Ascorbic acid administration produces an antidepressant-like effect: Evidence for the involvement of monoaminergic neurotransmission

Ascorbic acid is highly concentrated in the brain, being considered as a neuromodulator. This study investigated the effect of ascorbic acid in the tail suspension test (TST) and in the forced swimming test (FST) in mice and the contribution of the monoaminergic system to its antidepressant-like effect. Moreover, the effects of fluoxetine, imipramine and bupropion in combination with ascorbic acid in the TST were investigated. Ascorbic acid (0.1–10 mg/kg, i.p., 1–10 mg/kg p.o. or 0.1 nmol/mice i.c.v.) produced an antidepressant-like effect in the TST, but not in the FST, without altering the locomotor activity. The effect of ascorbic acid (0.1 mg/kg, i.p.) in the TST was prevented by i.p. pre-treatment with NAN-190 (0.5 mg/kg), ketanserin (5 mg/kg), MDL72222 (0.1 mg/kg), prazosin (62.5 µg/kg), yohimbine (1 mg/kg), propranolol (2 mg/kg), haloperidol (0.2 mg/kg), sulpiride (50 mg/kg), but not with SCH23390 (0.05 mg/kg, s.c.). Additionally, ascorbic acid (1 mg/kg, p.o.) potentiated the effect of subeffective doses (p.o. route) of fluoxetine (1 mg/kg), imipramine (0.1 mg/kg), or bupropion (1 mg/kg) in the TST. The combined treatment of ascorbic acid with antidepressants produced no alteration in the locomotion in the open-field test. In conclusion, our results show that administration of ascorbic acid produces an antidepressant-like effect in TST, which is dependent on its interaction with the monoaminergic system. Moreover, ascorbic acid caused a synergistic antidepressant-like effect with conventional antidepressants. Therefore, the present findings warrant further studies to evaluate the therapeutical relevance of ascorbic acid for the treatment of depression and as a co-adjuvant treatment with antidepressants.     

Evidence for the involvement of the monoaminergic system in the antidepressant-like action of two 4-amine derivatives of 10,11-dihydro-5H-dibenzo [a,d] cycloheptane in mice evaluated in the tail suspension test

Our previous study described the synthesis of 4-amine derivatives of 10,11-dihydro-5H-dibenzo-alkylamine-cycloheptane, 4-amine (3-N,N-dimethylpropylamine)-10,11-dihydro-5H-dibenzo[a,d] cycloheptane-5-one (ADDCH1), and 1,2,3,4,8,9-hexahydro-dibenzocycloheptane[4,4a,5-ef]1,4-diazepin (ADDCH2), and the characterization of their antidepressant-like effect in the forced swimming test in mice. This study investigated the involvement of monoaminergic pathways in the antidepressant-like effect of these compounds in mice evaluated in the tail suspension test (TST), another animal model to screen antidepressant drugs. Our results show that the immobility time in the TST was significantly reduced by ADDCH1 (15 to 50 mg/kg, i.p.) or ADDCH2 (30 and 50 mg/kg, i.p.). The antidepressant-like effect of ADDCH1 (30 mg/kg, i.p.) in the TST was prevented by pre-treatment of mice with methysergide (2 mg/kg, i.p.), a non-selective serotonin receptor antagonist, p-chlorophenylalanine methylester (pCPA, 100 mg/kg, i.p.), an inhibitor of serotonin synthesis, prazosin (62.5 microg/kg, i.p.), an alpha1-adrenoceptor antagonist, or yohimbine (1 mg/kg, i.p.), an alpha2-adrenoceptor antagonist. In contrast, the antidepressant-like effect of ADDCH2 was antagonized only by yohimbine (1 mg/kg) or haloperidol (50 microg/kg, i.p.), a dopamine D2/D3/D4 receptor antagonist, and was not affected by methysergide, pCPA or prazosin. Altogether, the present results strongly suggest the differential involvement of monoaminergic systems, serotonin/noradrenaline (ADDCH1) and noradrenaline/dopamine (ADDCH2) pathways, respectively, in the antidepressant-like effect of dibenzosuberone compounds.     

Phytocannabinoids as novel therapeutic agents in CNS disorders

The Cannabis sativa herb contains over 100 phytocannabinoid (pCB) compounds and has been used for thousands of years for both recreational and medicinal purposes. In the past two decades, characterisation of the body's endogenous cannabinoid (CB) (endocannabinoid, eCB) system (ECS) has highlighted activation of central CB₁ receptors by the major pCB, Δ⁹-tetrahydrocannabinol (Δ⁹-THC) as the primary mediator of the psychoactive, hyperphagic and some of the potentially therapeutic properties of ingested cannabis. Whilst Δ⁹-THC is the most prevalent and widely studied pCB, it is also the predominant psychotropic component of cannabis, a property that likely limits its widespread therapeutic use as an isolated agent. In this regard, research focus has recently widened to include other pCBs including cannabidiol (CBD), cannabigerol (CBG), Δ⁹tetrahydrocannabivarin (Δ⁹-THCV) and cannabidivarin (CBDV), some of which show potential as therapeutic agents in preclinical models of CNS disease. Moreover, it is becoming evident that these non-Δ⁹-THC pCBs act at a wide range of pharmacological targets, not solely limited to CB receptors. Disorders that could be targeted include epilepsy, neurodegenerative diseases, affective disorders and the central modulation of feeding behaviour. Here, we review pCB effects in preclinical models of CNS disease and, where available, clinical trial data that support therapeutic effects. Such developments may soon yield the first non-Δ⁹-THC pCB-based medicines.     

