Fig. 5

Zerumbone decreases Aβ deposition and microglial activation in APP/PS1 mice. Five-month-old APP/PS1–21 mice, five males and two females, were treated for 20 days with zerumbone (25 mg/kg by daily gavage). a–d Representative photomicrographs of β-amyloid (Aβ) immunohistochemical staining and ionized calcium-binding adaptor molecule 1 (Iba-1) immunohistochemical staining in the cortex of vehicle- and zerumbone-treated APP/PS1 mice. Zerumbone reduced Aβ deposition and microglial activation in the cortex of APP/PS1 mice. e–h Representative photomicrographs of Aβ immunohistochemical staining and Iba-1 immunohistochemical staining in the hippocampus of vehicle- and zerumbone-treated APP/PS1 mice. Zerumbone reduced Aβ deposition and microglial activation in the hippocampus of APP/PS1 mice. Scale bar in (a–h) = 100 mm. i Quantification of the numbers of Aβ plaques in the cortex and hippocampus of APP/PS1 mice. j Quantification of the percentage areas of the Aβ staining in the cortex and hippocampus of APP/PS1 mice. k Quantification of the percentage areas of the Iba-1 staining in the cortex and hippocampus of APP/PS1 mice. l Soluble and insoluble Aβ protein levels were measured in half-brain homogenates by ELISA. AD mice treated with Zerumbone decreased the concentration of Aβ in brains significantly. m Representative photomicrographs of glial fibrillary acidic protein (GFAP) immunofluorescence in the hippocampus of vehicle- and zerumbone-treated APP/PS1 mice. Statistical analysis showed no significant differences between the groups. n Shape analyses of two-dimensional somatic projections based on maximum length (L) and projection area (A) in confocal images of Iba-1-immunostained microglia using ImageJ. The somatic shape index (L:A ratio) increases in rod-shaped somata. The L, A, and L:A ratio of microglial somata were measured. o Representative photomicrographs of Aβ and Iba-1 double immunofluorescence in the cortex of vehicle- and zerumbone-treated APP/PS1 mice. Zerumbone treatment increased the phagocytosis of Aβ by Iba-1⁺ microglia (n = 7). Data are presented as median and interquartile ranges. *p < 0.05