Ethyl pyruvate ameliorate inflammatory response of sinonasal mucosa by inhibiting HMGB1 in rats with acute rhinosinusitis.

High mobility group box 1 (HMGB1) has been known to involve in the pathogenesis of many inflammatory diseases. The aim of this study was to establish animal model of acute rhinosinusitis (ARS), and determine whether ethyl pyruvate (EP) attenuate inflammatory response of sinonasal mucosa by inhibiting HMGB1 in ARS animals. Thirty-six Sprague Dawley (SD) rat were used as follows: six normal controls without intervention (group 1); thirty rats were used for establishment of ARS rats model by nasal insertion of Merocel sponge, and model rats without any treatments (group 2), treated with nasal drops of sterile saline (group 3), 10 µl EP (group 4), and 20 µl EP (group 5), twice a day for 5 days, respectively. Bacterial culture was done regularly and the main bacterial strains were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry. HMGB1 expression in sinonasal mucosa was detected by immunohistochemistry and RT-PCR. Serum levels of HMGB1, IL-6, and TNF-α were determined by ELISA. Data from 29 of 36 rats that had completed research were analyzed. Bacterial colony formation unit (CFU) of nasal secretion was significantly higher in each group of ARS rats compared with controls (p < 0.001). ARS rats treated with EP had only slightly decreased CFU, but significantly attenuated inflammatory response of sinonasal mucosa and decreased HMGB1 expression compared to those treated with saline alone (p < 0.001). Serum levels of HMGB1, IL-6 and TNF-α were significantly higher in ARS rats compared to controls, and decreased by EP treatments (p < 0.001). Nasal sponge packing led to acute inflammatory response of nasal sinus in rats, and increased the expression of HMGB1, IL-6, and TNF-α. Nasal drops with EP could attenuate the inflammation of sinonasal mucosa through inhibiting the expression of HMGB1, IL-6 and TNF-α in ARS rats.

Hydrogen Sulfide Inhibits Formaldehyde-Induced Senescence in HT-22 Cells via Upregulation of Leptin Signaling.

It has been previously demonstrated that hydrogen sulfide (H2S) prevents formaldehyde (FA)-induced neurotoxicity. However, the exact mechanisms underlying this protection remain to be fully elucidated. Neuronal senescence is involved in FA-induced neurotoxicity. Leptin signaling has anti-aging function. The present work was to investigate the protection of H2S against FA-induced neuronal senescence and the mediatory role of leptin signaling. FA-exposed HT-22 cells were used as the vitro model of FA-induced neuronal senescence. The senescence-associated ß-galactosidase (SA-ß-Gal) positive cell was detected by ß-galactosidase staining. The expressions of P16INK4a, P21CIP1, leptin, and lepRb (leptin receptor) were measured by western blot. The proliferation, viability, and apoptosis of cells were evaluated by Trypan blue exclusion assay, Cell Counting Kit-8 (CCK-8) assay, and Flow cytometry analysis, respectively. We found that H2S suppressed FA-induced senescence, as evidenced by the decrease in SA-ß-Gal positive cells, the downregulations of P16INK4a and P21CIP1, as well as decrease in cell growth arrest, in HT-22 cells. Also, H2S upregulated the expressions of leptin and lepRb in FA-exposed HT-22 cells. Furthermore, leptin tA (a specific inhibitor of the leptin) abolished the protective effects of H2S on FA-induced senescence and neurotoxicity (as evidenced by the increase in cell viability and the decrease in cell apoptosis) in HT-22 cells. These results indicated that H2S prevents FA-induced neuronal senescence via upregulation of leptin signaling. Our findings offer a novel insight into the mechanisms underlying the protection of H2S against FA-induced neurotoxicity. FA upregulates the expressions of P16INK4a and P21CIP1 via inhibiting leptin signaling, which in turn induces senescence in HT-22 cells; H2S downregulates the expressions of P16INK4a and P21CIP1 via reversing FA-downregulated leptin signaling, which in turn prevents FA-induced senescence in HT-22 cells.

Endosomal signaling of the receptor for calcitonin gene-related peptide mediates pain transmission.

