Protective effects of methanol extract of Acori graminei rhizoma and Uncariae Ramulus et Uncus on ischemia-induced neuronal death and cognitive impairments in the rat

Advanced researches of traditional uses, phytochemistry, pharmacology, and toxicology of medical Uncariae Ramulus Cum Uncis

ETHNOPHARMACOLOGICAL RELEVANCE

Medical Uncariae Ramulus Cum Uncis consists of Uncaria rhynchophylla (Miq.) Miq. ex Havil, Uncaria macrophylla Wall, Uncaria sinensis (Oliv.) Havil, Uncaria hirsuta Havil, and Uncaria sessilifructus Roxb, which belongs to the species widely used in the genus Uncaria. These species resource widely distributed in China and abroad, and the hook-bearing stem is the primary constituent enrichment site. There are many different forms and architectures of chemicals, depending on the extraction site. Traditional remedies employing URCU had been used widely in antiquity and were first compiled in renowned ancient masterpiece 'Mingyi Bielu ()' written by Hongjing Tao. In modern pharmacological studies, both the total extracts and the phytoconstituents isolated from URCU have been shown to have neuroprotective, antioxidant, anti-inflammatory, anticancer, antibacterial, and autophagy-enhancer properties.

AIM OF THE STUDY

This review concentrates on the traditional uses, phytochemistry, pharmacology, toxicology, and nanomaterials studies of URCU, with a perspective to assist with further research and advance.

MATERIAL AND METHODS

The Chinese and English literature studies of this review are based on these database searches including Science Direct, CNKI, Wiley online library, Spring Link, Web of Science, PubMed, Medalink, Google scholar, Elsevier, ACS Publications, iPlant, Missouri Botanical Garden, Plant of the World Online. The pertinent data on URCU was gathered.

RESULTS

Based on the examination of the genus Uncaria, 107 newly marked chemical compositions have been identified from URCU from 2015 to present, including alkaloids, terpenoids, flavonoids, steroids, and others. Pharmacological studies have demonstrated that URCU has a variety of benefits in diseases such as neurodegenerative diseases, cancer, cardiovascular diseases, diabetes, and migraine, due to its neuroprotective, anti-inflammatory, antioxidant, anti-tumor, anti-bacterial and anti-viral properties. According to metabolic and toxicological studies, the dosage, frequency, and interactions of the drugs that occur in vivo are of great significance for determining whether the organic bodies can perform efficacy or produce toxicity. The research on URCU-mediated nanomaterials is expanding and increasing in order to address the inadequacies of conventional Chinese medicine. The alkaloids in URCU have the capability to self-assemble with other classes of components in addition to being biologically active.

CONCLUSION

URCU plants are widely distributed, abundant in chemical constituents, and widely used in both traditional and modern medicine for a variety of pharmacological effects. The utilization of herbal medicines can be raised by assessing the pharmacological distinctions among several species within the same genus and may accelerate the modernization of traditional Chinese medicine. Controlling the concentration of drug administration, monitoring metabolic markers, and inventing novel nanotechnologies are effective strategies for synergistic influence and detoxification to alleviate the main obstacles that toxicity, low bioavailability, and poor permeability. This review can assist further research and advances.

Myricetin prevents sleep deprivation-induced cognitive impairment and neuroinflammation in rat brain via regulation of brain-derived neurotropic factor

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 sleep-deprived 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 brain-derived 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.

Ginsenoside Rg3 modulates spatial memory and fear memory extinction by the HPA axis and BDNF-TrkB pathway in a rat post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a serious mental disorder that can develop after exposure to extreme stress. Korean red ginseng, whose major active component is ginsenoside Rg3 (Rg3), is a widely used traditional antioxidant that has anti-inflammatory, anti-apoptotic and anxiolytics effects. This study investigated whether the administration of Rg3 ameliorated the memory deficit induced by a single prolonged stress (SPS) in rats. Male rats were dosed with Rg3 (25 or 50 mg/kg) once daily for 14 days after exposure to SPS. Rg3 administration improved fear memory and spatial memory might be involved in modulating the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and monoamine imbalance in the medial prefrontal cortex and hippocampus. It also increased the reduction in the brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) mRNAs expression, and the ratio of p-Akt/Akt in the hippocampus. Thus, Rg3 exerted memory-improving actions might be involved in regulating HPA axis and activating BDNF-TrkB pathway. Our findings suggest that Rg3 could be useful for preventing traumatic stress, such as PTSD.

Acorus tatarinowii Schott extract reduces cerebral edema caused by ischemia-reperfusion injury in rats: involvement in regulation of astrocytic NKCC1/AQP4 and JNK/iNOS-mediated signaling

Background

This study aimed to evaluate the effects of the Acorus tatarinowii Schott [Shi Chang Pu (SCP)] extract administered at the start of 2 h of middle cerebral artery occlusion (MCAo), followed by 3 d of reperfusion, and to determine mechanisms involved in anti-edema effects in the penumbra of the cerebral cortex.

Method

Rats were intraperitoneally administered the SCP extract at a dose of 0.25 g/kg (SCP-0.25 g), 0.5 g/kg (SCP-0.5 g), or 1 g/kg (SCP-1 g) at the start of MCAo.

Result

SCP-0.5 g and SCP-1 g treatments effectively reduced the cerebral infarct size, ameliorated cerebral edema, reduced blood–brain barrier permeability, and restored neurological function. SCP-0.5 g and SCP-1 g treatments markedly downregulated the levels of glial fibrillary acidic protein, Na⁺-K⁺-2Cl⁻ cotransporter type 1 (NKCC1), aquaporin 4 (AQP4), phospho-c-Jun N-terminal kinase (p-JNK)/JNK, inducible nitric oxide synthase (iNOS), 3-nitrotyrosine, intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor-A (VEGF-A), and zonula occluden-1 (ZO-1) and upregulated ZO-3 expression in the penumbra of the cerebral cortex 3 d after reperfusion.

Conclusions

SCP-0.5 g and SCP-1 g treatments exert neuroprotective effects against cerebral infarction and cerebral edema partially by mitigating astrocytic swelling and blood–brain barrier disruption. Moreover, the anti-cerebral edema effects of SCP extract treatments are possibly associated with the downregulation of astrocytic NKCC1/AQP4 and JNK/iNOS-mediated ICAM-1/MMP-9 signaling in the penumbra of the cerebral cortex 3 d after reperfusion.

