5 / 9
Page 13
Notes:
allied
academies
Archives of Industrial Biotechnology | Volume 2
May 14-15, 2018 | Montreal, Canada
World Yeast Congress
C
olorectal cancer (CRC) is one of the third most commonly
diagnosed cancers in westerns countries. Diet and life style
have important rules as preventive methods and still seem to
be the most efficient approach. Consumption of diet containing
agents with CRC preventive properties could reduce the risks of
CRC incidence. Cancer prevention properties could be obtained
via cancer cells cytotoxicity, apoptosis and antioxidant and via
enzymatic modulation. QR is a phase II detoxification enzyme
recognized to protect against toxic metabolites involved in
the first stage of carcinogenesis process and can decrease
chemical carcinogenicity compounds by transforming them
to compounds with less toxicity. β-glucuronidase enzyme can
release carcinogenic compounds in the colon. A reduction
in its activity can lead to a reduced exposure to carcinogenic
substance.
Saccharomyces boulardii and Kluyveromyces
marxianus
are well-known yeasts in food industry. Their
membranes are composed of insoluble (47%) and soluble
glucan (36%) and mannoprotein (0.45%). Our studies showed
that mannoprotein of
K. marxianus
exhibit the most relevant
antioxidant activity probably due to the presence of aromatic
amino acids and thiol groups but only insoluble glucan from
both yeast species can induce Quinone Reductase (QR) enzyme
activity. Cell wall extracts of both yeast cells, are able to inhibit
the growth of HT 29 cells and colon cancer cells by more than
50% and extracts of S. boulardii show the lowest IC50 values.
In vivo
studies with rats demonstrated that ingestion of crude
insoluble glucan (0∙5 mg kg-1 day-1), obtained from S. boulardii
cell wall exhibited colon cancer prevention properties and
enzymatic modulation is one of the mechanism observed. An
induction of more than 68% of the QR specific activity and a
reduction of more than 50% of the β-glucuronidase activity was
found. Also, a reduction of more than 45% in the total count of
aberrant crypt (AC), 50% of aberrant crypt foci (ACF) and a 73%
reductionof the total number of ACF containing 4-5ACper focus
in the animal colon was observed. Extraction of
S. boulardii
and
K. marxianus
yeast cell wall via simple and fast extraction can be
proposed for the development of a new nutraceuticals product
against colon cancer.
Speaker Biography
Monique Lacroix has completed her BSc and MSc in Food Sciences Technology in 1980
and 1982 respectively and PhD in Nutrition in 1986. She is a Professor at INRS-Institute
Armand-Frappier, Canada and Director of the Research Laboratories in Sciences Applied
to Food and of the Canadian Irradiation Centre. She is a Fellow of the International
Academy of Food Science and Technology (IAFoST) for her outstanding representatives
of international food science and technology. She received 4 awards for her most cited
publications in Food Sciences and for the best 10 research Partnership with Industries
for two partnerships. She has served as an expert member of several United Nations
Research Networks on Food Safety and on Nano Biopolymer using Gamma Irradiation.
She is also member of three Canadian networks: Canadian Food Processing Networks,
Research Network on Dairy Products in Québec and of the Institute of Nutraceuticals
and Functional Foods. She is author of more than 264 publications, 10 patents and 21
book chapters. Until today, she has supervised 14 Post-doc, 98 graduated students of
2nd and 3rd cycles and more than 315 trainees that come from all over the world. She
has been invited to present more than 188 conferences in major congresses, including
United Nations Conferences as a Member of Expert Committees.
e:
monique.lacroix@iaf.inrs.caMonique Lacroix
INRS-Institute Armand-Frappier, Canada
Yeast membrane constituents and their potential beneficial effect against Colorectal cancer