Background Shengui Sansheng Pulvis (SSP) has about 300 years history used for
stroke treatment, and evidences suggest it has beneficial effects on neuro-angiogenesis and cerebral energy metabolic amelioration post-
stroke. However, its protective action and mechanisms on blood-brain barrier (BBB) is still unknown. Purpose Based on multiple neuroprotective properties of
vasoactive intestinal peptide (VIP) in
neurological disorders, we investigate if SSP maintaining BBB integrity is associated with VIP pathway in rat permanent
middle cerebral artery occlusion (MCAo) model. Methods Three doses of SSP extraction were administered orally. Evaluations of motor and balance abilities and detection of
brain edema were performed, and BBB permeability were assessed by
Evans blue (EB) staining. Primary brain microvascular endothelial cells (BMECs) were subjected to
oxygen-
glucose deprivation, and incubated with high dose SSP
drug-containing serum and VIP-antagonist respectively. Transendothelial electrical resistance (TEER) assay and
Tetramethylrhodamine isothiocyanate (
TRITC)-
dextran (4.4 kDa) and
fluorescein isothiocyanate (
FITC)-dextran (70 kDa) were used to evaluate the features of paracellular junction. Western blot detected the expressions of
Claudin-5, ZO-1,
Occludin and
VE-cadherin,
matrix metalloproteinase (
MMP) 2/9 and
VIP receptors 1/2, and immunofluorescence staining tested VIP and
Claudin-5 expressions. Results Our results show that SSP significantly reduces EB infiltration in dose-dependent manner in vivo and attenuates
TRITC-
dextran and
FITC-dextran diffusion in vitro, and strengthens endothelial junctional complexes as represented by decreasing
Claudin-5, ZO-1,
Occludin and
VE-cadherin degradations and
MMP 2/9 expression, as well as promoting TEER in BMECs after
ischemia. Moreover, it suggests that SSP notably enhances VIP and its receptors 1/2 expressions. VIP-antagonist exacerbates paracellular barrier of BMECs, while the result is reversed after incubation with high dose SSP
drug-containing serum. Additionally, SSP also improve
brain edema and motor and balance abilities after
ischemic stroke. Conclusions we firstly demonstrate that the ameliorated efficacy of SSP on BBB permeability is related to the enhancements of VIP and its receptors, suggesting SSP might be an effective therapeutic agent on maintaining BBB integrity post-
stroke.