Herb-Derived Products: Natural Tools to Delay and Counteract Stem Cell Senescence

Cellular senescence plays a very important role in organismal aging increasing with age and in age-related diseases (ARDs). This process involves physiological, structural, biochemical, and molecular changes of cells, leading to a characteristic trait referred to "senescence-associated secretory phenotype (SASP)." In particular, with aging, stem cells (SCs) in situ exhibit a diminished capacity of self-renewal and show a decline in their functionality. The identification of interventions able to prevent the accumulation of senescent SCs in the organism or to pretreat cultured multipotent mesenchymal stromal cells (MSCs) prior to employing them for cell therapy is a main purpose of medical research. Many approaches have been investigated and resulted effective to prevent or counteract SC senescence in humans, as well as other animal models. In this work, we have reviewed the chance of using a number of herb-derived products as novel tools in the treatment of cell senescence, highlighting the efficacy of these agents, often still far from being clearly understood.

Extracts or Active Components from Acorus gramineus Aiton for Cognitive Function Impairment: Preclinical Evidence and Possible Mechanisms

Extracts or active components from Acorus gramineus Aiton (EAAGA) have been clinically used for cognition impairment more than hundreds of years and are still used in modern times in China and elsewhere worldwide. Previous studies reported that EAAGA improves cognition impairment in animal models. Here, we conducted a preclinical systematic review to assess the current evidence of EAAGA for cognition impairment. We searched 7 databases up until June 2019. Methodological quality for each included studies was accessed according to the CAMARADES 10-item checklist. The primary outcome measures were neurobehavioral function scores evaluated by the Morris water maze test, electrical Y-maze test, step-down test, radial eight-arm maze test, and step-through test. The secondary outcome measures were mechanisms of EAAGA for cognition function. Finally, 34 studies involving 1431 animals were identified. The quality score of studies range from 1 to 6, and the median was 3.32. Compared with controls, the results of the meta-analysis indicated EAAGA exerted a significant effect in decreasing the escape latency and error times and in increasing the length of time spent in the platform quadrant and the number of platform crossings representing learning ability and memory function (all P < 0.01). The possible mechanisms of EAAGA are largely through anti-inflammatory, antioxidant, antiapoptosis activities, inhibition of neurotoxicity, regulating synaptic plasticity, protecting cerebrovascular, stimulating cholinergic system, and suppressing astrocyte activation. In conclusion, EAAGA exert potential neuroprotective effects in experimental cognition impairment, and EAAGA could be a candidate for cognition impairment treatment and further clinical trials.

Potential effect of herbal antidepressants on cognitive deficit: Pharmacological activity and possible molecular mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

Cognitive symptom is a "core" symptom of major depressive disorder (MDD) patients with clear deficit in memory, social and occupational function, and may persist during the remitting phase. Therefore, the remission of cognitive symptom has been considered as one of the main objectives in the treatment of MDD. Herbal antidepressants have been used to treat MDD, and there has been great advances in the understanding of the ability of these herbs to improve cognitive deficit linked to brain injury and various diseases including depression, Alzheimer disease, diabetes and age-related disorders. This systematic review summarizes the evidence from preclinical studies and clinical trials of herbal antidepressants with positive effects on cognitive deficit. The potential mechanisms by which herbal antidepressants prevent cognitive deficit are also reviewed. This review will facilitate further research and applications.

MATERIALS AND METHODS

We conducted an open-ended, English restricted search of MEDLINE (PubMed), Web of Science and Scopus for all available articles published or online before 31 December 2019, using terms pertaining to medical herb/phytomedicine/phytochemical/Chinese medicine and depression/major depressive disorder/antidepressant and/or cognitive impairment/cognitive deficit/cognitive dysfunction.

RESULTS

7 prescriptions, more than 30 individual herbs and 50 phytochemicals from China, Japan, Korea and India with positive effects on the depressive state and cognitive deficit are reviewed herein. The evidence from preclinical studies and clinical trials proves that these herbal antidepressants exhibit positive effects on one or more aspects of cognitive defect including spatial, episodic, aversive, and short- and long-term memory. The action mode of the improvement of cognitive deficit by these herbal antidepressants is mediated mainly through two pathways. One pathway is to promote hippocampal neurogenesis through activating brain derived neurotrophic factor-tropomyosin-related kinase B signaling. The other pathway is to prevent neuronal apoptosis through the inhibition of neuro-inflammation and neuro-oxidation.

CONCLUSION

These herbal antidepressants, having potential therapy for cognitive deficit, may prevent pathological processes of neurodegenerative diseases. Furthermore, these herbal medicines should provide a treasure trove, which will accelerate the development of new antidepressants that can effectively improve cognitive symptom in MDD. Studies on their molecular mechanisms may provide more potential targets and therapeutic approaches for new drug discovery.

Korean Traditional Medicine in Treating Patients with Mild Cognitive Impairment: A Multicenter Prospective Observational Case Series

In Korea, patients with mild cognitive impairment can choose to receive treatment of Korean medicine, and Korean medicine hospitals provide specialized medical care for the prevention and management of cognitive disorders. The aim of the study is to explore the role of Korean medicine therapy for patients with mild cognitive impairment in a real clinical setting. Fifteen patients with amnestic mild cognitive impairment were enrolled in this prospective observational study in three Korean medicine hospitals. Korean medicine treatments were delivered by experienced professionals and not restricted to standardized treatment. Outcome measures were prospectively planned to examine the Korean-Montreal Cognitive Assessment (K-MoCA), Korean-Mini Mental State Examination (K-MMSE), and other detailed neuropsychological assessment at the baseline and after 12 and 24 weeks of treatment. Korean medicine treatment for MCI treatment in the real-world clinical setting included herbal medicine and acupuncture. The most frequently used herbs in herbal decoctions were Acori Graminei Rhizoma, Polygalae Radix, and Poria Sclerotium Cum Pini Radix. The herbal medicine formulae used in this study were classified into three categories: tonifying Qi (33.3%), tonifying kidney (46.7%), and calming liver (20%) formulae. In the cognitive ability assessment, the K-MoCA score significantly improved after treatment (mean difference 2.6; 95% CI: 1.3 to 3.9, p=0.001). The K-MMSE score slightly increased after treatment; however, the improvement was not statistically significant (mean difference 0.8; 95% CI: −0.5 to 2.0, p=0.195). In detailed neuropsychological assessment, the cognitive domains of executive functions and memory after the treatment were distinctively improved. In this prospective observational case series, we could see the real clinical environments of treating patients with mild cognitive impairment in Korean medicine hospitals. Patients treated with Korean medicine showed improved results in the neuropsychological assessment after 12 and 24 weeks.

