MMP9 and brain edema: Additionally, the neuro-inflammation leads to increase in brain matrix metalloproteinase 9 (MMP-9) level that digest tight junction proteins such as occludin causing apparent disruption in BBB integrity and hence cerebral edema (Dhanda and Sandhir 2018; Sepehrinezhad et al. 2020; Abo El gheit et al. 2020).