Visit our Expo - Redox and Inflammation signaling 2012

VIII. Inflammation specific signaling Poster VIII, 27
Melphalan reduces the severity of experimental colitis in mice by blocking tumor
necrosis factor-alpha signaling pathway
Galina V. Shmarina, Alexander L. Pukhalsky, Vladimir A. Alioshkin and Alex
Sabelnikov
Research Centre for Medical Genetics, Moscow 115478, Gabrichevsky Institute of
Epidemilogy and Microbilogy, Moscow 125212, Russia, East Carolina University,
Greenvill, NC 27858, U.S.A. E-mail: osugariver@medgen.ru
In acute DSS-induced colitis nuclear factor (NF)-kappaB-dependent inflammatory cytokines
including tumor necrosis factor (TNF)-alpha are known to be up-regulated. We examined the
effects of alkylating drug melphalan on the sensitivity of mouse fibroblasts to TNF-alphainduced
cytitoxicity in vitro and on intestinal inflammation and NF-kappa B activation in
vivo. In vitro, low concentrations of melphalan protected fibroblastoid cells (L929) against
TNF-alpha-mediated apoptosis. The cells were pre-incubated with 0.0001 mg/ml of
melphalan for 1 h and then treated with recombinant TNF-alpha. A significant decrease in the
number of dead cells in comparison to the control (TNF-alpha treated cells without preincubation
with melphalan) was observed. In vivo, daily administration of melphalan
markedly reduced the severity of murine experimental colitis as determined by clinical and
quantitative histological criteria. Male BALB/c mice were exposed to 5 % (w/v) dextran
sulfate sodium (DSS) dissolved in drinking water for 5 days with or without daily melphalan
injections (0.025 mg/kg body weight, i.p.). Time-matched controls consisted of mice received
melphalan only, and those injected with phosphate buffered saline. At day 6 the mice were
sacrificed and the general signs of colitis had been evaluated. DSS-mice exhibited a
significant loss of the intestine length, pronounced elevation in blood white cells and marked
increase in relative spleen weight. Such changes were not so evident in DSS-mice treated with
melphalan. Histological analysis of colon biopsies showed that melphalan protected against
both the neutrophil infiltration and mucosal destruction. Furthermore, colonic NF-kappaB
DNA-binding activity, up-regulated in DSS-induced colitis, was suppressed by melphalan
treatment. Taken together, these results suggest that alkylating drug melphalan applied in noncytotoxic
concentrations may reduce the severity of experimental colitis in mice by blocking
TNF-alpha signaling pathway.
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