggest that a cholinergic system present in the vlPAG, but not in the dPAG, is involved with cardiovascular system control. Moreover, these cardiovascular responses evoked by Ach are mediated by muscarinic receptors.

Pharmacological enhancement of endocannabinoid signaling reduces the cholinergic toxicity of diisopropylfluorophosphate.

Diisopropylfluorophosphate (DFP) elicits cholinergic toxicity by inhibiting acetylcholinesterase, leading to accumulation of the neurotransmitter acetylcholine and excessive stimulation of cholinergic receptors throughout the body. Endocannabinoids inhibit the release of neurotransmitters including acetylcholine via a widely distributed retrograde signaling pathway. Endocannabinoid signaling is therefore a potential therapeutic target for the management of OP poisoning. We first evaluated the relative in vitro and in vivo (2.5mg/kg, sc) effects of DFP on cholinesterase, fatty acid amide hydrolase (FAAH, an endocannabinoid degrading enzyme), monoacylglycerol lipase (MAGL, another endocannabinoid degrading enzyme) and cannabinoid receptor (CB1) binding in rat hippocampus. The effects of WIN 55212-2 (cannabinoid receptor agonist, 1.5mg/kg), URB597 (FAAH inhibitor, 3mg/kg), URB602 (MAGL inhibitor, 10mg/kg) or AM404 (endocannabinoid uptake inhibitor, 10mg/kg) on DFP toxicity were then examined. Adult male rats were given either peanut oil or DFP followed immediately by vehicle or one of the four cannabinomimetic drugs. Functional signs of toxicity were evaluated for 24h and then rats were sacrificed for neurochemical measurements. DFP inhibited cholinesterase, FAAH, MAGL and CB1 receptor binding in vitro in a concentration-dependent manner, with highest and lowest potency against cholinesterase and FAAH, respectively. In vivo, DFP inhibited hippocampal cholinesterase (89%) and FAAH (42%), but had no significant effect on MAGL or CB1 binding. Rats treated with DFP alone showed typical signs of cholinergic toxicity including involuntary movements and excessive secretions (SLUD signs). WIN 55212-2, URB597, URB602 and AM404 all significantly reduced involuntary movements following DFP exposure in a time-dependent manner, and most (URB597, URB602 and AM404) also significantly reduced DFP-induced SLUD signs. These results suggest that enhancing endocannabinoid signaling can attenuate the acute toxicity of DFP and provide rationale for further investigations on the role of endocannabinoids in cholinergic toxicity.

Effect of Moringa oleifera Lam. seed extract on ovalbumin-induced airway inflammation in guinea pigs.

To determine the therapeutic potential of herbal medicine Moringa oleifera Lam. family: Moringaceae in the control of allergic diseases, the efficacy of the ethanolic extract of the seeds of the plant (MOEE) against ovalbumin (OVA)-induced airway inflammation in guinea pigs was examined. During the experimental period, the test drugs (MOEE or dexamethasone) were administered by oral route prior to challenge with aerosolized 0.5% OVA. Bronchoconstriction tests were performed and respiratory parameters (i.e., tidal volume and respiratory rate) were measured. At the end of experiment, blood was collected from each animal to perform total and differential counts and serum was used for assay of IL-4, IL-6, and TNFalpha. Lung lavage fluid (BAL) was collected for estimation of cellular content and cytokine levels. Lung tissue histamine assays were performed using the homogenate of one lobe from each animal; a separate lobe and the trachea were subjected to histopathology to measure the degree of any airway inflammation. The results suggest that in OVA-sensitized control animals that did not receive either drug, tidal volume (V(t)) was decreased, respiration rate (f) was increased, and both the total and differential cell counts in blood and BAL fluid were increased significantly. MOEE-treatment of sensitized hosts resulted in improvement in all parameters except BAL TNFalpha and IL-4. Moreover, MOEE-treatment also showed protection against acetylcholine-induced broncho-constriction and airway inflammation which was confirmed by histological observations. The results of these studies confirm the traditional claim for the usefulness of this herb in the treatment of allergic disorders like asthma.