Effects of Gap 26, a Connexin 43 Inhibitor, on Cirrhotic Cardiomyopathy in Rats.

Introduction Cirrhotic cardiomyopathy (CCM) is recognized by impaired cardiac responsiveness to stress, prolonged QT interval, and systolic and diastolic dysfunctions. Connexins are a family of transmembrane proteins that play a key role in cardiac physiology. Connexin 43 (Cx43) inhibition showed cardio-protective effects. Peptide drug Cx43 inhibitor, Gap 26, could inhibit gap junction 43. This study was designed to evaluate the effects of a connexin mimetic peptide, Gap 26, in the CCM model in rats. Methods The cirrhosis was induced through carbon tetrachloride (CCl4). On day 56, electrocardiography (ECG) was recorded, spleen weight was measured, and tissue and serum samples were collected. Further, Cx43 mRNA expression in heart tissue was checked. Results The chronotropic responses decreased in the CCl4/saline and increased in the CCl4/Gap. The spleen weight, QTc interval, and brain natriuretic peptide (BNP), tumor necrosis factor-alpha (TNF-α), aspartate aminotransferase (AST), alanine transaminase (ALT), and malondialdehyde (MDA) levels elevated in the CCl4/saline, and the spleen weight, QTc interval, and MDA and ALT levels were reduced by Gap 26 treatment. The level of nuclear factor (erythroid-derived 2) factor 2 (Nrf2) decreased in the CCl4/saline. The Cx43 expression was downregulated in the CCl4/saline and upregulated with the Gap 26 treatment. Conclusion Gap 26 not only alleviated the chronotropic hyporesponsiveness and the severity of liver damage and upregulated the atrial Cx43 expression, but it also had an antioxidant effect on the heart.

Desmopressin enhances random-pattern skin flap survival in rats: Possible role of vasopressin Type-1a and 2 receptors.

BACKGROUND: Many drugs have been explored for their role in improving skin flap survival. 1-deamino-8-D-arginine vasopressin (DDAVP or desmopressin) is a synthesized form of anti-diuretic hormone (ADH) and a selective agonist for vasopressin type-2 receptors (V2 receptors). Desmopressin has been shown to improve endothelial function, induce vasodilation, and reduce inflammation. We aimed to evaluate its efficacy in enhancing flap survival and assess the role of vasopressin receptors in this process. MATERIALS AND METHODS: We randomly assigned six male Wistar rats to each study group. Different doses of desmopressin were injected intraperitoneally to find the most effective amount (8 µg/rat). SR-49059, a selective V1a receptor antagonist, was given at 2µg/rat before providing the most effective dose of desmopressin (8µg/rat). Histopathological assessments, quantitative measurements of interleukin-1ß (IL-1ß), Tumor necrosis factor-alpha (TNF-α), and Nuclear Factor-κB (NF-κB), optical imaging, and measurement of the expression levels of V2 receptor in the rat skin tissue were performed. RESULTS: Desmopressin (8µg/rat) significantly reduced the mean percentage of necrotic area compared to the control group (19.35% vs 73.57%). Histopathological evaluations revealed a notable reduction in tissue inflammation, edema, and degeneration following administration of desmopressin (8). The expression of the V2 receptor was increased following desmopressin administration. It also led to a reduction in IL-1ß, TNF-α, and NF-κB levels. The protective effect of desmopressin on flap survival was reversed upon giving SR-49059. The optical imaging revealed enhanced blood flow in the desmopressin group compared to the control group. CONCLUSIONS: Desmopressin could be repurposed to improve flap survival. V1a and V2 receptors probably mediate this effect.

Potential use of angiotensin receptor blockers in skin pathologies.

Renin-angiotensin system (RAS) components such as angiotensin II, angiotensin receptors (AT1R and AT2R), and angiotensin-converting enzyme (ACE) are expressed in different cell types of the skin. Through AT1R, angiotensin II increases proinflammatory cytokines contributing to fibrosis, angiogenesis, proliferation, and migration of immune cells to the skin. In contrast, AT2R suppresses the effects mentioned above. Many studies show that angiotensin receptor blockers (ARBs) and angiotensin-converting enzymes (ACEi) reduce the proinflammatory cytokines and fibrogenic factors including transforming growth factor ß (TGF-ß), Connective tissue growth factor (CTGF), and IL-6. This review article provides a detailed research study on the implications of ARBs in wound healing, hypertrophic scar, and keloids. We further discuss the therapeutic potentials of ARBs in autoimmune and autoinflammatory skin diseases and cancer, given their anti-fibrotic and anti-inflammatory effects.

