Cannabidiol improves nonmotor symptoms, attenuates neuroinflammation and favors hippocampal newborn neuronal maturation in a rat model of Parkinsonism.

OBJECTIVE: To investigate the effects of cannabidiol (CBD) on emotional and cognitive symptoms in rats with intra-nigral 6-hydroxydopamine (6-OHDA) lesions. METHODS: Adult male Wistar rats received bilateral intranigral 6-OHDA infusions and were tested in a battery of behavioral paradigms to evaluate nonmotor symptoms. The brains were obtained to evaluate the effects of CBD on hippocampal neurogenesis. RESULTS: 6-hydroxydopamine-lesioned rats exhibited memory impairments and despair-like behavior in the novelty-suppressed feeding test and forced swim test, respectively. The animals also exhibited dopaminergic neuronal loss in the substantia nigra pars compacta (SNpc), striatum, and ventral tegmental area and a reduction of hippocampal neurogenesis. Cannabidiol decreased dopaminergic neuronal loss in the SNpc, reduced the mortality rate and decreased neuroinflammation in 6-OHDA-lesioned rats. In parallel, CBD prevented memory impairments and attenuated despair-like behavior that were induced by bilateral intranigral 6-OHDA lesions. Repeated treatment with CBD favored the neuronal maturation of newborn neurons in the hippocampus in Parkinsonian rats. CONCLUSION: The present findings suggest a potential beneficial effect of CBD on nonmotor symptoms induced by intra-nigral 6-OHDA infusion in rats.

The 5-HT1A receptor as a serotonergic target for neuroprotection in cerebral ischemia.

Cerebral ischemia due to stroke or cardiac arrest greatly affects daily functioning and the quality of life of patients and has a high socioeconomic impact due to the surge in their prevalence. Advances in the identification of an effective pharmacotherapy to promote neuroprotection and recovery after a cerebral ischemic insult are, however, limited. The serotonin 1A (5-HT1A) receptor has been implicated in the regulation of several brain functions, including mood, emotions, memory, and neuroplasticity, all of which are deleteriously affected by cerebral ischemia. This review focuses on the specific roles and mechanisms of 5-HT1A receptors in neuroprotection in experimental models of cerebral ischemia. We present experimental evidence that 5-HT1A receptor agonists can prevent neuronal damage and promote functional recovery induced by focal and transient global ischemia in rodents. However, indiscriminate activation of pre-and postsynaptic by non-biased 5-HT1A receptor agonists may be a limiting factor in the anti-ischemic clinical efficacy of these compounds since 5-HT1A receptors in different brain regions can mediate diverging or even contradictory responses. Current insights are presented into the 'biased' 5-HT1A post-synaptic heteroreceptor agonist NLX-101 (also known as F15599), a compound that preferentially and potently stimulates postsynaptic cortical pyramidal neurons without inhibiting firing of serotoninergic neurons, as a potential strategy providing neuroprotection in cerebral ischemic conditions.

Anxiolytic-like and proneurogenic effects of Trichilia catigua ethyl-acetate fraction in mice with cerebral ischemia

Abstract Trichilia catigua A. Juss., Meliaceae, known as "catuaba" in Brazil, has been popularly used as a tonic for fatigue, impotence and memory deficits. Previously, we have demonstrated that T. catigua ethyl-acetate fraction exerted antidepressive-like effects in mice. Affective-like symptoms are also well recognized outcome of cerebral ischemia in clinical and preclinical settings. Therefore, here we evaluated the effects of ethyl-acetate fraction on the emotional outcomes and its relation with hippocampal neurogenesis in ischemic mice. Male Swiss mice were subject to the bilateral common carotid occlusion during 20 min. The animals received ethyl-acetate fraction (400 mg/kg, orally) 30 min before and once per day during 7 days after reperfusion. Emotional outcomes were assessed using the open field test, elevated zero maze, and the tail suspension test. After the behavioral testing, the animals were sacrificed and their brains were processed to immunohistochemistry and Nissl staining. Ischemic mice exhibited anxiogenic-like behaviors in the elevated zero maze, hippocampal neurodegeneration and decreased hippocampal neurogenesis. The anxiogenic-like effect was counteracted by ethyl-acetate fraction administration. Furthermore, ethyl-acetate fraction restored the number of newborn neurons in the dentate gyrus of hippocampus of ischemic mice. In conclusion, T. catigua ethyl-acetate fraction promoted functional recovery and restored hippocampal neurogenesis in ischemic mice.

Avaliação da atividade ansiolítica e antidepressiva do extrato fluido e fração aquosa de folhas de Passiflora alata Curtis em camundongos / Evaluation of anxiolytic and antidepressant activities in mice with fluid extracts and aqueous fraction obtained from the leaves of Passiflora alata

O extrato fluido (EF), preparado segundo a Farmacopéia Brasileira, e sua fração aquosa (FA) obtidos de folhas de Passiflora alata foram administrados por via oral em camundongos. Seus efeitos comportamentais foram avaliados por modelos que detectam a atividade ansiolítica e antidepressiva de drogas, tais como: o labirinto em cruz elevado (LCE) e o teste da suspensão pela cauda (TSC). Efeitos sobre a atividade locomotora geral dos animais foram monitorados no campo aberto. Efeitos sedativos foram observados com EF (100 e 300 mg kg-1) e EA (100, 300 e 600 mg kg-1), caracterizados por uma diminuição do número de entradas nos braços fechados do LCE e uma diminuição no número de cruzamentos e levantamentos no campo aberto. No TSC, a administração de EF (100 mg kg-1) ou FA (100 e 300 mg kg-1) resultou em aumento do tempo de imobilidade. Esses resultados são relevantes, pois contribuem para validar o uso popular dessa planta.

The fluid extract (FE), prepared according to the Brazilian Pharmacopoea, obtained from the leaves of Passiflora alata and its aqueous fraction (AF), were administered by oral route to mice, and the behavioural effects were evaluated using animal models that detect anxiolytic and antidepressant activities, such as the elevated plus maze (EPM) and the tail suspension test (TST). Effects on general motor activity were monitored in the open . Sedative effects were observed with FE (100 and 300 mg kg-1) and AF (100, 300 and 600 mg kg-1) and were characterized by a decreased number of entries in the enclosed arms of the EPM and a decrease in the number of crossings and rearing in the open . In the TST, FE (100 mg kg-1) and AF (100 and 300 mg kg-1) induced an increase in the immobility time. These results are relevant because they contribute to validate the traditional use of this plant.