Neuroinflammation is an important process underlying a wide variety of neurodegenerative diseases. Carvacrol (CAR) is a phenolic monoterpene commonly used as a food additive due to its antibacterial properties, but it has also been shown to exhibit strong antioxidative, anti-inflammatory, and neuroprotective effects. Here, we sought to investigate the effects of CAR on inflammation in the hippocampus and prefrontal cortex, as well as the molecular mechanisms underlying these effects. In our study, lipopolysaccharide was injected into the lateral ventricle of rats to induce memory impairment and neuroinflammation. Daily administration of CAR (25, 50, and 100 mg/kg) for 21 days improved recognition, discrimination, and memory impairments relative to untreated controls. CAR administration significantly attenuated expression of several inflammatory factors in the brain, including interleukin-1β, tumor necrosis factor-α, and cyclooxygenase-2. In addition, CAR significantly increased expression of brain-derived neurotrophic factor (BDNF) mRNA, and decreased expression of Toll-like receptor 4 (TLR4) mRNA. Taken together, these results show that CAR can improve memory impairment caused by neuroinflammation. This cognitive enhancement is due to the anti-inflammatory effects of CAR medicated by its regulation of BDNF and TLR4. Thus, CAR has significant potential as an inhibitor of memory degeneration in neurodegenerative diseases.
Animals ; Brain ; Brain-Derived Neurotrophic Factor ; Cyclooxygenase 2 ; Cytokines ; Discrimination (Psychology) ; Food Additives ; Hippocampus ; Inflammation ; Lateral Ventricles ; Lipopolysaccharides ; Memory ; Necrosis ; Neurodegenerative Diseases ; Neuroprotective Agents ; Phenol ; Prefrontal Cortex ; Rats ; RNA, Messenger ; Toll-Like Receptor 4

OBJECTIVE: To examine the anti-obesity effects of ginsenosides in Korea Red Ginseng (KRG, Panax ginseng) in rats fed with a high-fat diet (HFD). METHODS: Twenty-five 4-week-old obesity rats after receiving an HFD for 5 weeks; subsequently, they were additionally treated with ginsenosides Rb1, Rd, Rg1, or Re (10 mg/kg, intraperitoneal injection) for a further 3 weeks (n=5 in each group). The control rats were fed a normal diet. The food consumption, body weight, locomotor activity, serum lipids, adipose tissues, nitric oxide (NO) expression, leptin, neuropeptide Y (NPY), cholecystokinin (CCK) in the brains were measured. RESULTS: In the HFD-fed rats, body weight, body fat mass, serum levels of leptin and NO were significantly higher than in the control rats (P<0.05 or P<0.01). However, the treatment of Rd, Re, and Rb1 markedly decreased body fat mass and body weight (P<0.05). The serum level of leptin and NO in ginsenoside-treated rats were markedly lower than the control group (P<0.01). The expression of NPY and CCK in the hypothalamic nuclei showed insignificant difference among groups. However, the expression of NPY immunoreactive neurons in the hypothalamus was significantly reduced in the Rb1-treated group (P<0.05). CONCLUSION PD-type ginsenoside Rb1 from the crude saponins of KRG may be a useful compound for the treatment of obesity and related disorders through the modulation of peripheral and central appetite-regulating signals.

Post-traumatic stress disorder (PTSD) is a trauma-induced psychiatric disorder characterized by impaired fear extermination, hyperarousal, and anxiety that may involve the release of monoamines in the fear circuit. The reported pharmacological properties of tetramethylpyrazine (TMP) include anti-cancer, anti-diabetic, anti-atherosclerotic, and neuropsychiatric activities. However, the anxiolytic-like effects of TMP and its mechanism of action in PTSD are unclear. This study measured several anxiety-related behavioral responses to examine the effects of TMP on symptoms of anxiety in rats after single prolonged stress (SPS) exposure by reversing the serotonin (5-HT) and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Rats were given TMP (10, 20, or 40 mg/kg, i.p.) for 14 days after SPS exposure. Administration of TMP significantly reduced grooming behavior, increased the time spent and number of visits to the open arm in the elevated plus maze test, and significantly increased the number of central zone crossings in the open field test. TMP administration significantly reduced the freezing response to contextual fear conditioning and significantly restored the neurochemical abnormalities and the SPS-induced decrease in 5-HT tissue levels in the prefrontal cortex and hippocampus. The increased 5-HT concentration during TMP treatment might be partially attribute to the tryptophan and 5-hydroxyindoleacetic acid mRNA level expression in the hippocampus of rats with PTSD. These findings support a role for reducing the altered serotonergic transmission in rats with PTSD. TMP simultaneously attenuated the HPA axis dysfunction. Therefore, TMP may be useful for developing an agent for treating psychiatric disorders, such those observed in patients with PTSD.
Animals ; Anxiety ; Arm ; Freezing ; Grooming ; Hippocampus ; Humans ; Models, Animal* ; Prefrontal Cortex ; Rats* ; RNA, Messenger ; Serotonin ; Stress Disorders, Post-Traumatic* ; Thymidine Monophosphate ; Tryptophan