Neuroprotective effects of Lasmiditan and Sumatriptan in an experimental model of post-stroke seizure in mice: Higher effects with concurrent opioid receptors or KATP channels inhibitors.

BACKGROUND: Early post-stroke seizure frequently occurs in stroke survivors within the first few days and is associated with poor functional outcomes. Therefore, efficient treatments of such complications with less adverse effects are pivotal. In this study, we investigated the possible beneficial effects of lasmiditan and sumatriptan against post-stroke seizures in mice and explored underlying mechanisms in their effects. METHODS: Stroke was induced by double ligation of the right common carotid artery in mice. Immediately after the ligation, lasmiditan (0.1 mg/kg, intraperitoneally [i.p.]) or sumatriptan (0.03 mg/kg, i.p.) were administered. Twenty-four hours after the stroke induction, seizure susceptibility was evaluated using the pentylenetetrazole (PTZ)-induced clonic seizure model. In separate experiments, naltrexone (a non-specific opioid receptor antagonist) and glibenclamide (a KATP channel blocker) were administered 15 min before lasmiditan or sumatriptan injection. To evaluate the underlying signaling pathways, ELISA analysis of inflammatory cytokines (TNF-α and IL-1ß) and western blot analysis of anti- and pro-apoptotic markers (Bcl-2 and Bax) were performed on mice isolated brain tissues. RESULTS: Lasmiditan (0.1 mg/kg, i.p.) and sumatriptan (0.03 mg/kg, i.p.) remarkably decreased seizure susceptibility in stroke animals by reducing inflammatory cytokines and neuronal apoptosis. Concurrent administration of naltrexone (10 mg/kg, i.p.) or glibenclamide (0.3 mg/kg, i.p.) with lasmiditan or sumatriptan resulted in a higher neuroprotection against clonic seizures and efficiently reduced the inflammatory and apoptotic markers. CONCLUSION: Lasmiditan and sumatriptan significantly increased post-stroke seizure thresholds in mice by suppressing inflammatory cytokines and neuronal apoptosis. Lasmiditan and sumatriptan seem to exert higher effects on seizure threshold with concurrent administration of the opioid receptors or KATP channels modulators.

Albendazole ameliorates inflammatory response in a rat model of acute mesenteric ischemia reperfusion injury.

BACKGROUND: Acute mesenteric ischemia is known as a life threatening condition. Re-establishment of blood flow in this condition can lead to mesenteric ischemia reperfusion (MIR) injury which is accompanied by inflammatory response. Still, clear blueprint of inflammatory mechanism underlying MIR injury has not been provided. Interestingly, Albendazole has exhibited notable effects on inflammation and cytokine production. In this study, we aimed to evaluate outcomes of MIR injury following pretreatment with Albendazole with respect to assessment of mesenteric inflammation and ischemia threshold. METHODS: Male rats were randomly divided into sham operated, vehicle treated, Albendazole 100 mg/kg and Albendazole 200 mg/kg groups. MIR injury was induced by occlusion of superior mesenteric artery for 30 min followed by 120 min of reperfusion. Samples were utilized for assessment of epithelial survival and villous height. Immunohistochemistry study revealed intestinal expression of TNF-α and HIF-1-α. Gene expression of NF-κB/TLR4/TNF-α/IL-6 was measured using RTPCR. Also protein levels of inflammatory cytokines in serum and intestine were assessed by ELISA method. RESULTS: Histopathological study demonstrated that pretreatment with Albendazole could ameliorate decline in villous height and epithelial survival following MIR injury. Also, systemic inflammation was suppressed after administration of Albendazole. Analysis of possible participating inflammatory pathway could demonstrate that intestinal expression of NF-κB/TLR4/TNF-α/IL-6 is significantly attenuated in treated groups. Eventually, IHC study illustrated concordant decline in mesenteric expression of HIF-1-α/TNF-α. CONCLUSION: Single dose pretreatment with Albendazole could ameliorate inflammatory response and enhance ischemia threshold following induction of MIR injury. More studies would clarify existing causality in this phenomenon.

Montelukast suppresses the development of irritable bowel syndrome phenotype possibly through modulating NF-κB signaling in an experimental model.