G protein-coupled receptors (GPCRs) are considered to function primarily at the plasma membrane, where they interact with extracellular ligands and couple to G proteins that transmit intracellular signals. Consequently, therapeutic drugs are designed to target GPCRs at the plasma membrane. Activated GPCRs undergo clathrin-dependent endocytosis. Whether GPCRs in endosomes control pathophysiological processes in vivo and are therapeutic targets remains uncertain. We investigated the contribution of endosomal signaling of the calcitonin receptor-like receptor (CLR) to pain transmission. Calcitonin gene-related peptide (CGRP) stimulated CLR endocytosis and activated protein kinase C (PKC) in the cytosol and extracellular signal regulated kinase (ERK) in the cytosol and nucleus. Inhibitors of clathrin and dynamin prevented CLR endocytosis and activation of cytosolic PKC and nuclear ERK, which derive from endosomal CLR. A cholestanol-conjugated antagonist, CGRP8-37, accumulated in CLR-containing endosomes and selectively inhibited CLR signaling in endosomes. CGRP caused sustained excitation of neurons in slices of rat spinal cord. Inhibitors of dynamin, ERK, and PKC suppressed persistent neuronal excitation. CGRP8-37-cholestanol, but not unconjugated CGRP8-37, prevented sustained neuronal excitation. When injected intrathecally to mice, CGRP8-37-cholestanol inhibited nociceptive responses to intraplantar injection of capsaicin, formalin, or complete Freund's adjuvant more effectively than unconjugated CGRP8-37 Our results show that CLR signals from endosomes to control pain transmission and identify CLR in endosomes as a therapeutic target for pain. Thus, GPCRs function not only at the plasma membrane but also in endosomes to control complex processes in vivo. Endosomal GPCRs are a drug target that deserve further attention.

Effects of formaldehyde inhalation on humoral immunity and protective effect of Nigella sativa oil: An experimental study.

AIM: This study was carried out to determine the effects of formaldehyde (FA) inhalation on the humoral immunity of rats and the protective effect of Nigella sativa (NS) oil. MATERIALS AND METHODS: The rats (n = 33) were divided into five groups, with five animals in the control group (FA-free air) and seven in the other four groups. Group FA1 was exposed to FA (5 ppm), group FA + NS1 was treated with NS and exposed to FA (5 ppm), group FA2 was exposed to FA (10 ppm), and group FA + NS2 was treated with NS and exposed to FA (10 ppm). At the end of a 4-week study period, blood samples were collected. Enzyme-linked immunosorbent assay was used to determine the levels of serum total immunoglobulin A (IgA), total immunoglobulin M (IgM), total immunoglobulin G (IgG), and complement 3 (C3). RESULTS: FA inhalation significantly increased serum IgA, IgM, and C3 levels and decreased serum IgG levels compared with the control group. NS administration decreased serum IgA, IgM, and C3 levels, which were induced by FA inhalation. CONCLUSION: FA inhalation significantly increased acute antibody responses and C3 levels in a dose-dependent manner compared with the control group. FA inhalation decreased the secondary immune response compared with the control group. Levels of acute antibody responses and complement following exposure to FA inhalation returned to normal following treatment with NS (immunoregulatory effect). However, NS did not affect the secondary immune response.

Effect of L-Cysteine Pretreatment on the Control of Formaldehyde and Browning of the Culinary-Medicinal Shiitake Mushroom, Lentinus edodes (Higher Basidiomycetes) during Drying and Canning Processes.

Fresh culinary-medicinal Shiitake mushrooms (Lentinus edodes) were pretreated by soaking in 0.1 mg/mL of L-cysteine solution for 1 hour; then the variation in formaldehyde content and browning degree were studied during hot air-drying and canning processes. The results indicated that L-cysteine pretreatment significantly inhibited the increase of formaldehyde content and browning during the drying process; these increases in the pretreatment groups ranged from 7.0% to 14.0% and 65.4% to 68.9%, respectively, of that of the control groups. While the L-cysteine pretreatment did not seem to have a significant effect on controlling the formaldehyde content during the canning process, the increase of the browning degree of the canned products of the pretreatment groups ranged from 64.8% to 78.5% of that of the control groups, indicating the inhibitive effect of L-cysteine on browning during the canning process of L. edodes. Overall, L-cysteine pretreatment improved the sensory quality of both dried and canned L. edodes.

