Chronic hypoxic stress results in deposition of
lipofuscin granules in the CA3 region of hippocampal neurons which contributes to neurodegeneration and accelerated neuronal aging. Oxidative stress and mitophagy during
hypoxia are crucial to cause aggregation of these
lipofuscin granules in hypoxic neurons.
Salidroside, a
glucoside derivative of β-
Tyrosol, has been reported to protect hypoxic neurons through maintenance of mitochondrial activity. The present study is aimed at investigating the potential of
Salidroside in preventing mitophagy during chronic
hypoxia and identification of the molecular targets and underlying signaling mechanisms. In-silico analysis for interaction of
salidroside with Bcl-xL was carried out using VLife MDS software. The prophylactic efficacy of
Salidroside for amelioration of global
hypoxia induced neuronal aging was studied in adult male Sprague-Dawley rats exposed to hypobaric
hypoxia simulating an altitude of 7600 m for 21 days.
Salidroside was supplemented at a daily dose of 25 mg kg-1b.w. p.o. during hypoxic exposure. Ultra-structural and immune-histological studies were conducted to study
lipofuscin aggregation and mitophagy. In-silico findings on
salidroside mediated stabilization of Bcl-xL were validated by investigating its effect on downstream signaling molecules involved in mitophagy. Administration of
Salidroside reduced deposition of
lipofuscin in hypoxic CA3 hippocampal neurons and prevented mitophagy.
Salidroside stabilizes Bcl-xL in hypoxic neurons resulting in inhibition of PGAM5
phosphatase activity and maintenance of FUNDC1 in phosphorylated state.
Salidroside mediated inhibition of pFUNDC1 dephosphorylation prevents FUNDC1-LC3 II interaction which is crucial for mitophagy. The present study demonstrates potential of
Salidroside in preventing
lipofuscin deposition during chronic hypoxic stress.