The Possible Anti-nociceptive Effect of Troxerutin and Neural Interactions Using Formalin and Writhing Tests in Mice

Interleukin-33 mediates formalin-induced inflammatory pain in mice

ABSTRACTEpilepsy, a chronic neurological disorder affecting around 65 million people globally, is characterized by recurrent, unprovoked epileptic seizures. Psilocin, the active metabolite of psilocybin, a well‐known psychedelic compound, has recently gained attention for its potential antidepressant and anxiolytic properties. This study aims to investigate the anticonvulsant effects of psilocin. The study utilizes behavioral seizure models and electrophysiological recordings in mice to assess the anticonvulsant efficacy of psilocin. The pentylenetetrazole (PTZ) test for clonic seizures and the maximal electroshock (MES) test for generalized tonic–clonic seizures are employed. Cortical electrical activity is monitored to provide insights into the compound's effects on neuronal activity. The involvement of kynurenine pathway, opioidergic and nitrergic systems, as well as cannabinoid receptors using agonist/antagonist paradigms. Western blotting was employed to evaluate the expression levels of key receptors and enzymes implicated in psilocin's anticonvulsant effects. The findings indicate a possible modulation of seizure activity by psilocin, with modest doses (3 mg/kg, i.p.) demonstrating potential anticonvulsant effects. Remarkably, the administration of 1‐MT, L‐NAME, naltrexone, sildenafil, and AM‐251 led to a diminishment of the anticonvulsant effects of psilocin, underscoring the involvement of the kynurenine pathway, nitrergic and opioidergic systems, cGMP, and the CB1 receptor in mediating the anticonvulsant effects of psilocin, respectively. Based on western blotting analysis, the upregulation of 5‐HT1A but not 5‐HT2A and the downregulation of IDO and CB1 expression following psilocin administration were observed. Acute administration of psilocin exerts anticonvulsant effects that might be mediated at least in part through the kynurenine pathway, opioidergic, serotonergic, and nitrergic systems.

The effects of L-arginine and L-NG-nitro arginine methyl ester (L-NAME) on human blood coagulation and fibrinolysis were studied in vitro using computerized thromboelastography and native whole blood. L-Arginine (8-80 microM) prolonged the split point (SP), reaction time (R) and biKoatugulierung time (K); and diminished the angle (alpha), maximum amplitude (MA) and TEG index. L-NAME (0.5-50 microM) shortened SP, R and K and increased alpha, MA and the TEG index in a concentration-dependent manner. Neither L-arginine nor L-NAME had any effect on clot lysis. SP and R indicated the initiation of fibrin-strand formation, therefore L-arginine delayed, while L-NAME promoted the processes leading to fibrin formation. K and alpha reflect the rate of clot formation and involve fibrin build-up and platelets. Thus, L-arginine inhibited and L-NAME enhanced the rate of clot formation. MA (clot strength) involves the integrity of fibrin strands and platelet aggregation, and again L-arginine was inhibitory, while L-NAME enhanced this interaction. The TEG index indicates the coagulability of the sample; L-arginine was anticoagulant while L-NAME had procoagulant effects. These results are consistent with the inhibitory effects of NO on platelet function and of the platelet-aggregating properties of NOS inhibitors. In addition, NO may play an inhibitory role in the process leading to fibrin formation and also on the interactions between platelets and fibrin. Such effects may be important when considering the clinical use of drugs that affect the NO-cGMP pathway.

