Acute EPA-induced learning and memory impairment in mice is prevented by DHA.

Eicosapentaenoic acid (EPA), an omega-3 fatty acid, has been widely used to prevent cardiovascular disease (CVD) and treat brain diseases alone or in combination with docosahexaenoic acid (DHA). However, the impact of EPA and DHA supplementation on normal cognitive function and the molecular targets of EPA and DHA are still unknown. We show that acute administration of EPA impairs learning and memory and hippocampal LTP in adult and prepubescent mice. Similar deficits are duplicated by endogenously elevating EPA in the hippocampus in the transgenic fat-1 mouse. Furthermore, the damaging effects of EPA are mediated through enhancing GABAergic transmission via the 5-HT6R. Interestingly, DHA can prevent EPA-induced impairments at a ratio of EPA to DHA similar to that in marine fish oil via the 5-HT2CR. We conclude that EPA exhibits an unexpected detrimental impact on cognitive functions, suggesting that caution must be exercised in omega-3 fatty acid supplementation and the combination of EPA and DHA at a natural ratio is critical for learning and memory and synaptic plasticity.

Protective effect of gui zhi (Ramulus Cinnamomi) on abnormal levels of four amino acid neurotransmitters by chronically ma huang (Herb Ephedra) intoxicated prefrontal cortex in rats treated with a ma huang-gui zhi herb pair.

ETHNOPHARMACOLOGICAL RELEVANCE: The Herb Ephedra (Ma Huang in Chinese)-Ramulus Cinnamomi (Gui Zhi in Chinese) herb pair is a classic traditional Chinese herb pair used to treat asthma, nose and lung congestion, and fever with anhidrosis. In previous study, we found that chronic administration of ma huang induced obvious neurodegeneration in rat brains, with the prefrontal cortex showing the greatest effect. Gui zhi decreased hyperactivity produced by repeated ma huang administration, and attenuated oxidative stress in rat prefrontal cortex induced by ma huang. AIM OF THE STUDY: The study was aimed to investigate the protective effect of gui zhi on ma huang-induced abnormal levels of four amino acid neurotransmitters in rat prefrontal cortex. MATERIALS AND METHODS: All ma huang and ma huang-gui zhi herb pair extracts were prepared using methods of traditional Chinese medicine and were normalized based on the ephedrine content. Two-month-old male Sprague-Dawley rats (6 rats/group) were administered ma huang or ma huang-gui zhi herb pair extracts for 1, 3, 5 or 7 days (ephedrine = 48 mg/kg). The contents of ephedrine, glutamate (Glu), aspartic acid (Asp), glycine (Gly), and gamma-aminobutyric acid (GABA) in the prefrontal cortex were determined using ultra-high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) at 0.5, 1.0, 5.0 h after administration. RESULTS: Ma huang significantly enhanced the levels of GABA, Gly, Glu and Asp in the prefrontal cortex, while gui zhi partially abolished the effects. CONCLUSIONS: Ma huang-induced neurotoxicity may be associated with its effects on amino acid neurotransmitters. Gui zhi is a promising neuroprotective agent against for ma huang-induced neurotoxicity. The information presented in this study will help supplement the available data for future ma huang-gui zhi herb pair compatibility studies.

Involvement of norepinephrine and serotonin system in antidepressant-like effects of hederagenin in the rat model of unpredictable chronic mild stress-induced depression.

