1992 Volume 12 Issue 1 Pages 19-26
Caffeine through drinking water, at low (100μg/ml), moderate (200 and 400μg/ml) and high (800μg/ml) doses, as well as by intragastric administration at 40 and 160mg/kg doses, increased the hepatic and pulmonary cytochrome P-450 (Cyt. P-450) levels in mice. The extent of elevation in the enzyme levels was dependent on the dose of caffeine. Maximum inducibility of hepatic arylhydrocarbon hydroxylase (AHH) was observed at the highest doses of caffeine by the two modes of treatment. However, the activities of AHH at the highest doses were not statistically different from the enzyme activities at the lowest doses. Caffeine treatment of animals through drinking water did not change the pulmonary AHH activity, whereas the intragastric administration of caffeine increased the enzyme activity in the lungs. Moreover, intragastric administration was more effective in inducing the hepatic AHH activity. Maximum increases in hepatic and pulmonary glutathione-S-transferase (GST), and in hepatic reduced glutathione (GSH), by the two modes of caffeine treatment of the animals was similar. The enhancement in AHH, Cyt. P-450, GST, and GSH may account for the anticarcinogenic activity of caffeine.