Irritable bowel syndrome (IBS) is a functional gut disorder with multi-factorial pathophysiology that causes recurring pain or discomfort in the abdomen, as well as altered bowel habits. Montelukast, a well-known cysteinyl leukotriene receptor 1 (CysLT1R) antagonist, is widely used for the anti-inflammatory management of asthma. The present study aimed to evaluate the effects of pharmacological inhibition of CysLT1R on acetic acid-induced diarrhea-predominant IBS (D-IBS) in rats. Behavioral pain responses to noxious mechanical stimulation were decreased in the montelukast-treated rats as compared to the model animals following colorectal distension (CRD)-induced visceral hypersensitivity. Stool frequency decreased dose-dependently by montelukast in IBS rats exposed to restraint stress. A significantly shorter immobility time was also observed in IBS rats who received montelukast vs IBS group in the forced swimming test (depression-like behavior). Furthermore, there were significant decreases in the NF-κB protein expression, inflammatory cytokine (TNF-α, and IL-1ß) levels, and histopathological inflammatory injuries concomitant with increased anti-inflammatory cytokine, IL-10, in montelukast-treated rats compared with the IBS group. Cysteinyl leukotriene production and CysLT1R mRNA expression showed no remarkable differences among the experimental groups. The present results suggest the possible beneficial effects of montelukast in the management of D-IBS symptoms. The molecular mechanism underlying such effects, at least to some extent, might be through modulating CysLT1R-mediated NF-κB signaling. Yet, more studies are required to demonstrate the clinical potential of this drug for IBS therapy.

Bunium persicum essential oil reduced acetic acid-induced rat colitis through suppression of NF-κB pathway.

OBJECTIVE: The aim of this study was to evaluate the anti-inflammatory effect of B. persicum essential oil on colonic inflammation and the role of suppression of NF-κB pathway in rat colitis induced by acetic acid solution. MATERIALS AND METHODS: Induction of acute colitis was done by intra-luminal instillation of 2 ml of acetic acid (4%) diluted in normal saline. Two hours after colitis induction, 0.2% tween 80 in normal saline, prednisolone (4 mg/kg) or B. persicum essential oil (100, 200, and 400 mg/kg) were administered to the rats orally and continued for 5 consecutive days. The severity of macroscopic and microscopic damages was assessed. Myeloperoxidase and TNF-α activity was evaluated by biochemical analysis and ELISA respectively and protein expression of p-NF-κB was assessed by immunohistochemistry (IHC). RESULTS: Prednisolone and B. persicum essential oil (100, 200, and 400 mg/kg) decreased macroscopic and microscopic injuries compared to the acetic acid group. On the other hand, prednisolone and B. persicum essential oil (200 and 400 mg/kg) decreased the activity of MPO and TNF-α in the colon tissue of rats compared with the acetic acid group. Furthermore, they suppressed the expression of p-NF-κB protein induced by acetic acid administration. CONCLUSION: It is suggested that the anti-inflammatory effect of B. persicum essential oil on acetic acid-induced colitis in rats may be due to the suppression of NF-κB pathway.

Evaluation of the effect of heat shock protein 70 targeted drugs on cirrhotic cardiomyopathy in biliary cirrhotic rats.

AIMS: Liver cirrhosis leads to cirrhotic cardiomyopathy (CCM) and chronotropic incompetence (CI). Heat shock protein 70 (Hsp70) regulates cellular apoptosis and autophagy in stress. Teprenone modulates the Hsp70 and protects against cellular injury. Thus, we aimed to evaluate the effect of teprenone on CI in biliary cirrhotic rats. MAIN METHODS: Liver cirrhosis was induced in male Wistar rats through bile duct ligation (BDL). The chronotropic responses and QT interval were studied through electrocardiography (ECG) in sham, cirrhotic, and cirrhotic/teprenone (100 mg/kg) pre-treated groups. Brain natriuretic peptide (BNP), tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and monocyte chemo-attractant protein-1 (MCP-1), and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were investigated in serum. The Hsp70, B-cell lymphoma 2 (Bcl-2), and B-cell lymphoma 2-associated X protein (Bax) expressions were quantified through real-time polymerase chain reaction (Real-time PCR). KEY FINDINGS: The chronotropic responses were decreased significantly in cirrhotic and cirrhotic/teprenone groups. The QT interval and serum BNP, TNF-α, IL-6, ALT, AST, and MCP-1 levels were increased significantly in the cirrhotic and decreased significantly, except BNP, in the cirrhotic/teprenone group. The Hsp70 and Bax expressions increased significantly in cirrhotic and decreased significantly in the cirrhotic/teprenone group while the Bcl-2 decreased significantly in cirrhotic and increased significantly in the cirrhotic/teprenone group. SIGNIFICANCE: Teprenone does not relieve the CI and BNP changes in CCM while other indices are treated. Given that CCM is a multifactorial disease and needs to target other genes and proteins concurrent with Hsp70 to relieve CCM.

