Abstract
Aims: This study was designed to demonstrate potential neuroprotective
and autophagic activity of exenatide in rodent AD model. Methods: Thirty
adult Sprague-Dawley male rats were divided into 3 groups (10 rats
each); Group 1; control normal group, Group 2; AD pathological group,
Group 3; exenatide treated group. All drugs were given intraperitoneal
(IP) for 42 days. Behavioral changes using Morris water maze test has
been evaluated, gene expressions of beclin-1 and the mammalian target of
rapamycin (mTOR) in the hippocampus were assessed. Examination of
hippocampal tissue using hematoxylin & eosin (H&E) stain and
ultrastructural analyses were also done. Data were analyzed by using the
statistical package for the social sciences (SPSS). Results: Exenatide
alleviated both behavioral and pathological changes compared to
pathological group. Exenatide treated group was found to improve
autophagic activity by increasing beclin-1 and decreasing mTOR gene
expression. Exenatide treatment significantly prevented hippocampal
neuronal degeneration demonstrated by H&E. Moreover, accumulation of
autophagic vacuoles in ultrastructure study of hippocampus, alleviated
in exenatide group compared to pathological group indicating enhanced
autophagic activity by exenatide. Conclusion: The results of the present
study clearly indicated exenatide might have beneficial effects on
impaired cognitive performance and hippocampal neuronal viability in AD
by increasing autophagic activity. Increased beclin-1 seems to be the
initiating player in this disease modifying effect and this supports the
assumption of a disease modifying activity of exenatide through the
autophagic activity.