American ginseng, Panax quinquefolium (L.), is traditionally used in folk medicine. It exhibits a range of anti-inflammatory, hepatoprotective, anti-diabetic, anti-obesity, anti-hyperlipidemic and anti-carcinogenic effects. Its main components are ginsenosides, also known as panaxosides or triterpene saponins. In order to obtain high yields of ginsenosides, different methods of controlled production are involved, i.e., with hairy root cultures. However, they are still employed under in vitro conditions. Our studies revealed that hairy root cultures subjected to an elicitation process can be considered as a potent source of ginsenosides. The present study examines the biological activity of ginseng hairy root cultures against the Caco-2 human adenocarcinoma cell line. Among our six different clones of P. quinquefolium hairy roots, extracts B and Be (treated with elicitor) were the strongest inhibitors of the cellular metabolic activity. While all extracts induced DNA damage, B and Be also generated reactive oxygen species (ROS) in a concentration-dependent manner, which was correlated with the depletion of the mitochondrial membrane potential and induction of apoptosis. These findings indicate that further research concerning P. quinquefolium hairy root cultures should focus on the activity of rare ginsenosides and other biologically active compound profiles (i.e., phenolic compounds).
Keywords: ATP; Caco-2; Panax quinquefolium L.; apoptosis; cytotoxicity; genotoxicity; ginsenosides; hairy roots; mitochondrial membrane potential; necrosis.