The role of central mechanisms in the anti-inflammatory effect of amitriptyline on carrageenan-induced paw edema in rats

Does Calcified Neurocysticercosis Affect Migraine Characteristics and Treatment Responsiveness? A Case-Control Study

Recently, inflammation and free-radical release has been described in the surrounding brain parenchyma of seemingly inert calcified lesions of neurocysticercosis. These free radicals can induce migraine by stimulating calcitonin gene-related peptide release. This stipulated mechanism led us to hypothesize that calcified neurocysticercosis may increase migraine severity. This case-control study included patients (migraine with calcified neurocysticercosis) and control subjects (migraine without calcified neurocysticercosis) in a 1:1 ratio. Headache frequency, visual analog scale (VAS) score, and Migraine Disability Assessment (MIDAS) score were assessed at baseline and at the end of 3 months. To compare treatment responsiveness between patients and control subjects, we treated both groups identically so that difference in treatment would not confound the results. Each group comprised 78 patients. Baseline headache frequency (11.3 ± 3.3 versus 7.9 ± 3.4), VAS score (7.5 ± 1.1 versus 6.0 ± 1.2), and MIDAS score (15 ± 7.6 versus 9.6 ± 4.5) were significantly greater in patients than control subjects. Interestingly, the change from baseline to the end of 3 months in headache frequency (6.0 ± 1.7 versus 2.8 ± 1.4), VAS score (2.6 ± 0.02 versus 1.4 ± 0.01), and MIDAS score (8.3 ± 5.0 versus 3.6 ± 2.0) were significantly greater in patients than control subjects. Our study emphasizes that calcified lesions of neurocysticercosis are not inert, and cause an increase in the frequency and severity of migraine attacks. Interestingly, these patients also showed a better response to treatment with amitriptyline, possibly resulting from its anti-inflammatory action. Further studies are warranted to explore possible inflammatory mechanisms in calcified neurocysticercosis, which influences migraine physiology.

Amitriptyline-Based Biodegradable PEG-PLGA Self-Assembled Nanoparticles Accelerate Cutaneous Wound Healing in Diabetic Rats

The aim of this work was to study the healing activity of amitriptyline (Amitrip) in rat diabetic wounds. A nanoformula of the drug was prepared as Amitrip-based biodegradable PEG-PLGA self-assembled nanoparticles (Amitrip-NPs) with a mean particle size of 67.4 nm. An in vivo investigation was conducted to evaluate the wound-healing process of Amitrip-NPs in streptozotocin-induced diabetic rats. Wound contraction was accelerated in rats treated with Amitrip-NPs. Histological examinations confirmed these findings, with expedited remodeling and collagen deposition in the NPs-treated animals. The formula showed anti-inflammatory activities as demonstrated by inhibition of interleukin-6 (IL-6) expression and tumor necrosis factor-α (TNF-α) expression, as well as enhanced expression of interleukin-10 (IL-10). In addition, Amitrip-NPs protected against malondialdehyde (MDA) buildup and superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic exhaustion. The pro-collagen activity of Amitrip-NPs was confirmed by the observed enhancement of hydroxyproline wounded skin content, upregulation of Col 1A1 mRNA expression and immune expression of collagen type IV expression. Further, Amitrip-NPs significantly increased expression transforming growth factor-β1 (TGF-β1), vascular endothelial growth factor-A (VEGF-A), platelet-derived growth factor-B (PDGF-B) and cluster of differentiation 31 (CD31). In conclusion, the developed Amitrip-NPs expedited wound healing in diabetic rats. This involves anti-inflammatory, antioxidant, pro-collagen and angiogenic activities of the prepared NPs. This opens the gate for evaluating the usefulness of other structurally related tricyclic antidepressants in diabetic wounds.

