0.5mg of natural ginsenoside mixture and 0.8μCl of synthesized 14C-ginsenosides were administered orally to rat and killed at one hour after the ginsenoside administration and the liver was fractionated into nuclear fraction, mitrochondria,
microsomes
and cytosol fraction. Radioactivity distribution in subcellular fractions of the liver showed that 32% of total radioactivity absorbed in the liver was in cytosol fraction but a significant portion of the radioactivity was also found in
mitochondria
(26.6%) and microsomal fraction (18.1%). 5.8% of the total radioactivity was recovered from the nuclear fraction as well. This suggested that ginsenosides might be distributed into all subcellular fractions. Activities of mitochondrial aldehyde
dehydrogenase, lactate dehydrogenase and malate dehydrogenase of the liver of rat at two hours after the ginsenoside administration found appreciably stimulated, suggesting that the ginsenoside concentration in the liver might be around 10-5%,
since
optimum concentration for most enzyme catalyzed reactions in vitro were known to be 10-6~10-4%. A significant portion of the radioactivity recovered from subcellular fractions of the liver was found in protein fractions, suggesting that proteins
might
interact with ginsenosides, Examination of protein-ginsenoside interation by gel filtration, equilibrium dialysis and amonium sulfate precipitation technique suggested that proteins and ginsenosides do not covalently but weakly combined. When
ginsenoside Rb1 and Rg1 were incubated with rat liver cytosolic enzymes for 20 min, the above ginsenosides were hydrolyzed quickly, suggesting that ginsenosides might be rapidly hydrolyzed and metabolized in the liver. It was also observed in
vitro
that
the ginsenosides such as Rb1 and Rg1 were easily hydrolyzed by rat liver cytosol preparation suggesting that absorbed ginsenosides might by quickly hydrolyzed and metabolized in the liver
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