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The extract of artichoke Cynara cardunculus L. (CCE) was investigated for its potential antigenotoxic and antioxidant effects using four experimental model systems. In the Saccharomyces cerevisiae mutagenicity/ antimutagenicity assay, CCE significantly reduced the frequency of 4-nitroquinoline-N-oxide-induced revertants at the ilv1 locus and mitotic gene convertants at the trp5 locus in the diploid Saccharomyces cerevisiae tester strain D7. In the simultaneous toxicity and clastogenicity/anticlastogenicity assay, it exerted an anticlastogenic effect against N-nitroso-N′ ′ ′ ′ ′-methylurea-induced clastogenicity in the plant species Vicia sativa L. On the contrary, despite CCE not being mutagenic itself, in the preincubation Ames assay with metabolic activation, it significantly increased the mutagenic effect of 2-aminofluorene in the bacterial strain Salmonella typhimurium TA98. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, CCE exhibited considerable antioxidant activity. The SC 50 value representing 0.0054% CCE corresponds to an antioxidant activity of 216.8 μ μ μ μ μM ascorbic acid which was used as a reference compound. Although the mechanism of CCE action still remains to be elucidated, different possible mechanisms are probably involved in the CCE antigenotoxic effects. It could be concluded that CCE is of particular interest as a suitable candidate for an effective chemopreventive agent.

Nowadays naturally occuring compounds with the potential antimutagenic and anticarcinogenic effects are of great importance for their prospective use in cancer chemoprevention and treatment. The new water soluble derivative of microbial polysaccharide β-D-glucan-carboxymethyl glucan (CMG) belongs to such a category of natural substances. CMG isolated from the cell wall of baker's yeast Saccharomyces cerevisiae is included into the class of biopolymers known as biological response modifiers (BRMs) with a broad range of activities, above all ones interfering with cancer therapy. It was demonstrated on four experimental model systems that biological and consequential medicinal importance of CMG is based on the combined application with another active compound. In the Saccharomyces cerevisiae antimutagenicity assay CMG significantly reduced ofloxacin-induced mutagenicity in the yeast strain D7. CMG exerted bioprotective (anti-toxic and antimutagenic) effect after its simultaneos application with methyl methanesulphonate on the repair-deficient strain uvs10 of the unicellular green alga Chlamydomonas reinhardtii. In the Vicia sativa simultaneous phytotoxicity and anticlastogenicity assay CMG exerted statistically significant anticlastogenic efect against maleic hydrazide-induced clastogenicity in Vicia sativa L. Only in the Salmonella/microsome assay CMG did not exert statistically significant antigenotoxic effect, despite of the fact that it reduced 9-aminoacridine-induced mutagenicity in S. typhimurium TA97, but his + revertants decreasing was statistically significant only at the highest CMG concentration used. The data presented unambiguously documented that even biopolysaccharides (e.g., derivatives of β-glucan) belonging to the most abundant class of natural biopolymers may contribute to cancer prevention and therapy.

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