Amitriptyline Downregulates Chronic Inflammatory Response to Biomaterial in Mice

Recent data has signaled that in addition to its therapeutic indications as antidepressant and analgesic, amitriptyline (AM) exerts anti-inflammatory effects in humans and experimental animal models of acute inflammation. We tested the hypothesis that this compound could also modulate the chronic inflammatory process induced by synthetic matrix in mice. Polyether-polyurethane sponge disks were implanted subcutaneously in 9-week-old male C57BL/6 mice. The animals received by oral gavage 5.0 mg/kg of amitriptyline for seven consecutive days in two treatment regimens. In the first series, the treatment was initiated on the day of surgery and the implants removed at day 7 post-implantation. For the assessment of the effect of amitriptyline on chronic inflammation, the treatment was initiated 7 days post-implantation and the sponge discs removed 14 after implantation. The inflammatory markers evaluated, myeloperoxidase - MPO, nitrite content, IL-6, IFN-γ, TNF-α, CXCL1 and CCL2 levels, and NF-κB transcription factor activation were reduced in implants when the treatment began 7 days post-implantation (chronic inflammation). In contrast, only mast cell number, MPO activity and activation of NF-κB pathway decreased when the treatment began soon after implantation (sub-acute inflammation) in 7-day old implants. The anti-inflammatory effects of amitriptyline described here, extend its range of actions as a potential agent able to attenuate long-term inflammatory processes.

Neuroprotective and anti-inflammatory activity of DAT inhibitor R-phenylpiracetam in experimental models of inflammation in male mice

R-phenylpiracetam (R-PhP, (4R)-2-(4-phenyl-2-oxopyrrolidin-1-yl)acetamide) is an optical isomer of phenotropil, a clinically-used nootropic drug that improves physical condition and cognition. Recently, R-PhP was shown to bind to the dopamine transporter (DAT). Since growing evidence suggests that dysfunction of the dopaminergic system is associated with persistent neuroinflammation, the aim of this study was to determine whether R-PhP, an inhibitor of DAT, has neuroprotective and anti-inflammatory effects in male mice. The pharmacokinetic profiles of R-PhP in mouse plasma and its bioavailability in brain tissue were assessed. To study possible molecular mechanisms involved in the anti-inflammatory activity of R-PhP, target profiling was performed using radioligand binding and enzymatic activity assays. To clarify the neuroprotective and anti-inflammatory effects of R-PhP, we used a lipopolysaccharide (LPS)-induced endotoxaemia model characterized by reduced body temperature and overexpression of inflammatory genes in the brain. In addition, the antinociceptive and anti-inflammatory effects of R-PhP were tested using carrageenan-induced paw oedema and formalin-induced paw-licking tests. R-PhP (50 mg/kg) reached the brain tissue 15 min after intraperitoneal (ip) and peroral (po) injections. The maximal concentration of R-PhP in the brain tissues was 28 µg/g and 18 µg/g tissue after ip and po administration, respectively. In radioligand binding assays, DAT was the only significant molecular target found for R-PhP. A single ip injection of R-PhP significantly attenuated the LPS-induced body temperature reduction and the overexpression of inflammatory genes, such as tumour necrosis factor-α (TNF-α), interleukin 1 beta (IL-1β) and inducible nitric oxide synthase (iNOS). Seven-day po pretreatment with R-PhP dose-dependently reduced paw oedema and the antinociceptive response, as shown by the carrageenan-induced paw oedema test. In addition, R-PhP decreased the nociceptive response during the inflammatory phase in the formalin-induced paw-licking test. Our study showed that R-PhP possesses neuroprotective and anti-inflammatory effects, demonstrating the potential of DAT inhibitors as effective therapeutics.

Design and synthesis of some new 2,3′-bipyridine-5-carbonitriles as potential anti-inflammatory/antimicrobial agents

Aim: Inflammation may cause accumulation of fluid in the injured area, which may promote bacterial growth. Other reports disclosed that non-steroidal anti-inflammatory drugs may enhance progression of bacterial infection. Results: This work describes synthesis of new series of 2,3′-bipyridine-5-carbonitriles as structural analogs of etoricoxib, linked at position-6 to variously substituted thio or oxo moieties. Biological screening results revealed that compounds 2b, 4b, 7e and 8 showed significant acute and chronic AI activities and broad spectrum of antimicrobial activity. In addition, similarity ensemble approach was applied to predict potential biological targets of the tested compounds. Then, pharmacophore modeling study was employed to determine the most important structural parameters controlling bioactivity. Moreover, title compounds showed physicochemical properties within those considered adequate for drug candidates. Conclusion: This study explored the potential of such series of compounds as structural leads for further modification to develop a new class of dual AI-antimicrobial agents.

