Ka´zmierczak-Bara´nska 2 1Medical University of Warsaw, Warsaw, Poland 2Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Lodz, Poland Polysaccharide fractions
Trang 1ABSTRACTS 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
1Medical University of Warsaw, Warsaw, Poland
2Centre of Molecular and Macromolecular Studies, Polish Academy of 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 748g/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
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