Additive anxiolytic-like effect of citicoline and ACPA in the non-acute restraint stress (NARS) and acute restraint stress (ARS) mice.

The cannabinoid system plays a key role in stress-related emotional symptoms such as anxiety. Citicoline is a supplemental substance with neuroprotective properties that alleviates anxiety-related behaviors. There is a relation between the actions of cannabinoids and cholinergic systems. So, we decided to evaluate the effects of intracerebroventricular (i.c.v.) infusion of cannabinoid CB1 receptor agents on citicoline-produced response to anxiety-like behaviors in the non-acute restraint stress (NARS) and acute restraint stress (ARS) mice. For i.c.v. microinjection of drugs, a guide cannula was inserted in the left lateral ventricle. ARS was induced by movement restraint for 4 h. Anxiety-related behaviors were assessed using an elevated plus maze (EPM). The results showed that induction of ARS for 4 h decreased the percentage of time spent in the open arms (%OAT) and the percentage of entries to the open arms (%OAE) without affecting locomotor activity, showing anxiogenic-like behaviors. i.c.v. infusion of ACPA (1 µg/mouse) induced an anxiolytic-like effect due to the enhancement of %OAT in the NARS and ARS mice. Nonetheless, i.c.v. microinjection of AM251 (1 µg/mouse) decreased %OAT in the NARS and ARS mice which suggested an anxiogenic-like response. Intraperitoneal (i.p.) administration of citicoline (80 mg/kg) induced an anxiolytic-like effect by the augmentation of %OAT in the ARS mice. Furthermore, when ACPA and citicoline were co-administrated, ACPA potentiated the anxiolytic-like effect induced by citicoline in the NARS and ARS mice. On the other hand, when AM251 and the citicoline were co-injected, AM251 reversed the anxiolytic-like response induced by the citicoline in the NARS and ARS mice. The results of this research exhibited an additive effect between citicoline and ACPA on the induction of anxiolytic-like response in the NARS and ARS mice. Our results indicated an interaction between citicoline and cannabinoid CB1 receptor drugs on the control of anxiety-like behaviors in the NARS and ARS mice.

Synergistic antidepressant-like effect of citicoline and CB 1 agonist in male mice.

BACKGROUND: The endocannabinoid system plays a key role in the control of many emotional-correlated reactions such as stress, depressed mood, and anxiety. Moreover, citicoline has neuroprotective properties and indicates beneficial effects in the treatment of depressive problems. Acute restraint stress (ARS) is an experimental model used for the induction of rodent models of depression. OBJECTIVE: This research was designed to assess the effects of intracerebroventricular (i.c.v.) injection of cannabinoid CB1 receptor agents on citicoline-induced response to depression-like behaviors in the non-acute restraint stress (NARS) and ARS mice. METHODS: For i.c.v. microinjection, a guide cannula was implanted in the left lateral ventricle of male mice. The ARS model was carried out by movement restraint for 4 h. Depression-related behaviors were assessed by forced swimming test (FST), tail suspension test (TST), and splash test. RESULTS: The results exhibited that the ARS mice showed depressive-like responses. I.c.v. infusion of ACPA (1 µg/mouse) induced an antidepressant-like effect in the NARS and ARS mice by reduction of immobility time in the FST and TST as well as enhancement of grooming activity time in the splash test. On the other hand, i.c.v. microinjection of AM251 dose-dependently (0.5 and 1 µg/mouse) induced a depressant-like effect in the NARS mice. I.p. injection of citicoline (80 mg/kg) induced an antidepressant-like response in the NARS and ARS mice. Furthermore, ACPA (0.25 µg/mouse, i.c.v.) potentiated the antidepressant-like response induced by citicoline (20 mg/kg, i.p.) in the NARS and ARS mice. However, AM251 (0.25 µg/mouse, i.c.v.) reversed the antidepressant-like effect produced by the citicoline (80 mg/kg, i.p.) in the NARS and ARS mice. Interestingly, our results indicated a synergistic effect between citicoline and ACPA based on the induction of an antidepressant-like effect in the NARS and ARS mice. CONCLUSIONS: These results suggested an interaction between citicoline and cannabinoid CB1 receptors on the modulation of depression-like behaviors in the NARS and ARS mice.

Interaction between citalopram and omega-3 fatty acids on anxiety and depression behaviors and maintaining the stability of brain pyramidal neurons in mice.

