Effectiveness of traditional Chinese medicine in Alzheimer disease

Literature review on the interdisciplinary biomarkers of multi-target and multi-time herbal medicine therapy to modulate peripheral systems in cognitive impairment

Alzheimer's disease (AD) is a chronic progressive neurodegenerative disease characterized by the deposition of amyloid-beta (Aβ) peptide and neurofibrillary tangles in the brain. The approved drug for AD has certain limitations such as a short period of cognitive improvement effect; moreover, the development of drug for AD therapeutic single target for Aβ clearance in brain ended in failure. Therefore, diagnosis and treatment of AD using a multi-target strategy according to the modulation of the peripheral system, which is not only limited to the brain, is needed. Traditional herbal medicines can be beneficial for AD based on a holistic theory and personalized treatment according to the time-order progression of AD. This literature review aimed to investigate the effectiveness of herbal medicine therapy based on syndrome differentiation, a unique theory of traditional diagnosis based on the holistic system, for multi-target and multi-time treatment of mild cognitive impairment or AD stage. Possible interdisciplinary biomarkers including transcriptomic and neuroimaging studies by herbal medicine therapy for AD were investigated. In addition, the mechanism by which herbal medicines affect the central nervous system in connection with the peripheral system in an animal model of cognitive impairment was reviewed. Herbal medicine may be a promising therapy for the prevention and treatment of AD through a multi-target and multi-time strategy. This review would contribute to the development of interdisciplinary biomarkers and understanding of the mechanisms of action of herbal medicine in AD.

Based on Network Pharmacology and Molecular Dynamics Simulations, Baicalein, an Active Ingredient of Yiqi Qingre Ziyin Method, Potentially Protects Patients With Atrophic Rhinitis From Cognitive Impairment

Cognition may be improved by the active ingredients of the Yiqi Qingre Ziyin method in patients with atrophic rhinitis (AR). This study aimed to identify potential targets of the Yiqi Qingre Ziyin method for the treatment of patients with cognitive impairment. Nasal mucosal tissue samples from patients with AR were subjected to proteomic assays, and differentially expressed proteins were obtained. To explore the mechanism of AR leading to mild cognitive impairment (MCI), a differential analysis of AR related differential proteins in the MCI related GSE140831 dataset was performed. Most AR-related differential proteins are also differentially expressed in peripheral blood tissues of MCI, have similar biological functions and are enriched in similar pathways. These co-expressed differential factors in AR and MCI are known as common differential proteins of AR and MCI (CDPAM). Based on the analysis and validation of the random forest, support vector machine and neural network models, CDPAM acted as a diagnostic marker for MCI risk. Cytochrome C (CYCS) was significantly upregulated in the peripheral blood of patients with MCI. The active ingredients in the Yiqi Qingre Ziqin method were obtained and targeted 137 proteins. Among these targeted proteins, CYCS belong to the CDPAM set. Molecular docking and molecular dynamics analysis revealed that baicalein, an active ingredient in the Yiqi Qingre Ziyin method, stably targeted the CYCS protein. Results of the enrichment analysis revealed that the up-regulation of CYCS expression may have a defensive effect on the cells to resist foreign stimuli. Therefore, baicalein, an active ingredient in the Yiqi Qingre Ziyin method, may prevent the development and progression of MCI by targeting the CYCS protein.

Treatment effects on event-related EEG potentials and oscillations in Alzheimer's disease

Alzheimer's disease dementia (ADD) is the most diffuse neurodegenerative disorder belonging to mild cognitive impairment (MCI) and dementia in old persons. This disease is provoked by an abnormal accumulation of amyloid-beta and tauopathy proteins in the brain. Very recently, the first disease-modifying drug has been licensed with reserve (i.e., Aducanumab). Therefore, there is a need to identify and use biomarkers probing the neurophysiological underpinnings of human cognitive functions to test the clinical efficacy of that drug. In this regard, event-related electroencephalographic potentials (ERPs) and oscillations (EROs) are promising candidates. Here, an Expert Panel from the Electrophysiology Professional Interest Area of the Alzheimer's Association and Global Brain Consortium reviewed the field literature on the effects of the most used symptomatic drug against ADD (i.e., Acetylcholinesterase inhibitors) on ERPs and EROs in ADD patients with MCI and dementia at the group level. The most convincing results were found in ADD patients. In those patients, Acetylcholinesterase inhibitors partially normalized ERP P300 peak latency and amplitude in oddball paradigms using visual stimuli. In these same paradigms, those drugs partially normalize ERO phase-locking at the theta band (4-7 Hz) and spectral coherence between electrode pairs at the gamma (around 40 Hz) band. These results are of great interest and may motivate multicentric, double-blind, randomized, and placebo-controlled clinical trials in MCI and ADD patients for final cross-validation.

