Memory formation in the hippocampus is formed and maintained by circadian clock genes during sleep. Sleep deprivation (SD) can lead to memory impairment and neuroinflammation, and there remains no effective pharmacological treatment for these effects. Myricetin (MYR) is a common natural flavonoid that has various pharmacological activities. In this study, we investigated the effects of MYR on memory impairment, neuroinflammation, and neurotrophic factors in sleepdeprived rats. We analyzed SD-induced cognitive and spatial memory, as well as pro-inflammatory cytokine levels during SD. SD model rats were intraperitoneally injected with 10 and 20 mg/kg/day MYR for 14 days. MYR administration significantly ameliorated SD-induced cognitive and spatial memory deficits; it also attenuated the SD-induced inflammatory response associated with nuclear factor kappa B activation in the hippocampus. In addition, MYR enhanced the mRNA expression of brainderived neurotropic factor (BDNF) in the hippocampus. Our results showed that MYR improved memory impairment by means of anti-inflammatory activity and appropriate regulation of BDNF expression. Our findings suggest that MYR is a potential functional ingredient that protects cognitive function from SD.

Phytoceramide (Pcer) is found mainly in plants and yeast. It can be neuroprotective and immunostimulatory on various cell types. In this study, the therapeutic effect of Pcer was explored using the carrageenan/kaolin (C/K)-induced arthritis rat model and fibroblast-like synoviocytes (FLS). Pcer treatment (1, 10, and 30 mg/kg/day) were given to the arthritic rats for 6 days after disease induction. Weight distribution ration (WDR), knee thickness, squeaking score, serum levels of proinflammatory mediators, and histological analysis were measured and performed to evaluate arthritic symptoms in the rat model. In interleukin (IL)‑1β‑stimulated FLS, proinflammatory mediators were measured after Pcer (1-30 µM) treatment. Arthritic symptoms in rats with Pcer treatment were significantly decreased at days 4 to 6 after C/K arthritis induction. Inflammation in the knee joints were also significantly decreased in rats with Pcer treatment. Furthermore, in IL-1β‑stimulated FLS, the expressions of proinflammatory mediators were also inhibited by Pcer. As shown by the results, Pcer has anti-arthritic effects in the C/K rat model and in synovial cells, suggesting that Pcer has the potential to be a useful agent in arthritis treatment.

Abnormal adaptation of the stress-response system following traumatic stress can lead to alterations in the hypothalamic-pituitary-adrenal (HPA) axis that may contribute to the development of post-traumatic stress disorder (PTSD). The present study used several behavioral tests to investigate the anxiolytic-like and antidepressant activity of L-tetrahydropalmatine (L-THP) in an experimental rat model of anxiety and depression induced by single prolonged stress (SPS), an animal model of PTSD. Male rats were treated intraperitoneally (i.p.) with vehicle or varied doses of THP 30 min prior to SPS for 8 consecutive days. Daily THP (50 mg/kg) administration significantly increased the number and duration of open arm visits in the elevated plus maze (EPM) test, reduced the anxiety index, increased the risk assessment, and increased the number of head dips over the borders of the open arms after SPS. THP was also associated with increased time spent at the center of the open field, reduced grooming behaviors in the EPM test, and reduced time spent immobile in the forced swimming test (FST). It also blocked the decrease in neuropeptide Y (NPY) and the increase in corticotrophin-releasing factor (CRF) expression in the hypothalamus. This is the first study to determine that THP exerts pronounced anxiolytic-like and antidepressant effects on the development of the behavioral and biochemical symptoms associated with PTSD, indicating its prophylactic potential. Thus, THP reversed several behavioral impairments triggered by the traumatic stress of SPS and is a potential non-invasive therapeutic intervention for PTSD.
Animals ; Anxiety* ; Arm ; Axis, Cervical Vertebra ; Depression ; Grooming ; Head ; Humans ; Hypothalamus ; Male ; Models, Animal ; Neuropeptide Y ; Physical Exertion ; Rats* ; Risk Assessment ; Stress Disorders, Post-Traumatic