This research was done to examine the combination of citalopram, an antidepressant drug, and omega-3 in a mice model of depression. Mice received citalopram (1 and 2 mg/kg) or omega-3 (10 and 20 mg/kg) daily over 30 days. Then, they were exposed to acute and chronic restraint stress to assess the possible increasing effect of omega-3 on the antidepressant and anxiolytic effects of citalopram. Elevated plus-maze (EPM) and forced swimming test (FST) were used to assess anxiety and depression symptoms in non-restraint stress (NRS), acute restraint stress (ARS), and chronic restraint stress (CRS) mice. The results indicated that induction of acute and chronic restraint stress reduced %OAT (Open arm time) and %OAE (Open arm entrance) in the EPM test but enhanced immobility time in the FST, showing anxiogenic- and depressive-like effects. These stresses reduced the stability of pyramidal neurons in the prefrontal cortex (PFC) and hippocampus. Aone and combination administration with citalopram and omega-3 induced anxiolytic- and antidepressant-like effects in NRS, ARS, and CRS mice. This combination usage increased the stability of pyramidal neurons in the PFC and hippocampus. These results suggested an interaction between citalopram and omega-3 upon the induction of anxiolytic- and antidepressant-like effects as well as augmentation of the ratio of pyramidal live to dark neurons in the PFC and hippocampus of the ARS and CRS mice.

Synergistic effect between citalopram and muscimol upon induction of anxiolytic- and antidepressant-like effects in male mice: An isobologram analysis.

Background: There is evidence that both the GABAergic system and serotonin reuptake inhibitor (SSRI) such as citalopram are involved in the modulation of anxiety and depression processes. In this research, we examined the effects of GABAA receptor agents and citalopram on anxiety- and depression-related behaviors and their interaction in male mice. Methods: For intracerebroventricular (i.c.v.) infusion, a guide cannula was implanted in the left lateral ventricle. Anxiety and depression behaviors were evaluated using the elevated plus-maze (EPM) and forced swimming test (FST). Results: The results revealed that i.c.v. microinjection of muscimol (1 µg/mouse) enhanced % OAT (open arm time) and % OAE (open arm entries) in the EPM test and decreased immobility time in the FST without affecting locomotor activity, presenting anxiolytic- and antidepressant-like behaviors in the EPM and FST, respectively. On the other hand, i.c.v. microinjection of bicuculline (1 µg/mouse) reduced % OAT and % OAE without affecting locomotor activity and immobility time, presenting an anxiogenic-like effect. Moreover, i.p. administration of citalopram (8 mg/kg) increased %OAT and %OAE and reduced immobility time with no effect on locomotor activity, showing anxiolytic- and antidepressant-like responses in male mice. Furthermore, i.c.v. infusion of an ineffective dosage of muscimol potentiated the anxiolytic- and antidepressant-like responses induced by i.p. injection of citalopram in male mice. When citalopram and bicuculline were co-injected, a non-significant dose of bicuculline reversed the anxiolytic-like effect of citalopram in male mice. Also, the data revealed synergistic anxiolytic- and antidepressant-like behaviors between citalopram and muscimol in male mice. Conclusions: The results suggested an interaction between citalopram and GABAergic agents on the modulation of anxiety and depression behaviors in male mice.

Nano-Stevia reduces the liver injury caused by streptozotocin (STZ)-induced diabetes in rats by targeting PEPCK/GCK genes, INSR pathway and apoptosis.

Objectives: Extensive application of stevia in the treatment of type 2 diabetes mellitus (DM) has been proven by a large number of previous studies. We prepared stevia loaded in nanoniosomes (nanostevia) to improve its bioavailability, functionality, and stability and explore its protective effects and underlying mechanisms in the liver of STZ-induced diabetic rats. Methods: Single-dose intraperitoneal injection of STZ (50 mg/kg body weight) was used to establish diabetic model. The mRNA levels of PEPCK and GCK genes and the protein level of INSR were evaluated by Real time-PCR and Western blot assays, respectively. TUNEL assay was used to detect apoptotic cell death in the liver tissue. Results: Diabetic rats exhibited significantly reduced levels of INSR (*** P < 0.001) as well as elevated levels of PEPCK (*** P < 0.001). Both stevia and nano-stevia were capable of increasing levels of GCK and INSR and reducing levels of PEPCK (## P < 0.01 and ### P < 0.001, respectively). In addition, significantly increased number of apoptotic cell death was seen in the liver tissue of diabetic rats (*** P < 0.001) which was markedly mitigated by treatment with both Stevia and nano-Stevia (#P < 0.05 and ## P < 0.01, respectively). Conclusion: Both stevia and nano-stevia demonstrates potent anti-apoptotic activity in the liver tissue of diabetic rats by targeting PEPCK/GCK genes and INSR pathway. These finding show that nano-stevia has more potential to reduce the liver injury caused by STZ-induced diabetes in rats and hence can be considered a valid agent and alternative therapy for attenuating complications of type 2 DM. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-023-01278-2.

