Fig. 3.

The effect of ferulic acid (FA) and vanillic acid (VA) on the expression of tight junction proteins. The mRNA expression of (A) zonula occludens 1 (ZO-1), (B) occludin, and (C) claudin-1 was quantitated by real-time PCR, and the protein expression of (D) ZO-1, (E) occludin, and (F) claudin-1 was detected by immunohistochemical staining. In real-time PCR, the data were shown as means ± SD (n = 6) of mRNA relative expressions. In immunohistochemical staining, the pictures shown were the representative of 6 individual stained sections photographed at 100× magnification, and tight junction proteins were stained yellow or brown-yellow. Scale bar, 10 μm. CTL, a basal diet; FA, a basal diet containing 4,000 mg/kg ferulic acid; VA, a basal diet supplemented with 4,000 mg/kg vanillic acid. Data were shown as means ± SD (n = 6). Single asterisk (∗) refers to a significant difference (P < 0.05).