Evaluation of the central and peripheral effects of doxepin on carrageenan-induced inflammatory paw edema in rat

The anti-inflammatory effects of anti-depressants have been demonstrated recently. Doxepin, a tricyclic antidepressant drug (TCA), has some special properties in comparison with the other members of its family. It has some H1, H2, alpha-1 adrenergic and muscarinic receptor blocking effects. It revealed also anti-nociceptive and relatively potent sedative effects. This study was aimed to evaluate its possible anti-inflammatory effect in a well-established animal model. Male Wistar rats weighing 200-250 g were used in carrageenan-induced inflammatory paw edema model. The test and control drugs were injected by intraperitoneal (i.p.) and intracerebral (i.c.v.) routes. The anti-inflammatory activity of doxepin (15, 30 and 60 mg/kg, i.p. and 50 and 100 μg/rat, i.c.v.) and the reference drug, dexamethasone (2 mg/kg, i.p.) were evaluated by determination and comparison of some involved biological markers including the paw volume, cytokine levels (interleukin 6 (IL-6), IL-1β, tumor necrosis factor α (TNFα)), myeloperoxidase (MPO) activity and histopathological parameters. All i.p. doses of doxepin showed significant anti-inflammatory effect. It also significantly reduced MPO activity and cytokine levels and improved histopathologic parameters of carrageenan-injected paw tissues. I.c.v. administration of the drug did not show any significant reduction of carrageenan-induced paw edema. Although the exact mechanism of the anti-inflammatory effect of doxepin is not clear, it seems that reduced leukocyte migration and pro-inflammatory cytokines play important role in its anti-inflammatory effect. Also central sites are not involved in the anti-inflammatory effect of the drug.

Evaluation of central and peripheral effects of doxepin on acetic acid-induced colitis in rat and the involved mechanisms

Anti-colitis effect of antidepressants has been demonstrated recently. Doxepin, a tricyclic antidepressant drug (TCA), with potent H₁, H₂, alpha₁ adrenergic and muscarinic receptor blocking effects could be a good candidate for investigation for its anti-colitis activity. Moreover high prevalence of depression in patients who suffer from IBD (inflammatory bowel disease), defends this idea that adjuvant therapy with an antidepressant drug which has anti-inflammatory effect, may exert favorable effects in the control of the disease. In this study colitis was induced by acetic acid instillation into rat's colon. Doxepin was injected by intraperitoneal (10, 20, 40 mg/kg, twice daily, i.p.) or intracerebroventricular (50 and 100 microgram/rat, i.c.v.) routes to separate the mechanisms are absolutely exerted centrally or mediated both centrally and peripherally prior to induction of colitis. Dexamethasone (2 mg/kg/day, i.p.) was used as reference drug. All the treatments continued for three successive days. The effectiveness of drug was evaluated by determination of cytokines (TNFα, IL6 and IL1β) and myeloperoxidase (MPO) activity as well as macroscopic scores and histopathological parameters. Doxepin after i.p. administration was effective to reduce colitis severity through reduction in the macroscopic and microscopic colonic parameters, MPO activity and cytokines levels. Intracerebroventricular administration of the drug in contrast, did not show any significant protective effect suggesting no important central mechanisms for anti-colitis activity of doxepin. Doxepin as an ancient antidepressive drug has anti-colitis and anti-inflammatory properties which are mainly exerted peripherally so it could be introduced as a good candidate for depressed people who suffered from IBD disorders.

