The effective therapy of cyclosporine A with drug delivery system in experimental colitis.

Cyclosporine A (CyA) is a useful immunosuppressive agent for steroid-dependent or steroid-refractory ulcerative colitis. However, side effects have been reported in clinical trials of ulcerative colitis treated with CyA. Biodegradable microspheres (MS) have been investigated as drug delivery system. We evaluated the effect of a drug delivery system with poly(d,l-lactic acid)-MS containing CyA. Colitis was induced in C57BL/6 mice by 3% dextran sulfate sodium (DSS). Mice with DSS-induced colitis were treated with oral administration of CyA or CyA-MS: CyA (0.2 mg/kg/day)-MS; CyA (2 mg/kg/kg)-MS). Serum levels of CyA were significantly less elevated after oral administration of CyA (2 mg/kg/day)-MS compared with CyA (2 mg/kg/day) (CyA (2 mg/kg/day), 44.7 ± 0.8 ng/ml; CyA (2 mg/kg/day)-MS, 7.7 ± 1.3 ng/ml). The body weight at day 10 was significantly recovered in the mice treated with CyA (0.2 mg/kg/day)-MS and CyA (2 mg/kg/day)-MS compared with CyA (0). The histological score and myeloperoxidase activity in the mice treated with CyA-MS was significantly lower than CyA (0). Gene expressions of interleukin-1β (IL-1β), IL-6, and CXCL1 in the mice treated with CyA (0.2 mg/kg/day)-MS and CyA (2 mg/kg/day)-MS were downregulated compared with CyA (0)-MS. CyA-MS might be possible to treat ulcerative colitis effectively by decreasing the total dosage without the elevation of the serum level or the side effects of CyA.