We examined whether wogonin (WO) improved hippocampal neuronal activity, behavioral alterations and cognitive impairment, in rats induced by administration of trimethyltin (TMT), an organotin compound that is neurotoxic to these animals. The ability of WO to improve cognitive efficacy in the TMT-induced neurodegenerative rats was investigated using a passive avoidance test, and the Morris water maze test, and using immunohistochemistry to detect components of the acetylcholinergic system, brain-derived neurotrophic factor (BDNF), and cAMP-response element-binding protein (CREB) expression. Rats injected with TMT showed impairments in learning and memory and daily administration of WO improved memory function, and reduced aggressive behavior. Administration of WO significantly alleviated the TMT-induced loss of cholinergic immunoreactivity and restored the hippocampal expression levels of BDNF and CREB proteins and their encoding mRNAs to normal levels. These findings suggest that WO might be useful as a new therapy for treatment of various neurodegenerative diseases.
Animals ; Brain-Derived Neurotrophic Factor ; Cholinergic Neurons ; Cognition Disorders ; Cyclic AMP Response Element-Binding Protein ; Immunohistochemistry ; Learning ; Memory ; Neurodegenerative Diseases ; Neurons* ; Rats* ; RNA, Messenger ; Water

Previous studies have demonstrated that repeated administration of the exogenous stress hormone corticosterone (CORT) induces dysregulation in the hypothalamic-pituitary-adrenal (HPA) axis and results in depression and anxiety. The current study sought to verify the impact of catechin (CTN) administration on chronic CORT-induced behavioral alterations using the forced swimming test (FST) and the elevated plus maze (EPM) test. Additionally, the effects of CTN on central noradrenergic systems were examined by observing changes in neuronal tyrosine hydroxylase (TH) immunoreactivity in rat brains. Male rats received 10, 20, or 40 mg/kg CTN (i.p.) 1 h prior to a daily injection of CORT for 21 consecutive days. The activation of the HPA axis in response to the repeated CORT injections was confirmed by measuring serum levels of CORT and the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. Daily CTN administration significantly decreased immobility in the FST, increased open-arm exploration in the EPM test, and significantly blocked increases of TH expression in the locus coeruleus (LC). It also significantly enhanced the total number of line crossing in the open-field test (OFT), while individual differences in locomotor activities between experimental groups were not observed in the OFT. Taken together, these findings indicate that the administration of CTN prior to high-dose exogenous CORT significantly improves helpless behaviors, possibly by modulating the central noradrenergic system in rats. Therefore, CTN may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression and anxiety disorders.
Animals ; Anxiety ; Anxiety Disorders ; Axis, Cervical Vertebra ; Brain ; Catechin* ; Corticosterone* ; Depression* ; Humans ; Hypothalamus ; Individuality ; Locus Coeruleus ; Male ; Models, Animal* ; Motor Activity ; Neurons ; Physical Exertion ; Rats* ; Tyrosine 3-Monooxygenase

In the article, incorrect images were placed in Fig. 8.

The purpose of this study was to examine whether ginsenoside Rg3 (GRg3) could improve learning and memory impairments and inflammatory reactions induced by injecting lipopolysaccharide (LPS) into the brains of rats. The effects of GRg3 on proinflammatory mediators in the hippocampus and the underlying mechanisms of these effects were also investigated. Injection of LPS into the lateral ventricle caused chronic inflammation and produced deficits in learning in a memory-impairment animal model. Daily administration of GRg3 (10, 20, and 50 mg/kg, i.p.) for 21 consecutive days markedly improved the LPS-induced learning and memory disabilities demonstrated on the step-through passive avoidance test and Morris water maze test. GRg3 administration significantly decreased expression of pro-inflammatory mediators such as tumor necrosis factor-alpha, interleukin-1beta, and cyclooxygenase-2 in the hippocampus, as assessed by reverse transcription-polymerase chain reaction analysis and immunohistochemistry. Together, these findings suggest that GRg3 significantly attenuated LPS-induced cognitive impairment by inhibiting the expression of pro-inflammatory mediators in the rat brain. These results suggest that GRg3 may be effective for preventing or slowing the development of neurological disorders, including Alzheimer's disease, by improving cognitive and memory functions due to its anti-inflammatory activity in the brain.
Alzheimer Disease ; Animals ; Brain ; Cyclooxygenase 2 ; Hippocampus ; Immunohistochemistry ; Inflammation ; Interleukin-1beta ; Lateral Ventricles ; Learning* ; Memory* ; Models, Animal ; Nervous System Diseases ; Rats* ; Tumor Necrosis Factor-alpha ; Water