In vitro biological assessment of Homalium zeylanicum and isolation of lucidenic acid A triterpenoid

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Current investigation supports antioxidant, anti-diabetic activities of H. zeylanicum.

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Current investigation also supports anti-inflammatory activity of H. zeylanicum.

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The research successfully isolated and analysed structure of lucidenic acid A.

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Lucidenic acid A reported first time in the bark of H. zeylanicum.

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Lucidenic acid A produces a significant anti-inflammatory activity.

Homalium zeylanicum (Gardner) Benth. (Flacourtiaceae) is a medicinal plant useful in controlling rheumatism, inflammation and diabetes. The objective of this work evaluates in vitro antioxidant, antidiabetic, and antiinflammatory properties of hydroalcohol extract of bark of H. zeylanicum (HAHZ). It also describes isolation and structure determination of lucidenic acid A, which is the first report in this plant. In order to explain the role of antioxidant principles, DPPH, nitric oxide, hydroxyl, superoxide and metal chelating assays were performed. Antidiabetic and anti-inflammatory activities were investigated by quantifying α-amylase, α-glucosidase and protein denaturation inhibitory activities of HAHZ. Biochemical estimations were performed. The chemical structure of the triterpenoid was elucidated using ¹H, ¹³C NMR and high resolution-MS. IC₅₀ of DPPH, nitric oxide, hydroxyl, superoxide and metal chelating activities were of 36.23 ± 0.27, 40.11 ± 0.32, 35.23 ± 0.57, 43.34 ± 0.22 and 11.54 ± 0.08 μg/mL, respectively. IC₅₀ of α-amylase and α-glucosidase activities were 29.12 ± 0.54, and 18.55 ± 0.15 μg/mL. Total phenolic and total flavonoid contents were recorded at 233.65 mg/g GAE and 172.7 mg/g QE. Regarding kinetic behaviour, HAHZ showed competitive inhibition on α-glucosidase and mixed competitive inhibition on α-amylase. Lucidenic acid A was confirmed by spectroscopic studies. Anti-inflammatory activity of lucidenic acid A was determined by using protein denaturation assay with IC₅₀ 13 μg/mL but HAHZ showed 30.34 ± 0.13 μg/mL. Phenols and flavonoids could be attributed to inhibition of intestinal carbohydrases for anti-diabetic activities whereas triterpenoids could be responsible for anti-inflammatory activity of H. zeylanicum.

Anti-inflammatory Effect of Amitriptyline on Ulcerative Colitis in Normal and Reserpine-Induced Depressed Rats

Depressive disorders are more common among persons with chronic diseases such as inflammatory bowel disease and anti-inflammatory effect of some antidepressants such as amitriptyline has been reported. Acetic acid colitis was induced in both reserpinised (depressed) and non-reserpinised (normal) rats. Reserpinised groups received reserpine (6 mg/kg, i.p.) one hour prior to colitis induction. Then Amitriptyline (5, 10, 20 mg/kg, i.p.) was administered to separate groups of male Wistar rats. All treatments were carried out two hours after colitis induction and continued daily for four days. Dexamethasone (1 mg/kg) and normal saline (1 mL/kg) were used in reference and control groups, respectively. At day five, animals were euthanized and colonic tissue injuries were assessed macroscopically and pathologically. Myeloperoxidase activity as a marker of neutrophil infiltration was also measured in colonic tissues. Results showed that reserpine (6 mg/kg, i.p.) intensified colitic condition. Compared to control, amitriptyline (10, 20 mg/kg) and dexamethasone significantly decreased weight of colon and ulcer index in normal and reserpine-induced depressed rats. Myeloperoxidase activity and pathological assessments also proved anti-inflammatory effect of amitriptyline. Our results suggest that amitriptyline, a tricyclic antidepressant, could reduce inflammatory and ulcerative injuries of colon both in normal and depressed rats. So among the wide spread anti-depressant drugs, amitriptyline is a good choice to treat depression comorbidities in patients with IBD.

