CHEMOPREVENTIVE POTENTIAL OF THE TANNASE-MEDIATED BIOTRANSFORMATION
OF GREEN TEA
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Juliana Alves Macedo , Alessandra Gambero , Gabriela Alves Macedo , Marcelo Lima Ribeiro
Food Science Department, Faculty of Food Engineering, Campinas State University, P.O.
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Box 6121, 13083-862, SP, Brazil. Unidade Integrada de Farmacologia e Gastroenterologia
(UNIFAG), São Francisco University, Av. São Francisco de Assis 218, Bragança Paulista, SP,
Brazil.
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Green tea (Camellia sinensis) contains several tea polyphenols, including
epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin. The
aim of this study was to evaluate the chemopreventive potential of green tea extracts, as well as
epigallocatechin gallate after the enzymatic biotransformation catalyzed by the non-commercial
Paecilomyces variotii tannase.The results have shown that the biotransformation of green tea
extract and EGCG significantly increased their antioxidant potential, the ORAC assay
demonstrated a 55% higher antioxidant capacity for the biotransformed green tea extract, and
46% more for the EGCG treated sample. The tumoral cell antiproliferative sulforhodamine
(SRB) assay, demonstrated that biotransformation reduced the toxicity of the EGCG sample
without anuling its antiproliferative effects on the HT29 and PG100 cell lines, and increased the
antiproliferative capacity of the green tea extract (up to 30%). The data from the Cancer-related
gene expression analysis, performed with the interaction of the samples in PG100 cells and the
Human Cancer PathwayFinder™ RT² Profiler™ PCR Array; showed that either native and
biotransformed green tea and/or EGCG up regulated the expression of APAF1, CASP8,
CDKN1A and FAS; on the other hand we observed a down regulation of CDK2 and 4, bcl2,
bcl2L1, E2F1, and c-myc; in general, these results indicate pro-apoptotic function. Importantly,
this study has demonstrated the usefulness of the nutrigenomics perspective and tools in
evaluating the benefits of biotechnological modifications of natural food molecules. Using this
perspective, we have identified methods to improve the nutraceutical potential of one of the
most widely consumed beverages - green tea.