Background/AimsThe aim of present study is to estimate the effects of Melissa officinalis L. (MO) on visceral hypersensitivity (VH), defecation pattern and biochemical factors in 2 experimental models of irritable bowel syndrome (IBS) and the possible role of nitric oxide.MethodsTwo individual models of IBS were induced in male Wistar-albino rats. In the acetic acid model, the animals were exposed to rectal distension and abdominal withdrawal reflex, and the defecation patterns were determined. In the restraint stress model, the levels of TNF-α, myeloperoxidase, lipid peroxidation, and antioxidant powers were determined in the (removed) colon. Rats had been treated with MO, L-NG-nitroarginine methyl ester (L-NAME), aminoguanidine (AG), MO + AG, or MO + L-NAME in the mentioned experimental models.ResultsHypersensitive response to rectal distension and more stool defecation in control rats have been observed in comparison to shams. MO-300 significantly reduced VH and defecation frequency in comparison to controls. VH and defecation pattern did not show significant change in AG + MO and L-NAME + MO groups compared to controls. Also, significant reduction in TNF-α, myeloperoxidase, thiobarbituric acid reactive substances (TBARS), and an increase in antioxidant power in MO-300 group was recorded compared to controls. AG + MO and L-NAME + MO groups showed a reverse pattern compared to MO-300 group.ConclusionsMO can ameliorate IBS by modulating VH and defecation patterns. Antioxidant and anti-inflammatory properties along with its effect on the nitrergic pathway seem to play important roles in its pharmacological activity.

Inhibition of Inducible Nitric Oxide Synthase Ameliorates Myocardial Ischemia/Reperfusion Injury − Induced Acute Renal Injury

1. Nitric oxide (NO) is known from previous studies to be the principle transmitter in NANC inhibitory nerves supplying the hamster urethra. However, the identity of the cotransmitter(s) responsible for the responses remaining following block with L-NG-nitroarginine methyl ester (L-NAME) is not known. 2. Electrical field stimulation (EFS) of circular strips of hamster proximal urethra precontracted with arginine vasopressin (AVP 10(-8) M), and in the presence of phentolamine (10(-6) M), propranolol (10(-6) M) and atropine (10(-6) M), caused frequency-dependent relaxation, which was attenuated by suramin (10(-4) M) and reactive blue 2 (RB2; 2 x 10(-4) M), but not by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS; 10(-4) M), alpha-chymotrypsin (10-50 u ml(-1)) or by the vasoactive intestinal polypeptide (VIP) antagonist, [Lys1, Pro2,5, Arg3,4, Tyr6]-VIP, (5 x 10(-7)-10(-6) M). In the presence of indomethacin (10(-6) M) frequency-dependent relaxations to EFS were enhanced, particularly at the lower frequencies of stimulation. EFS-induced relaxation was blocked by tetrodotoxin (10(-6) M), indicating its neurogenic origin. 3. Exogenous ATP (10(-7)-10(-3) M) produced concentration-related relaxations which were attenuated by the P2-purinoceptor antagonists suramin (10(-4) M) and RB2 (2 x 10(-4) M) but not by PPADS (10(-4) M). ATP-induced relaxations were also reduced significantly by indomethacin (10(-6) M). The inhibitory responses to ATP were urothelium- and NO-independent, since they were not affected by either removal of urothelium or by L-NAME (10(-4) M). 4. Exogenous VIP (10(-9)-10(-7) M) induced concentration-related relaxations which were not affected by urothelium removal, L-NAME (10(-4) M), alpha-chymotrypsin (10-50 u ml(-1)) or by [Lys1, Pro2,5, Arg3,4, Tyr6]-VIP (3 x 10(-7)-10(-6) M). Nevertheless, suramin (10(-4) M) and RB2 (2 x 10(-4) M) but not PPADS (10(-4) M) antagonized the VIP-induced relaxant responses. Calcitonin gene-related peptide (CGRP: 10(-9)-10(-7) M) was devoid of any effect or only elicited a small relaxant response in AVP-precontracted strips. 5. Exogenous prostaglandin E2 (PGE2; 10(-9)-3 x 10(-6) M) and the NO donor, sodium nitroprusside (SNP; 10(-8)-3 x 10(-5) M) elicited concentration-related relaxations on the hamster proximal urethra which were not attenuated by suramin (10(-4) M), RB2 (2 x 10(-4) M), or by PPADS (10(-4) M), indicating a specific inhibitory effect of the antagonists used. 6. In summary, these results are consistent with the view that ATP is an inhibitory transmitter released from inhibitory nerves supplying the NANC relaxation of hamster proximal urethra. The relaxant effect of ATP is NO- and urothelium-independent. The present study did not demonstrate whether VIP is released from parasympathetic nerves during EFS, since both alpha-chymotrypsin and [Lys1, Pro2,5, Arg3,4, Tyr6]-VIP were ineffective on neurogenic responses.