Beneficial Effects of Maprotiline in a Murine Model of Colitis in Normal and Reserpinised Depressed Rats

Background. Anti-inflammatory and immunomodulatory activities have been reported for maprotiline, a strong norepinephrine reuptake inhibitor. In addition, some other antidepressant drugs have shown beneficial effects in experimental colitis. Methods. All the animals were divided into normal and depressed groups. In normal rats colitis was induced by instillation of 2 mL of 4% acetic acid and after 2 hours, maprotiline (10, 20, and 40 mg/kg, i.p.) was administered. In reserpinised depressed rats, depression was induced by injection of reserpine (6 mg/kg, i.p.), 1 h prior to colitis induction, and then treated with maprotiline (10, 20, and 40 mg/kg). Treatment continued daily for four days. Dexamethasone (1 mg/kg, i.p.) was given as a reference drug. On day five following colitis induction, animals were euthanized and distal colons were assessed macroscopically, histologically, and biochemically (assessment of myeloperoxidase activity). Results. Maprotiline significantly improved macroscopic and histologic scores and diminished myeloperoxidase activity in both normal and depressed rats while reserpine exacerbated the colonic damage. Conclusion. Our data suggests that the salutary effects of maprotiline on acetic acid colitis are probably mediated first through depressive behavioral changes that could be mediated through the brain-gut axis and second for the anti-inflammatory effect of the drug.

Study on anti-inflammatory and immunomodulatory effects of clomipramine in carrageenan- and lipopolysaccharide-induced rat models of inflammation

The aim of the present study was to evaluate the anti-inflammatory effect of clomipramine in carrageenan- and lipopolysaccharide-induced (LPS-induced) models of inflammation by investigating the changes in serum levels of the pro-inflammatory cytokine TNF-α and the anti-inflammatory cytokines IL-10 and TGF-β after single and repeated administration of the drug.

In order to study the effect of single and repeated doses of clomipramine on carrageenan-induced paw oedema, male Wistar rats were divided in five groups (n = 8): control, positive control group and three experimental groups treated with 5, 10 and 20 mg/kg bw clomipramine, respectively. The effect of single and repeated doses of clomipramine on serum cytokine levels was studied as animals were divided in four groups: two control groups treated with saline and two experimental groups treated with clomipramine 20 mg/kg bw. Carrageenan and LPS were injected immediately after clomipramine or saline injection. Serum cytokine concentrations were tested by enzyme immunoassay.

Following acute administration only the highest dose that was used inhibited the carrageenan-induced inflammation. Oedema inhibition was observed with 5, 10 and 20 mg/kg bw clomipramine after repeated administration. Single and repeated administration of clomipramine at a dose of 20 mg/kg bw did not significantly change the serum levels of TGF-1β, IL-10 and TNF-α when compared to the controls in carrageenan-induced inflammation. Following LPS-induced inflammation clomipramine significantly increased the serum levels of TGF-1β after repeated administration and decreased TNF-α in rats after single-dose and repeated pretreatment with 20 mg/kg bw clomipramine. A significant increase in the levels of IL-10 in relation to this inflammatory model was observed only in single dose treated animals.

Clomipramine possesses an anti-inflammatory effect in the carrageenan-induced model of exudative inflammation. In LPS-induced inflammation, clomipramine showed an immunomodulatory effect, decreasing TNF-α and increasing TGF-1β after repeated administration, and increasing IL-10 after a single dose.

Anti-inflammatory Activity of Stachys Pilifera Benth

Background:

Stachys piliferaBenth has long been used to treat infectious diseases as well as respiratory and rheumatoid disorders in Iranian folk medicine. Antioxidants, antitumor, and antimicrobial properties of the plant have been reported.

Objectives:

This experimental study was designed to evaluate systemic and topical anti-inflammatory effects of the hydro-alcoholic extract from aerial parts of Stachys pilifera (HESP).