Tyrosol-loaded Nano-niosomes Attenuate Diabetic Injury by Targeting Glucose Metabolism, Inflammation, and Glucose Transfer.

INTRODUCTION: Regarding the increasing prevalence of type 2 diabetes, it has become a global concern, making it imperative to control. Chemical drugs commonly recommended for diabetes treatment cause many complications and drug resistance over time. METHODS: The polyphenol tyrosol has many health benefits, including anti-diabetic properties. Tyrosol's efficacy can be significantly increased when it is used as a niosome in the treatment of diabetes. In this study, Tyrosol and nano-Tyrosol are examined for their effects on genes implicated in type 2 diabetes in streptozotocin-treated rats. Niosome nanoparticles containing 300 mg surfactant (span60: tween60) and 10 mg cholesterol were hydrated in thin films with equal molar ratios. After 72 hours, nano-niosomal formulas were assessed for their physicochemical properties. MTT assays were conducted on HFF cells to assess the cellular toxicity of the nano niosome contacting optimal Tyrosol. Finally, the expression of PEPCK, GCK, TNF-ɑ, IL6, GLUT2 and GLUT9 was measured by real time PCR. RESULTS: Physiochemical properties of the SEM images of niosomes loaded with Tyrosol revealed that the nanoparticles had a vehicular structure. In this study, there were two stages of release: initial release (8 hours) and sustainable release (72 hours). Meanwhile, free form drugs were considerably more toxic than niosomal drugs in terms of their cellular toxicity. An in vivo comparison of oral Tyrosol gavage with nano-Tyrosol showed a significant increase in GCK (P<0.001), GLUT2 (P<0.001), and GLUT9 (P<0.001). Furthermore, nano-Tyrosol decreased the expression of TNF-ɑ (P<0.05), PEPCK (P<0.001), and IL-6 (P<0.05) that had been increased by diabetes mellitus. The results confirmed nano-Tyrosol's anti-diabetic and anti-inflammatory effects. CONCLUSION: These findings suggest that nano-Tyrosol has potential applications in diabetes treatment and associated inflammation. Further research is needed to better understand the mechanism of action.

A synergistic analgesic effect of morphine in combination with the CB1 receptor agonist, ACPA, in normal, hypothyroid, and hyperthyroid male rats.

Both cannabinoid and opioid receptors are involved in pain behavior. The administration of morphine and cannabis in rats has been shown to decrease thyroid weight and thyroid­stimulating hormone (TSH) levels. We hypothesized that the third ventricle, due to its adjacency to the hypothalamus, is involved in the modulation of hypothalamic­pituitary­thyroid axis activity and descending pain pathways. The present study examined the effect of intra­third ventricle administration of morphine and cannabis agents on the modulation of pain behavior in normal, hypothyroid (increased serum TSH), and hyperthyroid (decreased serum TSH) rats using the tail­flick test. The results indicated that intra­third ventricle injection of AM251 (CB1 receptor antagonist) caused hyperalgesia, while intra­third ventricle administration of ACPA (CB1 receptor agonist) and morphine produced analgesia in normal, hypothyroid, and hyperthyroid rats. A non­effective dose of morphine (0.5 µg/rat) did not attenuate hyperalgesia induced by an effective dose of AM251. Co­injection of ACPA and morphine into the third ventricle induced anti­nociceptive effect in normal, hypothyroid, and hyperthyroid rats. An isobolographic analysis demonstrated a synergistic effect between ACPA and morphine in the production of the anti­nociceptive effect. Consequently, the third ventricle may modulate pain behavior induced by cannabinoid and opioid receptors via descending pain pathways in normal, hypothyroid, and hyperthyroid rats.