Anti-inflammatory effect of amitriptyline in a rat model of acetic acid-induced colitis: the involvement of the TLR4/NF-kB signaling pathway.

Inflammatory bowel disease (IBD) consists of ulcerative colitis and Crohn's disease, which affects gastrointestinal tract. The immune-mediated inflammation is mostly considered as the pathogenesis of IBD. It has been demonstrated that amitriptyline exerts anti-inflammatory influence; therefore, the aim of the current experiment is to evaluate the anti-inflammatory impact of amitriptyline on intestinal disorders following acetic acid-induced colitis in rats. Thirty male Wistar rats were randomly divided into five groups, including sham, control, dexamethasone (2 mg/kg), and amitriptyline (10 and 20 mg/kg). Intrarectal administration of acetic acid was applied to colitis induction in all study groups except for sham group. Animals were treated by oral administration of dexamethasone or amitriptyline. While macroscopic and microscopic lesions appeared after colitis induction treatment with dexamethasone and amitriptyline 10 and 20 mg/kg significantly improved lesions. Moreover, Toll-like receptor 4 (TLR4) and nuclear factor binding kappa light-chain (NF-ĸB expression), tumor necrosis factor-alpha (TNF-α) level, and myeloperoxidase (MPO) activity were increased after colitis induction, whereas treatment with dexamethasone (2 mg/kg) or amitriptyline (10 and 20 mg/kg) caused a noticeable decrease in the TLR4 and pNF-ĸB expression, TNF-α level, and MPO activity. In conclusion, amitriptyline plays an anti-inflammatory role through the suppression of TLR4/pNF-ĸB signaling pathway in the rat model of acute colitis.

Protective Effects of Spermidine Against Cirrhotic Cardiomyopathy in Bile Duct-Ligated Rats.

Cirrhotic cardiomyopathy is a critical factor that causes morbidity and mortality in crucial conditions such as liver transplantation. In animal model, the common pathophysiologic mechanisms of cirrhotic cardiomyopathy are similar to those associated with bile duct ligation (BDL). Overproduction of inflammatory and oxidant markers plays a crucial role in cirrhotic cardiomyopathy. Spermidine, a multifunctional polyamine, is known for its antioxidant and anti-inflammatory effects. In this study, we investigated the effects of spermidine on development of cirrhotic cardiomyopathy in BDL rats. Rats were randomly housed in 6 groups. Except the normal and sham groups, BDL was performed for all the control and spermidine groups. Seven days after operation, 3 different doses of spermidine (5, 10 and 50 mg/kg) were administrated until day 28, in spermidine groups. At the end of the fourth week, the electrocardiography (ECG) and papillary muscle isolation were performed. The serum level of tumor necrosis factor-a (TNF-α), interleukin-1ß (IL-1ß), and IL-10 and cardiac level of superoxide dismutase, glutathione (GSH). and malondialdehyde (MDA) were assessed. Furthermore, the nuclear factor-κB (NF-κB) expression was assessed by western blot. Cardiac histopathological changes were monitored. The serum levels of magnesium (Mg) and potassium (K) were investigated. Control group, exhibited exaggerated signs of cirrhotic cardiomyopathy in comparison with the sham group. Co-administration of spermidine at the dose of 10 mg/kg in BDL rats significantly improved the cardiac condition, reduced the inflammatory mediators, and increased antioxidant enzymes. In addition, the histopathologic findings were in accordance with the other results of the study. Besides, there was no significant alteration in serum levels of Mg and K. This study demonstrates that spermidine at the dose of 10 mg/kg significantly improved the cirrhotic cardiomyopathy in BDL model in rats.

Risperidone attenuates acetic acid-induced colitis in rats through inhibition of TLR4/NF-kB signaling pathway.

