Charlie Xue and coauthors from Guangdong Provincial Academy of Chinese Medical Sciences and Guangdong Provincial Hospital of Chinese Medicine, China, and RMIT University, Australia, performed a comprehensive, systematic search of the Encyclopedia of Traditional Chinese Medicine, a database of more than 1,000 Chinese medical books dating back to the fourth century.
In the article "Memory Impairment, Dementia and Alzheimer's Disease in Classical and Contemporary Traditional Chinese Medicine”, the authors describe specific mentions of signs and symptoms of memory impairment associated with ageing and the formulas and ingredients most commonly used to treat these disorders.
They note that Alzheimer’s Disease is a significant and increasing health issue in China and other Asian countries. Traditional medicines are commonly used in China for prevention and/or treatment of dementia, and it is a growing field of academic research.
The study sates: “The selection criteria identified 1498 citations of dementia and memory impairments derived from 277 different books written from circa 363 to 1945. In 91 of these citations, memory impairment was associated with ageing and was broadly consistent with the clinical features of Alzheimer’s Disease.
“Although the interventions varied in name, Poria cocos, Polygala tenuifolia, Rehmannia glutinosa, Panax ginseng, and Acorus species consistently appeared as ingredients in multiple formulas for memory impairment in the context of ageing.”
While researchers point out that historical use alone does not provide evidence that any of the traditional medicines were effective for memory impairment or Alzheimer’s Disease, they suggest experimental studies of the five most common and/or their constituents suggest benefits are plausible.
“P. ginsenghas improved cognitive outcomes in some clinical trials,” they write. “In rats with experimentally induced memory impairment, the ginsenosides Rg1 and Rg5 improved memory and task performance and the ginsenosides Rg1, Rg3, and Rg5 have all demonstrated down regulatory effects on beta-amyloid. The compound catalpol from R. glutinosa has shown neuroprotective effects in cells treated with beta-amyloid, and it may be able to increase the synthesis of neurotransmitter acetylcholine.”
Meanwhile an extract of P. tenuifolia was reported to protect neurones from damage by beta-amyloid, and in cognitively impaired mice, a triterpenoid saponin from Polygala roots improved learning and memory.
Furthermore, “the combination of Polygala, Acorus, and Poriaspecies showed antioxidant functions and improved learning in memory-impaired mice,” they add.
They suggest these and other traditional medicines may provide fertile fields for research into interventions for the management of memory impairments and Alzheimer’s disease.
“Many of the traditional medicines frequently used as ingredients in classical formulas for memory impairment consistent with clinical features of Alzheimer’s disease remain in contemporary use, and experimental studies suggest biological activities relevant to Alzheimer’s disease,” they concluded.
Source: The Journal of Alternative and Complementary Medicine
Volume: 22 Issue 9: September 1, 2016. doi:10.1089/acm.2016.0070
“Memory Impairment, Dementia, and Alzheimer's Disease in Classical and Contemporary Traditional Chinese Medicine”
Authors: Charlie Xue, et al.