Comparison of biological activity and composition of extracts from Rhaponticum carhamoides grown on Polish and Siberian plantations

A wide range of plant compounds gained attention as pharmaceuticals, cosmetics or food supplements. Therefore obtaining high-quality plant material for research and industrial purposes is of great importance. The biochemical profile of plant material may be influenced e.g. by soil quality or climate. Rhaponticum carthamoides (Willd) Iljin, used in Asian folk medicine, grows naturally in Siberia, Sayan and Altai Mountains. This plant synthesizes a wide range of secondary metabolites, famous for their anabolic (ecdysteroids, [1]) and antioxidant (flavonoids, [2]) properties. In 2003 the first Polish plantation was established in Lubiewice by FITOSTAR™. Since the geographic and climatic conditions differ from the natural ones, we checked whether the extracts' composition and biological activities are similar. Polish plant material was collected every five days during summer 2006 from two fields differing in soil class. Siberian material was supplied by FITOSTAR™. Three leaf extracts (aqueous, methanolic and chloroform) were analysed for their composition and biological activities. Chemical composition was compared using Matrix-assisted Laser Desorption/Ionization mass spectrometry (MALDI-MS). Two matrices (2,5-dihydroxybenzoic acid and α-cyano-4-hydroxycinnamic acid) were employed and the range of compounds of ca. 100–1000 MW was screened, showing that Polish extracts are more abundant. We also examined the extracts' capacity to prevent lipid peroxidation, to scavenge DPPH free radical and to reduce molybdenum. Statistically significant differences were observed only in the DPPH assay for methanolic extracts (IC₅₀=16,9 and 34,5µg/ml for Polish and Siberian plants respectively). Cytotoxicity of Polish and Siberian plants (MTT assay) was also similar and rather low (IC₅₀ >100µg/ml for aqueous extracts). Therefore we assume, that introducing R. carthamoides to Polish growing (climatic and soil) conditions is possible and may result in obtaining adequate plant material.

References: [1] Slama K. et al. (1996) Experientia 52: 702–706; [2] Miliauskas G. et al. (2005) J. Nat. Prod. 68: 168–172