Polyphenols from the sagebrush Artemisia tridentata ssp. tridentata affect the redox state of cultured hepatocytes by direct and indirect mechanisms.

Basin big sagebrush ( Nutt. ssp. (Asteraceae)), is a widespread North American shrub which produces a variety of polyphenolic compounds. Although sagebrush has been used as a traditional remedy by natives and settlers to the region, the polyphenols in ssp have not been highly investigated for their bioactive properties. To determine whether these polyphenols affect the intracellular redox state, we measured their ability to neutralize radicals and in a human liver carcinoma cell line (HepG2), and their effects on intracellular glutathione levels. Extracts from ssp. decreased the oxidation of 2'7'-dichlorofluorescin and in cultured cells. Cells treated with polyphenolic extracts showed increased levels of glutathione in a time and dose-dependent manner. Approximately 48 polyphenolic compounds were distinguishable in extracts, by HPLC/UV absorbance detection. Mass spectroscopy was used to identify thirteen compounds as aesculin, aesculetin, apigenin, apigenin-7-O-glucoside, axillarin, casticin, chlorogenic acid, isoscopoletin, kaempferol, luteolin, methyl-axillarin, quercetin, and scopoletin. These results indicate that polyphenols produced in ssp. affect the redox state of living cells by multiple mechanisms.