The activation of supraspinal GPR40/FFA1 receptor signalling regulates the descending pain control system.

BACKGROUND AND PURPOSE: The ω-3 polyunsaturated fatty acids exert antinociceptive effects in inflammatory and neuropathic pain; however, the underlying mechanisms remain unclear. Docosahexaenoic acid-induced antinociception may be mediated by the orphan GPR40, now identified as the free fatty acid receptor 1 (FFA1 receptor). Here, we examined the involvement of supraspinal FFA1 receptor signalling in the regulation of inhibitory pain control systems consisting of serotonergic and noradrenergic neurons. EXPERIMENTAL APPROACH: Formalin-induced pain behaviours were measured in mice. Antinociception induced by FFA1 receptor agonists was examined by intrathecal injections of a catecholaminergic toxin, 5-HT lowering drug or these antagonists. The expression of FFA1 receptor protein and c-Fos was estimated by immunohistochemistry, and the levels of noradrenaline and 5-HT in the spinal cord were measured by LC-MS/MS. KEY RESULTS: FFA1 receptors colocalized with NeuN (a neuron marker) in the medulla oblongata and with tryptophan hydroxylase (TPH; a serotonergic neuron marker) and dopamine ß-hydroxylase (DBH; a noradrenergic neuron marker). A single i.c.v. injection of GW9508, a FFA1 receptor agonist, increased the number of c-Fos-positive cells and the number of neurons double-labelled for c-Fos and TPH and/or DBH. It decreased formalin-induced pain behaviour. This effect was inhibited by pretreatment with 6-hydroxydopamine, DL-p-chlorophenylalanine, yohimbine or WAY100635. Furthermore, GW9508 facilitated the release of noradrenaline and 5-HT in the spinal cord. In addition, GW1100, a FFA1 receptor antagonist, significantly increased formalin-induced pain-related behaviour. CONCLUSION AND IMPLICATIONS: Activation of the FFA1 receptor signalling pathway may play an important role in the regulation of the descending pain control system.

Inhibition of peripheral anion exchanger 3 decreases formalin-induced pain.

We determined the role of chloride-bicarbonate anion exchanger 3 in formalin-induced acute and chronic rat nociception. Formalin (1%) produced acute (first phase) and tonic (second phase) nociceptive behaviors (flinching and licking/lifting) followed by long-lasting evoked secondary mechanical allodynia and hyperalgesia in both paws. Local peripheral pre-treatment with the chloride-bicarbonate anion exchanger inhibitors 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid and 4-acetamido-4'-isothiocyanato-2,2'-stilbenedisulfonic acid prevented formalin-induced nociception mainly during phase 2. These drugs also prevented in a dose-dependent fashion long-lasting evoked secondary mechanical allodynia and hyperalgesia in both paws. Furthermore, post-treatment (on day 1 or 6) with 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid reversed established hypersensitivity. Anion exchanger 3 was expressed in dorsal root ganglion neurons and it co-localized with neuronal nuclei protein (NeuN), substance P and purinergic P2X3 receptors. Furthermore, Western blot analysis revealed a band of about 85 kDa indicative of anion exchanger 3 protein expression in dorsal root ganglia of naïve rats, which was enhanced at 1 and 6 days after 1% formalin injection. On the other hand, this rise failed to occur during 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid exposure. These results suggest that anion exchanger 3 is present in dorsal root ganglia and participates in the development and maintenance of short and long-lasting formalin-induced nociception.