临床护理路径在选择性吻合器痔切闭术(TST)围术期的应用

目的 探讨临床护理路径(CNP)在选择性吻合器痔切闭术(TST)围术期护理的应用效果。方法 将60例混合痔行TST手术的患者随机分为对照组和实验组各30例。以整体护理为基础,对照组给予传统常规护理,实验组应用CNP方法进行护理。比较两组患者的住院天数、医疗费用、并发症的发生率、疾病相关知识掌握情况及患者满意度。结果 实验组患者的住院天数明显缩短,医疗费用下降,并发症的发生率降低,疾病相关知识掌握情况及患者满意度均明显提高(P<0.01)。结论 在混合痔行TST围术期中应用CNP护理方法优于传统护理,患者效果满意,适合临床路径的管理模式。     

Racial differences in sleep architecture: the role of ethnic discrimination

African Americans have been consistently shown to have less deep (slow wave sleep; SWS) and more light (Stages 1 and 2) sleep than Caucasian Americans. This paper explored whether discrimination, a stressor that uniquely impacts certain ethnic groups, contributes to differences in sleep architecture. The sleep of 164 African and Caucasian Americans was examined with laboratory based polysomnography (PSG). Experiences of perceived discrimination (The Scale of Ethnic Experience) and sociodemographic factors were also assessed. After adjusting for age, body mass index (BMI), socioeconomic status (SES) and smoking status, African Americans slept approximately 4.5% more total sleep time (TST) in Stage 2 sleep and 4.7% less TST in SWS than Caucasian Americans (ps < .05). Perceived discrimination was a partial mediator of ethnic differences in sleep architecture. Individuals who reported experiencing more discrimination slept more time in Stage 2 and less time in SWS (ps < .05). Results suggest that the impact of stress related to ethnic group membership plays a part in explaining differences in sleep architecture.     

Lipopolysaccharide affects exploratory behaviors toward novel objects by impairing cognition and/or motivation in mice: Possible role of activation of the central amygdala

Lipopolysaccharide (LPS) produces a series of systemic and psychiatric changes called sickness behavior. In the present study, we characterized the LPS-induced decrease in novel object exploratory behaviors in BALB/c mice. As already reported, LPS (0.3-5 μg/mouse) induced dose- and time-dependent decreases in locomotor activity, food intake, social interaction, and exploration for novel objects, and an increase in immobility in the forced-swim test. Although the decrease in locomotor activity was ameliorated by 10 h postinjection, novel object exploratory behaviors remained decreased at 24 h and were observed even with the lowest dose of LPS. In an object exploration test, LPS shortened object exploration time but did not affect moving time or the frequency of object exploration. Although pre-exposure to the same object markedly decreased the duration of exploration and LPS did not change this reduction, LPS significantly impaired the exploration of a novel object that replaced the familiar one. LPS did not affect anxiety-like behaviors in open-field and elevated plus-maze tests. An LPS-induced increase in the number of c-Fos-immunoreactive cells was observed in several brain regions within 6 h of LPS administration, but the number of cells quickly returned to control levels, except in the central amygdala where the increase continued for 24 h. These results suggest that LPS most prominently affects object exploratory behaviors by impairing cognition and/or motivation including continuous attention and curiosity toward objects, and that this may be associated with activation of brain nuclei such as the central amygdala.     

Antidepressant-like effect of the ethanolic extract from Suanzaorenhehuan Formula in mice models of depression

Ethnopharmacological relevance

Suanzaorenhehuan Formula (SHF) is a Chinese herbal formula for the treatment of depression-like disorders. It contains four herbs: Semen Ziziphi spinosae, Cortex Albiziae, Radix Paeoniae Alba and Semen Platycladi. The present study is to investigate the antidepressant-like effect of the ethanolic extract of SHF and its possible mechanisms.

Materials and methods

Mouse models of depression including the tail suspension test (TST), forced swimming test (FST) and chronic unpredicted mild stress (CUMS) were used to evaluate the effects of SHF extract. The mechanisms were examined by measuring monoamine neurotransmitters in mice hippocampus and frontal cortex, testing monoamine oxidase enzyme (MAO) activities in brain of CUMS-exposed mice.

Results

After one-week treatment, SHF extract (50, 100 and 200 mg/kg) induced a significant decrease on immobility time in TST. After two-week treatment, SHF extract (50, 100 and 200 mg/kg) led to a reduction in the immobility period in TST and FST. The 5-HT levels in mice hippocampus were increased only after 200 mg/kg SHF extract treatment. The noradrenaline (NE) levels were increased after 200 mg/kg SHF extract treatment in mice hippocampus and frontal cortex. SHF extract (50, 100 and 200 mg/kg) significantly inhibited monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B) after 21-day CUMS exposure.