The effect of nicotine on antidepressant and anxiolytic responses induced by citalopram and citicoline in mice.

The effect of nicotine on both anxiety and depression has been broadly studied. Moreover, citalopram and citicoline play a role in the modulation of anxiety and depression. This study was designed to examine the effects of nicotine on the antidepressant and anxiolytic responses induced by citalopram and citicoline in mice. Anxiety­ and depression­related behaviors were assessed with the elevated plus maze and forced swim test, respectively. The results showed that subcutaneous administration of nicotine decreased open­arm time (OAT) and open­arm entries (OAE) but increased immobility time, suggesting anxiogenic­like and depressive­like effects. Intraperitoneal administration of citalopram increased OAT but decreased immobility time, indicating that citalopram induced anxiolytic­like and antidepressant­like responses. Additionally, an injection of citicoline increased OAE but decreased immobility time, revealing anxiolytic­like and antidepressant­like effects. Interestingly, the subthreshold dose of nicotine potentiated the citalopram and citicoline effects on OAT and immobility time, which revealed anxiolytic­like and antidepressant­like behaviors. Locomotor activity was not significantly changed by any doses of the drugs. In conclusion, these findings suggest that interactions between nicotine and citalopram or citicoline occur upon induction of anxiolytic and antidepressant responses in mice.

Additive effect of histamine and muscimol upon induction of antinociceptive and antidepressant effects in mice.

We investigated the effects of histamine and GABAA receptor agents on pain and depression-like behaviors and their interaction using a tail-flick test and the forced swimming test (FST) in male mice. Our data revealed that intraperitoneal administration of muscimol (0.12 and 0.25 mg/kg) increased the percentage of maximum possible effect (%MPE) and area under the curve (AUC) of %MPE, indicating an antinociceptive response. Intraperitoneal injection of bicuculline (0.5 and 1 mg/kg) decreased %MPE and AUC of %MPE, suggesting hyperalgesia. Moreover, muscimol by reducing the immobility time of the FST elicited an antidepressant-like response but bicuculline by enhancing the immobility time of the FST caused a depressant-like response. Intracerebroventricular (i.c.v.) microinjection of histamine (5 µg/mouse) enhanced %MPE and AUC of %MPE. i.c.v. infusion of histamine (2.5 and 5 µg/mouse) decreased immobility time in the FST. Co-administration of different doses of histamine along with a sub-threshold dose of muscimol potentiated antinociceptive and antidepressant-like responses produced by histamine. Cotreatment of different doses of histamine plus a noneffective dose of bicuculline reversed antinociception and antidepressant-like effects elicited by histamine. Cotreatment of histamine, muscimol, and bicuculline reversed antinociceptive and antidepressant-like behaviors induced by the drugs. The results demonstrated additive antinociceptive and antidepressant-like effects between histamine and muscimol in mice. In conclusion, our results indicated an interaction between the histaminergic and GABAergic systems in the modulation of pain and depression-like behaviors.

Effect of citicoline and transcranial direct current stimulation on depressive-like behaviors in mice & quot.

Recent investigations revealed the positive role of transcranial direct current stimulation (tDCS) in the treatment of depressive-like behavior & quot. Citicoline is a dietary supplement. It acts as a neuroprotective factor for the treatment of neurological disorders. The aim of this research was to evaluate a possible interaction between tDCS and citicoline on the modulation of depressive-like behavior s & quot in male mice. For tDCS, an electrode was surgically implanted in the left prefrontal of the brain of male mice & quot. Acute restraint stress was induced by movement restraint for 4 h. Locomotor activity and depressive-like behaviors & quot were examined by open field test (OFT), forced swimming test (FST), and tail suspension test (TST). The results indicated that the intraperitoneal (i.p.) administration of citicoline, left prefrontal anodal tDCS, and co-treatment of citicoline and tDCS had no significant effect on locomotor activity. I.p. injection of citicoline (30 mg/kg) decreased immobility time in the FST and TST, showing an antidepressant-like effect & quot. Moreover, the application of left prefrontal anodal tDCS (0.2 mA) for 20 min induced antidepressant-like effect & quot by reducing immobility time in the FST and TST. Co-administration of citicoline (7 and 15 mg/kg) along with tDCS (0.1 mA) decreased immobility time in the FST and TST, indicating an antidepressant-like effect & quot. Therefore, it can be concluded that administration of citicoline in combination with tDCS enhanced the efficacy of tDCS for remedy of depressive-like behaviors & quot.