Sertraline inhibits formalin-induced nociception and cardiovascular responses

The objective of the present study was to determine the antihyperalgesic effect of sertraline, measured indirectly by the changes of sciatic afferent nerve activity, and its effects on cardiorespiratory parameters, using the model of formalin-induced inflammatory nociception in anesthetized rats. Serum serotonin (5-HT) levels were measured in order to test their correlation with the analgesic effect. Male Wistar rats (250-300 g) were divided into 4 groups (N = 8/per group): sertraline-treated group (Sert + Saline (Sal) and Sert + Formalin (Form); 3 mg·kg-1·day-1, ip, for 7 days) and saline-treated group (Sal + Sal and Sal + Form). The rats were injected with 5 percent (50 µL) formalin or saline into the right hind paw. Sciatic nerve activity was recorded using a silver electrode connected to a NeuroLog apparatus, and cardiopulmonary parameters (mean arterial pressure, heart rate and respiratory frequency), assessed after arterial cannulation and tracheotomy, were monitored using a Data Acquisition System. Blood samples were collected from the animals and serum 5-HT levels were determined by ELISA. Formalin injection induced the following changes: sciatic afferent nerve activity (+50.8 ± 14.7 percent), mean arterial pressure (+1.4 ± 3 mmHg), heart rate (+13 ± 6.8 bpm), respiratory frequency (+4.6 ± 5 cpm) and serum 5-HT increased to 1162 ± 124.6 ng/mL. Treatment with sertraline significantly reduced all these parameters (respectively: +19.8 ± 6.9 percent, -3.3 ± 2 mmHg, -13.1 ± 10.8 bpm, -9.8 ± 5.7 cpm) and serum 5-HT level dropped to 634 ± 69 ng/mL (P < 0.05). These results suggest that sertraline plays an analgesic role in formalin-induced nociception probably through a serotonergic mechanism.

Sertraline inhibits formalin-induced nociception and cardiovascular responses.

The objective of the present study was to determine the antihyperalgesic effect of sertraline, measured indirectly by the changes of sciatic afferent nerve activity, and its effects on cardiorespiratory parameters, using the model of formalin-induced inflammatory nociception in anesthetized rats. Serum serotonin (5-HT) levels were measured in order to test their correlation with the analgesic effect. Male Wistar rats (250-300 g) were divided into 4 groups (N = 8/per group): sertraline-treated group (Sert + Saline (Sal) and Sert + Formalin (Form); 3 mg·kg-1·day-1, ip, for 7 days) and saline-treated group (Sal + Sal and Sal + Form). The rats were injected with 5% (50 µL) formalin or saline into the right hind paw. Sciatic nerve activity was recorded using a silver electrode connected to a NeuroLog apparatus, and cardiopulmonary parameters (mean arterial pressure, heart rate and respiratory frequency), assessed after arterial cannulation and tracheotomy, were monitored using a Data Acquisition System. Blood samples were collected from the animals and serum 5-HT levels were determined by ELISA. Formalin injection induced the following changes: sciatic afferent nerve activity (+50.8 ± 14.7%), mean arterial pressure (+1.4 ± 3 mmHg), heart rate (+13 ± 6.8 bpm), respiratory frequency (+4.6 ± 5 cpm) and serum 5-HT increased to 1162 ± 124.6 ng/mL. Treatment with sertraline significantly reduced all these parameters (respectively: +19.8 ± 6.9%, -3.3 ± 2 mmHg, -13.1 ± 10.8 bpm, -9.8 ± 5.7 cpm) and serum 5-HT level dropped to 634 ± 69 ng/mL (P < 0.05). These results suggest that sertraline plays an analgesic role in formalin-induced nociception probably through a serotonergic mechanism.

Activation of spinal mu- and delta-opioid receptors potently inhibits substance P release induced by peripheral noxious stimuli.