Traditional Chinese herbal medicine for vascular dementia

BACKGROUND

Traditional Chinese herbal medicine (TCHM) is widely used for treating vascular dementia (VaD) in China. Recent studies of a number of TCHMs have demonstrated in vitro biological activity and therapeutic effects in animals, but the published clinical evidence has not been systematically appraised.

OBJECTIVES

To evaluate the efficacy and safety of TCHMs listed in either the Chinese Pharmacopoeia (CP) or the Chinese National Essential Drug List (NEDL) that are used to treat VaD. A secondary aim was to identify promising TCHMs for further clinical research.

SEARCH METHODS

We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's Specialised Register (on 14 March 2018) and also several Chinese biomedical databases: the Chinese Biological Medicine Database (January 1979 to May 2015), Wanfang database (January 1998 to May 2015), Chongqing VIP Information Co. Ltd or Weipu (January 1998 to May 2015) and the Chinese National Knowledge Infrastructure (January 1979 to May 2015).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of TCHMs compared to placebo, to Western medicine (WM) or to routine therapy for VaD risk factors. Eligible participants were men and women aged 18 years and above, diagnosed with VaD by any of the following four criteria: (1) Diagnostic and Statistical Manual of Mental Disorders (DSM) versions III, III-R, IV, IV-TR; (2) National Institute of Neurological Disorders and Stroke (NINDS-AIREN); (3) International Classification of Diseases 9 or 10; (4) the Hachinski or the Modified Hachinski Ischaemic Score. We required the use of an imaging technique to differentiate VaD from other dementias. We excluded (1) trials with participants diagnosed with mixed dementia or those that did not use an imaging technique to ascertain VaD; (2) trials of NEDL-listed Gingko biloba or Huperzine A as experimental interventions, to avoid duplication of existing Cochrane Reviews; (3) trials using acupuncture alone as the experimental intervention; (4) trials using another CP- or NEDL-listed TCHM (except for Huperzine A and Gingko which are popular in Western practice) as the control intervention; and (5) trials using purely non-pharmacological interventions as the control intervention unless explicitly described as 'routine therapy for VaD risk factors'.

DATA COLLECTION AND ANALYSIS

We assessed the risks of bias using the Cochrane 'Risk of bias' tool and adapted the Outcome Reporting Bias in Trials (ORBIT) classification system for outcome reporting bias. We assessed TCHM effects on five clinically important outcomes: cognition, global performance, safety, activities of daily living and behaviour and summarised the effects using mean differences for continuous outcomes and risk ratios or risk differences for binary outcomes. We stratified the studies into those that estimated the TCHM versus 'no treatment' effect and those that estimated the TCHM versus the WM effect, with further stratification by the specific TCHM tested or by one of the four modes of action. We pooled using a random-effects model. Due to substantial clinical and design heterogeneity, we did not estimate an 'overall TCHM effect'.

MAIN RESULTS

We only found studies (47 studies, 3581 participants) for 18 of the 29 eligible TCHMs as defined by our inclusion criteria. All were superiority trials conducted in China between 1997 and 2013, with most employing a two-arm parallel design with sample sizes ranging from 26 to 240 and a median treatment duration of 12 weeks (range: 2 to 24 weeks).We found that reporting and trial methodology were generally poor; in particular, there was a lack of information on randomisation, an absence of blinding of participants and outcome assessors and incomplete reporting of adverse events (AEs). None of the 30 trials published from 2007 onwards adopted the CONSORT recommendations for reporting RCTs of herbal interventions.We found seven TCHMs which each had potentially large benefits in studies estimating the TCHM versus 'no treatment' effect and in studies estimating the TCHM versus the WM effect. Two TCHMs (NaoXinTong and TongXinLuo) were common to both groups. Three of these TCHMs - Nao XinTong, NaoMaiTai and TongXinLuo - had the strongest evidence to justify further research. Two TCHMs (NaoMaiTai and TongXinLuo) had a 5% or more increased risk of AEs compared to the 'no Treatment' control, but the quality of this evidence was poor.

AUTHORS' CONCLUSIONS

We found moderate- to very low-quality evidence of benefit and harm of TCHMs for VaD. Methodological inadequacies need to be addressed by better conducted and reported trials. We identified NaoMaiTai, NaoXinTong and TongXinLuo as warranting special research priority.

A Rho-kinase inhibitor reverses learning and memory deficits in a Rat model of chronic cerebral ischemia by altering Bcl-2/Bax-NMDAR signaling in the cerebral cortex

The current study investigated whether a Rho-kinase inhibitor alleviated impairments in a rat model of chronic cerebral ischemia and examined the specific pathological mechanisms by which Rho-kinase impacts neuronal damage and cognitive dysfunction. Adult Sprague-Dawley rats underwent permanent bilateral carotid artery occlusion (BCAO) to establish our chronic cerebral ischemia model. Chronic Y27632 administration reversed the abnormal behaviors of BCAO-treated rats in the Morris water maze. We performed Western blot analyses of the apoptosis-related proteins Bcl-2 and Bax to examine the potential mechanism underlying the beneficial effects of Y27632 on cerebral ischemia and showed for the first time that Y27632 reversed the decrease in the Bcl-2/Bax ratio in BCAO model rats. Y27632 restored the depression of NR2A- and NR2B-containing N-methyl-d-aspartate receptors (NMDARs) in the cerebral cortex of BCAO model rats. We also investigated these effects on middle cerebral artery occlusion (MCAO) model rats and observed some differences between the two models. In summary, our data provide evidence supporting the hypothesis that Rho-kinase inhibitors exert neuroprotective effects on cerebral ischemia. The Bcl-2/Bax-NMDAR signaling pathway in the cerebral cortex may be responsible for the protective effects of the Rho-kinase inhibitor, and this pathway may represent a pharmacological target for curative clinical strategies.

