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Lisosan G is a powder of grain registered as an alimentary integrator. The treatment of rats for 4 days with 0.5 g Lisosan G/kg had no effect on various drug metabolizing enzymes. Experiments in vitro showed that Lisosan G had radical scavenger activity. A confirmation of the antioxidative property of Lisosan G was also confirmed when it was administered in vivo to carbon tetrachloride (CCl(4))-intoxicated rats. The toxicity caused by CCl(4)-treatment of rats was restored to the control levels when the rats were given Lisosan G for 4 days before CCl(4). Lisosan G thus does not interfere with drug metabolizing system but has antioxidant properties and protects against CCl(4)-induced hepatotoxicity.

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Porcine cytochrome P450 (CYP) 1A2 was purified to electrophoretic homogeneity from the hepatic microsomes of beta-naphthoflavone-treated male pigs. In a reconstituted system, this enzyme showed a good catalytic activity towards caffeine, acetanilide, and methoxyresorufin, all known markers of mammalian CYP1A2. Using 3'- and 5'-rapid amplification of coding DNA (cDNA) ends (RACE), we amplified from the liver RNA of control pigs a full-length 1827 bp cDNA containing an open reading frame of 1548 bp which encoded a putative CYP1A2 protein of 516 amino acids and an estimated Mr of 58 380 Da. Reverse transcriptase-polymerase chain reaction (RT-PCR) experiments showed that the messenger RNA (mRNA) of CYP1A2 was expressed in liver, heart and nasal mucosa but not in lung, small intestine, kidney and brain. Using the pCW vector containing a N-terminal modified cDNA, pig CYP1A2 was expressed in Escherichia coli. 3-[(3-Chloroamidopropyl)dimethylmmonio]-1-propane-sulfonate (CHAPS)-solubilized E. coli preparations expressing CYP1A2 produced a functionally isoform which, in a reconstituted system, was catalytically active toward ethoxyresorufin and methoxyresorufin showing K(m)'s similar to those obtained with CYP1A2 purified from pig liver or human recombinant CYP1A2. Taken together, these results demonstrate that domestic pigs have a functionally active CYP1A2 gene well expressed in the liver with biochemical properties quite similar to those corresponding to the human enzyme.