AIM: The purpose of the present study is to explore the anti-inflammatory potential of risperidone in acetic acid-induced rat colitis through inhibition of TLR4/NF-kB pathway. METHODS: Acute colitis induction was done by intra-rectal administration of 2 mL of 4% diluted acetic acid solution. Two h after colitis induction, dexamethasone (2 mg/kg) as standard drugorrisperidone (2, 4 and 6 mg/kg) were administered orally to wistar rats for five consecutive days. 24 h after the last treatment, animals were sacrificed by cervical dislocation. Macroscopic and microscopic damage evaluation was done. Biochemical and ELISA methods were used to assess myeloid peroxidase (MPO) enzyme activity and tumor necrosis factor-α (TNF-α) level respectively. Moreover, immunohistochemistry (IHC) was performed to detect the expression of TLR4 and pNF-kBproteins. RESULTS: Dexamethasone (2 mg/kg) or risperidone (2, 4 and 6 mg/kg) improved acetic acid-induced macroscopic (p < .001) and microscopic lesions. Additionally, risperidone (2, 4 and 6 mg/kg) inhibited the activity of MPO and TNF-α (p < .01, p < .001) in the colon tissue compared to acetic acid group. Furthermore, bothdexamethasone and risperidone (2, 4 and 6 mg/kg) significantly reduced acetic acid-induced expression of TLR4and pNF-kB proteins (p < .05, p < .01, p < .001). CONCLUSION: The anti-inflammatory effect of risperidone on acetic acid-induced colitis in rats may involve inhibition of TLR4 and NF-kB signaling pathway.

Bupropion Ameliorates Acetic Acid-Induced Colitis in Rat: the Involvement of the TLR4/NF-kB Signaling Pathway.

Inflammatory bowel disease composed of ulcerative colitis and Crohn's disease is a disorder that may involve entire gastrointestinal tract. Its pathogenesis is mainly an immune-mediated inflammation. Recently, it has been indicated that bupropion possesses anti-inflammatory properties; hence, the objective of this experiment is the investigation of the anti-inflammatory influence of bupropion on colonic lesions that emerged following the intrarectal administration of acetic acid. Thirty-six male Wistar rats were allocated randomly into six groups, including control, acetic acid, dexamethasone (2 mg/kg), and bupropion (40, 80, and 160 mg/kg). Colitis was induced by intrarectal administration of acetic acid in all study groups except control group, and animals were treated by oral administration of dexamethasone and bupropion. While macroscopic and microscopic lesions were observed after colitis induction, administration of dexamethasone and bupropion 160 mg/kg led to the remarkable improvement in lesions. In addition, the expression of TLR4 and NF-ĸB was decreased after colitis induction; however, treatment with dexamethasone (2 mg/kg) and bupropion (160 mg/kg) resulted in a significant decrease in their expression. Regarding biochemical factors, following colitis induction, TNF-α level and MPO activity were increased; nevertheless, dexamethasone (2 mg/kg) and bupropion (160 mg/kg) decreased the TNF-α and MPO activity. In conclusion, bupropion exerts anti-inflammatory influence through suppressing the TLR4 and NF-ĸB expression in the rat model of acute colitis.

Effect of vitamin D supplementation on CREB-TrkB-BDNF pathway in the hippocampus of diabetic rats.

OBJECTIVES: Cyclic AMP (adenosine monophosphate) response element-binding protein (CREB) and Brain-derived neurotrophic factor (BDNF) are reported to broadly involve in learning capacity and memory. BDNF exerts its functions via tropomyosin receptor kinase B (TrkB). BDNF transcription is regulated by stimulating CREB phosphorylation. The CREB-TrkB-BDNF pathway is reported to be affected by diabetes, which may contribute to its cognitive deficits. This study was conducted to investigate the effect of vitamin D supplementation on the hippocampal fraction of this pathway in an animal model of type-1 diabetes mellitus (T1DM). MATERIALS AND METHODS: Thirty-six adult male Sprague-Dawley rats were randomly divided into 4 groups as follows: Group 1: normal healthy rats (n=8); group 2: normal healthy rats receiving sesame oil supplementation as placebo (n=8); Group 3: diabetic rats receiving sesame oil (n=10); and Group 4: diabetic rats treated with 4300 IU/kg/week vitamin D dissolved in sesame oil (n=10). Diabetes was induced by intraperitoneal (IP) injection of streptozotocin. Blood and hippocampal samples were acquired at the end of the experiment. RNA was extracted from the hippocampus, and real-time PCR (polymerase chain reaction) was performed for BDNF and TrkB gene expression. RESULTS: Administration of vitamin D (4300 IU/kg/week) in a T1DM animal model increased CREB phosphorylation in the hippocampus, but the serum and hippocampal BDNF levels and TrkB and BDNF gene expression did not change significantly. CONCLUSION: Vitamin D increased hippocampal CREB phosphorylation in a T1DM animal model. Our findings showed that vitamin D might be protective against central nervous system complications in diabetes. However, future studies are warranted.

