Figure 5: A photomicrograph of buccal mucosa of rat in the methotrexate and green tea extract treated group, showing that the epithelium restores its integrity and thickness but it cover by irregular keratine laver, no congested blood vessels can be seen in the connective tissue (Al, H&E,x200; A2, PAS,x400). The collagen fibers stained blue and the cross sections of muscles appear nearly similar to that of the control group and stained deep red ( A3, Trichrome x400). Immunohistochemical expression of ki-67 in the buccal mucosa of rat showing mild positive immunoreaction in the nuclei of basal and sunrabasal epithelial cells (A4, A5, Immunohistochemistry x 400). Mild positive immunohistochemical expression of Bc1-2 in the epithelial cells cytoplasm of the buccal mucosa of rats (A6, immunohistochemistrv x 400).