Fig. 4

Histological examination of mice organs after exposure to Ref-Au or E175. A Haematoxylin–eosin staining of tissue sections from the jejunum, colon, liver and spleen of mice orally exposed to Ref-Au (10 µg/kg BW/d) or E175 (10 µg/kg BW/d) for 13 weeks. Arrows show inflammation of the intestinal mucosa with localized ulceration in the Ref-Au nanomaterial-treated group. In the E175-treated mice, arrowheads show erosion of the upper part of the villi. Magnification ×200. Mu: muscle; Vi: villi; Cr: crypt; Ep: epithelium; *: intestinal lumen; CV: central vein; SC: splenic corpuscle. B Histological score in the jejunum, colon, liver and spleen of mice orally exposed to Ref-Au (10 µg/kg BW/d) or E175 (10 µg/kg BW/d) for 13 weeks. Data are expressed as the mean ± SEM. *P < 0.05; one-way ANOVA with post hoc Tukey’s test