Immunohistochemical determination of cyclooxygenase-2 (COX-2) in hepatic, renal, gastric and intestinal tissues. Photomicrograph of a hepatic (A1), and renal (B1), gastric (C1) and intestinal (D1) sections of a rat from a normal control group. Photomicrograph of a hepatic (A2), and renal (B2), gastric (C2) and intestinal (D2) sections prepared from a diclofenac-control rat. Photomicrograph of a hepatic (A3), and renal (B3), gastric (C3) and intestinal (D3) sections prepared from a rat treated with royal jelly (150 mg/kg/day, P.O.) for 30 days along with diclofenac treatment. Photomicrograph of a hepatic (A4), and renal (B4), gastric (C4) and intestinal (D4) sections prepared from a rat treated with royal jelly (300 mg/kg/day, P.O.) for 30 days along with diclofenac treatment (COX-2 immunohistochemistry, H&E X 100).