In the present study, the potential involvement of nitric oxide (NO) system in attenuating effects of low-intensity laser therapy (LILT) on naloxone-induced morphine withdrawal signs was evaluated. A hundred mice were rendered morphine-dependent using three escalating doses of morphine sulfate during three consecutive days. After the last dose on day 4, animals were given naloxone HCl (2 mg/kg s.c) to induce withdrawal signs. The effects of LILT (12.5 J/cm(2)) and L-NG-nitroarginine methyl ester (L-NAME) (10, 20, 50, and 100 mg/kg) and their coadministration on escape jump count and stool weight as typical withdrawal signs were assessed. LILT and L-NAME (20, 50, and 100 mg/kg) per se significantly decreased escape jump count and stool weight in morphine-dependent naloxone-treated mice (p < 0.01). Coadministration of LILT and L-NAME (20, 50, and 100 mg/kg) also reduced escape jump and stool weight (p < 0.05) but with no synergetic or additive response. Here, LILT at this fluence may show its maximal effects on NO and therefore no noticeable effects appeared during coadministration use. Moreover, LILT and L-NAME follow the same track of changes in escape jump and stool weight. Conceivably, it seems that LILT acts partly via NO system, but the exact path is still obscure and rather intricate. The precise mechanisms need to be clarified.

1. Electrical field stimulation causes neurally-mediated relaxation of the ileocolonic sphincter that is due to activation of non-adrenergic and non-cholinergic (NANC) nerves. Recent studies have suggested that nitric oxide (NO) is the neurotransmitter that mediates relaxation. 2. Using intracellular recording techniques, we have tested whether NANC inhibitory junction potentials (i.j.ps) in the canine ileocolonic sphincter are also mediated by NO. 3. Electrical field stimulation elicited excitatory and inhibitory junction potentials: e.j.ps were blocked by atropine (10(-6) M) and tetrodotoxin (TTX; 10(-6) M); i.j.ps were also blocked by TTX and partially blocked by apamin (10(-6) M). I.j.ps were unaffected by atropine, phentolamine and propranolol (all at 10(-6) M). 4. The arginine analogues, L-NG-nitroarginine methyl ester (L-NAME) and NG-monomethyl-L-arginine (L-NMMA), decreased the amplitude of i.j.ps and L-arginine, but not D-arginine, partially restored the i.j.ps. 5. I.j.ps were also inhibited by oxyhaemoglobin (1%), but not by methaemoglobin. 6. Exogenous NO (10(-7) M to 3 x 10(-5) M) caused concentration-dependent hyperpolarizations that were similar in amplitude to the NANC nerve-evoked i.j.ps. Hyperpolarizations to NO were unaffected by L-NAME, but were blocked by oxyhaemoglobin. 7. Tetrodotoxin, L-NAME and oxyhaemoglobin all caused depolarization of resting membrane potential. 8. The specific guanosine 3':5'-cyclic monophosphate phosphodiesterase inhibitor, M&B 22948, caused hyperpolarization, increased the maximum level of hyperpolarization reached during i.j.ps, and increased the duration of i.j.ps. 9. These data further support the hypothesis that NANC neurotransmission in the ileocolonic sphincter is mediated by NO or an NO-releasing compound. The data also suggest that tonic release of NO, possibly from spontaneous firing of NANC nerves, may regulate resting membrane potential and tone in this sphincter.