Modulation of social and depression behaviors in cholestatic and drug-dependent mice: possible role of opioid receptors.

Objectives: Social behavior, a set of motivating activities critical for survival, is disturbed in cholestasis conditions and many substance abusers as well as psychiatric disorders. The documented loss of social interest in cholestatic patients may be associated with depressive symptoms. Interestingly, the endogenous opioid system is involved in the modulation of depression. Methods in this research: , we assessed the effect of cholestasis and drug dependence on social and depression behaviors using the Three-Chamber Paradigm Test, Forced Swim Test (FST), and Tail Suspension Test (TST) as well as Open Field Test (OFT) in male NMRI mice. Results: The results indicated that alone administration of morphine and tramadol, as well as co-administration of them, increased social motivation and novelty but decreased depression in bile duct ligated mice. Whereas, alone administration of naloxone (a µ-opioid receptor antagonist) and co-administration of it along with morphine and tramadol decreased social motivation and novelty while enhanced depression in the sham-operated and bile duct ligated mice. These administrations of drugs did not change locomotor activity compared to the control group. Conclusion: In conclusion, it appears that (i) both cholestasis and drug dependence impaired social motivation behavior, as well as induced depression-like behavior in the bile duct, ligated mice, (ii) alone administration of morphine and tramadol as well as co-treatment of them may protect against cholestasis and drug dependence induced abnormal behaviors, (iii) µ-opioid receptors play an important role in modulation of social motivation and depression behaviors in mice.

Intra-gastrically administration of Stevia and particularly Nano-Stevia reversed the hyperglycemia, anxiety, and memory impairment in streptozotocin-induced diabetic rats.

Type II diabetes mellitus is a group of metabolic disorders considered chronic hyperglycemia resulting from deficits in insulin secretion or insulin function. This disease usually links with various psychological problems such as anxiety and cognitive dysfunctions. Stevia (Stevia rebaudiana Bertoni) is a natural and healthy substitute sweetener for sugar and artificial sweeteners. It has become essential for human diets and food manufacturers. The aim of this research was to investigate the effects of Stevia and Nano-stevia on the regulation of anxiety and memory processes in male diabetic rats. The elevated plus-maze (EPM) test-retest procedure was used to assess anxiety and memory in male diabetic rats. The findings exhibited that induction of diabetes caused a distorted cellular arrangement in the liver tissue of male rats. On the other hand, intra-gastrically administration of Stevia (1 ml/kg) and nano-Stevia (1 ml/kg) indicated a normal appearance in the liver tissue of male diabetic rats. Moreover, induction of diabetes caused the augmentation of blood glucose, reduction in time spent in%open-arm time (%OAT) on the test day, and enhancement of%OAT on the retest day. Therefore, induction of diabetes in rats produced hyperglycemia, anxiogenic effect, and memory impairment and these responses were reversed by drug treatment. Furthermore, intra-gastrically application of Stevia (1 ml/kg) and nano-Stevia (1 ml/kg) reversed the hyperglycemia, anxiogenic effect, and memory impairment in male diabetic rats. Interestingly, Nano-Stevia exhibited the highest significant response rather than Stevia. In conclusion, the results of this research suggested the beneficial properties of Stevia and particularly Nano-Stevia on inducing anti-diabetic effects, anxiolytic behavior, as well as memory improvement in male diabetic rats.

Enhanced anxiolytic and analgesic effectiveness or a better safety profile of morphine and tramadol combination in cholestatic and addicted mice.

The involvement of the opioidergic system on anxiolytic and antinociceptive responses induced by cholestasis was investigated in cholestatic and addicted mice. Elevated plus-maze and tail-flick devices were used to assess anxiety and pain levels, respectively. The data indicated that induction of cholestasis and injection of opioid drugs including morphine and tramadol enhanced %OAT and %OAE but naloxone reduced %OAT and %OAE in the sham-operated and bile duct ligation (BDL) mice. Induction of cholestasis and addiction to morphine and tramadol prolonged tail-flick latency, which was reversed by naloxone. Coadministration of morphine and tramadol enhanced anxiolytic and analgesic effects in the sham-operated and BDL mice. It seems (a) cholestasis and addiction affect anxiety and pain behaviors, (b) µ-opioid receptors play a key role in anxiolytic and analgesic effects induced by cholestasis, and (c) cotreatment with morphine and tramadol augmented the effectiveness of them for induction of anxiolytic and analgesic effects both in cholestatic and addicted mice.