Post-traumatic stress disorder (PTSD) is a trauma-induced psychiatric disorder characterized by impaired fear extermination, hyperarousal, anxiety, depression, and amnesic symptoms that may involve the release of monoamines in the fear circuit. The present study measured several anxiety-related behavioral responses to examine the effects of berberine (BER) on symptoms of anxiety in rats after single prolonged stress (SPS) exposure, and to determine if BER reversed the dopamine (DA) dysfunction. Rats received BER (10, 20, or 30 mg/kg, intraperitoneally, once daily) for 14 days after SPS exposure. BER administration significantly increased the time spent in the open arms and reduced grooming behavior during the elevated plus maze test, and increased the time spent in the central zone and the number of central zone crossings in the open field test. BER restored neurochemical abnormalities and the SPS-induced decrease in DA tissue levels in the hippocampus and striatum. The increased DA concentration during BER treatment may partly be attributed to mRNA expression of tyrosine hydroxylase and the DA transporter in the hippocampus, while BER exerted no significant effects on vesicular monoamine transporter mRNA expression in the hippocampus of rats with PTSD. These results suggest that BER had anxiolytic-like effects on behavioral and biochemical measures associated with anxiety. These findings support a role for reduced anxiety altered DAergic transmission and reduced anxiety in rats with PTSD. Thus, BER may be a useful agent to treat or alleviate psychiatric disorders like those observed in patients with PTSD.
Animals ; Anxiety* ; Arm ; Berberine* ; Depression ; Dopamine* ; Grooming ; Hippocampus ; Humans ; Rats* ; RNA, Messenger ; Stress Disorders, Post-Traumatic* ; Tyrosine 3-Monooxygenase ; Vesicular Monoamine Transport Proteins

OBJECTIVE: High frequency stimulation (HFS) of the subthalamic nucleus (STN) is recognized as an effective treatment of advanced Parkinson’s disease. However, the neurochemical basis of its effects remains unknown. The aim of this study is to investigate the effects of STN HFS in intact and 6-hydroxydopamine (6-OHDA)-lesioned hemiparkinsonian rat model on changes of principal neurotransmitters, glutamate, and gamma-aminobutyric acid (GABA) in the striatum. METHODS: The authors examined extracellular glutamate and GABA change in the striatum on sham group, 6-OHDA group, and 6-OHDA plus deep brain stimulation (DBS) group using microdialysis methods. RESULTS: High-pressure liquid chromatography was used to quantify glutamate and GABA. The results show that HFS-STN induces a significant increase of extracellular glutamate and GABA in the striatum of 6-OHDA plus DBS group compared with sham and 6-OHDA group. CONCLUSION: Therefore, the clinical results of STN-HFS are not restricted to the direct STN targets but involve widespread adaptive changes within the basal ganglia.
Animals ; Basal Ganglia ; Chromatography, Liquid ; Deep Brain Stimulation ; gamma-Aminobutyric Acid* ; Glutamic Acid* ; Microdialysis ; Models, Animal ; Neurotransmitter Agents ; Oxidopamine ; Parkinson Disease ; Rats* ; Subthalamic Nucleus

The present study investigated the sedative effects of Sophora flavescens (SF) and its bioactive compound, matrine through performing locomotor activity test and the electroencephalography (EEG) analysis in the rat. The underlying neural mechanism of their beneficial effects was determined by assessing c-Fos immunoreactivity and serotonin (5-HT) in the brain utilizing immunohistochemical method and enzyme-linked immunosorbent assay. The results showed that SF and matrine administration had an effect on normalization of caffeine-induced hyperactivity and promoting a shift toward non-rapid eye movement (NREM) sleep. c-Fos-immunoreactivity and 5-HT level in the ventrolateral preoptic nucleus (VLPO), a sleep promoting region, were increased in the both SF and matrine-injected groups. In conclusion, SF and its bioactive compound, matrine alleviated caffeine-induced hyperactivity and promoted NREM sleep by activating VLPO neurons and modulating serotonergic transmission. It is suggested that SF might be a useful natural alternatives for hypnotic medicine.
Animals ; Brain ; Electroencephalography ; Enzyme-Linked Immunosorbent Assay ; Eye Movements ; Hypnotics and Sedatives* ; Methods ; Motor Activity ; Neurons ; Preoptic Area ; Rats ; Serotonin ; Sophora*

