PTGS2 and colitis: The onion bulb extract has been shown to both prevent and reverse colitis by modulating several pro-inflammatory signaling pathways, including the mechanistic target of rapamycin (mTOR), the mitogen-activated protein kinase family (MAPK), cyclooxygenase-2 (COX-2), and tissue inhibitors of metalloproteinases (TIMP), as well as several molecules involved in the apoptotic pathway (121, 133, 134).