Event-related brain potential changes after Choto-san administration in stroke patients with mild cognitive impairments

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.

Quantitative Analysis and Biological Efficacies regarding the Neuroprotective and Antineuroinflammatory Actions of the Herbal Formula Jodeungsan in HT22 Hippocampal Cells and BV-2 Microglia

Jodeungsan (JDS) is a traditional herbal formula that comprises seven medicinal herbs and is broadly utilized to treat hypertension, dementia, and headache. However, the effects of JDS and its herbal components on neurodegenerative diseases have not been reported. We examined the inhibitory effects of JDS and its seven components on neuronal cell death and inflammation using HT22 hippocampal cells and BV-2 microglia, respectively. Among its seven herbal components, Uncaria sinensis (US), Chrysanthemum morifolium (CM), Zingiber officinale (ZO), Pinellia ternata (PT), Citrus unshiu (CU), and Poria cocos (PC) exhibited significant neuroprotective effects in HT22 cells. In BV-2 cells, JDS significantly suppressed the production of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), indicating the antineuroinflammatory activity of JDS. In addition, the herbal extracts from ZO, Panax ginseng (PG), PT, CU, and PC exhibited inhibitory effects on the inflammatory response in microglia. These data imply that the JDS effect on neurodegeneration occurs via coordination among its seven components. To establish a quality control for JDS, a simultaneous analysis using five standard compounds identified hesperidin (37.892 ± 1.228 mg/g) as the most abundant phytochemical of JDS. Further investigation of the combinatorial activities of two or more standard compounds will be necessary to verify their antineurodegenerative regulatory mechanisms.

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.

Review of plants and their constituents in the therapy of cerebral ischemia

Cerebral ischemia is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. This leads to cerebral hypoxia and thus to the death of neuronal cells or stroke. The limited number of medicines currently available for patients following ischemic stroke and insufficient data on efficiency of these chemicals in the treatment of stroke led us to the search for novel therapeutic approaches. Recent studies have focused on the possible capacity of natural compounds extracted from vegetables and fruits, to prevent human disabilities caused by cerebral ischemia. In this review, we will discuss some plants and their constituents that may protect brain ischemia or delay the neurological disorders following a stroke. We have reviewed different studies in scientific databases that investigate herbal compounds and their effects on cerebral ischemia.

Therapeutic effects of traditional herbal medicine on cerebral ischemia: a perspective of vascular protection

Although many agents for acute ischemic stroke treatment have been developed from extensive preclinical studies, most have failed in clinical trials. As a result, researchers are seeking other methods or agents based on previous studies. Among the various prospective approaches, vascular protection might be the key for development of therapeutic agents for stroke and for improvements in the efficacy and safety of conventional therapies. Traditional medicines in Asian countries are based on clinical experiences and literature accumulated over thousands of years. To date, many studies have used traditional herbal medicines to prove or develop new agents based on stroke treatments mentioned in traditional medicinal theory or other clinical data. In the current review, we describe the vascular factors related to ischemic brain damage and the herbal medicines that impact these factors, including Salviae Miltiorrhizae Radix, Notoginseng Radix, and Curcumae Rhizoma, based on scientific reports and traditional medical theory. Further, we point out the problems associated with herbal medicines in stroke research and propose better methodologies to address these problems.

Kampo formulations, chotosan, and yokukansan, for dementia therapy: existing clinical and preclinical evidence

Cognitive deficits and behavioral and psychological symptoms of dementia (BPSD) are typical features of patients with dementia such as Alzheimer's disease (AD), vascular dementia (VD), and other forms of senile dementia. Clinical evidence has demonstrated the potential usefulness of chotosan (CTS) and yokukansan (YKS), traditional herbal formulations called Kampo medicines, in the treatment of cognitive disturbance and BPSD in dementia patients, although the indications targeted by CTS and YKS in Kampo medicine differ. The availability of CTS and YKS for treating dementia patients is supported by preclinical studies using animal models of dementia that include cognitive/emotional deficits caused by aging and diabetes, dementia risk factors. These studies have led not only to the concept of a neuronal basis for the CTS- and YKS-induced amelioration of cognitive function and emotional/psychiatric symptom-related behavior in animal models, but also to a proposal that ingredient(s) of Uncariae Uncis cum Ramulus, a medicinal herb included in CTS and YKS, may play an important role in the actions of these formulae in dementia patients. Further studies are needed to clarify the active ingredients of these formulae and their target endogenous molecules implicated in the anti-dementia drug-like actions.

Chotosan ameliorates cognitive and emotional deficits in an animal model of type 2 diabetes: possible involvement of cholinergic and VEGF/PDGF mechanisms in the brain

BACKGROUND

Diabetes is one of the risk factors for cognitive deficits such as Alzheimer's disease. To obtain a better understanding of the anti-dementia effect of chotosan (CTS), a Kampo formula, we investigated its effects on cognitive and emotional deficits of type 2 diabetic db/db mice and putative mechanism(s) underlying the effects.

METHODS

Seven-week-old db/db mice received daily administration of CTS (375 - 750 mg/kg, p.o.) and the reference drug tacrine (THA: 2.5 mg/kg, i.p.) during an experimental period of 7 weeks. From the age of 9-week-old, the animals underwent the novel object recognition test, the modified Y-maze test, and the water maze test to elucidate cognitive performance and the elevated plus maze test to elucidate anxiety-related behavior. After completing behavioral studies, Western blotting and immunohistochemical studies were conducted.