beta-asarone (BAS) is an active component of Acori graminei rhizoma, a traditional medicine used clinically in treating dementia and chronic stress in Korea. However, the cognitive effects of BAS and its mechanism of action have remained elusive. The purpose of this study was to examine whether BAS improved spatial cognitive impairment induced in rats following chronic corticosterone (CORT) administration. CORT administration (40 mg/kg, i.p., 21 days) resulted in cognitive impairment in the avoidance conditioning test (AAT) and the Morris water maze (MWM) test that was reversed by BAS (200 mg/kg, i.p). Additionally, as assessed by immunohistochemistry and RT-PCR analysis, the administration of BAS significantly alleviated memory-associated decreases in the expression levels of brain-derived neurotrophic factor (BDNF) and cAMP-response element-binding protein (CREB) proteins and mRNAs in the hippocampus. Also, BAS administration significantly restored the expression of Bax and Bcl-2 mRNAs in the hippocampus. Thus, BAS may be an effective therapeutic for learning and memory disturbances, and its neuroprotective effect was mediated, in part, by normalizing the CORT response, resulting in regulation of BDNF and CREB functions and anti-apoptosis in rats.
Animals ; Apoptosis* ; Brain-Derived Neurotrophic Factor ; Corticosterone* ; Dementia ; Hippocampus* ; Immunohistochemistry ; Korea ; Learning ; Medicine, Traditional ; Memory ; Memory, Short-Term* ; Neuroprotective Agents ; Rats* ; RNA, Messenger ; Water

Baicalein (BA), a plant-derived active flavonoid present in the root of Scutellaria baicalensis, has been widely used for the treatment of stress-related neuropsychiatric disorders including depression. Previous studies have demonstrated that repeated restraint stress disrupts the activity of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in depression. The behavioral and neurochemical basis of the BA effect on depression remain unclear. The present study used the forced swimming test (FST) and changes in brain neurotransmitter levels to confirm the impact of BA on repeated restraint stress-induced behavioral and neurochemical changes in rats. Male rats received 10, 20, or 40 mg/kg BA (i.p.) 30 min prior to daily exposure to repeated restraint stress (2 h/day) for 14 days. Activation of the HPA axis in response to repeated restraint stress was confirmed by measuring serum corticosterone levels and the expression of corticotrophin-releasing factor in the hypothalamus. Daily BA administration significantly decreased the duration of immobility in the FST, increased sucrose consumption, and restored the stress-related decreases in dopamine concentrations in the hippocampus to near normal levels. BA significantly inhibited the stress-induced decrease in neuronal tyrosine hydroxylase immunoreactivity in the ventral tegmental area and the expression of brain-derived neurotrophic factor (BDNF) mRNA in the hippocampus. Taken together, these findings indicate that administration of BA prior to the repeated restraint stress significantly improves helpless behaviors and depressive symptoms, possibly by preventing the decrease in dopamine and BDNF expression. Thus, BA may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression.
Animals ; Brain ; Brain-Derived Neurotrophic Factor ; Corticosterone ; Depression ; Dopamine ; Flavanones* ; Hippocampus ; Hypothalamus ; Male ; Neurons ; Neurotransmitter Agents ; Rats* ; RNA, Messenger ; Physical Exertion ; Scutellaria baicalensis ; Sucrose ; Tyrosine 3-Monooxygenase ; Ventral Tegmental Area

We examine whether Phellodendron amurense (PA) and its major alkaloid compound, berberine (BER), improved memory defects caused by administering scopolamine in rats. Effects of PA and BER on the acetylcholinergic system and pro-inflammatory cytokines in the hippocampus were also investigated. Male rats were administered daily doses for 14 days of PA (100 and 200 mg/kg, i.p.) and BER (20 mg/kg, i.p.) 30 min before scopolamine injection (2 mg/kg, i.p.). Daily administration of PA and BER improved memory impairment as measured by the passive avoidance test and reduced the escape latency for finding the platform in the Morris water maze test. Administration of PA and BER significantly alleviated memory-associated decreases in cholinergic immunoreactivity and restored brain-derived neurotrophic factor and cAMP-response element-binding protein mRNA expression in the hippocampus. PA and BER also decreased significantly the expression of proinflammatory cytokines such as interleukin-1beta, tumor necrosis factor-alpha and cyclooxygenase-2 mRNA in the hippocampus. These results demonstrated that PA and BER had significant neuroprotective effects against neuronal impairment and memory dysfunction caused by scopolamine in rats. These results suggest that PA and BER may be useful as therapeutic agents for improving cognitive functioning by stimulating cholinergic enzyme activity and alleviating inflammatory responses.
Animals ; Berberine ; Brain-Derived Neurotrophic Factor ; Cholinergic Neurons ; Cyclooxygenase 2 ; Cytokines ; Hippocampus ; Humans ; Interleukin-1beta ; Male ; Memory ; Neurons ; Neuroprotective Agents ; Phellodendron ; Rats ; RNA, Messenger ; Scopolamine Hydrobromide ; Tumor Necrosis Factor-alpha ; United Nations