β-Asarone Rescues Pb-Induced Impairments of Spatial Memory and Synaptogenesis in Rats

Chronic lead (Pb) exposure causes cognitive deficits. This study aimed to explore the neuroprotective effect and mechanism of β-asarone, an active component from Chinese Herbs Acorus tatarinowii Schott, to alleviate impairments of spatial memory and synaptogenesis in Pb-exposed rats. Both Sprague-Dawley developmental rat pups and adult rats were used in the study. Developmental rat pups were exposed to Pb throughout the lactation period and β-asarone (10, 40mg kg^-1, respectively) was given intraperitoneally from postnatal day 14 to 21. Also, the adult rats were exposed to Pb from embryo stage to 11 weeks old and β-asarone (2.5, 10, 40mg kg^-1, respectively) was given from 9 to 11 weeks old. The level of β-asarone in brain tissue was measured by High Performance Liquid Chromatography. The Morris water maze test and Golgi-Cox staining method were used to assess spatial memory ability and synaptogenesis. The protein expression of NR2B subunit of NMDA receptor, Activity-regulated cytoskeleton-associated protein (Arc/Arg3.1) and Wnt family member 7A (Wnt7a) in hippocampus, as well as mRNA expression of Arc/Arg3.1 and Wnt7a, was also explored. We found that β-asarone could pass through the blood brain barrier quickly. And β-asarone effectively attenuated Pb-induced reduction of spine density in hippocampal CA1 and dentate gyrus areas in a dose-dependent manner both in developmental and adult rats, meanwhile the Pb-induced impairments of learning and memory were partially rescued. In addition, β-asarone effectively up-regulated the protein expression of NR2B, Arc and Wnt7a, as well as the mRNA levels of Arc/Arg3.1 and Wnt7a, which had been suppressed by Pb exposure. The results suggest the neuroprotective properties of β-asarone against Pb-induced memory impairments, and the effect is possibly through the regulation of synaptogenesis, which is mediated via Arc/Arg3.1 and Wnt pathway.

Neurogenesis-Promoting Natural Product α-Asarone Modulates Morphological Dynamics of Activated Microglia

α-Asarone is an active constituent of Acori Tatarinowii, one of the widely used traditional Chinese Medicine to treat cognitive defect, and recently is shown to promote neurogenesis. Here, we demonstrated that low level (3 μM) of α-asarone attenuated LPS-induced BV2 cell bipolar elongated morphological change, with no significant effect on the LPS-induced pro-inflammatory cytokine expressions. In addition, time-lapse analysis also revealed that α-asarone modulated LPS-induced BV2 morphological dynamics. Consistently a significant reduction in the LPS-induced Monocyte Chemoattractant Protein (MCP-1) mRNA and protein levels was also detected along with the morphological change. Mechanistic study showed that the attenuation effect to the LPS-resulted morphological modulation was also detected in the presence of MCP-1 antibodies or a CCR₂ antagonist. This result has also been confirmed in primary cultured microglia. The in vivo investigation provided further evidence that α-asarone reduced the proportion of activated microglia, and reduced microglial tip number and maintained the velocity. Our study thus reveals α-asarone effectively modulates microglial morphological dynamics, and implies this effect of α-asarone may functionally relate to its influence on neurogenesis.

A herbal medicine for Alzheimer's disease and its active constituents promote neural progenitor proliferation

Aberrant neural progenitor cell (NPC) proliferation and self-renewal have been linked to age-related neurodegeneration and neurodegenerative disorders including Alzheimer’s disease (AD). Rhizoma Acori tatarinowii is a traditional Chinese herbal medicine against cognitive decline. In this study, we found that the extract of Rhizoma Acori tatarinowii (AT) and its active constituents, asarones, promote NPC proliferation. Oral administration of AT enhanced NPC proliferation and neurogenesis in the hippocampi of adult and aged mice as well as that of transgenic AD model mice. AT and its fractions also enhanced the proliferation of NPCs cultured in vitro. Further analysis identified α-asarone and β-asarone as the two active constituents of AT in promoting neurogenesis. Our mechanistic study revealed that AT and asarones activated extracellular signal-regulated kinase (ERK) but not Akt, two critical kinase cascades for neurogenesis. Consistently, the inhibition of ERK activities effectively blocked the enhancement of NPC proliferation by AT or asarones. Our findings suggest that AT and asarones, which can be orally administrated, could serve as preventive and regenerative therapeutic agents to promote neurogenesis against age-related neurodegeneration and neurodegenerative disorders.

Cardioprotective effect of rhizomes of Acorus gramineus against isoproterenol-induced cardiac damage in pigs

The present study was designed to evaluate the cardioprotective potential of water extract of rhizomes of Acorus gramineus (AGR) against isoproterenol (ISO)-induced myocardial infarction. Male pigs were orally administered with 250 or 500 mg/kg of AGR or with vehicle for 9 days, with concurrent subcutaneous injections of ISO on the 8th and 9th day. Administration of AGR significantly ameliorated ISO-induced cardiac dysfunctions as evidenced by the ventricular ST-segment interval and R-amplitude as well as the left ventricle fractional shortening and ejection fraction. Additionally, administration of AGR significantly attenuated increased cardiac injury markers, such as cardiac troponin T, tumor necrosis factor-α, and myeloperoxidase activity, and cardiac marker enzymes, and prevented the depletion of antioxidant parameters. Malondialdehyde formation was also inhibited by AGR. Based on the results, it is concluded that AGR possesses significant cardioprotective potential and may serve as an adjunct in the treatment and prophylaxis of myocardial infarction.

Acorus Linnaeus: a review of traditional uses, phytochemistry and neuropharmacology

Acorus Linnaeus is a herb used in many ancient medicinal systems. Phytochemical and neuropharmacological studies have revealed that many beneficial compounds possessed anticonvulsant, antiepileptic, neuroprotective, memory enhancing, and sedative properties.

Smart Soup, a traditional Chinese medicine formula, ameliorates amyloid pathology and related cognitive deficits

Alzheimer’s disease (AD) is a progressive neurodegenerative disease that causes substantial public health care burdens. Intensive efforts have been made to find effective and safe disease-modifying treatment and symptomatic intervention alternatives against AD. Smart Soup (SS), a Chinese medicine formula composed of Rhizoma Acori Tatarinowii (AT), Poria cum Radix Pini (PRP) and Radix Polygalae (RP), is a typical prescription against memory deficits. Here, we assessed the efficacy of SS against AD. Oral administration of SS ameliorated the cognitive impairment of AD transgenic mice, with reduced Aβ levels, retarded Aβ amyloidosis and reduced Aβ-induced gliosis and neuronal loss in the brains of AD mice. Consistently, SS treatment reduced amyloid-related locomotor dysfunctions and premature death of AD transgenic Drosophila. Mechanistic studies showed that RP reduced Aβ generation, whereas AT and PRP exerted neuroprotective effects against Aβ. Taken together, our study indicates that SS could be effective against AD, providing a practical therapeutic strategy against the disease.