The present study investigated the sedative effects of Sophora flavescens (SF) and its bioactive compound, matrine through performing locomotor activity test and the electroencephalography (EEG) analysis in the rat. The underlying neural mechanism of their beneficial effects was determined by assessing c-Fos immunoreactivity and serotonin (5-HT) in the brain utilizing immunohistochemical method and enzyme-linked immunosorbent assay. The results showed that SF and matrine administration had an effect on normalization of caffeine-induced hyperactivity and promoting a shift toward non-rapid eye movement (NREM) sleep. c-Fos-immunoreactivity and 5-HT level in the ventrolateral preoptic nucleus (VLPO), a sleep promoting region, were increased in the both SF and matrine-injected groups. In conclusion, SF and its bioactive compound, matrine alleviated caffeine-induced hyperactivity and promoted NREM sleep by activating VLPO neurons and modulating serotonergic transmission. It is suggested that SF might be a useful natural alternatives for hypnotic medicine.
Animals ; Brain ; Electroencephalography ; Enzyme-Linked Immunosorbent Assay ; Eye Movements ; Hypnotics and Sedatives* ; Methods ; Motor Activity ; Neurons ; Preoptic Area ; Rats ; Serotonin ; Sophora*

α-Synuclein (α-Syn) has a critical role in microglia-mediated neuroinflammation, which leads to the development of Parkinson's disease (PD). Recent studies have shown that bee venom (BV) has beneficial effects on PD symptoms in human patients or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxin-induced PD mice. This study investigated whether treatment with BV-derived phospholipase A2 (bvPLA2) would improve the motor dysfunction and pathological features of PD in human A53T α-Syn mutant transgenic (A53T Tg) mice. The motor dysfunction of A53T Tg mice was assessed using the pole test. The levels of α-Syn, microglia and the M1/M2 phenotype in the spinal cord were evaluated by immunofluorescence. bvPLA2 treatment significantly ameliorated motor dysfunction in A53T Tg mice. In addition, bvPLA2 significantly reduced the expression of α-Syn, the activation and numbers of microglia, and the ratio of M1/M2 in A53T Tg mice. These results suggest that bvPLA2 could be a promising treatment option for PD.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; alpha-Synuclein* ; Animals ; Bee Venoms* ; Bees* ; Fluorescent Antibody Technique ; Humans ; Mice ; Mice, Transgenic* ; Microglia* ; Parkinson Disease* ; Phenotype ; Phospholipases A2* ; Phospholipases* ; Spinal Cord

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

Pro-inflammatory cytokine and brain-derived neurotrophic factor (BDNF) are modulated in post-traumatic stress disorder (PTSD). This study investigated the effects of ibuprofen (IBU) on enhanced anxiety in a rat model of PTSD induced by a single prolonged stress (SPS) procedure. The effects of IBU on inflammation and BDNF modulation in the hippocampus and the mechanisms underlying for anxiolytic action of IBU were also investigated. Male Sprague-Dawley rats were given IBU (20 or 40 mg/kg, i.p., once daily) for 14 days. Daily IBU (40 mg/kg) administration signifi cantly increased the number and duration of open arm visits in the elevated plus maze (EPM) test, reduced the anxiety index in the EPM test, and increased the time spent in the center of an open fi eld after SPS. IBU administration signifi cantly decreased the expression of pro-inflammatory mediators, such as tumor necrosis factor-α, interleukin-1β, and BDNF, in the hippocampus, as assessed by reverse transcription-polymerase chain reaction analysis and immunohistochemistry. These fi ndings suggest that IBU exerts a therapeutic effect on PTSD that might be at least partially mediated by alleviation of anxiety symptoms due to its anti-inflammatory activity and BDNF expression in the rat brain.
Animals ; Anxiety ; Arm ; Brain ; Brain-Derived Neurotrophic Factor ; Hippocampus ; Humans ; Ibuprofen* ; Immunohistochemistry ; Inflammation ; Male ; Models, Animal* ; Necrosis ; Rats* ; Rats, Sprague-Dawley ; Stress Disorders, Post-Traumatic*