Materials and Methods:

Anti-inflammatory effects of HESP was studied in four well-known animal models of inflammation, including carrageenan- or formalin-induced paw edema in rat (thirteen groups, 6 rats per each group), and 12-O-tetradecanoylphorbol-13-acetate (TPA)- or xylene-induced ear edema in mouse (ten groups, 6 mice per each group). The rats received HESP (50-400 mg/ kg) orally 45 minutes before the subplantar injection of carrageenan or formalin. In TPA or xylene tests, HESP (1, 2.5, and 5 mg/ear) was applied topically simultaneous with these phlogistic agents on the ear mice. Finally, pathological examination of the inflamed tissues (paw and ear) was carried out.

Results:

Acute toxicity study of the extract showed that no rats were killed at 5000 mg/kg (LD50 > 5000 mg/kg). The extract (100 and 200 mg/ kg) significantly suppressed carrageenan-induced paw edema 1, 2, 3, and 4 hours after carrageenan challenge in comparison with the control group (P < 0.001). The HESP (100 and 200 mg/kg) also produced a considerable antiedematogenic effect in the formalin test over a period of 24 hours (P < 0.01). Furthermore, topical administration of the HESP (1, 2.5, and 5 mg/ear) inhibited TPA- and xylene-induced ear edema in comparison with the control group (P < 0.001). The pathological analysis of the paws and ears revealed that HESP was capable of reducing tissue destruction, cellular infiltration, and subcutaneous edema induced by the indicated phlogistic agents.

Conclusions:

The present data confirmed systemic and topical anti-inflammatory effects of Stachys pilifera which is comparable to indomethacin.

Assessment of cytotoxic and immunomodulatory properties of four antidepressants on primary cultures of abalone hemocytes (Haliotis tuberculata)

Pharmaceutical compounds like antidepressants found in surface waters raise concerns due to their potential toxicity on non-target aquatic organisms. This study aimed at investigating the in vitro cytotoxicity and immunomodulatory properties of four common antidepressants, namely Amitriptyline, Clomipramine, Citalopram and Paroxetine, on primary cultures of abalone hemocytes (Haliotis tuberculata), after 48 h-exposure. Effects on immunocompetence (phagocytosis, levels of reactive oxygen species, esterase activity and lysosomal membrane destabilization) were assessed. Results obtained by MTT assays revealed that acute toxicity is unlikely to occur in the environment since the LC50s of the four antidepressants are at the mg/L level. The different immunological endpoints displayed a biphasic response, with an increase at the lowest concentration (i.e. 1 μg/L) followed by a decrease at higher concentrations. Overall, Amitriptyline and Clomipramine, the two tricyclic antidepressants, had higher immunomodulatory capacities than the two selective serotonin reuptake inhibitors Citalopram and Paroxetine. Amitriptyline was the most potent and Citalopram the least potent drug in altering immune function in H. tuberculata.

Amitriptyline is efficacious in ameliorating muscle inflammation and depressive symptoms in the mdx mouse model of Duchenne muscular dystrophy

Mutations in the structural protein dystrophin underlie muscular dystrophies characterized by progressive deterioration of muscle function. Dystrophin-deficient mdx mice are considered a model for Duchenne muscular dystrophy (DMD). Individuals with DMD are also susceptible to mood disorders, such as depression and anxiety. Therefore, the study objectives were to investigate the effects of the tricyclic antidepressant amitriptyline on mood, learning, central cytokine expression and skeletal muscle inflammation in mdx mice. Amitriptyline-induced effects (10 mg kg(-1) daily s.c. injections, 25 days) on the behaviour of mdx mice were investigated using the open field arena and tail suspension tests. The effects of chronic amitriptyline treatment on inflammatory markers were studied in the muscle and plasma of mdx mice, and mood-associated monoamine and cytokine concentrations were measured in the amygdala, hippocampus, prefrontal cortex, striatum, hypothalamus and midbrain. The mdx mice exhibited increased levels of anxiety and depressive-like behaviour compared with wild-type mice. Amitriptyline treatment had anxiolytic and antidepressant effects in mdx mice associated with elevations in serotonin levels in the amygdala and hippocampus. Inflammation in mdx skeletal muscle tissue was also reduced following amitriptyline treatment as indicated by decreased immune cell infiltration of muscle and lower levels of the pro-inflammatory cytokines tumour necrosis factor-α and interleukin-6 in the forelimb flexors. Interleukin-6 mRNA expression was remarkably reduced in the amygdala of mdx mice by chronic amitriptyline treatment. Positive effects of amitriptyline on mood, in addition to its anti-inflammatory effects in skeletal muscle, may make it an attractive therapeutic option for individuals with DMD.

