The effectiveness and safety of Jihwang-eumja (Dihuang Yizi) compared to Western medications in patients with Alzheimer's disease: A systematic review and meta-analysis

Dementia is a complicated neurocognitive syndrome characterized by severe impairment in memory, orientation, understanding, calculation, learning, language, and judgment. Dementia is usually diagnosed when symptoms are severe enough to disturb social activities and personal relationships [1].

Over 55 million people have dementia worldwide, and it is estimated to reach 78 million by 2030 [2]. The total economic costs caused by dementia were 279.6 billion dollars in 2000 and increased by 948 billion dollars in 2016, with an annual growth rate of 15.94% [3]. Thus, dementia is considered one of the main burdens of an aging society.

In the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5), dementia is classified as a major neurocognitive disorder and its subtype is determined by its underlying etiology and cause. The most common subtype is Alzheimer's disease (AD), which accounts for approximately 63.6% of all dementia cases, including 42.0% of AD cases and 21.6% of cases of combined pathology of Alzheimer's disease and vascular dementia [4]. AD is characterized by progressive loss of synapses and neurons, accumulation of amyloid plaques, neurofibrillary tangles, and prominent cholinergic deficits. Additionally, the hippocampus and cerebral cortex atrophy occur at the microscopic level [5,6].

Currently, pharmacological treatment is only symptomatic and is unsatisfactory for permanently stabilizing the disease [6]. Acetylcholinesterase inhibitors are used to improve the cholinergic function, and N-methyl-d-aspartate antagonists are used to alleviate neuropsychiatric symptoms by decreasing glutamate-induced excitotoxicity and neurodegeneration [6]. However, side effects have been reported in 15–78% of the cases, including gastrointestinal symptoms, headache, insomnia, agitation, confusion, and cardiac arrhythmia [7].

In traditional Korean medicine, various herbal medications have been studied for AD. In 2016 and 2020, systematic reviews revealed the potential effects of herbal medicines on cognition, the activities of daily living (ADL), and the behavioral and psychological symptoms of dementia in patients with AD [8,9]. Nevertheless, these studies mainly included herbal medicines and single herb extracts, leading to difficult clinical applications in traditional Korean medicine.

Jihwang-eumja is initially found in <Seongjechongnok> [10] and introduced in the ‘Wind’ part of <Donguibogam, Miscellaneous disorders 1> [11] that treats disabled legs and dysarthria caused by kidney insufficiency, rendering qi incapable of reaching under the tongue. Of these, renal insufficiency is considered the main pathogenesis of dementia in Korean traditional medicine [12]. It was reported that Jihwang-eumja was more effective than donepezil in decreasing β-amyloid expression levels in rat brain tissue [13]. In addition, another study showed that Jihwang-eumja reduced the activation of monoamine oxidase and acetylcholinesterase in a rat model [14].

To date, however, no clinical studies or systematic reviews have investigated the clinical effectiveness of Jihwang-eumja in patients with AD. Based on the medical classics and experimental evidence, a systematic review and meta-analysis were conducted in this study to verify the effectiveness and safety of Jihwang-eumja compared to Western medications in cognitive function and ADL in patients with AD.

留言 (0)

沒有登入
gif