The efficacy and safety of zolpidem and zopiclone to treat insomnia in Alzheimer's disease: a randomized, triple-blind, placebo-controlled trial.

No prior studies have evaluated the efficacy and safety of zolpidem and zopiclone to treat insomnia of demented patients. This randomized, triple-blind, placebo-controlled clinical trial used these drugs to treat patients with probable, late onset Alzheimer's dementia (AD) (DSM V and NINCDS-ADRDA criteria) exhibiting insomnia (DSM V criteria and nocturnal NPI scores ≥ 2). Actigraphic records were performed for 7 days at baseline and for 14 days during the treatment period in 62 patients aged 80.5 years in average and randomized at a 1:1:1 ratio for administration of zolpidem 10 mg/day, zopiclone 7.5 mg/day or placebo. Primary endpoint was the main nocturnal sleep duration (MNSD), whereas secondary outcomes were the proportion of the night time slept, awake time after sleep onset (WASO), nocturnal awakenings, total daytime sleep time and daytime naps. Cognitive and functional domains were tested before and after drug/placebo use. Three participants under zopiclone use had intervention interrupted due to intense daytime sedation and worsened agitation with wandering. Zopiclone produced an 81 min increase in MNSD (95% confidence interval (CI): -0.8, 163.2), a 26 min reduction in WASO (95% CI: -56.2, 4.8) and a 2-episode decrease in awakening per night (95% CI: -4.0, 0.4) in average compared to placebo. Zolpidem yielded no significant difference in MNSD despite a significant 22 min reduction in WASO (95% CI: -52.5, 8.3) and a reduction of 1 awakening each night (95% CI: -3.4, 1.2) in relation to placebo. There was a 1-point reduction in mean performance in the symbols search test among zolpidem users (95% CI: -4.1, 1.5) and an almost eight-point reduction in average scores in the digit-symbol coding test among zopiclone users (95% CI: -21.7, 6.2). In summary, short-term use of zolpidem or zopiclone by older insomniacs with AD appears to be clinically helpful, even though safety and tolerance remain issues to be personalized in healthcare settings and further investigated in subsequent trials. This trial was registered in ClinicalTrials.gov Identifier: NCT03075241.

Effects of Caffeine on Behavioural and Cognitive Deficits in Rats.

There are many studies that have sought to find drug therapies to prevent harm arising from sepsis. Such studies have represented a progress in the support to septic patients and also in the development of new pharmacological alternatives. Our interest was to investigate the caffeine effect on sepsis behavioural and memory impairments. Male rats were anaesthetized and the surgery was made to allow exposure of the caecum, which was then squeezed to extrude a small amount of faeces from the perforation site, which was later placed back into the peritoneal cavity. This procedure, which served to generate experimental sepsis, is herein referred to as ceccum ligation and perforation (CLP). The caffeine (10 mg/kg) was administered by gavage route, once daily, during 7 or 14 consecutive days to investigate the effects of acute or subchronic caffeine treatment on long-term behavioural and cognitive deficits induced by CLP. On the last day, 1 hr after caffeine administration, the animals were submitted to open-field, elevated plus maze (EPM), forced swimming and step-down inhibitory avoidance tests. The results showed that caffeine increased the percentage of open arm entries and open arm time in the EPM test, and reduced the immobility time when compared to the sham-operated group. The caffeine also increased the latency in the inhibitory avoidance test platform. Our results demonstrated that the caffeine improved behavioural changes and improved the neurocognitive deficits of sepsis-surviving animals. It is possible that blockage of the adenosine receptors may be responsible for the results here observed.

Role of nicotine on cognitive and behavioral deficits in sepsis-surviving rats.

