Yokukansan improves behavioral and psychological symptoms of dementia by suppressing dopaminergic function

Impact of Plasma Donepezil Concentration on Behavioral and Psychological Symptoms of Dementia in Patients with Alzheimer’s Disease

Background/Aims

The behavioral and psychological symptoms of dementia (BPSD) detract from the quality of life of not only dementia patients but also their family members and caregivers. Donepezil is used to treat Alzheimer's disease and is metabolized via cytochrome P450 (CYP) 2D6 and CYP3A4/5. It is controversial whether donepezil improves or exacerbates BPSD. This study investigated the relationships among BPSD, the pharmacokinetics of donepezil including its metabolite, 6-O-desmethyl donepezil, genetic polymorphisms of CYPs and P-glycoprotein, and patient backgrounds in 52 patients with Alzheimer's disease.

Methods

BPSD were assessed using the Neuropsychiatric Inventory (NPI), with scores ≥20 points defined as severe BPSD. Plasma donepezil and 6-O-desmethyl donepezil concentrations were measured using liquid chromatography–tandem mass spectrometry.

Results

Although significant relationships between NPI scores and plasma donepezil concentrations were not seen, none of the 15 patients (29%) with high plasma donepezil concentrations (≥60 ng/mL) developed severe BPSD. Polymorphisms of CYP2D6, CYP3A5, and ABCB1 did not influence NPI scores. There were no significant relationships between NPI and patient background factors such as dosing regimen, concomitant use of other drugs, or laboratory test results. Two patients who underwent multiple blood samplings over 2 years showed an inverse correlation between plasma donepezil concentrations and NPI scores.

Discussion/Conclusions

These results indicate that higher plasma concentrations of donepezil contribute to preventing or alleviating rather than developing or deteriorating BPSD.

Herbal Medicine for Behavioral and Psychological Symptoms of Dementia: A Systematic Review and Meta-Analysis

Background: Dementia is a global health concern, causing serious health and socioeconomic burdens with population aging. The associated symptoms of dementia, called behavioral and psychological symptoms of dementia (BPSD), are factors contributing to the socioeconomic burden of dementia. Recently, herbal medicine (HM) has attracted attention as a potential complementary therapy for BPSD. Therefore, this systematic review was aimed at analyzing the effectiveness (or efficacy), safety, and research status of HM in BPSD management through a comprehensive review.

Methods: Thirteen electronic databases were searched comprehensively. Related clinical studies published until December 28, 2020, were collected. The methodological quality was evaluated using tools such as the Cochrane Collaboration’s risk of bias tool according to the study design. The effectiveness (or efficacy) was analyzed for randomized controlled trials (RCTs) only, and when sufficient homogeneity was assured, effect estimates were presented as mean difference (MD) and risk ratio (RR), with 95% confidence interval (CIs), through a meta-analysis.

Results: A total of 52 clinical studies, including 36 RCTs, were included in this review. As an adjunctive therapy, HM showed statistically significant benefits in BPSD severity assessed by the Behavior Pathology in Alzheimer’s Disease Rating Scale (combined with psychotropic drugs: MD = −3.48, 95% CI: −3.96 to −2.99; with anti-dementia drugs: MD = −2.81, 95% CI: −3.17 to −2.45) and Neuropsychiatric Inventory (with anti-dementia drugs: MD = −3.23, 95% CI: −4.06 to −2.40). Adverse events were significantly less frequent in the HM group (RR = 0.50; 95% CI: 0.28 to 0.88). However, the methodological quality of the RCTs included in this systematic review was not optimal overall.

Conclusion: According to the findings of this review, HM may be associated with additional benefits in BPSD treatment, particularly when used as an adjunct to conventional medications, including psychotropic and anti-dementia drugs. However, considering the methodological quality of the included RCTs, this clinical evidence is not robust. Nevertheless, dementia is a global health concern, and considering the limitations of conventional psychotropic drugs for BPSD, a major cause of the disease burden, HM appears to be a promising complementary therapy that warrants further research.

Decreased Behavioral Abnormalities After Treatment with Combined Donepezil and Yokukansankachimpihange in Alzheimer Disease: An Observational Study. The Osaki-Tajiri Project

INTRODUCTION

Yokukansan is one of the traditional herbal medicines (Kampo medicine in Japan) commonly used in the treatment of the Behavioral and Psychological Symptoms of Dementia (BPSD). We performed an observational study using yokukansankachimpihange, which contains a nobiletin-rich Citrus reticulata, to determine whether it could improve BPSD as well as cognitive impairment in patients with Alzheimer disease (NINCDS-ADRDA).

METHODS

Forty-six (23 vs. 23) patients were enrolled in the study sample (donepezil group vs. donepezil + yokukansankachimpihange group). The BPSD were assessed using the Frequency-Weighted Behavioral Pathology in Alzheimer Disease Rating Scale (BEHAVE-AD-FW). The Mini-Mental State Examination and the Digit Symbol test of WAIS-R were used to evaluate impairment of global cognitive function and executive function, respectively.

RESULTS

No significant changes in the cognitive functions or the total BPSD scores were noted for either treatment group. Regarding the subscales of the BPSD, the subscale of Diurnal Rhythm showed a significant decrease after the treatment, and those of Affective Disturbance and Anxiety and Phobias tended to be decreased. The donepezil + yokukansankachimpihange group had a lower rate of use of anti-psychotics compared with the donepezil group, although this was not statistically significant.

CONCLUSION

These results suggest that combined treatment of yokukansankachimpihange with donepezil has a positive clinical effect on improving the behavioral abnormalities, despite the lack of any effect on cognitive functions. Improvements in the diurnal rhythm may improve affective disturbance and anxiety. Thus, yokukansankachimpihange is considered to have a mild stabilizing effect on emotion.

Sansoninto as evidence-based remedial medicine for depression-like behavior

In vitro screening methods using cultured Neuro2a cells to examine the activation (phosphorylation) of extracellular signal-regulated kinase (ERK) 1/2 and promotion of neurite outgrowth revealed that the extracts of 5 Kampo (Japanese traditional) formulations have potential as medicines for the treatment of behavioral abnormalities. Since sansoninto (SAT) extract exerted stronger effects than the other candidates tested, we investigated whether its oral administration ameliorates the pathologies of some mouse models of behavioral impairments. The results obtained suggested that SAT extract exerted anti-depression-like effects in the forced swim test, which may be mediated by the up-regulated expression of brain-derived neurotrophic factor (BDNF) in the hippocampus. They may also be mediated by the enhanced phosphorylation of the cAMP response element-binding protein (CREB) via the mitogen-activated protein kinase (MAPK) cascade and Ca²⁺/calmodulin-dependent protein kinase II (CaMK II) cascade, a downstream signaling cascade of the N-methyl-D-aspartate (NMDA) receptor. These results indicate that the extract of SAT has potential as a new remedial medicine in the treatment of depression-like behavior.