TABLE 1

Effect of P. ginseng and P. quinquefolius extracts on CYP2B1 and CYP3A23 mRNA expression in primary cultures of rat hepatocytes

Primary cultures of rat hepatocytes were treated for 48 h with P. ginseng extract (0.1-1000 μg/ml), P. quinquefolius extract (0.1-1000 μg/ml), or culture medium (vehicle control). Cultured hepatocytes were also treated with PB (100 μM; as a positive control for CYP2B1), DEX (10 μM; as a positive control for CYP3A23), or 0.1% DMSO (vehicle control). Total RNA was isolated and reverse transcribed. CYP2B1 and CYP3A23 cDNAs were amplified in duplicate by real-time PCR using gene-specific primers. Data are expressed as the mean (± S.E.M.) fold-increase in mRNA expression (relative to the respective vehicle controls) in hepatocytes isolated from three individual rats.