The effects of citalopram, SB-334867 and orexin-1, alone or in various combinations, on the anxiogenic-like effects of REM sleep deprivation in male mice.

Sleep deprivation may induce anxiety. On the other hand, anxiety disorders elicit main changes in the quality of sleep. Moreover, orexin and citalopram play a role in the modulation of insomnia and mood diseases. Thus, we planned preclinical research to evaluate the effect of combinations of orexin agents and citalopram on anxiety behavior in rapid eye movement (REM) sleep-deprived mice. For drug intracerebroventricular (i.c.v.) infusion, the guide cannula was surgically implanted in the left lateral ventricle of mice. REM sleep deprivation was conducted via water tank apparatus for 24 h. The anxiety behavior of mice was evaluated using the elevated plus maze (EPM). Our results revealed that REM sleep deprivation reduced the percentage of open arm time (%OAT) and the percentage of the open arm entries (%OAE) but not closed arm entries (locomotor activity) in the EPM test, presenting an anxiogenic response ( P < 0.05). We found a sub-threshold dose of SB-334867, orexin-1 receptor antagonist, and orexin-1 which did not alter anxiety reaction in the REM sleep-deprived mice ( P > 0.05). Intraperitoneal (i.p.) injections of citalopram (5 and 10 mg/kg) increased both %OAT and %OAE ( P < 0.001) representing an anxiolytic effect, but not locomotor activity in the REM sleep-deprived mice. Interestingly, co-treatment of citalopram (1, 5 and 10 mg/kg; i.p.) and SB-334867 (0.1 µg/mouse; i.c.v.) potentiated the anxiolytic effect in the REM sleep-deprived mice. On the other hand, co-treatment of different dosages of citalopram along with a sub-threshold dose of orexin-1 did not alter %OAT, %OAE, and locomotor activity in the REM sleep-deprived mice. We found a synergistic anxiolytic effect of citalopram and SB-334867 in the REM sleep-deprived mice. These results suggested an interaction between citalopram and SB-334867 to prevent anxiogenic behavior in the REM sleep-deprived mice.

Osteogenic differentiation of pre-conditioned bone marrow mesenchymal stem cells with Nisin on modified poly-L-lactic-acid nanofibers.

Introduction: Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) are undifferentiated cells with self-renewing ability and multi-lineage differentiation beneficial for regenerative medicine. Nano scaffolds are novel materials employed in bone repair and regeneration. Nisin is a prebiotic that can increase stem cells' lifespan and proliferation. This study attempted to provide a proper strategy for bone marrow mesenchymal stem cells differentiation into the Osteocytes on a Poly-L-lactic-acid (PLLA) scaffold after pretreating with Nisin. Methods: MSC osteogenic differentiation was evaluated by measuring Calcium, Alkaline phosphatase, and quantitative tests such as Real-Time PCR, Acridine Orange, Alizarin Red, Von Kossa, and others. Results: The result of the MTT test showed that the optimal dose of Nisin prebiotic for the MSCs' preconditioning was 200 IU/mL on the 1st, 3rd, and 5th days of culture. Real-time PCR data indicated that the expression rate of ALP, Osteonectin, Osteocalcin, and Collagen I have increased in the presence of Nisin, while the RUNX-2 gene expression has decreased. Furthermore, the results of Alizarin Red and Von Kossa tests, as well as Scanning electron microscopy (SEM), revealed that the cell proliferation in the preconditioned samples with Nisin increased significantly. Conclusions: The study concluded that the cell proliferation and differentiation increased in samples pretreated with Nisin on the PLLA Nano scaffolds.

Synergistic antidepressant effects of citalopram and SB-334867 in the REM sleep-deprived mice: Possible role of BDNF.