In vivo anti-inflammatory properties of aerial parts of Nasturtium officinale

CONTEXT

Nasturtium officinale R. Br. (watercress) has long been used in Iranian folk medicine to treat hypertension, hyperglycemia, and renal colic. Moreover, anticancer, antioxidant, and hepatoprotective properties of N. officinale have been reported.

OBJECTIVE

In this study, anti-inflammatory activity of the hydro-alcoholic extract from aerial parts of N. officinale was investigated.

MATERIALS AND METHODS

Oral administration of the hydro-alcoholic extract of N. officinale (250, 500 and 750 mg kg(-1)) was investigated on two well-characterized animal models of inflammation, including carrageenan- or formalin-induced paw edema in rats. Then, the topical anti-inflammatory effect of N. officinale (2 and 5 mg/ear) was studied on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema. Finally, biopsy of the paw or ear was performed for pathological evaluation.

RESULTS

Acute toxicity tests of N. officinale in rats established an oral LD50 of >5 g kg(-1). The extract of watercress (250, 500 and 750 mg kg(-1)) significantly inhibited carrageenan-induced paw edema 1, 2, 3 and 4 h after carrageenan challenge (p < 0.001). The extract (500 mg kg(-1)) also showed considerable activity against formalin-evoked paw edema over a period of 24 h (p < 0.001). Furthermore, topical application of N. officinale (5 mg/ear) reduced TPA-induced ear edema (p < 0.05). Histopathologically, the extract decreased swelling and the tissue damage induced by carrageenan or TPA.

DISCUSSION AND CONCLUSION

Our findings indicate potent anti-inflammatory activity of N. officinale in systemic and topical application and propose its potential as an anti-inflammatory agent for treatment of inflammatory conditions.

Further studies on anti-inflammatory activity of maprotiline in carrageenan-induced paw edema in rat

Antidepressant drugs are commonly used for treatment of different medical disorders besides of psychiatric diseases. Accumulating evidence suggests that antidepressants exhibit anti-inflammatory activity in vivo and in vitro conditions, but the mechanisms of this property are not clear very well. In our earlier work, we demonstrated that i.c.v. and i.p. injection of maprotiline, as an antidepressant, decreased paw edema at the fourth hour after subplantar injection of carrageenan. Therefore, this work was undertaken to investigate anti-inflammatory effects of maprotiline in more details. Our results verified that i.p. (25 and 50 mg/kg) and i.c.v. (100 μg/rat) application of maprotiline significantly reduced paw edema at 1, 2, 3 and 4 h intervals after carrageenan challenge. Pathological examinations and MPO activity also showed that both i.p. and i.c.v. maprotiline considerably inhibited infiltration of PMN leucocytes into the inflamed paws. Additionally, i.p. and i.c.v. maprotiline at all applied doses noticeably declined levels of IL-1β into the site of inflammation, while only i.p. maprotiline at a dose of 50 mg/kg significantly decreased TNF-α levels in the carrageenan-injected paws. These results confirmed anti-edematogenic activity of i.p. and i.c.v. maprotiline in the carrageenan induced paw edema model and showed that these properties of maprotiline might be mediated through inhibition of PMN infiltration and release of IL-1β and TNF-α.

