During course of colitis, upregulation of COX-2 produces an arsenal of PGE2 and TXB2 which aggravates hyperemia and edema whereas in the intestine, while activation of iNOS led to NO release which weakens the integrity of colon by peroxynitrite synthesis, a powerful oxidizing agent which is formed through superoxide anion and NO reaction62. Here, NOS2 is linked to colitis.