A Systematic Review of Intervention Studies Examining Nutritional and Herbal Therapies for Mild Cognitive Impairment and Dementia Using Neuroimaging Methods: Study Characteristics and Intervention Efficacy

Neuroimaging facilitates the assessment of complementary medicines (CMs) by providing a noninvasive insight into their mechanisms of action in the human brain. This is important for identifying the potential treatment options for target disease cohorts with complex pathophysiologies. The aim of this systematic review was to evaluate study characteristics, intervention efficacy, and the structural and functional neuroimaging methods used in research assessing nutritional and herbal medicines for mild cognitive impairment (MCI) and dementia. Six databases were searched for articles reporting on CMs, dementia, and neuroimaging methods. Data were extracted from 21/2,742 eligible full text articles and risk of bias was assessed. Nine studies examined people with Alzheimer's disease, 7 MCI, 4 vascular dementia, and 1 all-cause dementia. Ten studies tested herbal medicines, 8 vitamins and supplements, and 3 nootropics. Ten studies used electroencephalography (EEG), 5 structural magnetic resonance imaging (MRI), 2 functional MRI (fMRI), 3 cerebral blood flow (CBF), 1 single photon emission tomography (SPECT), and 1 positron emission tomography (PET). Four studies had a low risk of bias, with the majority consistently demonstrating inadequate reporting on randomisation, allocation concealment, blinding, and power calculations. A narrative synthesis approach was assumed due to heterogeneity in study methods, interventions, target cohorts, and quality. Eleven key recommendations are suggested to advance future work in this area.

Neuroprotective effect of honokiol and magnolol, compounds from Magnolia officinalis, on beta-amyloid-induced toxicity in PC12 cells

Amyloid β peptide (Aβ) induced toxicity is a well-established pathway of neuronal cell death which might play a role in Alzheimer's disease. In this regard, the toxic effect of Aβ on a cultured Aβ-sensitive neuronal cell line was used as a primary screening tool for potential anti-Alzheimer's therapeutic agents. The effects of nine pure compounds (vitamin E, α-asarone, salidroside, baicolin, magnolol, gastrodin, bilobalide, honokiol and β-asarone) from selected Chinese herbs on neuronal cell death induced by Aβ in NGF-differentiated PC12 cells were examined. Only two of the studied compounds, honokiol and magnolol, significantly decreased Aβ-induced cell death. Further experiments indicated that their neuroprotective effects are possibly mediated through reduced ROS production as well as suppression of intracellular calcium elevation and inhibition of caspase-3 activity. The results provide for the first time a scientific rationale for the clinical use of honokiol and magnolol in the treatment of Alzheimer's disease.

Do culturally sensitive services for Chinese in-patients make a difference?

Hospitals in large cities provide services to an increasingly diverse linguistic and cultural clientele. Some strategies adopted to improve services to non-English speaking populations include the use of bilingual social workers, interpreters and printed translation tools. In order to identify gaps in culturally sensitive care in a Canadian teaching hospital, this study surveyed a consecutive sample of 279 Chinese in-patients to determine satisfaction with hospital experience, levels of information about hospital routines and awareness of on-site Chinese cultural services. Results were generally positive. However, satisfaction and information levels were significantly higher among those patients who were aware of culturally appropriate Chinese resources such as social workers, cultural interpreters, and culturally specific reference tools. Of particular interest are the 121 patients (44%) who were less comfortable with English, since awareness of culturally specific resources tended to make a greater difference to this sub-group. These results can potentially help health care providers improve services to patients and families from diverse cultural and linguistic groups.