Severity of middle cerebral artery occlusion determines retinal deficits in rats

Middle cerebral artery occlusion (MCAO) using the intraluminal suture technique is a common model used to study cerebral ischemia in rodents. Due to the proximity of the ophthalmic artery to the middle cerebral artery, MCAO blocks both arteries, causing both cerebral ischemia and retinal ischemia. While previous studies have shown retinal dysfunction at 48h post-MCAO, we investigated whether these retinal function deficits persist until 9days and whether they correlate with central neurological deficits. Rats received 90min of transient MCAO followed by electroretinography at 2 and 9days to assess retinal function. Retinal damage was assessed with cresyl violet staining, immunohistochemistry for glial fibrillary acidic protein (GFAP) and glutamine synthetase, and TUNEL staining. Rats showed behavioral deficits as assessed with neuroscore that correlated with cerebral infarct size and retinal function at 2days. Two days after surgery, rats with moderate MCAO (neuroscore <5) exhibited delays in electroretinogram implicit time, while rats with severe MCAO (neuroscore ≥5) exhibited reductions in amplitude. Glutamine synthetase was upregulated in Müller cells 3days after MCAO in both severe and moderate animals; however, retinal ganglion cell death was only observed in MCAO retinas from severe animals. By 9days after MCAO, both glutamine synthetase labeling and electroretinograms had returned to normal levels in moderate animals. Early retinal function deficits correlated with behavioral deficits. However, retinal function decreases were transient, and selective retinal cell loss was observed only with severe ischemia, suggesting that the retina is less susceptible to MCAO than the brain. Temporary retinal deficits caused by MCAO are likely due to ischemia-induced increases in extracellular glutamate that impair signal conduction, but resolve by 9days after MCAO.

Effects of Panax ginseng, Turnera diffusa and Heteropterys tomentosa extracts on hippocampal apoptosis of aged rats

Objective:

To verify if the medicinal plants Panax ginseng C.A. Mey, Turnera diffusa Willd. ex Schult., and Heteropterys tomentosa O. Mach., which are amply used by the population as tonics and cognition enhancers, could have a protective effect on cell death by apoptosis, since this could be one of the mechanisms of action of these substances.

Methods:

Aged male Wistar rats (n=24) were divided into four groups. Over 30 days, three groups received treatments with hydroalcoholic extracts of the plants, and one group received saline solution. A fifth group with young adult male Wistar rats (n=4) received saline solution during the same period. Using the TUNEL technique, the percentage of apoptosis in the hippocampus of these animals was evaluated.

Results:

No differences were observed between the percentage of apoptotic cells in the hippocampus of aged animals and of young control animals. The percentage of apoptosis in the hippocampus of aged animals treated chronically with the extracts from the three plants also did not differ from the percentage of apoptosis in the hippocampus of the control group of aged animals.

Conclusion:

Treatment with the hydroalcoholic extracts of Panax ginseng, Turnera diffusa, and Heteropterys tomentosa did not influence the apoptosis of the hippocampal cells of aged rats.

Traditional Korean East Asian medicines and herbal formulations for cognitive impairment

Hanbang, the Traditional Korean Medicine (TKM), is an inseparable component of Korean culture both within the country, and further afield. Korean traditional herbs have been used medicinally to treat sickness and injury for thousands of years. Oriental medicine reflects our ancestor’s wisdom and experience, and as the elderly population in Korea is rapidly increasing, so is the importance of their health problems. The proportion of the population who are over 65 years of age is expected to increase to 24.3% by 2031. Cognitive impairment is common with increasing age, and efforts are made to retain and restore the cognition ability of the elderly. Herbal materials have been considered for this purpose because of their low adverse effects and their cognitive-enhancing or anti-dementia activities. Herbal materials are reported to contain several active compounds that have effects on cognitive function. Here, we enumerate evidence linking TKMs which have shown benefits in memory improvements. Moreover, we have also listed Korean herbal formulations which have been the subject of scientific reports relating to memory improvement.

Simultaneous Determination of Volatile Constituents from Acorus tatarinowii Schott in Rat Plasma by Gas Chromatography-Mass Spectrometry with Selective Ion Monitoring and Application in Pharmacokinetic Study

A sensitive and specific gas chromatographic-mass spectrometry with selected ion monitoring (GC-MS/SIM) method has been developed for simultaneous identification and quantification of α -asarone, β-asarone, and methyl eugenol of Acorus tatarinowii Schott in rat plasma. Chromatographic separation was performed on a Restek Rxi-5MS capillary column (30 m × 0.32 mm × 0.25 μm), using 1-naphthol as internal standard (IS). MS detection of these compounds and IS was performed at m/z 178, 208, 208, and 144. Intra- and interday precisions of all compounds of interest were less than 10%. The recoveries are situated in the range of 92.4-105.2%. Pharmacokinetics of methyl eugenol confirmed to be one-compartment open model, α -asarone and β -asarone was two-compartment open model, respectively. The method will probably be an alternative to simultaneous determination and pharmacokinetic study of volatile ingredients in Acorus tatarinowii Schott.

Acorus gramineus inhibits microglia mediated neuroinflammation and prevents neurotoxicity in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Acorus gramineus Solander (Acoraceae, AG), is a widely distributed plant in Asian countries. Rhizome part of this plant has long been used as a traditional medicine for treating various symptoms including central nervous system (CNS) disorders.

AIM OF STUDY

The anti-neuroinflammatory effect of AG aqueous extract was investigated using in vitro cellular and in vivo Parkinson's disease (PD) mouse model.

MATERIALS AND METHODS

Lipopolysaccharide (LPS) is used to stimulate BV-2 microglial cells in vitro and the changes in neuroinflammatory expressional levels were measured using ELISA, Western blotting, RT-PCR and immunofluorescence techniques. In in vivo experiments, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mouse model of PD was developed followed by immunohistochemical analysis of specific brain tissues.

RESULTS

LPS-stimulation to BV-2 cells increased the production of nitric oxide (NO) and proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β. Pretreatment with AG extract inhibited the increased levels of NO and pro-inflammatory cytokines in LPS-stimulated BV-2 cells. Mechanistic study revealed that AG acts via the regulation of nuclear factor kappa B (NF-κB), mitogen-activated protein kinases (MAPKs) and TRIF-dependent signaling pathways. Further, AG protected MPTP-induced neuronal cell death and inhibited neuroinflammation in vivo.

