The impact of ginsenosides on cognitive deficits in experimental animal studies of Alzheimer's disease: a systematic review.
BACKGROUND
The efficacy of ginsenoside treatment on cognitive decline in individuals with Alzheimer's disease (AD) has yet to be investigated. In this protocal, we conducted a systematic review to evaluate the effect of ginsenosides on cognitive deficits in experimental rodent AD models.


METHODS
We identified eligible studies by searching seven electronic databases spanning from January 1980 to October 2014. We assessed the study quality, evaluated the efficacy of ginsenoside treatment, and performed a stratified meta-analysis and meta-regression analysis to assess the influence of the study design on ginsenoside efficacy.


RESULTS
Twelve studies fulfilled our inclusion criteria from a total of 283 publications. The overall methodological quality of these studies was poor. The meta-analysis revealed that ginsenosides have a statistically significant positive effect on cognitive performance in experimental AD models. The stratified analysis revealed that ginsenoside Rg1 had the greatest effect on acquisition and retention memory in AD models. The effect size was significantly higher for both acquisition and retention memory in studies that used female animals compared with male animals.


CONCLUSIONS
We conclude that ginsenosides might reduce cognitive deficits in AD models. However, additional well-designed and well-reported animal studies are needed to inform further clinical investigations.
Department of Integrated Chinese and Western Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan, 410011, PR China.|Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, PR China.|Key Laboratory of Chinese Gan of State Administration of Traditional Chinese Medicine of China, Changsha, 410008, Hunan, PR China.
Chenxia
C
Sheng
Department of Integrated Chinese and Western Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan, 410011, PR China.
Weijun
W
Peng
Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, PR China.|Key Laboratory of Chinese Gan of State Administration of Traditional Chinese Medicine of China, Changsha, 410008, Hunan, PR China.
Zi-An
ZA
Xia
Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, PR China.|Key Laboratory of Chinese Gan of State Administration of Traditional Chinese Medicine of China, Changsha, 410008, Hunan, PR China.
Yang
Y
Wang
Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, PR China.|Key Laboratory of Chinese Gan of State Administration of Traditional Chinese Medicine of China, Changsha, 410008, Hunan, PR China.
Zeqi
Z
Chen
Department of Integrated Chinese and Western Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan, 410011, PR China.
Nanxiang
N
Su
Department of Integrated Chinese and Western Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan, 410011, PR China. ericwangzhe@126.com.
Zhe
Z
Wang
D000544:Alzheimer Disease / Q000188:drug therapy*; D016229:Amyloid beta-Peptides / Q000502:physiology; D000818:Animals; D003071:Cognition / Q000187:drug effects; D003072:Cognition Disorders / Q000188:drug therapy*; D004195:Disease Models, Animal; D005260:Female; D036145:Ginsenosides / Q000494:pharmacology / Q000502:physiology / Q000627:therapeutic use*; D008568:Memory / Q000187:drug effects; D051379:Mice; D051381:Rats
D016229:Amyloid beta-Peptides; D036145:Ginsenosides