Histology
Colon tissues fixed in neutral buffered formalin were trimmed, processed, and embedded in paraffin. Then 5-µm thick sliced tissues of the paraffin block were stained by hematoxylin and eosin (H&E). H&E stained colonic tissue sections were then scored according to the following semi-quantitative measurement system for three parameters: 1) severity of inflammation (0 = rare inflammatory cells in the lamina propria; 1 = increased numbers of granulocytes in the lamina propria; 2 = confluence of inflammatory cells extending into the submucosa; and 3 = transmural extension of the inflammatory infiltrate); 2) crypt damage (0 = intact crypts; 1 = loss of the basal one third; 2 = loss of the basal two thirds; 3 = entire crypt loss; 4 = change of epithelial surface with erosion; and 5 = confluent erosion); and 3) ulceration (0 = absence of ulcer; 1 = 1 or 2 foci of ulcerations; 2 = 3 or 4 foci of ulcerations; and 3 = confluent or extensive ulceration). Values from these three parameters were added to give a maximal histological score of 11.