Effect of home-based light treatment on persons with dementia and their caregivers.

Sleep disorders are problematic for persons with dementia and their family caregivers. This randomized controlled trial with crossover evaluated the effects of an innovative blue-white light therapy on 17 pairs of home-dwelling persons with dementia and their caregivers. Subjects with dementia received blue-white light and control ('red-yellow' light) for six weeks separated by a four-week washout. Neither actigraphic nor most self-reported sleep measures significantly differed for subjects with dementia. For caregivers, both sleep and role strain improved. No evidence of retinal light toxicity was observed. Six weeks of modest doses of blue-white light appear to improve sleep in caregivers but not in persons with dementia. Greater or prolonged circadian stimulation may be needed to determine if light is an effective treatment for persons with dementia.

The Amazonian herbal Marapuama attenuates cognitive impairment and neuroglial degeneration in a mouse Alzheimer model.

UNLABELLED: Alzheimer's disease (AD) is expected to affect more than 22 million people worldwide by 2025, causing devastating suffering and enormous costs to families and society. AD is a multifactorial disease, with a complex pathological mosaic. In rodents, AD-like dementia can be induced by cerebral microinjection of Aß peptide, leading to amyloid deposits, amnesia and various features of neurodegeneration. Marapuama (Ptychopetalum olacoides) is regarded as a "brain tonic" in the Amazon region and shows a nootropic profile in rodents. AIM OF THE STUDY: Because a specific extract (POEE) of Marapuama was shown to possess promnesic and anti-amnesic properties, the aim of this study was to verify if POEE is also effective against Aß(1-42)-induced cognitive deficit in mice. Additionally, Aß deposits (Congo red), GFAP immunoreactivity (immunohistochemistry), and neurodegenerative changes in the hippocampal pyramidal layer (Nissl) were examined as measures of Aß(1-42)-induced neurodegeneration. MATERIALS AND METHODS: CF1 mice were subjected to the experimental Alzheimer model with the Aß(1-42) i.c.v. administration. The effects of POEE 800 mg/kg were evaluated over 14 consecutive days of treatment. RESULTS: The data show that 14 days of oral treatment with POEE (800 mg/kg) was effective in preventing Aß-induced cognitive impairment, without altering the levels of BDNF and with parallel reductions in Aß deposits and astrogliosis. CA1 hippocampus loss induced by Aß(1-42) was also diminished in POEE-treated mice. CONCLUSION: This study offers evidence of functional and neuroprotective effects of two weeks treatment with a Ptychopetalum olacoides extract against Aß peptide-induced neurotoxicity in mice. Given the multifactorial nature of neurodegeneration, the considerable potential for an AChE inhibitor displaying associated neuroprotective properties such as here reported warrants further clinic evaluation.

Acetylcholinesterase inhibition in cognition-relevant brain areas of mice treated with a nootropic Amazonian herbal (Marapuama).

The goal of acetylcholinesterase inhibitors (AChEIs) used to treat Alzheimer's patients is an improvement in cholinergic transmission. While currently available AChEIs have limited success, a huge impediment to the development of newer ones is access to the relevant brain areas. Promnesic, anti-amnesic and AChEI properties were identified in a standardized ethanol extract from Ptychopetalum olacoides (POEE), a medicinal plant favored by the elderly in Amazon communities. The purpose of this study was to provide conclusive evidence that orally given POEE induces AChE inhibition in brain areas relevant to cognition. Histochemistry experiments confirmed that the anticholinesterase compound(s) present in POEE are orally bioavailable, inducing meaningful AChE inhibition in the hippocampus CA1 (∼33%) and CA3 (∼20%), and striatum (∼17%). Ellman's colorimetric analysis revealed that G1 and G4 AChE isoforms activities were markedly inhibited (66 and 72%, respectively) in hippocampus and frontal cortex (50 and 63%, respectively), while G4 appeared to be selectively inhibited (72%) in the striatum. Western blotting showed that POEE did not induce significant changes in the AChE immunocontent suggesting that its synthesis is not extensively modified. This study provides definitive proof of meaningful anticholinesterase activity compatible with the observed promnesic and anti-amnesic effects of POEE in mice, reaffirming the potential of this extract for treating neurodegenerative conditions where a hypofunctioning cholinergic neurotransmission is prominent. Adequate assessment of the safety and efficacy of this extract and/or its isolated active compound(s) are warranted.

Effects of inhaled Linalool in anxiety, social interaction and aggressive behavior in mice.

Aromatherapy uses essential oils (EOs) for several medical purposes, including relaxation. The association between the use of aromas and a decrease in anxiety could be a valuable instrument in managing anxiety in an ever increasing anxiogenic daily life style. Linalool is a monoterpene commonly found as the major volatile component of EOs in several aromatic plant species. Adding to previously reported sedative effects of inhaled linalool, the aim of this study was to investigate the effects of inhaled linalool on anxiety, aggressiveness and social interaction in mice. Additionally, we investigated the effects of inhaled linalool on the acquisition phase of a step-down memory task in mice. Inhaled linalool showed anxiolytic properties in the light/dark test, increased social interaction and decreased aggressive behavior; impaired memory was only seen the higher dose of linalool. These results strengthen the suggestion that inhaling linalool rich essential oils can be useful as a mean to attain relaxation and counteract anxiety.