VSL#3 probiotic upregulates intestinal mucosal alkaline sphingomyelinase and reduces inflammation.

BACKGROUND: Alkaline sphingomyelinase, an enzyme found exclusively in bile and the intestinal brush border, hydrolyzes sphingomyelin into ceramide, sphingosine and sphingosine-1-phosphate, thereby inducing epithelial apoptosis. Reduced levels of alkaline sphingomyelinase have been found in premalignant and malignant intestinal epithelia and in ulcerative colitis tissue. Probiotic bacteria can be a source of sphingomyelinase. OBJECTIVE: To determine the effect of VSL#3 probiotic therapy on mucosal levels of alkaline sphingomyelinase, both in a mouse model of colitis and in patients with ulcerative colitis. METHODS: Interleukin-10 gene-deficient (IL10KO) and wild type control mice were treated with VSL#3 (10(9) colony-forming units per day) for three weeks, after which alkaline sphingomyelinase activity was measured in ileal and colonic tissue. As well, 15 patients with ulcerative colitis were treated with VSL#3 (900 billion bacteria two times per day for five weeks). Alkaline sphingomyelinase activity was measured through biopsies and comparison of ulcerative colitis disease activity index scores obtained before and after treatment. RESULTS: Lowered alkaline sphingomyelinase levels were seen in the colon (P=0.02) and ileum (P=0.04) of IL10KO mice, as compared with controls. Treatment of these mice with VSL#3 resulted in upregulation of mucosal alkaline sphingomyelinase activity in both the colon (P=0.04) and the ileum (P=0.01). VSL#3 treatment of human patients who had ulcerative colitis decreased mean (+/- SEM) ulcerative colitis disease activity index scores from 5.3+/-1.8946 to 0.70+/-0.34 (P=0.02) and increased mucosal alkaline sphingomyelinase activity. CONCLUSION: Mucosal alkaline sphingomyelinase activity is reduced in the intestine of IL10KO mice with colitis and in humans with ulcerative colitis. VSL#3 probiotic therapy upregulates mucosal alkaline sphingomyelinase activity.

Apoptosis induced by oxaliplatin in human colon cancer HCT15 cell line.

BACKGROUND: Oxaliplatin (L-OHP), active in a wide range of human and animal tumours, also CDDP-resistant, possesses unique molecular characteristics of action. However, the mechanisms by which the damage induced by L-OHP triggers a death signal are not yet fully defined. MATERIALS AND METHODS: After L-OHP treatment of the HCT15 human colon cancer cell line, apoptosis was evaluated by DNA laddering detection and by flow cytometry; the effect on specific caspase-3, -8 and -9 inhibitors, mitochondrial membrane permeability transition, cytochrome C release and expression of CD95 and CD95L were also assessed. RESULTS: HCT15 cells underwent apoptosis when treated with all used drug concentrations (7-25 microM). Treatment of cells with L-OHP resulted in the activation of caspase-8, -9 and -3, in a mitochondrial membrane depolarisation, and in an increase of CD95 receptor and CD95 ligand levels. CONCLUSION: The results correlated well with the ability of L-OHP to induce apoptosis and give further insights into the mechanisms underlying the L-OHP-induced apoptosis of tumor cells.