In these times, a world wide renaissance of the use of natural substances and medicinal plants takes place. Not replaceable position occupy the plant sorts which exert so-called immuno modulation activity. Significance of an immuno stimulation, meant as profilaxy and therapy of wide palette of diseases connected with the immunity system, strongly increases in the recent years. A row of phyto pharmaceuticals containing extracts from plants of the Echinacea Moench genus is nowadays exploited for the enhancement of defense mechanisms. Until now, however, we do not know all the constituents and biological effects of the most known sorts, i.e. Echinacea angustifolia DC. and Echinacea purpurea L.
Basing on the results of many years lasting studies done by several research teams (1,2,3,4) there may be stated that the effective substances in enumerated plants are: polysaccharides in aqueous extracts, lipophilic components as isobutylamides, polyenes, other oils, etc. in alcoholic extracts and partly in concentrated juices, cichoric acid and its derivatives as hydrophilic components of extracts as well. The filed of indication is indeed broad, from the local applications at treatment of wounds, exema, ulcucruris, and psoriasis up to the peroral and parenteral dosages when the cases as influenza, kataral infections, chronic diseases of upper breath pathways, prostatidis, polyartritis, or some types of cancer diseases are indicated. Good results were attained by the intravenous and intramuscle applications to support(improve) reduced body defense mechanizms, mainly at subcutaneous and chronic diseases. Extracts from these plants in the pellet or drop forms are used for the enhancement of body defense system, at light infections, for profilaxy at infections, and as a supporting therapy at long-term treatment by antibiotics.
In present work we have searched for a plant and cultivar of E. angustifolia that would demonstrate the cytotoxic activity after appropriate isolation of the active compounds. Ethanol-water soluble extract from fresh radix (EREx) and plants (EP) as well as the essential oils (ERS1, ERS2) were under study. Their cytotoxic activity on HeLa cells was compared with that of five compounds of plant origin: caffeic acid (CA), quercetin (Qe), chlorogenic acid (CHA), quercitrin (Qi), and mixture of flavonoids (F).
The cytotoxic efficiency of the extracts and essential oils decreased in the order EREx, ERS1, ERS2, EP, and antioxidants CA, Qe, CHA. Quercitrin and flavonoids showed no toxic effect in the concentration range 4-500 mg/ml. The extract from fresh radix (EREx) exhibited the most cytotoxic effect when compared with all compounds tested (lD50 = 19.6-33.7 mg/ml). Furthermore, the EREx and ERS1 prevented the treated cells to form multilayer focuses and thus probably exhibited their antineoplastic transformation capacity.
Key words: Echinacea, cytotoxic activity, imunological activity, caffeic acid, quercetin
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