This study was done to evaluate the effect of co-treatment of orexin agents along with citalopram on the modulation of depression-like behavior and the expression of BDNF in the prefrontal cortex (PFC) of sleep-deprived male mice. A sleep deprivation model was performed in which rapid eye movement (REM) sleep was completely prohibited, and non-REM sleep was intensely reduced for 24 h. For drug microinjection, the guide cannula was surgically fixed in the left lateral ventricle of mice. Furthermore, we used the open-field test (OFT), forced swim test (FST), tail suspension test (TST), and splash test for recording depression-like behavior as well as Real-Time PCR amplification for assessing the expression of BDNF in the PFC of REM sleep-deprived mice. Our results revealed that REM sleep deprivation did not change locomotor activity while increased depressive-like behavior in FST, TST, and splash tests. However, the expression of BDNF was decreased in the PFC. Intraperitoneally (i.p.) administration of citalopram induced antidepressant effect in the normal and REM sleep-deprived mice. Moreover, intracerebroventricular (i.c.v.) microinjection of a non-effective dose of SB-334867, an orexin antagonist, potentiated the antidepressant-like effect of citalopram. On the other hand, a non-significant dosage of orexin-1 reversed the antidepressant effect of citalopram in the normal and REM sleep-deprived animals. Furthermore, our results showed that injection of citalopram alone or with SB-334867 increased the mRNA expression level of BDNF in the PFC of REM sleep-deprived mice. These data suggest that REM sleep deprivation interferes with the neural systems underlying the depression-like process and supports a likely interaction of the orexin system with citalopram on the modulation of depression-like behavior in REM sleep-deprived mice.

An interaction between basolateral amygdala orexinergic and endocannabinoid systems in inducing anti-nociception in the rat formalin test.

The amygdala has emerged as the main brain center for the emotional affective dimension of pain and pain modulation. In the amygdala, orexin and cannabinoid receptors are expressed in relatively high concentrations. To investigate the possible interaction between the amygdala orexin and cannabinoid systems on the modulation of inflammatory pain, we conducted formalin, rotarod, and plethysmometer tests, as well as analyzing mRNA expression of orexin and cannabinoid receptors in male rats. The basolateral amygdala (BLA) was unilaterally implanted by a guide cannula. Our results showed that, compared to saline and DMSO/saline, intra-BLA microinjection of orexin-A (50 and 100 µM) decreased flinch response in the early phase, but not in the late phase of the formalin test. However, these injections had no significant effect on the mRNA expression level of BLA, orexin receptor type-1 (Orx1), and cannabinoid receptor type-1 (Cb1). Moreover, intra-BLA administration of Orx1 receptor antagonist (SB-334867; 50 nM) and Cb1 receptor antagonist (AM251; 250 and 500 nM) decreased flinch response only in the early phase of the formalin test as compared to the DMSO group. Although the intra-BLA infusion of orexin-A alone and along with SB-334867 or AM251 decreased flinch response in the early phase of the formalin test, intra-BLA co-microinjection of SB-334867/AM251/OrxA increased flinch response in both early and late phases of the formalin test when compared to the DMSO/OrxA group. Interestingly, in the SB-334867/AM251/OrxA group, the Cb1 receptor was upregulated in all groups in comparison to Orx1 receptors. Our results revealed an interaction between BLA, orexin-A, and Cb1 receptors in inducing anti-nociception in the formalin test.

Isobolographic analysis of the antidepressant interaction in two-drug combinations of citalopram, bupropion, and scopolamine in mice.

Depression and anxiety are psychiatric diseases that commonly occur together, and the patient burden and complexity increase when both are present. Comorbid anxiety and depression are often more resistant to common drug treatments such as antidepressants. Combination therapy is a suggested approach in treating these patients, where a decline of doses could reduce undesirable outcomes and still achieve optimal effects. We, therefore, conducted a preclinical study to assess the effect of two-drug combinations of citalopram, bupropion, and scopolamine on anxiety- and antidepressive-like behaviors in male NMRI mice and aimed to determine the nature of the interaction between components. Anxiety- or antidepressive-like activity of mice was assessed by the hole-board or forced swim test (FST), respectively. Our results revealed that citalopram (0.01-0.25 mg/kg; i.p.), bupropion (1-9 mg/kg; i.p.), or scopolamine (0.01-0.1 mg/kg; i.p.) diminished immobility time in the FST, suggesting an antidepressive-like effect. Citalopram decreased dead-dip counts in the hole-board, indicating an anxiogenic-like activity. All two-drug combinations, at inactive doses, exerted an antidepressive-like behavior. Only bupropion/scopolamine combination increased head-dip counts compared to the bupropion/saline group. Isobolographic analysis revealed an antidepressive synergy effect between citalopram plus bupropion, and an antidepressive additive impact between scopolamine plus citalopram or bupropion. It should be noted that the higher dose of each drug alone declined locomotor activity, while two-drug combinations did not affect this parameter. These results suggest a stronger antidepressive effect for citalopram/bupropion combination than other two-drug combinations.