CONTEXT: Previous studies from our laboratory indicated that both acute and subchronic administration of Fructus Akebiae (FAE) [the fruit of Akebiae quinata (Thunb.) Decne, (Lardizabalaceae)] produce antidepressant-like effects in animal depressive behavior tests. FAE contains approximately 70% of hederagenin (HG) as its main chemical component. OBJECTIVE: This study compared the antidepressant ability of FAE with that of HG in mice and further investigated the antidepressant-like effects and potential mechanisms of HG in rats subjected to unpredictable chronic mild stress (UCMS). MATERIALS AND METHODS: Mice received FAE (50 mg/kg) and HG (20 mg/kg) once a day via intragastric administration (i.g.) for 3 weeks. The anxiolytic and antidepressant activities of FAE and HG were compared using elevated plus maze (EPM) and behavioral despair tests including tail suspension test (TST) and forced swimming test (FST), respectively. Antidepressant effects of HG (5 mg/kg) were assessed using the UCMS depressive rat model. Moreover, the levels of monoamine neurotransmitters and relevant gene expression in UCMS rats' hippocampi were determined through high-performance liquid chromatography with electrochemical detection and real-time polymerase chain reaction techniques. RESULTS: The results of our preliminary screening test suggest that HG at 20 mg/kg, while not FAE at 50 mg/kg, significantly decreased the immobility in both TST and FST compared with the vehicle group when administered chronically; however, there were no significant differences observed between the HG and the FAE group. Chronic administration of HG failed to significantly reverse the altered crossing and rearing behavioral performance, time spent in the open arm and closed entries in the EPM, even if they showed an increased tendency, but HG significantly increased the percent of sucrose preference in the sucrose preference test (SPT) and decreased the immobility time in the FST. HG showed that significant increases of norepinephrine and serotonin levels and exhibited a tendency to increase the expression of 5-hydroxytryptamine (serotonin) 1A receptor mRNA, and to significantly decrease the expression of the mRNA for the serotonin transporter (5-HTT). However, there were no significant differences in the expression of the brain-derived neurotrophic factor. CONCLUSION: These findings confirm the antidepressant-like effects of HG in a behavioral despair test and UCMS rat model, which may be associated with monoamine neurotransmitters and 5-HTT mRNA expression.

Repeated administration of AC-5216, a ligand for the 18 kDa translocator protein, improves behavioral deficits in a mouse model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a severely disabling anxiety disorder that may occur following exposure to a serious traumatic event. It is a psychiatric condition that can afflict anyone who has experienced a life-threatening or violent event. Previous studies have shown that changes in 18 kDa translocator protein (TSPO) expression (or function), a promising target for treating neurological disorders without benzodiazepine-like side effects, may correlate with PTSD. However, few studies have investigated the anti-PTSD effects of TSPO ligands. AC-5216, a ligand for TSPO, induces anxiolytic- and anti-depressant-like effects in animal models. The present study aimed to determine whether AC-5216 ameliorates PTSD behavior in mice. Following the training session consisting of exposure to inescapable electric foot shocks, animals were administered AC-5216 daily during the behavioral assessments, i.e., situational reminders (SRs), the open field (OF) test, the elevated plus-maze (EPM) test, and the staircase test (ST). The results indicated that exposure to foot shocks induced long-term behavioral deficiencies in the mice, including freezing and anxiety-like behavior, which were significantly ameliorated by repeated treatment with AC-5216 but without any effect on spontaneous locomotor activity or body weight. In summary, this study demonstrated the anti-PTSD effects of AC-5216 treatment, suggesting that TSPO may represent a therapeutic target for anti-PTSD drug discovery and that TSPO ligands may be a promising new class of drugs for the future treatment of PTSD.

The extracts of Fructus Akebiae, a preparation containing 90% of the active ingredient hederagenin: serotonin, norepinephrine and dopamine reuptake inhibitor.

Fructus Akebiae is a traditional Chinese herbal extract that has been used for the treatment of depressive disorders in China. Previous studies demonstrated that Fructus Akebiae extracts (FAE) displayed a potent antidepressant-like activity in animal behavior tests and found that the specific active ingredient from the extracts of Fructus Akebiae is hederagenin. However, the underlying mechanism is unknown. Here we provide evidences that FAE enhances the signaling of central monoamines via inhibition of the reuptake of the extracellular monoamines including serotonin (5-HT), norepinephrine (NE) and dopamine (DA). In rat brain membrane preparations and HEK293 cells transfected with human serotonin transporter (SERT), NE transporter (NET) and DA transporter (DAT), we found that FAE displayed marked affinity to rat and cloned human monoamine transporters in ex vivo and in vitro experiments, using competitive radio ligand binding assay. In uptake assays using rat synaptosomes and transfected cells, FAE was found to significantly inhibit all three monoamine transporters in a dose- and time-dependent manner, with a comparable or better potency to their corresponding specific inhibitors. In contrast, FAE (10 µM), showed no significant affinity to a variety array of receptors tested from CNS. In support of our uptake data, in vivo microdialysis studies showed that administration of FAE (12.6, 25, 50 mg/kg) significantly increased extracellular concentrations of 5-HT, NE and DA in frontal cortex of freely moving rats. Taken together, our current study showed for the first time that FAE is a novel triple inhibitor of monoamine transporters, which may be one the mechanisms of its antidepressant activity.

