NEUROENDOCRINOLOGY, cilt.1, sa.1, ss.1-10, 2023 (SCI-Expanded)
Abstract
Aim: The
aim of this study was to investigate how melatonin administration for 3 days or
7 days following cerebral ischemia injury (CI/R) would affect autophagy, and
therefore, survival in neurons of the penumbra region. Moreover, it was also
aimed to determine how this melatonin treatment would affect the neurological
deficit score and rotarod and adhesive removal test durations.
Material
and Method: Focal CI (90 min) was
achieved in a total of 105 rats
utilizing a middle cerebral artery occlusion model. After the start of
reperfusion, the groups were treated with melatonin (10 mg/kg/day) for 3-days
or 7-days. On all groups, neurological deficit scoring, rotarod and adhesive removal test
were executed during reperfusion. Infarct areas were determined by TTC staining
at the end of the 3rd and 7th days of reperfusion.
Beclin-1, LC3, p62 and caspase-3 protein levels were assessed using Western blot and immunofluorescence
methods in
the brain tissues. Moreover, penumbra areas were evaluated by transmission electron microscopy
(TEM).
Results: Following
CI, it was observed that melatonin treatment improved the rotarod and adhesive
removal test durations from day 5 and reduced the infarct area after CI. It also induced autophagic
proteins Beclin-1, LC3 and p62 and suppressed the apoptotic protein cleaved
caspase-3. According to TEM findings, melatonin
treatment partially reduced the damage in neurons after CI.
Conclusion:
Melatonin treatment following CI reduced the infarct area and induced the
autophagic proteins Beclin-1, LC3 and p62 via inhibiting the apoptotic
caspase-3 protein.
In
addition, reflections of the melatonin treatment started to show on
neurological tests from the 5th day.
Keywords: Cerebral ischemia,
autophagy, melatonin, neurological deficit score, rotarod test, adhesive
removal test