CONCLUSION

Our results indicated that AG extract exerted anti-neuroinflammatory effects against activated microglia mediated insults through multiple signaling pathways and prevented in vivo neuronal cell death in mouse model of PD substantiating the traditional claims for its use in CNS disorders.

The Protective Effect of Black Ginseng Against Transient Focal Ischemia-induced Neuronal Damage in Rats

Black ginseng (BG) has been widely used as herbal treatment for improving physiological function. In order to investigate the neuroprotective action of this herbal medicine, we examined the influence of BG on the learning and memory of rats using the Morris water maze, and we studied the effects of BG on the central cholinergic system and neural nitric oxide synthesis in the hippocampus of rats with neuronal and cognitive impairment. After middle cerebral artery occlusion was applied for 2h, the rats were administered BG (100 or 400 mgkg(-1), p.o.) daily for 2 weeks, followed by training and performance of the Morris water maze test. The rats with ischemic insults showed impaired learning and memory on the tasks. Treatment with BG produced improvement in the escape latency to find the platform. Further, the BG groups showed a reduced loss of cholinergic immunoreactivity and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-positive neurons in the hippocampus compared to that of the ISC group. These results demonstrated that BG has a protective effect against ischemia-induced neuronal and cognitive impairment. Our results suggest that BG might be useful for the treatment of vascular dementia.

Propofol post-conditioning induced long-term neuroprotection and reduced internalization of AMPAR GluR2 subunit in a rat model of focal cerebral ischemia/reperfusion

We previously reported that propofol (20 mg/kg/h) post-conditioning provided acute (up to 24 h) neuroprotection in rats with transient middle cerebral artery occlusion. In this study, we extend these data by examining long-term protection and exploring underlying mechanisms involving AMPA receptor GluR2 subunit internalization. Rats were treated with propofol 20 mg/kg/h after 60 min of occlusion (beginning of reperfusion for 4 h). Propofol post-conditioning reduced infarct volume and improved spatial memory deficiencies (up to 28 days) induced by ischemia/reperfusion injury. Additionally, Propofol post-conditioning promoted neurogenesis in the dentate gyrus of hippocampus, as measured by bromodeoxyuridine and neuron-specific nuclear protein immunofluorescence-double staining at day 28 after reperfusion. Finally, propofol post-conditioning increased the surface expression of AMPA receptor GluR2 subunit, thus inhibited the internalization of this part until 28 days after stroke. In conclusion, our data suggest that propofol post-conditioning provides long-term protection against focal cerebral ischemia/reperfusion injury in rats. Furthermore, we found that the inhibition of AMPA receptor GluR2 subunit internalization may contributed to this long-term neuroprotection.

Amelioration of cerebral infarction and improvement of neurological deficit by a Korean herbal medicine, modified Bo-Yang-Hwan-O-Tang

OBJECTIVES

Modified Bo-Yang-Hwan-O-Tang (mBHT) is an improved herbal formula of BHT, which has been widely used to treat ischaemic stroke in East Asia, by the addition of five herbs having anti-ischaemic properties. In this study, we investigated whether mBHT would reduce cerebral ischaemic injury in rats.

METHODS

Sprague-Dawley rats were subjected to a 90-min middle cerebral artery occlusion (MCAO) and subsequent 22-h reperfusion. mBHT was administered either intraperitoneally twice 15 min before and 15 min after, or orally once 30 min or 120 min after the onset of MCAO (50 or 200 mg/kg each).

KEY FINDINGS

Intraperitoneal administration of mBHT markedly reduced the cerebral infarct size and neurological deficit caused by MCAO/reperfusion. mBHT treatment also significantly improved long-term survival rate after cerebral ischaemic injury. Oral administration of mBHT 30 min after ischaemia also markedly reduced the infarct size after cerebral ischaemia. The anti-ischaemic effect of mBHT was significantly, but not fully, reduced when mBHT-induced hypothermia was abolished. In cultured cortical neurons, we further found that mBHT decreased oxygen-glucose deprivation/re-oxygenation-evoked neuronal injury by inhibiting production of reactive oxygen species, decrease in mitochondrial transmembrane potential, and activation of caspase-3. However, mBHT did not inhibit N-Methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity.

CONCLUSIONS

Taken together, our data suggest that mBHT has multiple anti-ischaemic properties and would be a good therapeutic herbal prescription for the treatment of cerebral ischaemic stroke.

The neuroprotective effect of methanol extract of gagamjungjihwan and fructus euodiae on ischemia-induced neuronal and cognitive impairment in the rat

Gagamjungjihwan (GJ), a decoction consisting of five herbs including ginseng, Acori Graminei Rhizoma, Uncariae Ramulus et Uncus, Polygalae Radic and Frustus Euodiae (FE), has been widely used as herbal treatment for ischemia. In order to investigate the neuroprotective action of this novel prescription, we examined the influence of GJ and FE on learning and memory using the Morris water maze and studied their affects on the central cholinergic system in the hippocampus with neuronal and cognitive impairment. After middle cerebral artery occlusion was applied for 2 h, rats were administered GJ (200 mg kg(-1), p.o.) or FE (200 mg kg(-1), p.o.) daily for 2 weeks, followed by training and performance of the Morris water maze tasks. Rats with ischemic insults showed impaired learning and memory of the tasks. Pre-treatment with GJ and FE produced improvement in the escape latency to find the platform. Pre-treatments with GJ and FE also reduced the loss of cholinergic immunoreactivity in the hippocampus. The results demonstrated that GJ and FE have a protective effect against ischemia-induced neuronal and cognitive impairment. Our results suggest that GJ and FE might be useful in the treatment of vascular dementia.

Ameliorating effects of essential oil from Acori graminei rhizoma on learning and memory in aged rats and mice

Although there are normal cognitive changes that take place as a person becomes older, ageing in humans is generally associated with a deterioration of cognitive performance, in particular of learning and memory. There are a number of herbal medicines that are reported to improve brain function and intelligence. In the present study, the ameliorating effects of an essential oil extracted from Acori graminei rhizoma on learning and memory in aged, dysmnesia rats and mice were determined using the step-down passive avoidance test and Y maze. Oral administration of the essential oil (0.02, 0.04 and 0.08 g kg−1) to rats for 30 days and to mice for 15 days improved the latency and number of errors in aged, dysmnesia rats and mice. The cerebral neurotransmitters in aged rats given the essential oil (0.02, 0.04, 0.08 g kg−1) for 30 days were also investigated, and increased levels of norepinephrine, dopamine and serotonin, and decreased levels of acetylcholinesterase activity were found. The results suggest that the essential oil improves cognitive function in aged animals possibly by increasing norepinephrine, dopamine and serotonin relative levels, and by decreasing the activity of acetylcholinesterase in the cerebra.

