Dl-3-n-butylphthalide promotes remyelination process in cerebral white matter in rats subjected to ischemic stroke

Remyelination has been widely noticed as an important repair mechanism triggered after a stroke-induced white matter injury, but it often fails due to the lack of recruitment of the oligodendrocyte progenitor cells (OPCs) to the demyelinated area and the inadequate differentiation of OPCs. Racemic dl-3-n-butylphthalide (dl-NBP) has been reported to improve the functional recovery in animal models of vascular dementia, Alzheimer's disease (AD) and ischemic stroke. DI-NBP (70 mg/kg) by oral gavage for two weeks from day 7 after a stroke was administered in the study, the treatment promoted differentiation and maturation of OPCs in perilesional white matter and enhanced the length of crossing corticospinal tract (CST) fibers into the denervated hemispheres. These effects could be linked to increased expression levels of brain-derived neurotrophic factor (BDNF) and the reduced expression of neurite outgrowth inhibitor (NogoA) in the perilesional area in dl-NBP group. However, dl-NBP did not increase the numbers of neuron/glia type 2 (NG2)-positive and oligodendrocyte lineage transcription factor 2 (Olig2)-positive cells in the subventricular zone. Our data highlight the effects of dl-NBP in the remyelination process and reveal the therapeutic potential of this approach in cerebral ischemia.