Anxiety disorder is a great challenge for modern psychopharmacology. Although a variety of single drugs are used in the treatment of anxiety, it is important to search for new therapeutics with faster onset of action, fewer side effects and higher efficacy. In this work, we studied the possible anxiolytic action mechanism of two new arylpiperazine derivatives: compounds 4p N-(3-(4-(piperonyl)piperazin-1-yl)propyl)isonicotinamide and 3o N-(2-(4-(pyrimidin-2-yl)piperazin-1-yl)ethyl)picolinamide, focusing on their effects on the GABA-ergic and 5-HT systems. The elevated plus-maze test (EPM) was used for measuring anxiety. Additionally, in order to elucidate whether the new compounds have impact on the central redox balance, we conducted biochemical studies. In doing so, the relative activity of the enzymes responsible for glutathione metabolism -glutathione peroxidase and reductase (GPx and GR)- were measured. The results of the presented studies confirmed the anxiolytic effects of the new compounds 4p (60 mg/kg) and 3o (7.5 mg/kg), and suggested in the mechanism of their action, direct 5-HT1A receptors participation and indirect involvement of the GABA-ergic system. Furthermore, the compounds exerted significant agonistic effect with buspirone (BUS, the 5-HT1A partial agonist, 1 mg/kg i.p.) and diazepam (DZ, the classic benzodiazepine anxiolytic, 0.25 mg/kg s.c.), while WAY 100635 (N-{2-[4-(2-methoxyphenyl)-1-piperazinyl] ethyl}-N-(2-pyridyl) cyclohexanecarboxamide, a selective 5-HT1A antagonist, 0.1 mg/kg s.c.), but not flumazenil (a GABAA -BDZ receptor complex antagonist, 10 mg/kg i.p.) was able to reverse their anxiolytic effects in EPM. A concomitant decrease of GPx by the compound 4p (and to a lesser degree, by compound 3o) further seemed to confirm their anxiolytic and antioxidant activity. This article is protected by copyright. All rights reserved.

The anxiolytic effect of earlier reported piperazinediones was assessed by elevated plus maze (EPM), hole-board and open-field (OFT) tests. The rats were administered pretreatment of three different doses i.e. 2, 1 and 0.5 mg/kg of compounds 52, 53 and 55 for seven consecutive days. Compound 52 and diazepam showed increase in open arm entries, increase in time spent therein and total arm entries at 1 mg/kg dose. The compound also produced increase in the number of head dip, sniffing behavior and total number of squares crossed compared to diazepam. In OFT paradigm grooming behavior, number of central squares crossed and the time spent in central area did not reveal statistical differences for diazepam and compound 52 at 1 mg/kg dose. Flumazenil mediated antagonism experiments of these showed that they were acting through benzodiazepine site on GABAA receptor. The levels of 5HT and 5HIAA were estimated in amygdalar region. Level of 5HT was found to be equivalent in case of compound 52 and diazepam treatment at dose of 1 mg/kg. Interestingly, compound 52 did not display sedative effect at higher dose in both animal models. Thus, present study indicated that compound 52 produced anti-anxiety property through modulation of GABAergic transmission.

Nausea and vomiting after esophagogastroduodenoscopy have not been studied in detail. The aim of this study was to evaluate the risk factors for post-endoscopic nausea. We performed a case-control study at the Toyoshima Endoscopy Clinic. Eighteen patients with post-endoscopic nausea and 190 controls without post-endoscopic nausea were analyzed. We conducted univariate and multivariate logistic regression analyses with respect to patient age; sex; body height; body weight; the use of psychotropic drugs as baseline medications; and the dosing amounts of midazolam, pethidine, flumazenil and naloxone. On univariate analysis, post-endoscopic nausea was significantly related with patient age (odds ratio = 0.946); female sex (odds ratio = 10.85); body weight (odds ratio = 0.975); and the dose per kg body weight of pethidine (odds ratio = 53.03), naloxone (odds ratio = 1.676), and flumazenil (odds ratio = 1.26). On multivariate analysis, the dose per kg body weight of pethidine (odds ratio = 21.67, p = 0.004) and female sex (odds ratio = 13.12, p = 0.047) were the factors independently associated with post-endoscopic nausea. The prevalence of nausea after esophagogastroduodenoscopy was 0.49% (18/3,654). In conclusion, post-endoscopic nausea was associated with the dose of pethidine and female sex.

The aim of this study was to identify sleep-promoting substance from Polygonatum sibiricum rhizome extract (PSE) with the regulation of sleep architecture. PSE showed a decrease in sleep latency time and an increase in the sleeping time. In the electroencephalography analysis of rats, PSE (150 mg/kg) showed an increase of non-rapid eye movement by 38% and a decrease of rapid eye movement by 31% compared to the control. This sleep-promoting activity was found to be involved in the GABAA-BDZ receptor. The chemical structure of the pure compound was determined by the 1H and 13C nuclear magnetic resonance spectroscopy and gas chromatography mass spectrometry analysis; active compound was glyceryl-1-monolinoleate. The commercial standard glyceryl-1-monolinoleate showed a similar inhibitory concentration on [3H]-flumazenil binding to GABAA-BDZ receptors with final active fraction of PSE. The results indicate that glyceryl-1-monolinoleate is a major active compound responsible for the PSE-derived sleep promotion.