[Effect of Cordyceps sinensis sporocarp on learning-memory in mice].

OBJECTIVE: To study the effect of extracts of Cordyceps sinensis sporocarp on learning-memory in scopolamine treated mice and the possible mechanism. METHODS: ICR mice were randomly divided into five groups: sham control, model, piracetam and CSE 0.5, 1 g/kg. Lotomotor activity was assessed. Morris water maze was used to evaluate the memory ability of mice 30 min later after ip scopolamine 1.0 mg/kg BW. Then acitivity of AchE was measured after behavioral test. RESULTS: CSE had no influence on lotomotor activity. However, CSE 0.5, 1 g/kg both shortened escape latency and increased times of come-crossing platform in Morris water maze, meanwhile activity of AchE in the brain was decreased by CSE. CONCLUSION: CSE can significantly improve the learning and memory impairment in mice induced by scopolamine, which may be correlated with the inhibition of activity of AchE.

Antidepressant effect of the extracts from Fructus Akebiae.

Fructus Akebiae is a common ingredient in many traditional Chinese medicine complex prescriptions for the treatment of mental disorders. Previous studies indicate that the main chemical compositions of Fructus Akebiae are triterpenoid saponins with hederagenin as their sapogenin. In the present study, we enriched hederagenin from the extracts of Fructus Akebiae with a purity of approximately 70%. Using behavioral tests sensitive to antidepressant drugs, we demonstrated that acute and sub-chronic administration of the extracts of Fructus Akebiae produced antidepressant-like effects, as evidenced by decreases in the duration of immobility in forced swim and tail suspension tests in mice and reversal of chronic unpredicted mild stress-induced inhibition of sucrose consumption in rats. In addition, the extracts decreased the levels of plasma adrenocorticotrophic hormone and serum corticosterone in rats exposed to chronic unpredicted mild stress. Both behavioral and biochemical effects of the extracts were mimicked by the proven antidepressant escitalopram. These results suggest that the extracts of Fructus Akebiae exert antidepressant activity. Administration of the extracts may be beneficial for patients with depressive disorders.

[Effects of Ganoderma lucidum spores on HepG2 cells proliferation and growth cycle].

OBJECTIVE: To observe the effects of Ganoderma lucidum Spores (GLS) on proliferation and growth cycle in the human hepatoma cell line (HepG2 cells), and study its possible mechanism of activities. METHODS: The growth inhibition of GLS on HepG2 cells was detected by MTT assay. The DNA contents and the distribution of cell cycle were analyzed by flow cytometry. RESULTS: The results of MTT assays showed that GLS could inhibit the HepG2 cells growth at a dose and time-dependent manner directly; the inhibition rate of GLS (2500 microg/ml) on HepG2 cells after 72 h was a maximum up 51.4%. The results of flow cytometry experiments showed that GLS (3 mg/ml) could reduce the G2 phase of HepG2 cells and a clear apoptosis peak would be observed when GLS was 6 mg/ml. CONCLUSION: GLS has a direct inhibitory effect on tumor cell proliferation and its growth cycle, it can reduce the G2 phase; and high doses of GLS can also make tumor cells apoptosised.

Effects of Yizhi Capsule on learning and memory disorder and beta-amyloid peptide induced neurotoxicity in rats.

