The protective activity of pyridoxol L,2-pyrrolidon-5 carboxylate (metadoxine) was investigated in a rat model of carbon tetrachloride (CCL4)-induced hepatic fibrosis. After 6 weeks of CCl4 treatment, the animals developed fibrosis and inflammation of the liver while those treated with CCl4 + metadoxine had less severe lesions (P < 0.05). Since in liver fibroplasia there are quantitative changes of the extracellular matrix components and almost invariably a decrease in albumin synthesis, we have also investigated by Northern blot analysis the expression of the cellular fibronectin, pro-alpha 2(I)collagen and albumin genes. There were striking increases in fibronectin and pro-alpha 2(I)collagen mRNA contents in the livers of CCL4-treated animals and these enhancements were less evident in the metadoxine-treated rats. In contrast, albumin mRNA levels, almost identical in control and metadoxine-treated rats, were lower in the CCl4-treated animals. These data suggest that metadoxine might slow the development of CCl4-mediated liver fibrosis.