Likewise, UDCA is anti-apoptotic in a number of cell lines, but this effect has not been investigated in bone cells. Therefore, the consequences of bilirubin and LCA on apoptosis, and if UDCA has antiapoptotic effects have been assessed on osteoblastic cells. Material and Methods: The

experiments were performed in primary human osteoblasts (hOB) and human osteosarcoma cell selleck chemicals line (Saos-2). Cells were treated at different times and concentrations of camptothecin as proapoptotic agent, and UDCA, LCA and bilirubin. Apoptosis was determined by DNA fragmentation, caspase-3 activity, flow cytometry (annexin V-FITC labeling), and gene expression of Bcl-2-associated X protein (BAX) as antiapoptotic, and BCL2 and BCL2-like 1 protein (BCL2L) as proapoptotic genes, respectively. Results: Both LCA (10 μM) and bilirubin (50 μM) significantly induced cell apoptosis as indicated by DNA fragmentation (4.7 and

3.7 fold vs control, respectively, p<0.001), with parallel results by caspase-3 activity and flow cytometry. UDCA (100 μM) alone had no consequences on DNA fragmentation. However, UDCA (10 μM) reduced significantly the apoptotic effects of camptothecin (0.5 μM) by 61%, (p<0.001), and counteracted the apoptotic effects of LCA and bilirubin, as observed by DNA fragmentation (56% and 60%, respectively, p<0.001), caspase-3 activity and flow cytometry. Moreover, both bilirubin 50 μM and LCA 10 μM up-regulated BAX in Saos-2 cells, at levels as high as those observed with CAM 0.5 μM. UDCA (10 μM) down-regulated BAX Dabrafenib by 67 %, and it diminished or completely abolished the up-regulation of BAX induced by CAM, bilirubin and LCA, in a dose-dependent manner, in both Saos-2 and hOB cultures. Opposite effects of CAM, bilirubin and LCA were found regarding the expression of BCL2 and BCL2L1, the two genes linked to apoptosis repression. The addition of UDCA in the experiments, partially

PAK5 or totally counteracted the decreased expression of these two genes induced by bilirubin or LCA in a dose-dependent manner. Conclusions: Bilirubin and lithocholic acid induce apoptosis in osteoblastic cells. Ursodeoxycholic acid has clear antiapoptotic effects counteracting the consequences of these two substances increased in cholestasis. These results suggest that ursodeoxycholic acid may have further benefitial effects on neutralizing the decreased bone formation in patients with cholestasis. Disclosures: The following people have nothing to disclose: Silvia Ruiz-Gaspa, Marta Dubreuil, Nuria Guañabens, Andres Combalia, Pilar Peris, Ana Monegal, Albert Pares Background: Pruritus of acute viral hepatitis (AVH) is often the most troublesome symptom to treat. The exact pathogenesis of pruritus is unknown, but therapeutic options such as cholestyramine, ursodeoxycholic acid (UDCA), rifampicin, 5-HT receptor antagonists (Ondansetron), being used with variable outcomes. In one study Opioid antagonists (Naltrexone) has been tried clinically with good success in relieving pruritus.

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