Suppression of azoxymethane-induced colonic aberrant crypt foci by a nitric oxide synthase inhibitor

Objectives This study was carried out to investigate the experimental effects of Lonicerae Caulis and Bee-venom Acupuncture in Yanglingquan (陽陵泉, GB34) that have clinical efficacy in the Rheumatoid Arthritis. Methods Materials of present study are Lonicerae Caulis Extracts (LCE), Bee-Venom Acupuncture (BVP), Sprague-dawley rats (250 g or so, ♂), and various kinds of needing experimental studies. We measured several experimental items of the rats with the arthritis induced by Freund`s complete adjuvant (0.2 ml/kg), such as body weight, rate of paw edema, analgesic effect by hot plate method, WBC, TNF- cytokine and IL-10 cytokine. Rats were divided into four groups; Normal group that was treated with normal saline 1.0 ml (o.p) and (GB34) to normal rats, Control group that was treated with normal saline 1.0 ml (o.p) and (GB34) to pathologic model rats induced by Freund`s complete adjuvant 0.2 ml/kg, Experimental group A that was treated with LCE 1.0 ml (o.p) and normal saline (GB34) to pathologic model rats induced by Freund`s complete adjuvant 0.2 ml/kg and Experimental group B that was treated with LCE 1.0 ml (o.p) and BVP (GB34) to pathologic model rats induced by Freund`s complete adjuvant 0.2 ml/kg, and the experiment took over after 28 days. The results were analysed using SPSS for windows 12.0. Results Experimental group A showed the increase in body weight, paw licking times and IL-10 cytokine compared to Control group. Also it was decreased in rate of paw edema, WBC, and TNF- cytokine compared with Control group. Experimental group B showed the increase in body weight, paw licking times, and IL-10 cytokine compared to Control group, and showed the decrease in rate of paw edema, WBC and TNF- cytokine compared to Control group. Especially TNF- cytokine and rate of paw edema were accepted statistical significance compared with Control group. Conclusions It is suggested that Lonicerae Caulis (o.p) and Bee-venom Acupuncture (GB34) can be used in the treatment of rheumatoid arthritis.

Phosphatidylinositol 3-kinase may mediate isoproterenol-induced vascular relaxation in part through nitric oxide production

This study aimed to evaluate the effects of ciplukan (Physalis angulata L.) leaf ethanol extract on L-NG-nitroarginine methyl ester (L-NAME)-induced hypertensive rats. We randomly divided twenty-five Wistar rats into five groups. The sham group was given a PBS injection. The hypertensive group was injected with L-NAME on days 1 to 28. Three groups of hypertensive rats were given the extract on days 4 to 28. Blood pressure was measured using the tail-cuff method on days 0, 4, 10, and 27. The endothelial progenitor cells (EPCs) in the blood were measured by flow cytometry as a percentage of circulating angiogenic cells (CACs, CD34+/CD309+/CD45+) and endothelial colony-forming cells (ECFCs, CD34+/CD309+/CD45-). Serum NO and MDA levels, as well as serum SOD activity, were measured colorimetrically. Serum TNF-α levels were measured by the ELISA method. The ciplukan leaf extract reduced systolic and diastolic blood pressure, reduced the percentage of EPCs in the blood, increased serum NO levels, reduced MDA levels, increased serum SOD activity, and reduced serum TNF-α levels in L-NAME-induced hypertensive rats. It is concluded that ciplukan ethanol leaf extract exerts protective effects on L-NAME-induced hypertensive rats. These study results can strengthen the scientific basis of using ciplukan leaf ethanol extract to treat hypertension.

