Antiproliferative activity of the extracts and compounds of Centaurea arenaria on human tumour cell lines
As part of our ongoing research on the antiproliferative compounds from Hungarian species of the Asteraceae family, extracts of several Centaurea species native to Middle and Eastern Europe have been tested previously against human tumour cell lines (cervix adenocarcinoma (HeLa), breast adenocarcinoma (MCF7) and skin epidermoid carcinoma (A431)), using the MTT assay. . High cell proliferation inhibitory activity was recorded for n-hexane, chloroform and aqueous methanol extracts prepared from the whole plant of Centaurea arenaria M.B. ex Willd. The chloroform extract displayed the highest activity (higher than 85% at 10µg/ml concentration), and was therefore subjected to a bioassay-guided multistep separation procedure. Flavonoids (eupatilin, eupatorin, 3′-methyleupatorin, apigenin and isokaempferid), lignans (arctigenin, arctiin, matairesinol and (±)-syringaresinol), the sesquiterpene cnicin, serotonin conjugates (moschamine and cis-moschamine), β-amyrin and β-sitosterin-β-D-glycopyranoside were obtained for the first time from this species. The structure elucidations were performed by means of UV, MS and NMR spectroscopy. The isolated compounds were evaluated for their tumour cell growth inhibitory activities on abovementioned cells, and it was found that flavone, sesquiterpene and lignan-type compounds and a serotonin conjugate exerted pronounced concentration-dependent effects. The highest activities were demonstrated by the lignans arctigenin (IC50 0.73–4.47µM), arctiin (IC50 1.80–19.53µM) and matairesinol (IC50 7.51–36.23µM).
Acknowledgements: Financial support from the Hungarian Scientific Research Fund (grant OTKA K72771) and National Development Agency (grant TÁMOP 4.2.2–08/1) is gratefully acknowledged. The authors thank Dr. Tamás Rédei (Hungarian Academy of Sciences, Institute of Ecology and Botany, Vácrátót, Hungary) for the identification of the plant material.
References: 1. Réthy, B. et al. (2007) Phytother Res 21:1200–1208.