Memory-Enhancing Effects of the Crude Extract of Polygala tenuifolia on Aged Mice.

Zongyang Li,Xinmin Liu,Yamin Liu,Tai-Ping Fan,Yonghong Liao,Ruile Pan,Qi Chang,Liwei Wang,Zhi Guo

doi:10.1155/2014/392324

Abstract

Learning and memory disorders arise from distinct age-associated processes, and aging animals are often used as a model of memory impairment. The root of Polygala tenuifolia has been commonly used in some Asian countries as memory enhancer and its memory improvement has been reported in various animal models. However, there is less research to verify its effect on memory functions in aged animals. Herein, the memory-enhancing effects of the crude extract of Polygala tenuifolia (EPT) on normal aged mice were assessed by Morris water maze (MWM) and step-down passive avoidance tests. In MWM tests, the impaired spatial memory of the aged mice was partly reversed by EPT (100 and 200 mg/kg; P < 0.05) as compared with the aged control mice. In step-down tests, the nonspatial memory of the aged mice was improved by EPT (100 and 200 mg/kg; P < 0.05). Additionally, EPT could increase superoxide dismutase (SOD) and catalase (CAT) activities, inhibit monoamine oxidase (MAO) and acetyl cholinesterase (AChE) activities, and decrease the levels of malondialdehyde (MDA) in the brain tissue of the aged mice. The results showed that EPT improved memory functions of the aged mice probably via its antioxidant properties and via decreasing the activities of MAO and AChE.

Highlights

As a result of increased human life expectancy, age-related learning and memory disorders have become prevalent in the aging population, even in the absence of neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease
A number of studies have revealed that the root of Polygala tenuifolia could improve learning and memory function in animal models induced by scopolamine [5], KCN [6], β-amyloid peptide [7], stress, hypoxia [8], and accelerated senescence [9]
We aim to investigate the effects of the crude extract of Polygala tenuifolia (EPT) on learning and memory impairments of the normal aged mice

Summary

Introduction

As a result of increased human life expectancy, age-related learning and memory disorders have become prevalent in the aging population, even in the absence of neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. To tackle such a major global healthcare issue, it is vital to develop effective prophylactic and therapeutic agents for enhancing and maintaining memory functions before the onset of memory impairments [1,2,3]. The root of Polygala tenuifolia, a well-known medicinal plant in TCM, named as “Yuan Zhi,” has been commonly used as memory enhancer in China, and it is included in some traditional prescriptions treating central nervous system disturbances, such as amnesia and dementia [4]. There is less research to verify the memory-enhancing effects of Polygala tenuifolia on the normal aged animals

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Conclusion