ISOLATION AND IDENTIFICATION OF ANTICANCER AND ANTI-INFLAMMATORY SUBSTANCES IN PEUCEDANUM JAPONICUM THUNB.

Peucedanum japonicum Thunb. (Umbelliferae) is a wild perennial plant that reaches 60–100 cm in height, grows along the Korean coast. The plant, which has white flowers that bloom from June to August, is well-known for anti-fungal, anti-food poisoning, and anti-phlegm properties plus increasing stamina. In early spring, Koreans sometimes eat the young plants as an herb salad. To determine if P. japonicum contained anticancer and anti-inflammatory substances, leaves collected from a wild population, were air-dried, chopped and extracted with MeOH. The extract was evaporated to dryness, resuspended in water, and then fractionated with CHCl₃ and BuOH. CHCl₃ extracts were purified by repeated column chromatography and recrystallization. A total of three compounds were isolated and identified as hyuganin C, peucedanol, and 2,2-dimethyl-4,5-epoxy-2-(2-hydroxyethylidene)-cyclohexanone using ¹H-NMR, ¹³C-NMR, DEPT, ¹H-¹H COSY, HMQC, HMBC and IR. Isolated compounds were evaluated for in vitro cytotoxic activity against human cancer cell lines HL-60, A549 and MCF-7 using the sulforhodamine B (SRB) assay method. The hyuganin C showed the most potent cytotoxic activity against HL-60 cell (IC₅₀ = 13.2 μgL^-1). The effect of isolated compounds on lipopolysaccharide- (LPS) induced NO production in RAW 264.7 mouse macrophages was investigated by measuring the accumulated nitrite, as estimated by the Griess reaction, in the culture medium. When RAW 264.7 cells were treated with different concentrations of the isolated compounds together with LPS (1 μgL^-1) for 20 h, a significant dose-dependent inhibition of nitrite production was detected in the presence of hyuganin C. The IC₅₀ value of hyuganin C in inhibiting LPS-induced NO production was 1.2 μgL^-1. By contrast, the other isolated compounds did not show any inhibitory activity against LPS-induced NO production.