Abstract
Chios mastic gum (CMG), a resin derived from Pistacia lentiscus var. chia, is known since ancient times for its pharmacological activities. CYP1A1 and CYP1A2 enzymes are among the most involved in the biotransformation of chemicals and the metabolic activation of pro-carcinogens. Previous studies referring to the modulation of these enzymes by CMG have revealed findings of unclear biological and toxicological significance. For this purpose, the modulation of CYP1A1 and CYP1A2 enzymes in the liver of male Wistar rats following oral administration of CMG extract (CMGE), at the levels of mRNA and CYP1A1 enzyme activity, was compared to respective enzyme modulation following oral administration of a well-known bioactive natural product, caffeine, as control compound known to involve hepatic enzymes in its metabolism. mRNA levels of Cyp1a1 and Cyp1a2 were measured by reverse transcription real-time polymerase chain reaction and their relative quantification was calculated. CYP1A1 enzyme induction was measured through the activity of ethoxyresorufin-O-deethylase (EROD). The results indicated that administration of CMGE at the recommended pharmaceutical dose does not induce significant transcriptional modulation of Cyp1a1/2 and subsequent enzyme activity induction of CYP1A1 while effects of the same order of magnitude were observed in the same test system following the administration of caffeine at the mean daily consumed levels. The outcome of this study further confirms the lack of any toxicological or biological significance of the specific findings on liver following the administration of CMGE.