Ophiopogonin D protects against cerebral ischemia–reperfusion injury in rats by inhibiting STAT3 phosphorylation

Our aim is to explore the protective effect of ophiopogonin D (OPD) on cerebral ischemia/reperfusion injury (CIRI) and its relevant molecular mechanisms. OPD effect on brain injury of CIRI rats was evaluated using 2,3,5-triphenyltetrazolium chloride staining, neurological deficit score, brain water content, hematoxylin and eosin staining, Nissl staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling staining. Immunofluorescence, immunohistochemistry, qRT-PCR, Western blot, and relative kits were used for detecting inflammatory factors, oxidative stress related factors, and mRNA and protein levels. The Cell Counting Kit-8 assay and flow cytometry were applied for assessing the viability and apoptosis of oxygen-glucose deprivation)/reoxygenation (OGD/R)-induced PC12 cells. OPD ameliorated brain injury via inhibiting neurons apoptosis, oxidative stress, and inflammatory response in cerebral infarction rats. In addition, we found that OPD attenuated the apoptosis, oxidative stress and inflammatory response in OGD/R-induced PC12 cells. Both in CIRI rats and OGD/R-induced PC12 cells, OPD was demonstrated to inhibit signal transducer and activator of transcription 3 (STAT3) phosphorylation. Moreover, Colivelin TFA (a STAT3 activator) reversed OPD effect on the apoptosis, oxidative stress, and inflammatory response in OGD/R-induced PC12 cells. Our findings demonstrated that OPD could protect against CIRI in rats by inhibiting STAT3 phosphorylation.