Flavonoids are found in a vast number of dietary fruits and vegetables and play an important role in decreasing incidence of heart disease, cancer, stroke and other degenerative diseases, which is thought to occur through their ability to scavenge reactive free radicals. Previous work in our laboratory showed that flavonoid-containing polyphenolic extracts made from the foliage of Artemisia tridentata ssp. tridentata, or basin big sagebrush, possessed in vitro antioxidant properties. Glutathione, or GSH, is a small compound synthesized from amino acids which acts as a cellular antioxidant and is essential in protecting against the damaging effects of free radicals in the body. To investigate whether polyphenolic extracts of sagebrush act as antioxidants in cells through pathways involving GSH, cultured HepG2 human liver carcinoma cells were treated with sagebrush polyphenolic extracts and then harvested and the levels of GSH assayed. Sagebrush polyphenols caused a time dependence increase in intracellular GSH levels. At 4 hours the level of intracellular GSH either increased or decreased depending on the dose. Demonstration that sagebrush polyphenols have a positive effect on cellular anti-oxidant pathways may lead to their development as therapeutic or dietary supplements.

Effect of Polyphenols Extracted from Artemisia tridentata ssp. tridentata on Glutathione Levels in Cultured HepG2 Liver Cells