VEGFA and brain ischemia: 10% HS can alleviate BBB permeability induced by cerebral ischemia via downregulating the astrocyte‐derived VEGF protein in focal ischemic stroke in rats; the mechanism by which this occurs may involve HS reducing the release of IL‐1β by inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulating the astrocyte‐derived VEGF expression through the IL‐1β/IL1R1/NF‐кB signaling pathway in astrocytes.