Sepsis and its complications are important causes of mortality in intensive care units and sepsis survivors may present long-term cognitive and emotional impairments, including memory deficits and anxiety symptoms. In the present study, we investigated whether repeated nicotine administration can affect the behavioral changes in sepsis-surviving rats. Male Wistar rats were divided in two groups: sham-operated and experimental sepsis induced by cecal ligation and puncture (CLP). The animals were injected subcutaneously with nicotine (0.1 mg/kg) or vehicle once a day during 1 week before and/or 1 week after sepsis induction. Thirty minutes after the last administration (i.e., 7 days after surgery), the animals were tested in the open field, elevated plus-maze and step-down inhibitory avoidance tasks. The repeated nicotine treatment did not affect the survival rate in the sepsis group (50%). Moreover, no significant changes on locomotor activity were observed in the sepsis group while the treatment with nicotine during 1 week after surgery reduced the locomotion of sepsis-surviving rats in the open field. It is important to note that both schedules of nicotine treatment (prior and/or after CLP) improved the sepsis-induced anxiogenic-like responses. Interestingly, nicotine was able to improve short- and long-term inhibitory avoidance memory impairments, observed in sepsis survivors, only when administered during 2 consecutive weeks (i.e., prior and after CLP). Taken together, these results indicate that repeated nicotine administration does not alter the survival rate in rats submitted to CLP and provide new evidence that nicotine can improve long-lasting memory impairments and anxiogenic-like responses in sepsis-surviving animals.

Ethanolic extract from bulbs of Cipura paludosa reduced long-lasting learning and memory deficits induced by prenatal methylmercury exposure in rats.

Previous studies from our group have indicated important biological properties of the ethanolic extract (EE) and isolated compounds from the bulbs of Cipura paludosa (Iridaceae), a native plant widely distributed in northern Brazil. In the present study, the effects of chronic treatment with the EE on the memory of adult rats exposed to methylmercury (MeHg) during early development were assessed. Pregnant rats were treated by gavage with a single dose of MeHg (8 mg/kg) on gestational day 15, the developmental stage critical for cortical neuron proliferation. Adult offspring were administered orally with the EE of C. paludosa (1, 10 or 100mg/kg) over 14 consecutive days. EE improved short-term social memory in a specific manner and facilitated the step-down inhibitory avoidance of short- and long-term memory. MeHg exposure induced pronounced long-lasting impairments in social recognition memory that were improved by EE. Moreover, EE significantly increased the step-down latencies specifically during the short-term session in prenatal MeHg-exposed rats. These results demonstrate that EE reduced the long-lasting short-term learning and memory deficits induced by MeHg exposure. These findings may encourage further studies evaluating the cognitive enhancing properties of C. paludosa and its components on neuropathological conditions associated with exposure to environmental contaminants.

Anxiolytic and antidepressant-like effects of Melissa officinalis (lemon balm) extract in rats: Influence of administration and gender.

OBJECTIVE: To analyse the behavioral effects of Melissa officinalis extract in rats following acute or subacute treatment. MATERIALS AND METHODS: The behavioral effects of an acute or subacute (10-day course) orally administered M. officinalis (MO; 0, 30, 100 or 300 mg/kg) ethanol extract were evaluated in male and female Wistar rats in elevated plus-maze (EPM), forced swimming (FS) and open field (OF) tests. The effects of diazepam (DZP; 1 mg/kg) and fluoxetine (FXT; 10 mg/kg) were also assessed. RESULTS: In the EPM test, the percentage of open arm entries and open arm times of both males and females given the subacute M. officinalis ethanol extract were significantly higher than those of the vehicle-treated animals but were at levels similar to those observed in the DZP group, regardless of the treatment length. In the FS test, immobility duration was significantly lower in both males and females treated with the plant extract when compared to vehicle-treated counterparts. A 10-day treatment with FXT induced the same antidepressant response, regardless of gender, and was more effective than the M. officinalis extract. Male and female rats demonstrated distinct gender profiles, and treatment × gender interactions were observed. Locomotion in the EPM and OF tests was not significantly altered by treatments. CONCLUSION: The potential psychoactive properties of M. officinalis may provide a unique pharmacological alternative for certain psychiatric disorders; however, the efficacy appears to be dependent on both gender and administration length.