OBJECTIVE: To explore the effects of Yizhi Capsule (YZC) on learning and memory disorder and beta-amyloid peptide induced neurotoxicity in rats. METHODS: Various doses of YZC were administered to Sprague-Dawley (SD) rats for 8 consecutive days, twice a day. On the 8th day of the experiment, scopolamine hydrobromide was intraperitoneally injected to every rat and Morris water maze test and shuttle dark avoidance test were carried out respectively to explore the changes of learning and memory capacities in the rats. Besides, after the cerebral cortical neurons of newborn SD rats aged within 3 days were cultured in vitro for 7 days, drug serum containing YZC was added to the cultured neurons before or after beta amyloid peptide(25 - 35) (Abeta(25 - 35)) intoxication to observe the protective effect of YZC on neurotoxicity by MTT assay and to determine the LDH content in the supernatant. RESULTS: Compared with those untreated with YZC, the rats having received YZC treatment got superiority in shorter time of platform seeking in Morris water maze test, as well as elongated latent period and less times of error in shuttle dark avoidance test. On the cultured neurons, YZC drug serum could effectively increase the survival rate of Abeta(25 - 35) intoxicated neurons and reduce the LDH contents in cultured supernatant. CONCLUSION: YZC has an action of improving learning and memory disorder, and good protective effect on Abeta(25 - 35) induced neurotoxicity in SD rats.

[Determination of organochlorine pesticide residue in nine Chinese herbs by gas chromatography].

OBJECTIVE: To determine organochlorine pesticide residue in 9 Chinese herbs. METHODS: The organochlorine pesticides were extracted from the herbs with mixed solvents of n-hexane and acetone by a solid-phase extraction cartridge Florisil. Capillary gas chromatography was used to separate the samples. RESULTS: Good linearities were obtained for 11 organochlorine pesticides. The average recoveries at two concentration levels ranged from 79.9% to 89.0%,and from 86.3% to 104.8%, with relative standard deviations of 1.8% to 7.1%, respectively and detection limit of 2 g/kg. The residues of the organic pesticides exceeded national standard in Pogostemon cablin and Panax notoginseng. CONCLUSION: Capillary gas chromatography combined with electron capture detection provides a practical means for detecting organic pesticide residue in Chinese herbal medicines, and the limits of pesticide residues should be formulated in Chinese pharmacopoeia.

[General pharmacology of Danhong injection].

OBJECTIVE: To investigate the effect of Danhong injection on the cardiovascular, the respiratory, and the nervous systems in animals. METHODS: Using the pressure transducer, tension transducer and subcutaneous electrodes connected to a multifunctional signal processor, the femoral artery pressure, respiratory curve and electrocardiogram were recorded, respectively, in dogs before and after administration of Danhong injection. The effect of the injection on spontaneous activities was observed in mice using a multifunctional mouse activity recorder. The effects were also observed on coordinated movements by recording tilt-board falling times of the mice and on hypnosis induced by subthreshold dose of pentobarbital sodium by observing the disappearance of righting reflex. RESULTS: Danhong injection caused slight decrease in systolic blood pressure without obviously affecting the heart rate, diastolic blood pressure and respiratory system of anesthetized dogs 30 min after intravenous Danhong injection at the dose of 2.4 g/kg, but at the doses of 1.2 and 0.6 g/kg.b.w, the injection did not produce any significant impact. The coordinated movement and spontaneous activity and pentobarbital sodium-induced hypnosis in mice were not obviously affected by the 3 doses of Danhong injection. CONCLUSION: Danhong injection does not affect the respiratory functions of the dogs and nervous system of mouse with the exception of the systolic pressure at the 3 doses.

Effects of timosaponins on learning and memory abilities of rats with dementia induced by lateral cerebral ventricular injection of amyloid beta- peptide.

