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The study addressed the effect of colchicine and its derivatives on the protein levels of cytochrome P450 (CYP) 1A2, 2A6, 3A4, 2C9/19, and 2E1 isoforms. Primary human hepatocyte culture was the model of choice. Levels of individual CYP isoforms were detected using immunoblotting. Colchicine caused an increase of CYP2E1 protein content, colchiceine and N-deacetylcolchiceine induced isoforms CYP2C9, 2E1 and 3A4 whereas colchicoside induced CYP2C9 and 2E1. The levels of CYP1A2 and 2A6 were unaffected by any of tested compounds. Demecolcine and 3-demethylcolchicine had no effect on any studied P450 isoform. Since colchicine is an exclusive substrate of CYP3A4 whereas it induces CYP2E1, there is a suspicion rather at protein stabilization than at gene induction concerning induction origin.

Previously we have shown that perorally administered silymarin, a mixture of flavonolignans extracted from the seeds of Silybum marianum, possesses a hypocholesterolemic effect in rats fed high cholesterol diet enriched with fat. The aim of this paper was to complete the data concerning peroral and parenteral administration of silymarin. The rats fed standard laboratory diet did not respond to peroral administration of silymarin by decrease of serum cholesterol, but the mild increase in HDL cholesterol was found. Parenterally injected silymarin failed to reduce serum cholesterol both in rats fed high cholesterol diet and standard laboratory diet. The results suggest that silymarin could act either due to the fat-mediated improved bioavailability and/or by inhibiting of resorption of dietary cholesterol.

This article reviews chemical, pharmacological, and toxicological research relating to two principal benzo[c]phenanthridine alkaloids, namely sanguinarine and chelerythrine, in the period 1980-1994. The medical applications of these alkaloids in relation to their biological activities are discussed.

The cytotoxicity of 32 colchicinoids in isolated rat hepatocytes was studied. Their effect was examined by biochemical parameters-lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, lipid peroxidation and by changes in reduced glutathione level. Only compounds with methylsulfonyl group at C-10 were significantly hepatotoxic.

The effects of benzo[c]phenanthridine alkaloids sanguinarine (SA), chelerythrine (CHE), fagaronine (FA) and their dihydroderivates were tested on human leukocytes and lymphocytes, rat peritoneal mastocytes and primary cultured hepatocytes. The cytotoxicity of SA and CHE on hepatocytes is dose (35-100 microM) and time (1-3 h) dependent. Both alkaloids decrease chemiluminiscence of leukocytes and inhibit a creation of active E-rosets. The degranulation of mastocytes is inhibited only by CHE. Dihydroderivates of SA and CHE did not display any effect on studied cells, dihydrofagaronine exhibits a hepatotoxicity after 3 h.