Inhibitory effect of acetylshikonin from roots of lithospermum erythrorhizon on LDL oxidation and FPTase activity

Abstract

Lithospermum erythrorhizon has been known well as one of traditional medicine for fever reduction, detoxication, and blood circulation improvement. This study was carried out to isolate biological active compounds from roots of Lithospermum erythrorhizon and to investigate their low density lipoprotein (LDL) antioxidant and anticancer activities. The hexane extract of Lithospermi Radix has been separated on silica gel chromatography and a naphthoquinone pigment compound 1 has been isolated. The structure of the compound 1 has been identified by spectroscopic technique, including MS and NMR, as acetylshikonin (1). Acetylshikonin showed significantly inhibitory activity on Cu2+-induced human LDL oxidation with IC50 value of 8.8 μM and obvious anticancer effect by inhibiting farnesyl:protein transferase (FPTase) activity with IC50 value of 23 μM, which suggested that acetylshikonin might be useful for the treatment of atherosclerosis and cancer.