Immunohistochemical staining for caspase-3, cytochrome 2E1, and nuclear factor-kappa B in rat liver sections. Normal rats (a, b and c, respectively) showing few number of positive hepatocytes for caspase-3 and cytochrome 2E1 as brownish cytoplasmic stain and nuclear factor-kappa B as brownish nuclear stain (black arrows), thioacetamide-intoxicated rats (d, e, and f, respectively) showing few positive hepatocytes (centrilobular and periportal areas) with mild density for caspase-3, and many positive hepatocytes (centrilobular and periportal areas) with severe density cytochrome 2E1 and nuclear factor-kappa B (black arrows), meanwhile, silymarin (g, h, and i, respectively) and resveratrol (j, k, and l, respectively)-treated rats showing many positive hepatocytes (periportal areas) with moderate density for caspase-3 and few positive hepatocytes (periportal areas) with mild density cytochrome 2E1 and nuclear factor-kappa B (black arrows), (IHC, DAB, ×200)