OBJECTIVE: To investigate the effects of timosaponins, one group of the two major components of Anemarrhean asphodeloides Bge, on the learning and memory capacities of rats with dementia induced by amyloid beta-peptide (25-35) [Abeta (25-35)]. METHODS: Sixty SD rats were randomized into 6 groups (n=10) and except for those in the control group, all other rats were subjected to lateral cerebral ventriclar injection of aggregated Abeta (25-35) to prepare rat models of dementia. Twenty- four hours after the injection, the rats received intragastric administration of timosaponins at 3 different doses (treatment group) or Ginkgo biloba extract EGB761 on a daily basis for 14 consecutive days. From postoperative days 8 to 14 after Abeta (25-35) injection, Morris water maze test was performed to evaluate the effects of Abeta (25-35) and the therapeutic agents timosaponins on the learning and memory capacity of the rats. On day 14, the level of malonaldehyde (MDA), superoxide dismutase (SOD) activity and total antioxidation capacity in the brain tissue of the rats were measured. RESULTS: Abeta (25-35) induced significant learning and memory impairment in the rats, which had lowered SOD activity and total antioxidation capacity (P<0.01) with elevated MDA level (P<0.05). Compared with the rats in dementia model group, those receiving timosaponin treatment at different doses all manifested alleviation of learning and memory impairment (P<0.05), with enhanced SOD activity (P<0.05) and total antioxidation capacity (P<0.01) and reduced MDA level (P<0.05) in the brain tissue. CONCLUSION: Timosaponins can remarkably enhance the learning and memory capacities in rats with Abeta (25-35)-induced dementia, presumably in relation to their actions to promote the scavenging of the free radicals.

[Effects of ginkgolide on cerebral blood flow in dogs].

OBJECTIVE: To observe the effects of ginkgolide (GL) on the cerebral blood flow in dogs. METHODS: Dogs anesthetized with sodium pentobarbital were randomly divided into 5 groups, with 4 dogs in each group. Ginkgolide of 4.86, 14.6 and 43.7 mg/kg and Xingling Granule of 0.22 g/kg were administered by gavage to the dogs in each of 4 groups. The dogs in the other group were administered with edible oil (1 ml/kg) as control group. The cerebral blood flow, systolic blood pressure, diastolic blood pressure, mean arterial blood pressure and electro-cardiogram of the dogs were measured at different times after the administration. RESULTS: Ginkgolide of 4.86, 14.6 and 43.7 mg/kg had no obvious effects on the blood pressure and the heart rate. Ginkgolide of 14.6 and 43.7 mg/kg increased the cerebral blood flow 90 minutes after administration, and ginkgolide of 43.7 mg/kg obviously decreased the cerebral vascular resistance 150 minutes after administration. CONCLUSION: Ginkgolide can increase the cerebral blood flow and decrease the cerebral vascular resistance, and it has no obvious effects on blood pressure and heart rate in dogs.

[Fingerprinting of Panax notoginseng by high-performance liquid chromatography].

Fingerprinting of Panax notoginseng was performed by high-performance liquid chromatography using Agilent Hypersil C18 (250.0 mm x 4.0 mm, 5 microm) column with the mobile phase of acetonitrile and water and gradient elution. The detection wavelength was set at 203 nm. The method is simple and reliable to identify and evaluate the quality of Panax notoginseng.

[Effects of Yizhi capsule, a preparation of traditional Chinese medicines, on delayed neuronal death in hippocampal CA1 region and memory function of rats after ischemia-reperfusion injury].

OBJECTIVE: To observe the effects of Yizhi capsule, a preparation of traditional Chinese drugs on delayed neuronal death in the hippocampal CA1 region and memory function of rats after ischemia-reperfusion injury. METHODS: Rat models of acute reperfusion injury after global cerebral ischemia were induced by vertebral and carotid arteries occlusion, and 1, 2, 4, 8 and 40 d after model establishment, the neurons in the rat hippocampal CA1 region were obtained and immunohistochemically stained for counting. Morris water maze test was performed to observe the learning and memory capacities of the rats 40 d after the injury. RESULTS: The number of normal neurons was significantly higher in the rats treated with Yizhi capsule (100 mg/kg.b.w.) than in those without the treatment, and the former group of rats used significantly shorter time in finding the platform under the water surface in Morris water maze test. CONCLUSION: Yizhi capsule may protect the neurons in the hippocampal CA1 region and improve on the learning and memory dysfunction after global ischemia/reperfusion injury in rats.