In folk medicine, it has long been believed that odorous compounds derived from plant extracts can have anxiolytic effects. Among them, linalool, one of the terpene alcohols in lavender extracts, has been reported to have the anxiolytic effects. However, the anxiolytic nature of the linalool odor itself as well as its potential action through the olfactory system has not been thoroughly examined. In this study, we examined the anxiolytic effects of linalool odor with light/dark box test and with elevated plus maze (EPM), and found that linalool odor has an anxiolytic effect without motor impairment in mice. The effect was not observed in anosmic mice, indicating that it was triggered by olfactory input evoked by linalool odor. Furthermore, the effect was antagonized by flumazenil, indicating that the linalool odor-induced anxiolytic effect was mediated by γ-aminobutyric acid (GABA)ergic transmission via benzodiazepine (BDZ)-responsive GABAA receptors. These results provide information about the potential central neuronal mechanisms underlying the odor-induced anxiolytic effects and the foundation for exploring clinical application of linalool odor in anxiety treatments.

Few studies evaluate anesthesia in black-tailed prairie dogs (Cynomys ludovicianus). Isoflurane inhalant anesthesia is usedin this species most commonly, but injectable protocols are poorly described. Here we compared the physiologic effects, including anesthetic depth, vital signs, and hematologic changes, of anesthetic protocols using isoflurane or a combination ofdexmedetomidine, ketamine, and midazolam in black-tailed prairie dogs. In a randomized, complete crossover study design, intact male black-tailed prairie dogs (n = 9; age, 6 mo) were anesthetized by using a combination of dexmedetomidine (0.25mg/kg IM), ketamine (40 mg/kg IM), and midazolam (1.5 mg/kg IM). For reversal, atipamezole (0.15 mg/kg) and flumazenil(0.05 mg/kg) were administered 45 min after induction. For comparison, isoflurane was administered at 5% in 100% oxygen at 5 L/min in an anesthetic induction chamber, followed by maintenance isoflurane 2% in 2 L/min oxygen through a tightfitting facemask for 45 min. Induction and recovery time, respiratory rate, heart rate, body temperature, SpO2, indirect blood pressure, and reflexes were monitored every 5 min during the anesthetic period. Blood samples for venous blood gases, PCV, and refractometric total protein were obtained from the cranial vena cava at 5 min and 45 min. Both protocols appeared to achieve safe and effective anesthesia. Except for blood pressure, all vital signs differed between the 2 treatments. Isoflurane anesthesia resulted in a slightly longer induction and lower respiratory rate and body temperature but increased likelihood of absent reflexes. DKM anesthesia resulted in a faster induction and less hypothermia but also prolonged recovery and lower heart rate and SpO2 readings. These findings suggest that isoflurane provides a more stable and consistent anesthetic plane, whereas dexmedetomidine-ketamine-midazolam anesthesia may be an effective alternative for short procedures that require fast induction and limited analgesia.

Introduction: Sleeplessness is the most common sleep disorder. In this study, the hypnotic effect of macerated (HAME) and soxhlet (HASE) extract of Lagenaria vulgaris (fruit and seed) and Cucurbita pepo (fruit) were studied in mice. Methods: Extracts and fractions were administered intra-peritoneally (i.p.) in mice 30 min before the sodium pentobarbital (30 mg/kg, i.p.). Moreover, the influence of flumazenil or naloxone on the hypnotic effects of the extract and its toxic effects were evaluated. Results: The HAME and HASE of C. pepo prolonged the pentobarbital-induced sleep duration at dose of 200 mg/kg. The HAME of L. vulgaris (fruit) at dose of 200 mg/kg increased the sleeping time. The HAME and HASE of L. vulgaris (seed) increased sleep duration at doses of 50 and 100 mg/kg. Besides, flumazenil (2 mg/kg) reversed the effects of both diazepam (P < 0.001 vs. diazepam group), 200 mg/kg of HAME of C. pepo and 50 mg/kg of HAME and HASE of L. vulgaris (seed). All fractions especially ethyl-acetate fraction (EAF) of L. vulgaris (seed) increased the sleep duration. Naloxone reversed the hypnotic effect of HAME and HASE of L. vulgaris (seed). The extracts showed no neurotoxic effects on PC12 and L929 cell lines. Conclusion: The results showed that L. vulgaris (seed and fruit) and C. pepo potentiated pentobarbital hypnosis without toxic influence. The hypnotic effects of L. vulgaris seed was greater than its fruit and C. pepo. The GABA and opioid receptors may play role in the sleep-induction of L. vulgaris seed.