Aminoguanidine has both an anti-inflammatory effect on experimental colitis and a proliferative effect on colonic mucosal cells

Background: The aim of this study was to assess the effect of aminoguanidin e (AG) on developed colitis and cell proliferation. Methods: Colitis was in duced by means of trinitrobenzene sulphonic acid (TNB) in male Wistar rats weighing about 250 g. Seven days after induction of TNB colitis the rats we re divided into two groups at random, and one group was orally treated with 1.5 mu mol/kg AG each day. We assessed the effect of AG by measuring the m ucosal damage, the ulcer area, myeloperoxidase (MPO) activity, inducible ni tric oxide synthase (iNOs) activity, and nitrogen oxide in serum 7 days aft er the beginning of treatment. Results: AG significantly ameliorated the ma croscopic damage score (AG versus control, 5.25 +/- 0.80 versus 7.50 +/- 0. 50), the microscopic damage score (5.88 +/- 1.13 versus 9.25 +/- 0.31), ulc er area (0.57 +/- 0.14 versus 1.24 +/- 0.17 cm(2)), decreased MPO activity (51.5 +/- 9.4 versus 192.2 +/- 60 units/g tissue), and nitrogen oxide in se rum (27.2 +/- 1.4 versus 32.3 +/- 1.8 mu M) but did not decrease iNOs activ ity (8732 +/- 435 versus 8672 +/- 357 cpm/g tissue). Moreover, AG accelerat ed T84 cell proliferation in a dose-dependent manner. Conclusions: These re sults suggest that AG ameliorates TNB colitis not only by its anti-inflamma tory effect but also by accelerating the proliferation of colonic mucosal c ells. AG, accordingly, might well be a useful new medicine to ameliorate in flammatory bowel disease.