Fig. 2.

Dietary nitrate improves the expression of intestinal epithelia barrier-related proteins in aging mice. a–c Immunofluorescence staining of Claudin 1 (red), ZO-1 (magenta), E-cadherin (green) and 4′, 6-diamidino-2-phenylindole (DAPI) (blue) in the colonic tissues in different groups. Scale bar: 25 and 50 μm. Data were shown as mean ± SD (n = 5). d Western blot analysis of claudin 1, ZO-1, E-cadherin expression in colon tissues of young, aged and nitrate (n = 3 in each group). Data were shown as mean ± SD. ****Indicates significance at P < 0.0001, ***P < 0.001, **P < 0.01, *P < 0.05, ns no significant