Arthrocen, an avocado-soy unsaponifiable agent, improves acetic acid-induced colitis in rat by inhibition of NF-kB signaling pathway.

The goal of the current study was to evaluate the anti-inflammatory effect of Arthrocen against acetic acid-induced colitis in rats. Acute inflammation was produced through intrarectal administration of 2 ml diluted acetic acid (4%) solution. All interventions were carried out for 5 days after colitis induction. Arthrocen was administered orally at doses of 30, 60, and 120 mg kg-1  day-1 . Then, macroscopic and microscopic studies were performed. Myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) activity were measured by biochemical and ELISA methods, respectively. Immunohistochemistry was done to investigate the expression of pNF-κB. The results of this study demonstrated that Arthrocen reduced macroscopic and microscopic damage compared to the acetic acid group. Furthermore, Arthrocen decreased the activity of MPO and TNF-α as well as the protein expression of pNF-kB in rat colon tissue. The results of the current study revealed the anti-inflammatory activity of Arthrocen in acetic acid mediated colon inflammation through suppressing the NF-κB pathway. PRACTICAL APPLICATIONS: Inflammatory bowel disease (IBD) is an immune-mediated chronic relapsing disorder affecting the gastrointestinal tract (GIT) characterized by chronic bowel inflammation. A plant-based dietary supplement containing avocado and soy unsaponifiable extracts in a ratio of 1:2 is known as Arthrocen. Arthrocen can be used as a complementary drug beside current drugs in clinical trials for the treatment of IBD.

Silymarin-albumin nanoplex: Preparation and its potential application as an antioxidant in nervous system in vitro and in vivo.

In this study, we formulated silymarin-HSA nanoplex and assayed its ability to reduce LPS-induced toxicity in vitro and in vivo. Silymarin molecules were encapsulated into HSA nanoplex and the loading efficiency and characterization of fabricated nanoplex were performed by using HPLC, TEM, SEM, DLS, FTIR analysis, and theoretical studies. Afterwards, their protective effect against LPS (20 µg/ml) -induced toxicity in SH-SY5Y cells was investigated by MTT, ROS, and apoptosis assays. For in vivo experiments, rats were pre-treated with either silymarin or silymarin -HSA nanoplex (200 mg/kg) orally for 3 days and at third day received LPS by IP at a dose of 0.5 mg/kg, 150 min before scarification followed by SOD and CAT activity assay. The formulation of silymarin-HSA nanoplex showed a spherical shape with an average diameter between 50 nm and 150 nm, hydrodynamic radius of 188.3 nm, zeta potential of -26.6 mV, and a drug loading of 97.3%. In LPS-treated cells, pretreatments with silymarin-HSA noncomplex recovered the cell viability and decreased the ROS level and corresponding apoptosis more significantly than free silymarin. In rats, it was also depicted that, silymarin-HSA noncomplex can increase the SOD and CAT activity in brain tissue at LPS-triggered oxidative stress model more significantly than the free counterpart. Therefore, nanoformulation of silymarin improved its capability to reduce LPS-induced oxidative stress by restoring cell viability and elevation of SOD and CAT activity in vitro and in vivo, respectively. In conclusion, formulation of silymarin may hold a great promise in the development of antioxidant agents.

Thymol reduces acetic acid-induced inflammatory response through inhibition of NF-kB signaling pathway in rat colon tissue.

