TY - JOUR
T1 - Cancer therapy and prevention by green tea
T2 - Role of ornithine decarboxylase
AU - Bachrach, U.
AU - Wang, Y. C.
PY - 2002
Y1 - 2002
N2 - Green tea which is widely consumed in China, Japan and India, contains polyphenolic compounds, which account for 30% of the dry weight of the leaves. Most of the polyphenols are flavanols, of which (-)-epigallocatechin-3-gallate (EGCG) is most abundant. Epidemiological studies revealed that the incidences of stomach and prostate cancers are the lowest in the world among a population that consumes green tea on a regular basis. It has also been reported that the quantity of green tea consumed, plays an important role in reducing cancer risk and in delaying cancer outbreak and recurrence. Various systems were used to confirm anti-cancer activities of green tea and/or EGCG. These included experimental animals in which cancer was induced chemically. Cultured cells transformed chemically or by oncogenes were also used. These studies clearly demonstrated that green tea or EGCG have anticancer and cancer preventive properties. The mechanisms of these activities have also been studied in details. It has been shown that green tea and its active components interfere with signal transduction pathways. Thus the activities of various protein kinases are inhibited, the expression of nuclear proto-oncogenes declines and the activity of ornithine decarboxylase (ODC) is reduced. ODC, which catalyzes the rate-limiting step in the biosynthesis of polyamines is closely linked with cellular proliferation and carcinogenesis. Inhibitors of ODC, like α-difluoromethylornithine (DFMO) have long been used for cancer prevention and therapy. It has been suggested that polyamine depletion by green tea could offer one explanation for its anti-cancer activities.
AB - Green tea which is widely consumed in China, Japan and India, contains polyphenolic compounds, which account for 30% of the dry weight of the leaves. Most of the polyphenols are flavanols, of which (-)-epigallocatechin-3-gallate (EGCG) is most abundant. Epidemiological studies revealed that the incidences of stomach and prostate cancers are the lowest in the world among a population that consumes green tea on a regular basis. It has also been reported that the quantity of green tea consumed, plays an important role in reducing cancer risk and in delaying cancer outbreak and recurrence. Various systems were used to confirm anti-cancer activities of green tea and/or EGCG. These included experimental animals in which cancer was induced chemically. Cultured cells transformed chemically or by oncogenes were also used. These studies clearly demonstrated that green tea or EGCG have anticancer and cancer preventive properties. The mechanisms of these activities have also been studied in details. It has been shown that green tea and its active components interfere with signal transduction pathways. Thus the activities of various protein kinases are inhibited, the expression of nuclear proto-oncogenes declines and the activity of ornithine decarboxylase (ODC) is reduced. ODC, which catalyzes the rate-limiting step in the biosynthesis of polyamines is closely linked with cellular proliferation and carcinogenesis. Inhibitors of ODC, like α-difluoromethylornithine (DFMO) have long been used for cancer prevention and therapy. It has been suggested that polyamine depletion by green tea could offer one explanation for its anti-cancer activities.
KW - (-)-Epigallocatechin-3-gallate (EGCG)
KW - Amino acids
KW - Cancer prevention
KW - Cancer therapy
KW - Green tea
KW - Ornithine decarboxylase (ODC)
KW - Polyamines
KW - Polyphenols
UR - http://www.scopus.com/inward/record.url?scp=0036175264&partnerID=8YFLogxK
U2 - 10.1007/s726-002-8197-9
DO - 10.1007/s726-002-8197-9
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C2 - 12025870
AN - SCOPUS:0036175264
SN - 0939-4451
VL - 22
SP - 1
EP - 13
JO - Amino Acids
JF - Amino Acids
IS - 1
ER -