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[SANET-MG] neutraceuticals go mainline



Neutraceuticals such a green tea are going mainline in cancer treatment.
Organic foods are well documented to be richer in plant polyphenols
which are anti-cancer neutraceuticals. Organic foods can be promoted as
disease prevent treatments.
18 September 2004, Pages 1021-1022 lancet
Green tea: prevention and treatment of cancer by nutraceuticals

Richard Béliveau and Denis Gingras

Green tea[1] has always been considered by the Chinese and Japanese
peoples as a potent medicine for the maintenance of health, endowed with
the power to prolong life. Recently, Yean Lee and colleagues [2] looked
at the effects of the main active green tea constituent,
epigallocatechin-3-gallate (EGCG) on chronic lymphocytic leukaemia B
cells isolated from leukaemic patients. These cells are characterised by
their resistance to apoptosis because they secrete and bind vascular
endothelial growth factor (VEGF), a potent angiogenic cytokine that also
acts as a crucial survival factor for tumour cells. The researchers
showed that addition of EGCG to these cells markedly decreased
VEGF-receptor phosphorylation, leading to the disruption of the
VEGF-dependent autocrine pathway that protects the cells from apoptosis
and cell death.

These results support our observations[3] on the potent inhibition of
the activity of VEGF-receptor tyrosine kinase by components of green
tea, and provide strong evidence that this inhibitory effect may have
profound repercussions on tumours that depend on this cytokine for
progression. Of considerable importance is the low concentration of EGCG
required to trigger the observed biological effects, because
VEGF-receptor activity can be inhibited [3] and apoptosis of leukaemia B
cells can be induced [2] with concentrations of EGCG in the plasma after
moderate drinking of green tea (2–4 cups a day). [4] Although more
extensive investigation on the effects of this compound in patients with
chronic lymphocytic leukaemia B is required, these findings nevertheless
raise the interesting possibility that green tea could be used as a
combination agent for treating leukaemia.

VEGF is also crucially important to tumour angiogenesis, the process by
which tumours grow and invade surrounding host tissues.[5] In the
initial phases of tumour growth, angiogenesis is highly sensitive to
VEGF-receptor blockade. [6] Inhibition of VEGF-mediated signalling and
subsequent angiogenesis by low-dose delivery of EGCG, as seen in vitro,
[3 and 7] could thus have beneficial in-vivo effects against several
other types of cancer. This mechanism also provides a strong scientific
basis for the chemopreventive property of green tea that has been
inferred from several epidemiological studies which showed that frequent
drinking of green tea is inversely associated with the risk of
developing several types of human cancer, such as oesophageal cancer. [8]

With the notable exception of the use of retinoic acid for the treatment
of promyelocytic leukaemia,[9] the importance of nutraceuticals in
cancer prevention and treatment remains largely under-exploited despite
increasing evidence showing that these molecules have chemopreventive
and chemotherapeutic ability. Notwithstanding the considerable progress
made in the design of novel anticancer drugs in recent years, one clear
lesson from the past decades of research into cancer is that, although
we can treat cancer and induce remission, survival rates have changed
little in most cancers. Moreover, most anticancer drugs have several
toxic side-effects that may produce a poor quality of life for patients
and considerable cost in supportive care. Green tea and other
diet-derived compounds, such as curcumin, phyto-oestrogens and
carotenoids, [10] offer several advantages as anticancer products,
because these compounds are non-toxic, produce few side-effects, are
widely available, and are cheap. It would thus be interesting to examine
the beneficial effects of including green tea in the diet of patients
undergoing treatment for cancer as well as in patients at high risk of
recurrence, such as those in remission after treatment and those at risk
for a second neoplasm.

We believe that anticancer agents designed by nature and used for
several thousands of years with little toxicity may prove useful in
treating and preventing cancer. Results such as those obtained by Lee
and co-workers[2] show that food-derived chemicals constitute a
complementary source of anticancer agents.

We declare that we have no conflict of interest.


References
1. M Demeule, J Michaud-Levesque, B Annabi et al., Green tea catechins
as novel antitumor and antiangiogenic compounds. Curr Med Chem Anti-Canc
Agents 2 (2002), pp. 441–463. Abstract-MEDLINE | Abstract-EMBASE |
$Order Document

2. YK Lee, ND Bone, AK Strege, DF Jelinek and NE. Kay, VEGF receptor
phosphorylation status and apoptosis is modulated by a green tea
component, epigallocatechin-3-gallate (EGCG) in B cell chronic
lymphocytic leukemia. Blood 104 (2004), pp. 788–794. Abstract-Elsevier
BIOBASE | Abstract-EMBASE | Abstract-MEDLINE | $Order Document | Full
Text via CrossRef

3. S Lamy, D Gingras and R. Béliveau, Green tea catechins inhibit
vascular endothelial growth factor receptor phosphorylation. Cancer Res
62 (2002), pp. 381–385. Abstract-MEDLINE | Abstract-Elsevier BIOBASE |
Abstract-EMBASE | $Order Document

4. KM Pisters, RA Newman, B Coldman et al., Phase I trial of oral green
tea extract in adult patients with solid tumors. J Clin Oncol 19 (2001),
pp. 1830–1838. Abstract-Elsevier BIOBASE | Abstract-EMBASE |
Abstract-MEDLINE | $Order Document

5. J. Folkman, Fundamental concepts of the angiogenic process. Curr Mol
Med 3 (2003), pp. 643–651. Abstract-MEDLINE | Abstract-EMBASE | $Order
Document

6. G Bergers, S Song, N Meyer-Morse, E Bergsland and D. Hanahan,
Benefits of targeting both pericytes and endothelial cells in the tumor
vasculature with kinase inhibitors. J Clin Invest 111 (2003), pp.
1287–1295. Abstract-EMBASE | Abstract-Elsevier BIOBASE |
Abstract-MEDLINE | $Order Document | Full Text via CrossRef

7. Y Cao and R. Cao, Angiogenesis inhibited by drinking tea. Nature 398
(1999), p. 381. Abstract-EMBASE | Abstract-MEDLINE | $Order Document |
Full Text via CrossRef

8. YT Gao, JK McLaughlin, WJ Blot, BT Ji, Q Dai and JF. Fraumeni, Jr,
Reduced risk of esophageal cancer associated with green tea consumption.
J Natl Cancer Inst 86 (1994), pp. 855–858. Abstract-MEDLINE | $Order
Document

9. S de Botton, V Coiteux and S. Chevret, Outcome of childhood acute
promyelocytic leukemia with all-trans-retinoic acid and chemotherapy. J
Clin Oncol 22 (2004), pp. 1404–1412. Abstract-MEDLINE | $Order Document
| Full Text via CrossRef

10. AJ Gescher, RA Sharma and WP. Steward, Cancer chemoprevention by
dietary constituents: a tale of failure and promise. Lancet Oncol 2
(2001), pp. 371–379. SummaryPlus | Full Text + Links | PDF (723 K)

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