Liver protection by silymarin: in vitro effect on dissociated rat hepatocytes.

The liver-protective effects of silymarin have been investigated in isolated hepatocytes suspended in vitro in sucrose solutions of graded hypotonicity. Cells preincubated with the drug at the concentration of 10(-4) M were found to be entirely resistant or relatively little affected when exposed to hypotonic solutions which have a lethal effect on a considerable proportion of the control liver cells, as shown by the determination in the cell preparations (1) of the proportion trypan blue-positive (broken) cells, (2) of the protein synthesizing capacity. The protection was reduced but not abolished upon removal of the drug and cell washing. A smaller effect was observed with a drug concentration of 10(-5) M. At 10(-6) M the effect was no longer detectable. Chlorpromazine, a drug which belongs to the group of the so called "unspecific membrane stabilizers", was without effect in this test.