The effects of Tabernaemontana divaricata root extract on amyloid beta-peptide 25-35 peptides induced cognitive deficits in mice.
ETHNOPHAMACOLOGICAL RELEVANCE: Tabernaemontana divaricata (TD), a Thai medicinal herb, has been widely used as an analgesic, sedative, or a cough syrup. Moreover, it has been used in traditional rejuvenation remedies as for preventing forgetfulness and improving the memory.


OBJECTIVE
The present study aimed to determine the effect of TD on Abeta25-35 peptides induced cognitive deficits and acetylcholinesterase activity in mice.


METHODS
Mice were pretreated with TDE (250, 500 and 1,000 mg/kg body weight) for 28 days and then received i.c.v. injection of Abeta25-35 peptides. Cognitive performance was evaluated using the Morris water maze (MWM) and step-down avoidance test. The Ellman's colorimetric method was used to investigate the levels of cortical and hippocampal AChE activity.


RESULTS
Abeta25-35 peptides induced the memory impairment and the increased levels of cortical and hippocampal AChE activity. The consumption of TDE significantly improved the memory impairment and attenuated the brain levels of AChE activity induced by Abeta25-35 peptides.


CONCLUSIONS
These findings suggest that subchronic administration of TDE might prevent the Abeta25-35 peptides induced memory deficits by decreasing the AChE activity level. Therefore TDE could potentially be one of nootropic supplements for those elderly people suffering from dementia such as the AD patients.
Nakdook
Walika
W
Department of Physiology, Faculty of Medical Science Naresuan University, Phitsanulok 65000, Thailand.
Khongsombat
Onrawee
O
Taepavarapruk
Pornnarin
P
Taepavarapruk
Niwat
N
Ingkaninan
Kornkanok
K
D000110:Acetylcholinesterase / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000187:drug effects*; D000818:Animals; D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology; D008297:Male; D018782:Maze Learning; D051379:Mice; D008813:Mice, Inbred ICR; D010446:Peptide Fragments / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D018517:Plant Roots / Q000737:chemistry*; D030014:Tabernaemontana / Q000737:chemistry*
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D010936:Plant Extracts; C074636:amyloid beta-protein (25-35); D000110:Acetylcholinesterase