Reductions in levels of the Alzheimer's amyloid beta peptide after oral administration of ginsenosides

For millennia, ginseng and some of its components have been used to treat a wide variety of medical conditions, including age-related memory impairment. Because of its purported effects and apparently low rate of side effects, ginseng remains one of the top selling natural product remedies in the United States. Given its potential role for improving age-related memory impairments and its common use in China for the treatment of Alzheimer's disease-like symptoms, we analyzed the effects of commercially available preparations of ginseng on the accumulation of the Alzheimer's amyloid beta peptide (Abeta) in a cell-based model system. In this model system, ginseng treatment resulted in a significant reduction in the levels of Abeta in the conditioned medium. We next examined the effects of several compounds isolated from ginseng and found that certain ginsenosides lowered Abeta concentration in a dose-dependent manner with ginsenoside Rg3 having an approximate IC50 of under 25 microM against Abeta42. Furthermore, we found that three of these isolated components, ginsenoside Rg1, Rg3, and RE, resulted in significant reductions in the amount of Abeta detected in the brains of animals after single oral doses of these agents. The results indicate that ginseng itself, or purified ginsenosides, may have similarly useful effects in human disease.

Rhizoma acori graminei and its active principles protect PC-12 cells from the toxic effect of amyloid-beta peptide

The effects of water extracts of six medicinal herbs (Radix polygalae tenuifoliae, Radix salviae miltiorrhizae, Rhizoma acori graminei, Rhizoma pinelliae ternatae, Tuber curcumae and Scletrotium poriae cocos) on the cytotoxic action of Abeta(1-40) were tested with PC-12 cells. Only the extract of R. acori graminei (RAG) significantly decreased Abeta(1-40)-induced cell death. Further, eugenol and beta-asarone were isolated and identified as the major active principles. Both purified eugenol and beta-asarone protected PC-12 cells from the toxic effect of Abeta(1-40). Eugenol was active between 1 and 100 microM, and 10 microM eugenol gave approximately a 50% response. beta-Asarone was less potent and exhibited little, if any, activity at this concentration. Both eugenol and beta-asarone inhibited Ca(2+) intake by PC-12 cells: beta-asarone mainly inhibited basal Ca(2+) intake, whereas eugenol inhibited Abeta-induced Ca(2+) intake preferentially. These results suggest that eugenol may act by blocking Abeta-induced-Ca(2+) intake and provide a strong case for further pursuit of the therapeutic and prophylactic potentials of RAG and its active principles for the management of Alzheimer's disease.

In vitro antioxidant potentials of traditional Chinese medicine, Shengmai San and their relation to in vivo protective effect on cerebral oxidative damage in rats

The preventive effects of Shengmai San (SMS), a traditional Chinese herbal medicine (TCM), was studied on cerebral ischemia-reperfusion injury in rats as a model of antioxidant-based composite therapy. Two biochemical indicators of oxidative damage, thiobarbituric acid reactive substance (TBARS) formation and glutathione peroxidase (GPX) loss were measured in the brain after forebrain ischemia-reperfusion treatment and both were inhibited in all rats administered SMS (15 g original herbs/kg) 2 h before the ischemia-reperfusion. Histochemical study of the brain slice using TTC staining revealed that the SMS effectively reduced infarct area caused by the cerebral ischemia-reperfusion. The antioxidant potentials of SMS preparations were determined in vitro by five different assay methods and were related to the in vivo effectiveness of SMS in protection against brain damage. Inhibitory effect on TBARS formation in vivo showed better correlation with superoxide radical scavenging and DPPH quenching activity in vitro rather than with the other in vitro antioxidant indicators. On the other hand, the in vivo prevention of GPX activity loss showed better correlation with in vitro crocin bleaching inhibition than with the other in vitro antioxidant indicators. It was also suggested that the in vitro TBARS inhibitory activty of SMS is not a good indication to predict the in vivo effectiveness of SMS on inhibition of either TBARS formation or GPX activity loss.

Dementia research in China

There is little information on dementia research in China in the international literature. This paper is an overview of studies on dementia conducted in China. Studies on dementia research in China were identified through a literature search, as well as through consulting Chinese psychiatrists and neurologists with expertise in the field. These studies were then reviewed. Epidemiological studies on dementia in China find the rates of dementia at the lower end of rates in Caucasians. There seems to be regional variation in the ratio of vascular dementia to Alzheimer's disease in China. In addition to epidemiological studies, there are studies on the genetics, psychopathology, neurophysiology and drug treatment in dementia. There is much research activity in China in the field of dementia and further cross-cultural studies are useful to examine the cultural differences in various areas of dementia research.