Improvement of cognitive deficit and neuronal damage in rats with chronic cerebral ischemia via relative long-term inhibition of rho-kinase

(1) The role of activation of Rho-kinase in the pathogenesis of cognitive deficit and neuronal damage caused by chronic global ischemia is not clear. In this study, hydroxyfasudil, a Rho-kinase inhibitor, was found to improve the learning and memory performance significantly in rats with ischemia induced by chronic cerebral hypoperfusion after permanent bilateral carotid artery ligation (BCAL). This was observed by the administration of hydroxyfasudil (1 mg/kg or 10 mg/kg, once per day for 30 days) to ischemic rats and the measurements of escape latency and time spent in the target quadrant among the ischemic, sham, and ischemic plus hydroxyfasudil rats by the method of Morris water maze. (2) In electrophysiological study, hydroxyfasudil abolished the inhibition of long-term potentiation (LTP) in rats with ischemia. Morphologically, it also markedly reduced pathological changes such as neuronal cells loss and nuclei shrinkage in cortex and hippocampus of ischemic rats. Biochemical analysis showed that the inhibition of Rho-kinase by hydroxyfasudil reduced the amount of MDA and increased the activities of SOD and GPx in ischemic rats that had increased MDA and decreased SOD and GPx activities. (3) To explore mechanism (s) of the beneficial effects of hydroxyfasudil in ischemia, we performed immunohistochemistry and RT-PCR analyses of NMDA NR2B subunit and for the first time found that hydroxyfasudil increased the expression of NR2B in cortex and hippocampus at both protein and mRNA levels. (4) Taken together, our data further support the notion that the inhibition of Rho-kinase provides neuroprotective effects in cerebral ischemia.

Piracetam improves cognitive deficits caused by chronic cerebral hypoperfusion in rats

Piracetam is the derivate of gamma-aminobutyric acid, which improves the cognition,memory,consciousness, and is widely applied in the clinical treatment of brain dysfunction. In the present experiments, we study the effects of piracetam on chronic cerebral hypoperfused rats and observe its influence on amino acids, synaptic plasticity in the Perforant path-CA3 pathway and apoptosis in vivo. Cerebral hypoperfusion for 30 days by occlusion of bilateral common carotid arteries induced marked amnesic effects along with neuron damage, including: (1) spatial learning and memory deficits shown by longer escape latency and shorter time spent in the target quadrant; (2) significant neuronal loss and nuclei condensation in the cortex and hippocampus especially in CA1 region; (3) lower induction rate of long term potentiation, overexpression of BAX and P53 protein, and lower content of excitatory and inhibitory amino acids in hippocampus. Oral administration of piracetam (600 mg/kg, once per day for 30 days) markedly improved the memory impairment, increased the amino acid content in hippocampus, and attenuated neuronal damage. The ability of piracetam to attenuate memory deficits and neuronal damage after hypoperfusion may be beneficial in cerebrovascular type dementia.

DDPH: improving cognitive deficits beyond its alpha 1-adrenoceptor antagonism in chronic cerebral hypoperfused rats

DDPH (1-(2, 6-dimethylphenoxy)-2-(3, 4-dimethoxyphenylethylamino) propane hydrochloride), a candidate drug known to be an alpha(1)-adrenoceptor antagonist, can efficiently penetrate through blood brain barrier and inhibit the contraction of vascular smooth muscle in the brain. In rats with chronic cerebral hypoperfusion after permanent bilateral carotid artery ligation, we found that DDPH treatment at 6 or 12 mg/kg per day for 30 days significantly reversed pathological changes such as glial cell proliferation and nuclei shrinkage and reduced neuronal cell loss. In vivo electrophysiological studies revealed that DDPH increased long-term potentiation that was inhibited in these animals. In water maze tests, the percentage of time spent in the target quadrant (Q3) for ischemic rats (20.17+/-2.87%) was much shorter than that for the sham rats (45.39+/-3.68%), but DDPH at 12 mg/kg increased the time (39.58+/-3.77%) spent in Q3 in ischemic rats by 96.23%. These data suggested that DDPH improved the learning and memory performance significantly in rats with ischemia induced by bilateral carotid artery ligation. DDPH also lowered the levels of malondialdehyde (MDA), which was increased in the hypoperfused rats, and enhanced the activities of superoxide dismutase (SOD) and glutathione peroxidase, which were decreased in these rats. Further more, immunohistochemistry, RT-PCR assays and Western blot study demonstrated that DDPH attenuated the decreased expression of NMDAR2B (NR2B) in cortex and hippocampal CA1 region of the rats after bilateral carotid artery ligation. Our results suggest that DDPH may have favorable effects for the subjects in cerebrovascular insufficiency state following ischemic stroke.

Acori graminei rhizoma ameliorated ibotenic acid-induced amnesia in rats

In the present study, we investigated the effects of Acori graminei rhizoma (AGR) on learning and memory for the Morris water maze task and on the central cholinergic system of the rats with excitotoxic medial septum (MS) lesion. On the water maze test, the rats were trained to find a platform that was in a fixed position during 6 days and then they received a 60 s probe trial in which the platform was removed from the pool on the 7th day. Ibotenic lesioning of the MS impaired the performance on the maze test and it caused degeneration of choline acetyltransferase and acetylcholine esterase in the hippocampus, which are markers of the central cholinergic system. Daily administrations of AGR (100 mg kg⁻¹, i.p.) for 21 consecutive days produced reversals of the ibotenic acid-induced deficit in learning and memory. These treatments also reduced the loss of cholinergic immunoreactivity in the hippocampus that was induced by ibotenic acid. These results demonstrated that AGR ameliorated learning and memory deficits through their effects on the central nervous system, and neuroprotection was partly evaluated through the effect of AGR on the cholinergic system. Our studies suggest that AGR can possibly be used as treatment for Alzheimer's disease.

