TNF and Alzheimer disease: Metformin also downregulates glial activation markers Iba1 and GFAP in STZ-induced AD rats [167, 168, 172, 179], while reducing the overexpression of IL-1ß, IL-6, TNF-α and TGF-ß in both scopolamine- and STZ-induced models [170, 176, 177, 181].