ABSTRACTS New Biotechnology · Volume 25S · September 2009 1.1.26 Isolation, composition analysis, antioxidant activity and cytotoxicity of selenium-enriched polysaccharide frac- tions isolated from Lentinula edodes mycelial cultures J. Turło 1,∗ , B. Gutkowska 1 , F. Herold 1 , M. Cie ´ slak 2 , J. Ka ´ zmierczak- Bara ´ nska 2 1 Medical University of Warsaw, Warsaw, Poland 2 Centre of Molecular andMacromolecular Studies, PolishAcademyof Sciences, Lodz, Poland Polysaccharide fractions isolated from Lentinula edodes fruit- bodies and mycelium demonstrate strong immunomodulating, antioxidant and anticancer activity. We hypothesized, that polysaccharide fractions enriched in selenium would possess higher biological activity than non-enriched fractions, currently used to treat cancer. The first goal of this study was to iso- late selenium (Se)-enriched polysaccharide fractions of different molecular weight from L. edodes mycelium cultivated under the submerged conditions in Se-enriched medium, and to investigate their monosaccharide composition. The second objective was to determine, whether there is relationship between the Se-content in polysaccharide fractions and their antioxidant activity. Finally, we tested Se-enriched polysaccharides for their cytotoxic properties in HeLa (cervix carcinoma) and HUVEC (normal) cells. All results regarding Se-enriched polysaccharides were compared with that of reference polysaccharide fractions, extracted from mycelium not enriched in Se. Concentration of Se in the Se-enriched mycelium and in the polysaccharide fractions was determined by reversed-phase high- performance liquid chromatography (RP-HPLC). Total selenium amount in the L. edodes mycelium, cultivated in Se-enriched (20 ppm) medium, was 748 ␮g/g. About 13% of total mycelial sele- nium was combined to the polysaccharide fractions. Four Se-enriched polysaccharide fractions were isolated from the mycelium and from the culture medium. Monosaccharide composition of selenated polysaccharides was determined, after hydrolysis performed by the use of trifluoroacetic acid, by RP-HPLC method. Se-enriched fractions isolated from mycelium contained 34% of glucose, 9% of xylose, 15% of mannose and 23% of glu- cosamine. Se-enriched fractions of molecular weight 400 kDa and 200 kDa differed mainly in mannose and galactose content. Se- enriched polysaccharides extracted from the cultivation medium contained mainly glucose and mannose. Reference fractions con- tained mainly glucose (38%), xylose (25%) and mannose (15%). For in vitro determination of antioxidant properties of polysac- charide fractions DETBA and conjugated diene methods were used. Antioxidant activity of Se-enriched polysaccharides was enhanced by 50—400%, as compared with control polysaccharide fractions. The comparison of cytotoxic profiles of tested fractions revealed that, except for fraction of molecular weight 200 kDa isolated from the culture medium, other polysaccharides are not toxic toward HUVEC or HeLa cells. However, the Se-enriched mycelial polysac- charide fraction of high molecular weight significantly enhances viability of cells; this may be an effect of the increased antioxidant activity. doi:10.1016/j.nbt.2009.06.031 1.1.27 Effects of the natural sweetener (stevia) and the artificial sweetener (aspartame) on some biochemical parameters in normal and alloxan-induced diabetic rats N. Agamy High Institute of Public Health, Alexandria, Egypt One way to control excessive energy intake is to replace the calo- ries from sugar with a non-nutritive sweetener, aspartame received more attention in the media about its safety while stevia leaf or extracted form has been used in many countries as a sweetener and in traditional medicine for the treatment of diabetes but still not approved as a sweetener by the FDA. This study was under- taken to compare the effects of consumption of stevioside (as a natural sweetener) and aspartame (artificial sweetener) on glucose level, lipid profile, liver and kidney functions, acetylcholinesterase of normal and alloxan-induced diabetic rats. 140 male Wistar rats were used; half of them were injected with 120 mg/kg alloxan for the induction of diabetes. Both normal and diabetic groups were treated with stevioside and aspartame with three different doses (representing the ADI, twice ADI and four times ADI of each) for four weeks. Rats were sacrificed by cervi- cal decapitation and fasting blood specimens were collected and tested. Results showed that although treating diabetic rats with stevio- side doses resulted in lowering glucose levels than that of untreated diabetics that were ranging from 55.6% to 62.6%, they were still above the normal glucose range. The percentage decrease in glu- cose levels was dose dependent. The medium dose of stevioside significantly improved cholesterol (59%), liver enzymes activities of diabetic rats and returned them back to their normal ranges where the highest reductions of AST, ALT and ALP (more than 50%) were found in the medium and high doses with no significant differences among its different doses. Aspartame doses insignif- icantly affect glucose, lipid profile and liver enzymes. Urea and creatinine levels returned to their normal range. The percentage increase of acetylcholinesterase activity was higher on treating dia- betic rats with steviosides that reached 23.7% in its medium dose than on treating them with aspartame that reached 16.7% in high dose. Stevioside doses were more efficient in improving plasma glu- cose levels and acetylcholinesterase levels in diabetic rats than the corresponding doses of aspartame. The medium steviosides dose was more efficient in improving lipid profile and liver function enzymes levels while its low and high doses were more efficient in improving kidney function levels. The effect of different doses of steviosides on the biochemical parameters of normal rats was always within their normal range, by contrast, different doses of aspartame have a remarkable adverse effect on acetylcholinesterase levels even in normal rats. doi:10.1016/j.nbt.2009.06.032 S12 www.elsevier.com/locate/nbt . September 2009 1.1.26 Isolation, composition analysis, antioxidant activity and cytotoxicity of selenium-enriched polysaccharide frac- tions isolated from Lentinula edodes mycelial cultures J. Turło 1,∗ ,. University of Warsaw, Warsaw, Poland 2 Centre of Molecular andMacromolecular Studies, PolishAcademyof Sciences, Lodz, Poland Polysaccharide fractions isolated from Lentinula edodes fruit- bodies and. RP-HPLC method. Se-enriched fractions isolated from mycelium contained 34% of glucose, 9% of xylose, 15% of mannose and 23% of glu- cosamine. Se-enriched fractions of molecular weight 400 kDa and 200 kDa differed