SK-PC-B70M from Pulsatilla koreana improves scopolamine-induced impairments of memory consolidation and spatial working memory

Previous studies have shown that hederacolchiside-E from Pulsatilla koreana has neuroprotective effects and cognition-enhancing effects. Subsequently, in the current study, we demonstrate that oral administrations of oleanolic-glycoside saponins enriched fraction from P. koreana, designated as SK-PC-B70M, improve impairments in memory consolidation and spatial working memory by systemic injection of scopolamine, a muscarinic cholinergic receptor antagonist. In a step-through avoidance task, when the rats stepped through a dark chamber in a shuttle box, an electric shock was given and then SK-PC-B70M was administered 30 min later. Twenty-four hours later, the rats were placed in an illuminated chamber. The rats with SK-PC-B70M treatments showed longer response latencies than rats with only scopolamine. Spatial working memory was measured with a trial-unique matching-to-place task in a water maze which assessed memory for place information over varying lengths of delays. Three delay lengths were used: 1 min, 5 min, and 3 h. In comparison with the control rats, the rats with scopolamine treatments took significantly longer to find the platform in the second trial with 1- and 5-min delays. The rats with both scopolamine and SK-PC-B70M had significantly less search error compared with the rats with scopolamine only. These findings indicate that SK-PC-B70M has effects on reversing impairments of memory consolidation and working memory impairments induced by scopolamine.

Aqueous and hydroalcoholic extracts of Black Maca (Lepidium meyenii) improve scopolamine-induced memory impairment in mice

Lepidium meyenii Walp. (Brassicaceae), known as Maca, is a Peruvian hypocotyl growing exclusively between 4,000 and 4,500 m altitude in the central Peruvian Andes, particularly in Junin plateau. Previously, Black variety of Maca showed to be more beneficial than other varieties of Maca on learning and memory in ovariectomized mice on the water finding test. The present study aimed to test two different doses of aqueous (0.50 and 2.00 g/kg) and hydroalcoholic (0.25 and 1.00 g/kg) extracts of Black Maca administered for 35 days on memory impairment induced by scopolamine (1mg/kg body weight i.p.) in male mice. Memory and learning were evaluated using the water Morris maze and the step-down avoidance test. Brain acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities in brain were also determined. Both extracts of Black Maca significantly ameliorated the scopolamine-induced memory impairment as measured in both the water Morris maze and the step-down avoidance tests. Black Maca extracts inhibited AChE activity, whereas MAO activity was not affected. These results indicate that Black Maca improves scopolamine-induced memory deficits.

Timosaponin B-II improves memory and learning dysfunction induced by cerebral ischemia in rats

Sapogenins from Anemarrhenae asphodeloides was reported to improve the learning and memory abilities. In this study, we investigated the effect of Timosaponin B-II(TB-II), a purified extract from A. asphodeloidesb on rat vascular dementia (VD) produced by transient (2h) middle cerebral artery occlusion. The learning and memory abilities of rats were measured by water maze task and passive avoidance task. Daily oral administration of TB-II at two different dose levels of 100 and 200 mg/kg resulted in a significant improvement of the deficit in the learning of the water maze task, beginning 14 days after ischemia. Shortened mean escape latency was detected in TB-II group compared with model group during the same trial days. TB-II treatment also significantly reversed the ischemia-induced retention deficit determined by a one trial step-down type of passive avoidance task. Meanwhile, the expression of interleukin-10, an anti-inflammatory cytokine, and its receptor were significantly increased in TB-II treated VD rats. The results presented the first evidence of a neuroprotective effect of TB-II in the model of vascular dementia. We suggest that the anti-dementia effect by TB-II is derived at least in part from its anti-inflammatory properties.

Neuroprotective Effect of Palmul-Chongmyeong-Tang on Ischemia-Induced Learning and Memory Deficits in the Rat

Ginseng Radix, Atractylodis Macrocephalae Rhizoma, Poria, Glycyrrhizae Radix, Angelicae Gigantis Radix, Ligusticum Rhizoma, Rehmanniae Radix, Paeoniae Radix, Acori Graminei Rhizoma, and Polygalae Radix have been widely used as herbal medicine against ischemia. In order to test the neuroprotective effect of a novel prescription, the present study examined the effects of Palmul-Chongmyeong-Tang (PMCMT) consisting of these ten herbs on learning and memory in the Morris water maze task and the central cholinergic system of rats with cerebral ischemia-induced neuronal and cognitive impairments. After middle cerebral artery occlusion (MCAO) for 2 h, rats were administered with saline or PMCMT (200 mg/kg, p.o.) daily for 2 weeks, followed by their training to the tasks. In the water maze test, the animals were trained to find a platform in a fixed position during 6 d and then received a 60 s probe trial on the 7th day following removal of the platform from the pool. Rats with ischemic insults showed impaired learning and memory of the tasks and treatment with PMCMT produced a significant improvement in escape latency to find the platform in the Morris water maze. Consistent with behavioral data, treatment with PMCMT also reduced the loss of cholinergic immunoreactivity in the hippocampus induced by cerebral ischemia. These results demonstrated that PMCMT has a protective effect against ischemia-induced neuronal and cognitive impairments. The present study suggested that PMCMT might be useful in the treatment of vascular dementia.

Effect of Acori graminei Rhizoma on contractile dysfunction of ischemic and reperfused rat heart

Acori graminei Rhizoma is one of the best-known traditional herbal medicines frequently used for the treatment of cardiovascular symptoms in Asian countries. The anti-ischemic effect of Acori graminei Rhizoma on ischemia-induced isolated rat heart was investigated through analysis of changes in perfusion pressure, aortic flow, coronary flow, and cardiac output. The subjects in this study were divided into two groups, an ischemia-induced group without any treatment (I), and an ischemia-induced group with Acori graminei Rhizoma treatment (I+AGR). There were no significant differences in perfusion pressure, aortic flow, coronary flow, or cardiac output between the two groups before ischemia was induced. The supply of oxygen and buffer was stopped for 10 min to induce ischemia in isolated rat hearts, and Acori graminei Rhizoma was administered while inducing ischemia. The data showed that Acori graminei Rhizoma treatment significantly prevented decreases in perfusion pressure, aortic flow, coronary flow, and cardiac output under an ischemic condition. In addition, hemodynamics (except heart rate) of the AGR-treated group was significantly recovered 60 min after reperfusion compared to the control group, (systolic aortic pressure: 85.5% vs. 62.5%, aortic flow volume: 68.1% vs. 49.4%, coronary flow volume: 86.8% vs. 60.1%, and cardiac output: 73.1% vs. 54.1%, p<0.01). These results suggest that Acori graminei Rhizoma has distinct anti-ischemic effects.