Over the past few years, δ-opioid receptors (DOPRs) and µ-opioid receptors (MOPRs) have been shown to interact with each other. We have previously seen that expression of MOPR is essential for morphine and inflammation to potentiate the analgesic properties of selective DOPR agonists. In vivo, it is not clear whether MOPRs and DOPRs are expressed in the same neurons. Indeed, it was recently proposed that these receptors are segregated in different populations of nociceptors, with MOPRs and DOPRs expressed by peptidergic and nonpeptidergic fibers, respectively. In the present study, the role and the effects of DOPR- and MOPR-selective agonists in two different pain models were compared. Using preprotachykinin A knock-out mice, we first confirmed that substance P partly mediates intraplantar formalin- and capsaicin-induced pain behaviors. These mice had a significant reduction in pain behavior compared with wild-type mice. We then measured the effects of intrathecal deltorphin II (DOPR agonist) and DAMGO (MOPR agonist) on pain-like behavior, neuronal activation, and substance P release following formalin and capsaicin injection. We found that both agonists were able to decrease formalin- and capsaicin-induced pain, an effect that was correlated with a reduction in the number of c-fos-positive neurons in the superficial laminae of the lumbar spinal cord. Finally, visualization of NK(1) (neurokinin 1) receptor internalization revealed that DOPR and MOPR activation strongly reduced formalin- and capsaicin-induced substance P release via direct action on primary afferent fibers. Together, our results indicate that functional MOPRs and DOPRs are both expressed by peptidergic nociceptors.

Biochanin A, a naturally occurring inhibitor of fatty acid amide hydrolase.

BACKGROUND AND PURPOSE: Inhibitors of fatty acid amide hydrolase (FAAH), the enzyme responsible for the metabolism of the endogenous cannabinoid (CB) receptor ligand anandamide (AEA), are effective in a number of animal models of pain. Here, we investigated a series of isoflavones with respect to their abilities to inhibit FAAH. EXPERIMENTAL APPROACH: In vitro assays of FAAH activity and affinity for CB receptors were used to characterize key compounds. In vivo assays used were biochemical responses to formalin in anaesthetized mice and the 'tetrad' test for central CB receptor activation. KEY RESULTS: Of the compounds tested, biochanin A was adjudged to be the most promising. Biochanin A inhibited the hydrolysis of 0.5 microM AEA by mouse, rat and human FAAH with IC(50) values of 1.8, 1.4 and 2.4 microM respectively. The compound did not interact to any major extent with CB(1) or CB(2) receptors, nor with FAAH-2. In anaesthetized mice, URB597 (30 microg i.pl.) and biochanin A (100 microg i.pl.) both inhibited the spinal phosphorylation of extracellular signal-regulated kinase produced by the intraplantar injection of formalin. The effects of both compounds were significantly reduced by the CB(1) receptor antagonist/inverse agonist AM251 (30 microg i.pl.). Biochanin A (15 mg.kg(-1) i.v.) did not increase brain AEA concentrations, but produced a modest potentiation of the effects of 10 mg.kg(-1) i.v. AEA in the tetrad test. CONCLUSIONS AND IMPLICATIONS: It is concluded that biochanin A, in addition to its other biochemical properties, inhibits FAAH both in vitro and peripherally in vivo.

The antidepressant phenelzine protects neurons and astrocytes against formaldehyde-induced toxicity.

Reactive aldehydes have been implicated in the etiology of several neurological and psychiatric disorders, and there is considerable interest in drugs to counteract the actions of these aldehydes. Increased formaldehyde (FA) and up-regulation of semicarbazide-sensitive amine oxidase, which forms FA from methylamine, have been implicated in disorders such as cerebrovascular disorders, alcohol abuse, diabetes and Alzheimer's disease. Phenelzine (PLZ), a monoamine oxidase inhibitor, is an antidepressant that has recently received attention for its neuroprotective/neurorescue properties. We investigated FA-induced toxicity and the effects of PLZ using rat primary cortical neurons and astrocytes and found that FA induced toxicity in neurons and astrocytes by multiple means. In astrocytes, FA decreased glutamate transporter expression, inhibiting glutamate uptake. PLZ reversed the decrease of glutamate uptake and the alteration of the second messengers, AKT and p38, induced by FA. PLZ alone affected the GLT-1 glutamate transporter in opposite directions in astrocytes and neurons. Thus, PLZ has multiple actions in neurons and astrocytes that may contribute to its neuroprotection.

Aqueous extract of Asiasari radix inhibits formalin-induced hyperalgesia via NMDA receptors.