Antidepressants can treat inflammatory bowel disease through regulation of the nuclear factor-κB/nitric oxide pathway and inhibition of cytokine production: A hypothesis

Inflammatory bowel disease (IBD) is a group of inflammatory disorders mainly affecting the colon and small intestine. The main types of IBD are Crohn’s disease (CD) and ulcerative colitis (UC). UC is restricted to the large intestine whereas CD can affect any part of the gastrointestinal tract. Treating this disorder depends on the form and level of severity. Common treatment involves an anti-inflammatory drug, such as mesalazine, and an immunosuppressant, such as prednisone. Several signaling pathways, including nuclear factor (NF)-κB and nitric oxide (NO), and genetic and environmental factors are believed to play an important role in IBD. Amitriptyline is a commonly used antidepressant with known anti-inflammatory activities. Amitriptyline also acts on the NF-κB/NO pathway or cytokine production. Therefore, we hypothesize that antidepressants like amitriptyline can be pioneered and considered effective as an innovative and effective therapeutic in the treatment and attenuation of development of IBD in adjusted doses.

Spinal serotonin 5-HT7 and adenosine A1 receptors, as well as peripheral adenosine A1 receptors, are involved in antinociception by systemically administered amitriptyline

The present study explored a link between spinal 5-HT(7) and adenosine A(1) receptors in antinociception by systemic amitriptyline in normal and adenosine A(1) receptor knock-out mice using the 2% formalin test. In normal mice, antinociception by systemic amitriptyline 3mg/kg was blocked by intrathecal administration of the selective adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) 10 nmol. Blockade was also seen in adenosine A(1) receptor +/+ mice, but not in -/- mice lacking these receptors. In both normal and adenosine A(1) receptor +/+ mice, the selective 5-HT(7) receptor antagonist (2R)-1-[(3-hydroxyphenyl)sulfonyl]-2-[2-(4-methyl-1-piperidinyl)ethyl]pyrrolidine hydrochloride (SB269970) 3 μg blocked antinociception by systemic amitriptyline, but it did not prevent antinociception in adenosine A(1) receptor -/- mice. In normal mice, flinching was unaltered when the selective 5-HT(7) receptor agonist (2S)-(+)-5-(1,3,5-trimethylpyrazol-4-yl)-2-(dimethylamino)tetralin (AS-19) 20 μg was administered alone, but increased when co-administered intrathecally with DPCPX 10 nmol or SB269970 3 μg. Intrathecal AS-19 decreased flinching in adenosine A(1) receptor +/+ mice compared to -/- mice. Systemic amitriptyline appears to reduce nociception by activating spinal adenosine A(1) receptors secondarily to 5-HT(7) receptors. Spinal actions constitute only one aspect of antinociception by amitriptyline, as intraplantar DPCPX 10 nmol blocked antinociception by systemic amitriptyline in normal and adenosine A(1) receptor +/+, but not -/- mice. Adenosine A(1) receptor interactions are worthy of attention, as chronic oral caffeine (0.1, 0.3g/L, doses considered relevant to human intake levels) blocked antinociception by systemic amitriptyline in normal mice. In conclusion, adenosine A(1) receptors contribute to antinociception by systemic amitriptyline in both spinal and peripheral compartments.

Intracerebroventricular administration of galanin antagonist sustains insulin resistance in adipocytes of type 2 diabetic trained rats

The aim of this study is to investigate whether galanin (GAL) central receptors are involved in regulation of insulin resistance. To test it, a GAL antagonist, M35 was intracerebroventricularly administrated in trained type 2 diabetic rats. The euglycemic-hyperinsulinemic clamp test was conducted for an index of glucose infusion rates. The epididymal fat pads were processed for determination of glucose uptake and Glucose Transporter 4 (GLUT4) amounts. The Gal mRNA expression levels in hypothalamus were quantitatively assessed too. We found an inhibitory effect of M35 on glucose uptake into adipocytes, Gal mRNA expression levels in hypothalamus, glucose infusion rates in the clamp test and GLUT4 concentration in plasma membranes and total cell membranes of adipocytes. The ratios of GLUT4 contents of the former to the latter in M35 groups were lower. These results suggest a facilitating role for GAL on GLUT4 translocation and insulin sensitivity via its central receptors in rats.

Endogenous opiates and behavior: 2010

This paper is the thirty-third consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2010 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).