Cytotoxicity studies of lasalocid and silibinin in rat hepatoma cell culture
The cvtoprotective effect of silibinin in course of cytotoxicity induced by lasalocid had been measured in rat hepatoma FaO cell line. In the course of the study, MTT test (cellular metabolism), coomassie brillant blue binding test - CBB (total cellular proteins), and LDH release test (membrane integrity) were applied. In addition, changes in the cell morphology after 24 h treatment were observed by light microscopy. The effective concentrations, EC₅₀ were quantified for each compound alone, whereas the nature of their co-action was assessed by isobologram plotting. Lasalocid EC₅₀ ranged from 4 to 10 µM and microphotographs showed significant morphological changes of the cells after 24 h exposure. Silibinin EC₅₀ ranged from 40 to 42 µM for MTT and CBB assays, and 63 µM for LDH assay, and no significant morphological changes occurred. When lasalocid EC₅₀ was used in combination with silibinin in 1-250 µM concentrations, the EC₅₀ values were plotted at 36 µM and 72 µM in MTT and LDH assays, respectively. Thus co-actions of the two drugs led to significant diminishing of lasalocid cytotoxicity in respect to cellular metabolism and membrane integrity. The isobolograms showed remarkable antagonistic effect of silibinin in the course of lasalocid cytotoxic action. Although a considerable interaction was concisely relevant to hepatoma cell line FaO, the promising results incline to extend the study on other in vitro models (primary hepatocytes), as well as to investigate in vivo the cytoprotective effect of silibinin against lasalocid in target animals.
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