ETHNOPHARMACOLOGICAL RELEVANCE: Asiasari radix is prepared from Asiasarum sieboldii F. Maekawa or Asiasarum heterotropoides F. Maekawa var. mandshuricum F. Maekawa, widely used for treatment of various tussive, inflammatory, allergic diseases and pain. AIM OF STUDY: The antinociceptive effects of Asiasari radix extract (ARE) in mice were examined. MATERIALS AND METHODS: Tail-flick, tail-pressure, hot-plate and formalin tests were used to evaluate its antinociceptive activity. Moreover, N-methyl-D-aspartic acid (NMDA)-induced nociceptive response was also examined. RESULTS: Oral administration of ARE did not affect the responses of the tail-flick, tail-pressure, or hot-plate test or the first phase of the formalin tests, but it dose-dependently decreased the duration of nociceptive behavior in the second phase, as did diclofenac, a non-steroidal anti-inflammatory drug. ARE also inhibited nociceptive behaviors induced by the intrathecal injection of NMDA, although diclofenac did not affect these behaviors. Pretreatment with bicuculline, a GABA(A) antagonist, reduced the antinociceptive effects of ARE on the formalin- or NMDA-induced behaviors. Muscimol, a GABA(A) agonist, exhibited antinociceptive effects in the formalin test and NMDA-induced behaviors in a manner similar to that of ARE. On the other hand, diclofenac significantly inhibited cyclooxygenase (COX)-1 and -2 activities, while ARE did not. CONCLUSION: These results suggest that ARE may inhibit development of hyperalgesia via NMDA receptors based on activation of GABA(A) receptors in the spinal cord.

Novel prodrugs of tegafur that display improved anticancer activity and antiangiogenic properties.

New and more potent prodrugs of the 5-fluorouracyl family derived by hydroxymethylation or acyloxymethylation of 5-fluoro-1-(tetrahydro-2-furanyl)-2,4(1H,3H)-pyrimidinedione (tegafur, 1) are described. The anticancer activity of the butyroyloxymethyl-tegafur derivative 3 and not that of tegafur was attenuated by the antioxidant N-acetylcysteine, suggesting that the increased activity of the prodrug is in part mediated by an increase of reactive oxygen species. Compound 3 in an in vitro matrigel assay was found to be a more potent antiangiogenic agent than tegafur. In vivo 3 was significantly more potent than tegafur in inhibiting 4T1 breast carcinoma lung metastases and growth of HT-29 human colon carcinoma tumors in a mouse xenograft. In summary, the multifunctional prodrugs of tegafur display selectivity toward cancer cells, antiangiogenic activity, and anticancer activities in vitro and in vivo, superior to those of tegafur. 5-fluoro-1-(tetrahydro-2-furanyl)-2,4(1 H,3 H)-pyrimidinedione (tegafur, 1), the oral prodrug of 5-FU, has been widely used for treatment of gastrointestinal malignancies with modest efficacy. The aim of this study was to develop and characterize new and more potent prodrugs of the 5-FU family derived by hydroxymethylation or acyloxymethylation of tegafur. Comparison between the effect of tegafur and the new prodrugs on the viability of a variety of cancer cell lines showed that the IC50 and IC90 values of the novel prodrugs were 5-10-fold lower than those of tegafur. While significant differences between the IC50 values of tegafur were observed between the sensitive HT-29 and the resistant LS-1034 colon cancer cell lines, the prodrugs affected them to a similar degree, suggesting that they overcame drug resistance. The increased potency of the prodrugs could be attributed to the antiproliferative contribution imparted by formaldehyde and butyric acid, released upon metabolic degradation. The anticancer activity of the butyroyloxymethyl-tegafur derivative 3 and not that of tegafur was attenuated by the antioxidant N-acetylcysteine, suggesting that the increased activity of the prodrug is in part mediated by an increase of reactive oxygen species. Compound 3 in an in vitro matrigel assay was found to be a more potent antiangiogenic agent than tegafur. In vivo 3 was significantly more potent than tegafur in inhibiting 4T1 breast carcinoma lung metastases and growth of HT-29 human colon carcinoma tumors in a mouse xenograft. In summary, the multifunctional prodrugs of tegafur display selectivity toward cancer cells, antiangiogenic activity and anticancer activities in vitro and in vivo, superior to those of tegafur.