1. Nitric oxide (NO) may serve as a non-adrenergic, non-cholinergic (NANC) neurotransmitter released from enteric inhibitory nerves in the gastrointestinal tract. We tested whether guanosine 3':5'-cyclic monophosphate (cyclic GMP) may serve as a second messenger in transducing the NO signal into inhibitory junction potentials (i.j.ps) and relaxation in the canine proximal colon. 2. The membrane permeable analogue of cyclic GMP, 8-bromo cyclic GMP (8-Br-cyclic GMP) mimicked the effects of NO by hyperpolarizing cells near the myenteric border of the circular muscle layer and shortening slow waves in cells near the submucosal surface of the circular muscle layer. 8-Br-cGMP also inhibited spontaneous phasic contractions. 3. The specific cyclic GMP phosphodiesterase inhibitor, M&B 22948, hyperpolarized cells near the myenteric border and prolonged the duration of i.j.ps. M&B 22948 also inhibited phasic contractile activity. 4. Methylene blue failed to reduce significantly the amplitude and duration of i.j.ps and had variable effects on contractions. 5. Cyclic GMP levels were assayed in unstimulated muscles and in muscles exposed to exogenous NO and electrical field stimulation. Both stimuli hyperpolarized membrane potential, inhibited contractions, and elevated cyclic GMP levels. 6. Treatment of muscles with L-NG-nitroarginine methyl ester (L-NAME) increased spontaneous contractile activity and lowered cyclic GMP levels. The inhibitory effect of M&B 22948 on contractions was greatly reduced after muscles were treated with L-NAME. 7. These data support the concept that the effects of NANC nerve stimulation and NO (which may be one of the enteric inhibitory transmitters) may be mediated by cyclic GMP.

The purpose of this study was to investigate the impact of genetic deletion of NOS3 in CAV1-/- mice on aqueous humor outflow function using a mouse genetic double knockout model (DKO, NOS3-/- CAV1-/-). IOP was measured in DKO, NOS3 KO, CAV1 KO, and wild-type (WT) mice by rebound tonometry. Outflow facility was measured by perfusing enucleated mouse eyes at multiple pressure steps. Sodium nitroprusside (SNP) and L-NG-nitroarginine methyl ester (L-NAME) was administered topically, whereas the contralateral eyes served as vehicle controls. IOP was measured in both eyes before drug treatment and 1 hour after the last drug treatment. Mock aqueous humor ± the nitric oxide (NO) donor SNP or NOS inhibitor L-NAME was perfused into enucleated eyes. IOP was 11 ± 0.23 mm Hg in DKO mice, which was similar to WT mice and significantly lower than CAV1 KO mice (n = 18, P > 0.05). NOS3 deletion in CAV1-/- mice resulted in a 1.9-fold increase in conventional outflow facility (Ccon) compared with CAV1 KO mice (n = 7, P < 0.05). Topical application of NO donor SNP did not significantly change IOP (n = 18, P > 0.05) or Ccon in DKO mice (SNP, n = 20; vehicle, n = 11, P > 0.05). Topical application of L-NAME significantly increased IOP in WT, DKO, and CAV1 mice by reducing Ccon. Nitrotyrosine and PKG levels of DKO mice were similar to, whereas sGC was lower than, WT mice (P < 0.05). Genetic deletion of NOS3 in CAV1-deficient mice restored IOP and conventional aqueous humor drainage to WT level. NOS3 and CAV1 interaction is important to IOP regulation.

Nitric oxide (NO) has been found to have various actions in the body. Recently, considerable attention has been focused on the intimate relationship between the intracellular production of NO and morphological or functional changes in ciliated cells. The aim of this study was to clarify the functional significance of NO in the nasal mucosa. Healthy, adult, pigmented guinea pigs were randomly divided into one control and three experimental groups. The animals were instilled with either lipopolysaccharide (LPS) only or LPS plus dexamethasone or NG-nitro L-arginine methyl ester (L-NAME). The effect of NO on the nasal epithelium was analyzed morphologically by scanning electron microscopy and physiologically by ciliary beat frequency (CBF) measurement. The origin of NO was also investigated using a fluorescent indicator for NO, namely 4,5-diaminofluorescein diacetate. LPS induced damage of cilia 3 days after the first instillation, while dexamethasone or L-NAME seemed to attenuate the effect of LPS. NO production was localized in ciliated cells and the main source of NO in ciliated cells is suggested to be inducible NO synthase. The greater number of ciliated cells of LPS-treated animals produced a larger amount of NO compared with normal animals. LPS also induced a decrease in CBF, which was inhibited by dexamethasone or L-NAME. It is suggested that NO may play an important role in pathological changes in the nasal mucosa.