CellCept 500mg CellCept 500 contains Mycophenolate Mofetil, an immunosuppressive agent that functions as a prodrug for mycophenolic acid. It acts by non-competitively inhibiting inosine monophosphate dehydrogenase (IMPDH), an enzyme crucial for the de novo synthesis of purines in activated T and B lymphocytes. By blocking lymphocyte proliferation and antibody formation, it dampens the body's immune attack against non-self tissue, effectively preventing organ rejection in allogeneic renal, cardiac, or hepatic transplant recipients.