RESULTS

Compared with age-matched non-diabetic control strain (m/m) mice, db/db mice exhibited impaired cognitive performance and an increased level of anxiety. CTS ameliorated cognitive and emotional deficits of db/db mice, whereas THA improved only cognitive performance. The phosphorylated levels of Akt and PKCα in the hippocampus were significantly lower and higher, respectively, in db/db mice than in m/m mice. Expression levels of the hippocampal cholinergic marker proteins and the number of the septal cholinergic neurons were also reduced in db/db mice compared with those in m/m mice. Moreover, the db/db mice had significantly reduced levels of vasculogenesis/angiogenesis factors, vascular endothelial growth factor (VEGF), VEGF receptor type 2, platelet-derived growth factor-B, and PDGF receptor β, in the hippocampus. CTS and THA treatment reversed these neurochemical and histological alterations caused by diabetes.

CONCLUSION

These results suggest that CTS ameliorates diabetes-induced cognitive deficits by protecting central cholinergic and VEGF/PDGF systems via Akt signaling pathway and that CTS exhibits the anxiolytic effect via neuronal mechanism(s) independent of cholinergic or VEGF/PDGF systems in db/db mice.

A chinese herbal medicine, tokishakuyakusan, reduces the worsening of impairments and independence after stroke: a 1-year randomized, controlled trial

In post-stroke patients, the recurrence of stroke and progression of impairments lead to a bedridden state and dementia. As for their treatments, only anti-hypertension and anti-coagulation therapies to prevent the recurrence of stroke are available. In Asia, post-stroke patients with impairments are often treated with herbal medicine. The present study evaluated the effectiveness of tokishakuyakusan (TS) in improving the impairment and independence in post-stroke patients. Thirty-one post-stroke patients (mean age = 81.4 years) were recruited and enrolled. Participants were randomly assigned to the TS group (n = 16) or non-treatment (control) group (n = 15) and treated for 12 months. Impairments were assessed using the Stroke Impairment Assessment Set (SIAS). Independence was evaluated using the functional independence measure (FIM). For each outcome measure, mean change was calculated every 3 months. The results were that impairments according to SIAS did not significantly change in the TS group. In contrast, SIAS significantly worsened in the control group. There was a significant difference between the two groups. In each term of SIAS, affected lower extremity scores, abdominal muscle strength, function of visuospatial perception, and so forth. in the TS group were better than those in the control group. Independence according to FIM did not change significantly in the TS group. In contrast, FIM significantly worsened in the control group. There was also a significant difference between the two groups. In conclusion, TS was considered to suppress the impairments of lower limbs and to exert a favorable effect on cerebral function for post-stroke patients.

Treatment of behavioral and psychological symptoms of Alzheimer-type dementia with Yokukansan in clinical practice

The efficacy and safety of the kampo medicine Yokukansan (YKS, TJ-54) in the treatment of behavioral and psychological symptoms of dementia (BPSD) were investigated in patients with Alzheimer's disease (AD) in an open-label study. This study included 26 patients who had been diagnosed as having AD and were not treated with donepezil hydrochloride. These patients were administered YKS (7.5g/day) for four weeks to investigate the changes in neuropsychological test results and care burden in the period from the start to completion of the study treatment. The Neuropsychiatric Inventory (NPI) was used for evaluation of BPSD, the Mini-Mental State Examination (MMSE) for evaluation of cognitive functions, the Zarit burden interview for evaluation of the caregiver's burden, Disability Assessment of Dementia (DAD) for evaluation of activities of daily living (ADL) and Self-Rating Depression Scale (SDS) for evaluation of the caregiver's depression. No significant change was seen in MMSE and DAD after four weeks of treatment, but the mean NPI total score decreased significantly. Furthermore, among the NPI subscales, a statistically significant decrease in score was not seen, however, a clinically significant decrease was seen in terms of hallucinations, agitation, anxiety, irritability or abnormal behavior. No significant changes were seen in caregiver's burden after four weeks of treatment. No serious adverse reactions to YKS were observed. The results of this study suggested that YKS may be an effective and well-tolerated drug in the treatment of BPSD in AD patients.

[Medicinal interest of Poria cocos (= Wolfiporia extensa)]

The sclerotium of Poria cocos has been used in the Chinese pharmacopoeia during thousands of years. In this note several aspects about the biology and nomenclature of this fungus are summarized, with emphasis on its composition and therapeutic applications.

A randomized cross-over study of a traditional Japanese medicine (kampo), yokukansan, in the treatment of the behavioural and psychological symptoms of dementia

The effectiveness and safety of yokukansan (TJ-54), a traditional Japanese medicine (kampo) for the treatment of the behavioural and psychological symptoms of dementia (BPSD), were evaluated in 106 patients diagnosed as having Alzheimer's disease (AD) (including mixed-type dementia) or dementia with Lewy bodies. Patients were randomly assigned to group A (TJ-54 treatment in period I and no treatment in period II; each period lasting 4 wk) or group B (no treatment in period I and TJ-54 treatment in period II). BPSD and cognitive functions were evaluated using the Neuropsychiatric Inventory (NPI) and the Mini-Mental State Examination (MMSE), respectively. Activities of daily living (ADL) were evaluated using Instrumental Activities of Daily Living (IADL) in outpatients and the Barthel Index in in-patients. For the safety evaluation, adverse events were investigated. Significant improvements in mean total NPI score associated with TJ-54 treatment were observed in both periods (Wilcoxon test, p=0.040 in period I and p=0.048 in period II). The mean NPI scores significantly improved during TJ-54 treatment in groups A and B (p=0.002 and p=0.007, respectively) but not during periods of no treatment. Among the NPI subscales, significant improvements were observed in delusions, hallucinations, agitation/aggression, depression, anxiety, and irritability/lability. The effects of TJ-54 persisted for 1 month without any psychological withdrawal symptoms in group A. TJ-54 did not show any effect on either cognitive function or ADL. No serious adverse reactions were observed. The present study suggests that TJ-54 is an effective and well-tolerated treatment for patients with BPSD.