Salvianolic acid B alleviates neurological injury by upregulating stanniocalcin 1 expression

Salvianolic acid B (Sal B) is a representative component of phenolic acids derived from the dried root and rhizome of Salvia miltiorrhiza Bge. (Labiatae), which promotes angiogenesis in myocardial infarction and diabetic cardiomyopathy. However, whether Sal B has a neuroprotective function in ischemic stroke by promoting angiogenesis is still unclear.In the present study, ischemic stroke models were induced in rats by middle cerebral artery occlusion (MCAO), and Sal B (10 or 20 mg/kg/d) was intraperitoneally injected according to a previous study. Neurological deficits were evaluated by the modified Longa five-point scale, modified Bederson scores and cerebral infarction sizes by triphenyltetrazolium chloride (TTC) staining. Apoptotic cells were tested by cleaved-caspase3 immunofluorescence staining and an in situ cell death (TUNEL) detection kit. Human umbilical vein endothelial cells (HUVECs) exposed to hypoxia were used to investigate the effects of Sal B on angiogenesis and tube formation in vitro.Sal B ameliorated the neurological deficits, decreased the cerebral infarction volumes in rats with ischemic stroke, significantly increased the expression of vascular endothelial growth factor receptor 2 (VEGFR2) and VEGFA and promoted angiogenesis both in vivo and in vitro. Furthermore, Sal B increased stanniocalcin 1 (STC1) expression, induced the phosphorylation of protein kinase B (AKT) and mammalian target of rapamycin (mTOR) activity, enhanced cell migration, and activated VEGFR2/VEGFA signaling in endothelial cells.This study showed that Sal B promoted angiogenesis and alleviated neurological apoptosis in rats with ischemic stroke by promoting STC1.