Antidepressant fluoxetine and its potential against colon tumors

Figure 2 Fluoxetine modulates nuclear factor kappa-B nuclear activity among subepithelial colonic cells. For this figure, groups of female C57BL/6 mice (25 g) consisted of control (CTRL) animals or received methylnitronitrosoguanidine (MNNG) treatment [four successive doses of MNNG (5 mg/mL; intrarectal deposits of 100 µL) twice a week for 2 wk], FLX treatment (30 mg/kg per day; intraperitoneal, ip) or MNNG + FLX treatment. FLX treatment was started after 2 wk from the end of MNNG treatment, and continued for the next 4 wk. All mice were euthanized by CO₂ exposure at week 8. Individual autopsies were performed and colon tissue samples were fixed in paraformaldehyde buffer (4%; 24 h). All experimental protocols were approved by the Internal Animal Care, Ethical and Use Committee (n° 068/2012). Immunohistochemistry was performed with anti-nuclear factor kappa-light-chain-enhancer of activated B cells [nuclear factor kappa-B (NF-κB), p50; clone C-19], nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB), alpha (IκB-α; clone N-20), beta (IκB-β; clone H-4). Antibodies were acquired from Santa Cruz Biotechnology (Heidelberg, Germany). A: Representative histological image of a colonic-longitudinal section labeled with anti-NF-κB antibody, picture taken at × 400 magnification and scale bar of 45 μm inserted. A cytoplasmic anti-NF-κB antibody positively cell detected within cryptal area (inset below; × 1000 magnification of the boxed region, middle-left). Nuclear-NF-κB protein detected in stromal cells (inset right-side; × 1000 magnification of the boxed region, middle-right). Graph shows the relative number of nuclear-NF-κB positive cells within colonic subepithelial areas (PCCS; ^bP < 0.01 vs MNNG without FLX, n = 4; FLX + MNNG, n = 4); B: Relative number of IκB-α positive cells (^aP < 0.05 vs MNNG without FLX, n = 4; FLX+MNNG, n = 4); and C: IκB-β positive cells within colon stromal areas (^aP < 0.05 vs MNNG without FLX, n = 5; FLX + MNNG, n = 4). FLX: Fluoxetine. PCCS: Pericryptal colonic stroma.