Title:A Review of Three Commonly Used Herbs Which Enhance Memory and New Evidences Which Show Their Combination Could Improve Memory in Young Animals
Volume: 17
Issue: 16
Author(s): Fei Hong, Liju Wang, Sharon L. Wu, H. C. Tang, Ou Sha, Maria S.M. Wai and David T. Yew*
Affiliation:
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong,China
Keywords:
Gingko biloba, Polygala tenuifolia, Lycii fructus, memory, aging, herbal interaction.
Abstract: Background: This review looks into the herbs Gingko biloba, Polygala tenuifolia, and Lycii
fructus for their widely studied neuroprotective properties. In particular, we investigated memory enhancing
effect of these herbs, and their potential synergetic effect on memory with new data. Sixmonth
treated mice demonstrated shorter escape latency in water maze and shorter arrival time in a
consolidated memory task. Immunochemistry showed evident increase in superoxide dismutase activities
in the prefrontal cortex, implying protection against free radicals during aging. Discrete increase of
catecholaminergic neurons was found in the prefrontal cortex, hippocampus, corpus striatum, and midbrain,
suggesting better memory and better control on mood and behavior. Necrotic cells in the brain
decreased as indicated by immunocytochemistry of lactic dehydrogenase. Terminal deoxynucleotidyl
transferase dUTP nick end labeling showed no apoptotic cells in most brain areas in high dose group.
Biochemistry revealed increase of dopaminergic cells in treatment groups at prefrontal cortex, and in
the hippocampus and cerebellum of the high dose group. Most 6-month groups showed increase of serotonin
in all three areas. For the high dose group, GABA increased in the hippocampus but not prefrontal
cortex, which would help induce sleep at night. Protein kinase C increased in most groups at
prefrontal cortex, hippocampus and cerebellum, signifying increase of possible signal transduction
pathways for memory or other nervous activations.
Conclusion: Our results intimate that the interaction of the three herbs exerts beneficial effects on
memory, associated cognitive function, and necrosis. Future investigations based on the present data
shall aid development of clinically relevant medication.
