Combined Phloretin and Human Platelet-rich Plasma Effectively Preserved Integrities of Brain Structure and Neurological Function in Rat after Traumatic Brain Damage.

Background: This study tested whether phloretin (a brain-edema inhibitors) would augment therapeutic impact of human-derived platelet-rich plasma (hPRP) on attenuating brain-hemorrhagic volume (BHV) and preserving the neurologic function in rodent following acute traumatic brain damage (TBD).

Methods: Rats (n=40) were separated into group-1 (sham-control), group-2 (TBD), group-3 [TBD + phloretin (80mg/kg/dose by intra-peritoneal administration at 30min and days 2/3 followed-by TBD), group-4 (TBD + PRP/80μL by left intra-carotid-artery injection at 3h after TBD) and group-5 (TBD + phloretin + hPRP) and cerebral tissues were harvested by day 28 after TBD.

Results: The brain MRI at day 28 revealed that the BHV was lowest in group 1, highest in group 2 and significantly lower in group 5 than in groups 3/4, but it was similar between groups 3/4, whereas neurological function displayed a opposite pattern of BHV among the groups (all p<0.0001). By 72h, the protein levels of upstream (HGMB1/TLR-2/TLR-4/MyD88/Mal/TRAM/ TRIF/TRAF6/IKK-α/IKK-ß/p-NF-κB) and downstream (IL-1ß/TNF-α/iNOS) inflammation signalings, apoptosis (caspase3/PARP) and fibrosis (Smad3/TGF-ß) biomarkers and flow cytometric assessment of inflammation cells (CD11b/c+//Ly6G+/PMO+) and early (AN-V+/PI-)/late (AN-V+/PI+) mononuclear-cell apoptosis displayed a similar manner of BHV among the groups (all p<0.0001). Cell number of inflammatory (CD68+/MMP9+) and brain-swelling/myelin-damaged (AQP4+/ GFAP+) mediators revealed a similar way, whereas the neuronal-myelin (Doublecortin+/NeuN/nestin) mediators exhibited an inverse manner of BHV among the groups (all p<0.0001).

Conclusion: Combination of phloretin and hPRP regimen was better than just one treatment to offer synergic benefits for protecting the brain against TBD.