Background: Pyrroloquinoline quinone is an anionic, water-soluble compound with antioxidant
characteristic. The role of pyrroloquinoline quinone in pharmacology and nutrition has attracted
wide attention of researchers. Although a few experiments have confirmed that pyrroloquinoline
quinone plays an obvious effective role in neuroprotection. There are few reports about the effect
of pyrroloquinoline quinone on traumatic brain injury. Traumatic brain injury is one of the leading
causes for adult disability and death. So far, there are no effective treatment methods for the injury because
of its complex pathophysiology.
Method: In the present study, a model of traumatic brain injury in rat was established to study the role
of pyrroloquinoline quinone in central nervous system injury.
Results: The results showed that the protein expression of cleaved-Caspase 3/Caspase 3 increased after
traumatic brain injury and the expression decreased by treatment with 2mM pyrroloquinoline quinone.
Terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) staining displayed that
the TUNEL positive signals were up-regulated after traumatic brain injury and were down-regulated
after treatment with 2mM pyrroloquinoline quinone. The protein expression of LC3II/LC3I or
lysosome-associated membrane protein 2(LAMP2) was elevated after traumatic brain injury and reduced
after administration with 2mM pyrroloquinoline quinone. Transmission electron microscopy
showed that the number of autophagosomes increased markedly after traumatic brain injury and decreased
on administration of 2mM pyrroloquinoline quinone. Electroencephalogram indicated that
pyrroloquinoline quinone improved brain electrophysiological function after traumatic brain injury.
The results of CCK-8 test showed that pyrroloquinoline quinone could increase the viability of primary
astrocyte treated with Glutamate. Lactate dehydrogenase (LDH) assay demonstrated that pyrroloquinoline
quinone decreased LDH content in primary astrocyte exposed to Glutamate.
Conclusion: Pyrroloquinoline quinone could play a neuroprotective role after traumatic brain injury in
rat, which might be associated with inhibiting apoptosis and autophagy caused by traumatic brain injury.