AIM: The aim of the present study was to evaluate the anti-inflammatory effect of thymol in acetic acid-induced rat colitis through inhibiting the NF-κB signaling pathway. METHODS: Colitis was induced by intra-rectal administration of 2 mL of diluted acetic acid (4%) solution using a flexible plastic rubber catheter in Wistar rats. Colitis was induced on the first day and all treatments were applied 5 days after the induction of colitis. Thymol was dissolved in 0.2% tween 80 in saline and administered orally at doses of 10, 30, and 100 mg/kg per day. Macroscopic and histopathologic investigations were done. The expression of myeloperoxidase (MPO) and tumor necrosis factor-α (TNF-α) was determined by immunohistochemistry (IHC) assay. The protein expression level of pNF-κB p65 was measured by the Western blot technique. RESULTS: Treatment with thymol reduced mucosal and histological damages compared to the acetic acid group. Our results showed that thymol markedly inhibited the production of MPO and TNF-α in the colon tissue of the acetic acid-induced group. In addition, thymol decreased acetic acid-induced up-regulation of pNFκB p65 protein. CONCLUSIONS: The results of our study suggest that thymol exerts an anti-inflammatory effect in acetic acid-induced rat colitis by inhibiting the NF-κB signaling pathway and downregulating TNF-α and MPO expressions.

Acute Activation of α7-Nicotinic Receptors by Nicotine Improves Rodent Skin Flap Survival Through Nitrergic System.

BACKGROUND: Recent reports have identified angiogenic, anti-inflammatory, and antioxidant properties of acute treatment with nicotine via activation of nicotinic acetylcholine receptors (nAChRs). In addition, the nitric oxide (NO) pathway is involved in ischemic reperfusion injuries. OBJECTIVES: We investigated the effects of acute pretreatment with nicotine in a rat model of random-pattern skin flap and the potential role of the NO pathway. METHODS: The Sprague-Dawley rats received increasing doses of (-)-nicotine (0.5, 1, 1.5, 2, and 3 mg/kg) before the procedure. Dorsal skin flaps with caudal pedicles were elevated at the midline, and flap survival was evaluated 7 days after surgery. In addition, animals received an α7-nAChR antagonist, methyllycaconitine, with nicotine. Quantitative reverse transcription polymerase chain reaction was also applied to measure the dermal expression of α7-nAChR. Next, a nonselective NO synthase inhibitor, N-nitro-L-arginine methyl ester hydrochloride; a selective inducible NO synthase inhibitor, aminoguanidine; and an NO precursor, L-arginine, were administered with nicotine. RESULTS: Nicotine at doses of 1, 1.5, and 2 mg/kg significantly increased flap survival, whereas the protective effects of nicotine disappeared at higher doses. Methyllycaconitine completely reversed the protective effects of nicotine and the elevated cutaneous expression of α7-nAChR in nicotine-pretreated rats. In addition, systemic administration of N-nitro-L-arginine methyl ester hydrochloride or aminoguanidine with an effective dose of nicotine caused a significant decrease in flap survival. Conversely, coinjection of a subeffective dose of L-arginine with the subeffective dose of nicotine significantly boosted its protective effects. CONCLUSIONS: Acute pretreatment with nicotine by stimulating the expression and activation of cutaneous α7-nAChR improves skin flap survival, which is partially mediated through modulation of the NO pathway.

Melatonin ameliorates TNBS-induced colitis in rats through the melatonin receptors: involvement of TLR4/MyD88/NF-κB signalling pathway.

AIM: The aim of the present study is to investigate the anti-inflammatory effect of melatonin in trinitrobenzene sulfonic acid (TNBS)-induced rat colitis through the inhibition of Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signalling pathway and activation of melatonin receptor. METHODS: Colitis was induced in Wistar rats by administration of 100 mg/kg TNBS dissolved in 0.25 ml of 50% ethanol solution using a flexible plastic rubber catheter into the colon via the anus. This resulted in incidence of colitis on the first day, and all treatments were conducted for 10 days after induction of colitis. Melatonin was administered intraperitoneally (i.p.) at doses of 1, 5, and 10 mg/kg/day. Luzindole (non-selective MT1/MT2 receptor antagonist) was administered i.p. at dose of 5 mg/kg/day 15 min prior to melatonin injection. During the experiment, animals were monitored for the appearance of diarrhoea, body weight loss, and rectal bleeding. Myeloid peroxidase enzyme and tumour necrosis factor-α (TNF-α) activities were detected by immunohistochemistry. The protein expression level of TLR4, myeloid differentiation factor 88 (MyD88), NF-κB p65, and inhibitor of kappa B (I-κB) were detected by western blotting analysis. RESULTS: Treatment with melatonin improved weight loss, mucosal, and histological damage compared with TNBS group. In addition, melatonin decreased TNBS-induced up-regulation of TLR4, MyD88, and NF-κB p65, and increased down-regulation of I-κB proteins. On the other hand, the administration of luzindole resulted in the inhibition of melatonin effects. CONCLUSIONS: It seems that the inhibition of TLR4/NF-κB signalling pathway may mediate the anti-inflammatory effects of melatonin in TNBS-induced rat colitis.

