Cytotoxic compounds against adenocarcinoma alveolar epithelial A549 cells from Paeoniae Radix

It has been known that Paeoniae Radix (PR) contains monoterpene glycosides showing a variety of biological activities such as anti-spasmodic, anti-inflammatory, anti-viral, neuroprotectiveand sedative effects. This study aimed to find the cytotoxic compounds isolated from the dichloromethane (CH₂Cl₂)-and ethyl acetate-soluble fractions of PR. As results, thirteen compounds (1-13) were isolated and the chemical structures were identified. In addition, the human alveolar adenocarcinoma cell line (A549) was treated with isolated compounds to determine the cytotoxic effect via evaluation of cell viability. The reduction of A549 cell viability was shown as following order; gallic acid (8) > (2S)-naringenin (9) > methyl gallate (10) > 6'-O-benzoylpaeoniflorin (7) > palmitic acid (3). Especially, 7 did not show the cytotoxicity in the human lung fibroblast cell line (MRC-5). The effect of 7 on the cell viabilities in A549 and MRC-5 is firstly reported in this study. Further study is required to find out the cytotoxic mechanism and the selectivity for the cancer cells of 7 in detail.