GABA-ergic agents modulated the effects of histamine on the behaviour of male mice in the elevated plus maze test.

NEW FINDINGS: What is the central question of this study? Is there an interaction between histamine and the GABAergic system in modulation of anxiety in mice? What is the main finding and its importance? There is a synergistic anxiogenic effect between histamine and bicuculline in mice. This effect may be due to a direct or an indirect effect of the histaminergic system on the GABAergic system. ABSTRACT: It has been documented that both histaminergic and GABAergic systems participate in the neurobiology of anxiety behaviour. In the current research, we investigated the effects of the histaminergic system and GABAA receptor agents on anxiety-related behaviours and their interaction using the elevated plus maze test in mice. Intraperitoneal (i.p.) administration of muscimol (0.12 and 0.25 mg/kg) increased the open arm time (OAT) (P < 0.001) without affecting the open arm entries (OAE) and locomotor activity, showing an anxiolytic effect. i.p. injection of bicuculline (0.5 and 1 mg/kg) decreased OAT (P < 0.001) but not OAE and locomotor activity, suggesting an anxiogenic behaviour. Intracerebroventricular (i.c.v.) microinjection of histamine (2.5 and 5 µg/mouse) resulted in a decline in OAT (P < 0.001) but not OAE and locomotor activity, indicating an anxiogenic response. Co-administration of histamine with GABAergic agents, muscimol (0.06 mg/kg; i.p.) and bicuculline (0.25 mg/kg; i.p.), decreased (P < 0.001) and increased (P < 0.05), respectively, the anxiogenic-like response to the effective dose (5 µg/mouse; i.c.v.) of histamine. In addition, co-treatment of effective doses of histamine (2.5 and 5 µg/mouse;i.c.v.) with an effective dose of muscimol (0.12 mg/kg; i.p.) and a non-effective dose of bicuculline (0.25 mg/kg; i.p.) significantly decreased OAT (P < 0.001), suggesting a likely interaction between the histaminergic and GABAergic systems in the regulation of anxiety. The results demonstrated a synergistic anxiogenic-like effect between histamine and bicuculline in mice. In conclusion, our results present an interaction between the histaminergic and GABAergic systems in anxiolytic/anxiogenic-like behaviours in the elevated plus maze test.

Intra­LPGi microinjection of glutamate receptors antagonists abolish 17ß­estradiol­induced analgesic effect in the ovariectomized rats.

This study was designed to investigate a possible interaction between 17ß­estradiol and glutamate receptors of the paragigantocellularis lateralis (LPGi) nucleus on pain coping behavior using the formalin test in ovariectomized (OVX) rats. The results showed that intra­LPGi injection of 17ß­estradiol declined flexing behavior in both phases of the formalin test. Still, it only diminished the late phase of licking behavior in the OVX rats. NMDA receptor antagonist, AP5, reversed the analgesic effect of 17ß­estradiol on flexing behavior in both phases of the formalin test in the OVX rats. The 17ß­estradiol­induced anti­nociceptive effect on the flexing duration was prevented by CNQX (AMPA receptor antagonist) only in the early phase of the formalin test in the OVX rats. AP5 and CNQX reduced the anti­nociceptive effect of 17ß­estradiol in the late phase, but not the early phase of licking response in the OVX rats. These results suggested: (i) The intra­LPGi injection of 17ß­estradiol is satisfactory in producing modest analgesia on the formalin­induced inflammatory pain in the OVX rats; (ii) Co­treatment of glutamate receptors (NMDA and AMPA) antagonists and 17ß­estradiol in the LPGi nucleus decrease the analgesic effect of 17ß­estradiol in the OVX rats; (iii) There is a possible association between 17ß­estradiol and glutamate receptors of the LPGi nucleus on pain coping behavior in the OVX rats.