The Concentration Screening Of The 8-methoxypsoralen Liposomal Gels And The Primary Pharmacodynamics Study

Objectives: To study the curative effect of experimental vitiligo to the 8-MOP liposomal gels, and to ensure the optimum concentration of 8-MOP liposomal gels.Methods: Different concentration levels of LMOP suspension were used to B16F1 murine melanoma cells in vitro, and comparing with 8-MOP liquors on the same concentration levels. MTT was used to study the proliferation of B16F1 cells. The melamin content was mesured by NaOH-assay, and the tyrosinase activity was detected by DOPA-oxidation. Comparing the proliferation rate, melanin content and tyrosinase activity of B16F1 cells, so as to preliminarily select the concentration levels of LMOP suspension. The experimental vitiligo models were prepared by chemical decolour method in Guinea Pigs. And we choose the Meladinine's recommeded level (0.15%) as high concentration, use the high, middle and low concentration levels (0.15%, 0.075 % , 0.03 % ) of LMOP gels to progress the pharmacodynamics comparative study, 8-MOP tincture (the dilution of Meladinine) was used as controll group, observing the melanin distribution, the number of DOPA active cells, the number of hair follicles contented melanin, the levels of ChE and MDA of the experimental vitiligo models.Results: Compared with 8-MOP liquor groups on the same concentration, in cultured B16F1 cells in vitro, LMOP groups in low concentrations (3, 7.5mg L-1 ) could significantly promote the proliferation, tyrosinase activity and melanin content (P<0.05) while significantly inhibit the proliferation and melanogenesis in high concentrations (15~ 30mg L-1, P<0.05) , furthermore B16F1 cells almost cannot exist in 30mg L-1 LMOP. In the treatment of experimental vitiligo, compared with 8-MOP tincture group, the regulation ability of 0.03% LMOP gel group was small, but MDA level of 0.03% group was the lowest of all; 0.075% LMOP gel group had significant differences regulation ability with 8-MOPtincture group (P<0.05) while MDA level lower than 8-MOP tincture group, but had no significance (P>0.05) . In 0.15% LMOP gel group, the regulation ability and MDA level were all highest, it suggest that it increase not only the curative effect but also the skin irritation at the same time.Conclusions: In clinical use, the optimum concentration of LMOP gel is 0.075%.