Conclusion

These findings demonstrated that ethanolic SHF extract produced an antidepressant-like effect and the mechanism of action involves the serotonergic, noradrenergic and monoamine oxidase enzyme systems although underlying mechanism still remains to be further elucidated.     

Involvement of monoaminergic systems in the antidepressant-like effect of Eugenia brasiliensis Lam. (Myrtaceae) in the tail suspension test in mice

Ethnopharmacological relevance

Several species of Eugenia L. are used in folk medicine for the treatment of various diseases. Eugenia brasiliensis is used for the treatment of inflammatory diseases, whereas Eugenia. uniflora is used for the treatment of symptoms related to depression and mood disorders, and is used in Brazil by the Guarani Indians as a tonic stimulant.

Aim of the study

To investigate the antidepressant-like effect of hydroalcoholic extracts of different plant species of genus Eugenia and to characterize the participation of the monoaminergic systems in the mechanism of action of the specie that afforded the most prominent antidepressant-like efficacy.

Materials and methods

In the first set of experiments, the effects of hydroalcoholic extracts of Eugenia beaurepaireana, Eugenia brasiliensis, Eugenia catharinae, Eugenia umbelliflora and Eugenia uniflora and the antidepressant fluoxetine (positive control) administered acutely by p.o. route were evaluated in the tail suspension test (TST) and locomotor activity was assessed in the open-field test in mice. In the second set of experiments, the involvement of the monoaminergic systems in the antidepressant-like activity of Eugenia brasiliensis was evaluated by treating mice with several pharmacological agonists and antagonists. The effects of the combined administration of sub-effective doses of Eugenia brasiliensis and the antidepressants fluoxetine, imipramine and bupropion were also evaluated.

Results

The administration of the extracts from Eugenia brasiliensis, Eugenia catharinae and Eugenia umbelliflora, but not Eugenia beaurepaireana and Eugenia uniflora, exerted a significant antidepressant-like effect, without altering locomotor activity. The behavioral profile was similar to fluoxetine. Pre-treatment of mice with ketanserin, haloperidol, SCH23390, sulpiride, prazosin and yohimbine prevented the reduction of immobility time induced by Eugenia brasiliensis. Treatment with sub-effective doses of WAY100635, SKF38393, apomorphine, phenylephrine, but not clonidine, combined with a sub-effective dose of Eugenia brasiliensis decreased the immobility time in the TST. Furthermore, the combined administration of sub-effectives doses of Eugenia brasiliensis with fluoxetine, imipramine and bupropion produced an antidepressant-like effect.

Conclusions

This study show, for the first time, the antidepressant-like effect of species of the genus Eugenia, especially Eugenia brasiliensis, whose effects in the TST seem to be mediated by serotoninergic (5-HT_1A and 5-HT₂ receptors), noradrenergic (α₁-adrenoceptor) and dopaminergic (dopamine D₁ and D₂ receptors) systems.     

改良TST术与Milligan-Morgan术治疗混合痔的临床对比观察

目的：探讨改良TST术治疗混合痔的临床疗效。方法选择40例Ⅱ～Ⅳ度混合痔患者,随机均分为2组（n=20）,试验组采用改良TST术治疗,对照组采用Milligan-Morgan术治疗,对比观察2组患者的疗效、手术时间、术中出血量、住院时间、恢复工作时间、术后并发症（术后出血、术后肛门水肿、疼痛、肛门坠胀）、第1次排便情况及总体满意度。结果2组在疗效、肛门坠胀方面比较差异无统计学意义,而在手术时间、住院时间、恢复工作时间、总体满意度及术中出血量、术后出血、肛门水肿、疼痛、排便情况方面,试验组显著优于对照组,差异有统计学意义（P<0.05）。结论改良TST术治疗混合痔疗效确切,术后并发症发生率低,疗程短,患者满意度高,是一种具有较高临床应用和推广价值的手术。     

High-mobility group box-1 was released actively and involved in LPS induced depressive-like behavior

Depression disorder is a common mental illness, of which the pathogenesis is not well understood. Studies suggest that immunity imbalance and up-regulation of pro-inflammatory cytokines may be associated with the pathogenesis of depression. High-mobility group box 1 protein (HMGB1) has gained much attention as an important player in innate immune responses and an modulating factor in several inflammatory diseases. Here we sought to explore the role of HMGB1 in the development of depression. Depression model was established with low dose of lipopolysaccharide (LPS) administration. Depressive behavior was reflected with increased immobility time in tail suspension test. Accompanying with depressive-like behavior, translocation of HMGB1 from nuclei to cytoplasm was observed by immunofluorescence assays. Meanwhile, no significant necrosis was observed evaluated by hematoxylin-eosin staining. These data indicated that HMGB1 was released actively in the central nervous system. In addition, treating the mice with human recombinant HMGB1 (rHMGB1) could induce the development of depressive-like behavior. Blockage of HMGB1 with GZA abrogated the depressive-like behavior induced by LPS or rHMGB1. These results implicated that HMGB1 was involved in LPS-induced depressive-like behavior.