Sagebrush is very chemically active and produces polyphenol in abundance. A limited number of wild animals, including the endangered sage-grouse Centrocercus urophasianus, browse selectively on sagebrush. It is hypothesized that observed dietary selectivity of wildlife is influenced by polyphenols present in individual sagebrush plants that impact wildlife’s ability to metabolize xenobiotics. The enzyme cytochrome P-450 1A1 (CYP1A1) belongs to the highly conserved CYP1A enzyme family, which catalyzes many reactions for the bioactivation and detoxification of xenobiotics. CYP1A1 expression is induced by some xenobiotics, including benzo[a]pyrene (BaP), many of which are also substrates of the enzyme. In this study, the effects of polyphenols extracted from browsed and non-browsed 3-tip Artemisia tripartita and Wyoming Artemisia tridentata ssp. Wyomingensis sagebrush on the expression of CYP1A1 were characterized. CYP1A1 was induced in cultured HepG2 human hepatocytes using BaP and the subsequent enzyme activity was measured in a fluorescent assay. Results show that sagebrush polyphenols from all sagebrush studied inhibit BaP-induced CYP1A1 expression in a dose dependent manner. This suggests that the polyphenols animals ingest consuming sagebrush may influence their ability to effectively metabolize and clear xenobiotics. This study will allow for a greater understanding of the way the chemical environment impacts wildlife.

Sagebrush Polyphenols Inhibit Detoxification Enzyme CYP1A1