Foeniculum vulgare essential oil ameliorates acetic acid-induced colitis in rats through the inhibition of NF-kB pathway.

AIM: The aim of the present study is to investigate the protective effects of Foeniculum vulgare essential oil on intestinal inflammation through the inhibition of NF-kB pathway in acetic acid-induced rat colitis. METHODS: Acute colitis was induced by intra-rectal administration of 2 mL of diluted acetic acid (4%) solution. Two hours after the induction of colitis, 0.2% tween 80 in normal saline, dexamethasone (2 mg/kg) and F. vulgare essential oil (100, 200, 400 mg/kg) were administered to the animals by oral gavage and continued for 5 consecutive days. Assessment of macroscopic and microscopic lesions was done. MPO activity was evaluated by biochemical method. Furthermore, TNF-α activity was detected by immunohistochemistry (IHC) and the expression level of p-NF-kB p65 protein was measured by western blot analysis. RESULTS: Dexamethasone and F. vulgare essential oil (200, 400 mg/kg) reduced the macroscopic and microscopic lesions compared to the acetic acid group (p < 0.01, p < 0.001). In addition, these agents decreased the activity of MPO (p < 0.01, p < 0.001) and the expression of TNF-α positive cells (p < 0.05, p < 0.01, p < 0.001) in the colon tissue compared to acetic acid group. Furthermore, they inhibited acetic acid-induced expression of p-NF-kB p65 protein (p < 0.05, p < 0.001). CONCLUSION: It is proposed that the anti-inflammatory activity of F. vulgare essential oil on acetic acid-induced colitis in rats may involve the inhibition of NF-kB pathway.

Application of nanostructured lipid carriers: the prolonged protective effects for sesamol in in vitro and in vivo models of ischemic stroke via activation of PI3K signalling pathway.

BACKGROUND: Treatment of the ischemic stroke has remained a major healthcare challenge. The phenolic compound, sesamol, has shown promising antioxidant and neuroprotective effects, however, fast clearance may negatively affect its efficiency. This, prompted us to incorporate sesamol into the nanostructured lipid carriers (S-NLCs) and evaluate its therapeutic potential in in vitro and in vivo models of ischemic stroke. METHODS: S-NLCs formulations were prepared by high-pressure homogenization followed by physicochemical characterization, evaluation of the bioactivity of the optimal formulation in oxygen-glucose deprivation (OGD) and global cerebral ischemia/reperfusion (I/R) injury and implication of phosphatidylinositol 3-kinase (PI3K) pathway in this regard. Two- or three-way ANOVA, Mann-Whitney U test, and Student's t-test were used for data analysis. RESULTS: Formation of S-NLCs which exhibited a controlled release profile, was confirmed by scanning electron microscope and differential scanning calorimetry. 1- and 8-h OGD followed by 24 h re-oxygenation significantly reduced PC12 cell viability, increased lactate dehydrogenase activity and the number of condensed nuclei, and induced oxidative stress as revealed by increased malondialdehyde level and decreased glutathione content and superoxide dismutase and catalase activities. Sesamol (80 and 100 µM) reduced the cytotoxicity, oxidative stress, and cellular damage only after 1-h OGD, while, S-NLCs (containing 80 and 100 µM of sesamol) were effective at both time points. Intravenous injections of S-NLCs (20 and 25 mg/kg) into rats markedly attenuated I/R-induced neurobehavioural deficits, cellular damage, and oxidative stress, while, free sesamol failed. Pre-treatment with PI3K inhibitor, LY294002, abolished the protective effects against OGD or I/R. CONCLUSIONS: S-NLCs improve the pharmacological profile of sesamol and provide longer lasting protective effects for this phenolic phytochemical. This nanoformulation by activating PI3K pathway may serve as a promising candidate for neuroprotection against the cerebral stroke or other neurodegenerative disorders. Sesamol-loaded NLCs, a promising nanoformulation against the ischemic stroke.