Effects of dibenzothioline and silymarin on the dry weight of isolated hepatocytes of rats acutely poisoned with phalloidin and alpha-amanitin.

The protective action of dibenzothioline and silymarin in the acute intoxication by phalloidin and alpha-amanitin has been studied on the basis of their ability to attenuate changes in dry mass distribution and class-pattern of the hepatocytes, as evaluated by microinterferometry. Protective agents were given to male rats 30 min before toxin, and the animals were sacrificed 3.0 h later. Both dibenzothioline and silymarin markedly counteract the toxic action of phalloidin and alpha-amanitin on the hepatocyte population, as revealed by a substantial prevention (a) of the striking displacement of hepatocytes in the intervals among the classes as regards phalloidin poisoning, and (b) of the number decrease of hepatocyte classes due to disappearance of the heaviest ones, of the shift of hepatocytes to the lighter classes, of the appearance of very light cells, of the displacement of hepatocytes into the class intervals and of the decrease in nuclear dry mass as regards alpha-amanitin. It is suggested that dibenzothioline and silymarin exert their protective action by a non-specific stabilization of the cell membrane.