Organic acid and formaldehyde treatment of animal feeds to control Salmonella: efficacy and masking during culture.

AIMS: To investigate whether treatment of animals feeds with organic acids/formaldehyde may mask the presence of Salmonella, when assessed by standard cultural methods. METHODS AND RESULTS: Four commercial treatments were applied at the manufacturers' recommended rates on feeds artificially inoculated with Salmonella. The recovery of Salmonella from these treated feeds was assessed after specific antagonists were added to the treatments during culture. A control group of treated feed received no antagonist. Masking of Salmonella was demonstrated when the addition of antagonists resulted in recovery of Salmonella from the treated feed, compared with a negative recovery when no antagonists were added. There were large variations in the efficacy of treatments, and masking was demonstrated with all four tested treatments. One formaldehyde-based product showed greater efficacy and less masking. Masking was greater when high levels of Salmonella were present in the feed. CONCLUSIONS: Some organic acid or formaldehyde-based feed treatments may mask the presence of Salmonella. SIGNIFICANCE AND IMPACT OF THE STUDY: Feeds may be deemed safe despite being contaminated with Salmonella. The use of antagonists during culture may help assess the level of Salmonella contamination when organic acid or formaldehyde treatments have been applied to feed ingredients.

Protective effect of NAC on formaldehyde-containing-ZOE-based root-canal-sealers-induced cyclooxygenase-2 expression and cytotoxicity in human osteoblastic cells.

Cyclooxygenase-2 (COX-2) is an inducible enzyme believed to be responsible for prostaglandin synthesis at site of inflammation. Recently, the activation of COX-2 expression may be one of the important pathogenesis of root-canal-sealers-induced periapical inflammation. However, little is known about whether chemical interaction can modulate the COX-2 expression and cytotoxicity induced by formaldehyde-containing-ZOE-based root canal sealers. The aim of this study was to investigate the effects of antioxidants such as catalase, superoxide dismutase (SOD), and N-acetyl-L-cysteine (NAC) on N2- and endomethasone-induced COX-2 mRNA gene and cytotoxicity in human osteoblastic cell line U2OS cells. Our data demonstrated that both formaldehyde-containing-ZOE-based root canal sealers were found to induce COX-2 mRNA gene expression in U2OS cells. The addition of glutathione (GSH) precursor NAC led to decrease the induction of COX-2 mRNA gene expression and cytotoxicity by both N2 and Endomethasone (p < 0.05). However, catalase and SOD lacked the ability to prevent cytotoxicity and COX-2 mRNA gene expression induced by N2 and Endomethasone (p > 0.05). The data presented here demonstrated that the activation of COX-2 mRNA gene expression may be one of the pathogenesis of formaldehyde-containing-ZOE-based root-canal-sealers-induced periapical inflammation. In addition, GSH depletion, but not the attack of oxygen free radicals, could be the mechanism for cytotoxicity and COX-2 mRNA gene expression induced by formaldehyde-containing-ZOE-based root canal sealers. NAC appears as a useful agent in protecting cell damage mediated by formaldehyde-containing-ZOE-based root canal sealers.

Vitamin E against oxidative damage caused by formaldehyde in frontal cortex and hippocampus: biochemical and histological studies.

