Effect of silybin on hepatic cell membranes after damage by polycyclic aromatic hydrocarbons (PAH)

Young female NMRI mice were given a single intraperitoneal injection of a PAH mixture containing 3 micrometers benzo(a)pyrene in a suspension of 0.5 ml tricapryline. 3 and 4 days later a number of the mice received injections of 100 mg/kg body weight of Silybin in the tail vein. Thin sections of the animals' livers were studied under the electron microscope using the freeze fracture technique. Following intraperitoneal injection of the PAH suspension, and without treatment with Silybin, marked dilatation of the intercellular space and frequent occurrence of intracytoplasmic vacuoles was observed in addition to pronounced alterations in the hepatocytic nuclei and mitochondria. Following the administration of Silybin these alterations were no longer observed, though 50% of the cell membranes exhibited a marked band-like proliferation of the tight junctions. This observation may be interpreted as supporting the postulated membrane-stabilizing effects of Silybin.