Formaldehyde (FA) can cause severe central nervous system impairment. But, there are only a few studies about biochemical and histopathological changes of frontal cortex and hippocampal tissue caused by FA toxicity. The aim of our study was to investigate these changes occurring after chronic formaldehyde toxicity in frontal cortex and hippocampal tissues, and protective effect of Vitamin E (vit E) against oxidative damage. Eighteen rats were divided into three groups: (1) control, (2) treated with FA (FAt), and (3) treated with FA and vit E (FAt+vit E) groups. After the treatment, the animals were sacrificed and frontal cortex and hippocampal tissues were removed for biochemical and histopathological investigation. FA significantly increased tissue malondialdehyde (MDA) and protein carbonyl (PC) levels and also decreased superoxide dismutase (SOD) and catalase (CAT) enzyme activities in frontal cortex and hippocampal tissue compared to control. Vit E treatment decreased MDA and PC levels and prevented inhibition of SOD and CAT enzymes in the tissues. In the FAt group, the neurons of both tissues became extensively dark and degenerated with picnotic nuclei. The morphology of neurons in FAt+vit E group was protected well, but not as neurons of the control group. The number of neurons in frontal cortex and hippocampal tissue of FAt group was significantly less than both control and FAt+vit E groups. It was concluded that vit E treatment might be beneficial in preventing FA-induced oxidative frontal cortex and hippocampal tissue damage, therefore, shows potential for clinical use.

Antinociceptive properties of ethanolic extract and fractions of Pterodon pubescens Benth. seeds.

We have previously demonstrated that the hydroalcoholic extract from Pterodon pubescens Benth. seeds (sucupira branca, Leguminosae) exhibits anti-arthritic activity and that its oleaginous extract (OEP) and PF1 fraction exhibit acute and topic anti-edematogenic activities. In this work, we studied the antinociceptive activity of OEP and its fractions on the acetic acid-induced abdominal constriction and formalin assays in SW male mice. OEP was obtained by ethanol extraction and its four fractions by sequential liquid-liquid extraction. PF2 GC/MS profile indicated it contains furane diterpenes derivatives of vouacapan and non-vouacapan compounds. The antinociceptive properties were demonstrated to OEP and predominantly to PF1 and PF2 by the writhing test. In the formalin assay, PF1 inhibited both phases and PF2 inhibited mainly the late one. Then, PF1 and PF2 seemed to present antinociceptive effects by different mechanisms, peripheral and/or central inhibitory ones, and showed maximum antinociceptive properties with very low doses, providing a rationale for its popular use in pain disorders.

Antinociceptive and anti-inflammatory activities of Acacia pennata wild (Mimosaceae).

The butanolic fraction of dried leaves of Acacia pennata (Mimosaceae) was tested for analgesic and anti-inflammatory activities in animal models. It showed significant protective effects against chemical stimuli (acetic acid and formalin) in the mouse. It also produced a significant increase of the threshold of sensitivity to pressure-induced pain in the rats. The extract revealed an inhibitory effect in carrageenin-induced rat paw oedema in the late phase. The results suggested that a peripheral mechanism is involved in the analgesic, associated to anti-inflammatory effect (NSAIDs-like). Among the class of compounds characterized in this fraction, flavonoids may be mainly responsible for the pharmacological activities.

Validation of a simple automated movement detection system for formalin test in rats.

AIM: To investigate the validity and sensitivity of an automatic movement detection system developed by our laboratory for the formalin test in rats. METHODS: The effects of systemic morphine and local anesthetic lidocaine on the nociceptive behaviors induced by formalin subcutaneously injected into the hindpaw were examined by using an automated movement detection system and manual measuring methods. RESULTS: Formalin subcutaneously injected into the hindpaw produced typical biphasic nociceptive behaviors (agitation). The mean agitation event rate during a 60-min observation period increased linearly following increases in the formalin concentration (0.0%, 0.5%, 1.5%, 2.5%, and 5%, 50 microL). Systemic application of morphine of different doses (1, 2, and 5 mg/kg) 10-min prior to formalin injection depressed the agitation responses induced by formalin injection in a dose-dependent manner, and the antinociceptive effect induced by the largest dose (5 mg/kg) of morphine was significantly antagonized by systemic application of the opioid receptor antagonist naloxone (1.25 mg/kg). Local anesthetic lidocaine (20 mg/kg) injected into the ipsilateral ankle subskin 5-min prior to formalin completely blocked the agitation response to formalin injection. These results were comparable to those obtained from manual measure of the incidence of flinching or the duration time of licking/biting of the injected paw. CONCLUSION: These data suggest that this automated movement detection system for formalin test is a simple, validated measure with good pharmacological sensitivity suitable for discovering novel analgesics or investigating central pain mechanisms.