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Broccoli Extracts May Fight Prostate Cancer Pittsburgh Researcher Says
Broccoli Has Also Been Shown to Protect Against Cancer
Broccoli Stimulates Body's Production of Cancer-fighting Substances
Eat Your Broccoli and Avoid Prostate Cancer
Hot Water Kills Broccoli's Benefits
Researchers Study Broccoli-Derived Chemicals to Prevent Cancer
Super-Broccoli Bred to Fight Cancer
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Broccoli:
a wealth of phytochemicals
Broccoli may contain more cancer-preventing nutrients than any other plant. In
1992, scientists identified a broccoli compound called sulforaphane that helps
mobilize the body’s natural cancer-fighting resources and reduces the risk of
developing cancer.(54-60)
Sulforaphane has been shown to block the formation of tumors initiated by
chemical carcinogens. Moreover, sulforaphane has been demonstrated to induce
cancer cell death via the apoptosis (natural cell death) process.(61,62)
A large amount of data shows that sulforaphane and other broccoli compounds act
as cancer chemopreventive agents by favorably modifying carcinogen metabolism
via modulation of both Phase 1 and Phase 2 detoxification enzyme systems.(62-66)
These results suggest that broccoli compounds prevent cancer by activating
detoxifying enzyme systems and inducing cancer cell apoptosis.
Phase II detoxifying enzymes, such as glutathione S-transferase, play an
important role in the detoxification of chemical carcinogens. Recent studies
have demonstrated that sulforaphane not only induces beneficial glutathione
S-transferases but also inhibits of some major P450 enzymes that block the
detoxification of organic poisons.(64,67,68)
Studies show that high human gastrointestinal tissue levels of glutathione
S-transferase protect against a wide range of cancers. One study showed that a
sulforaphane analog increased glutathione-S-transferase activity in all organs
studied including the small intestine, liver and stomach. This study showed
sulforaphane to be more potent than indole-3-carbinol in boosting beneficial
glutathione S-transferase.(68)
Inhibiting DNA-adduct formation is known to reduce incidence of mammary tumor
incidence. Sulforaphane was shown in one study to inhibit chemical-induced DNA
adduct formation by 68% to 80%, suggesting that this extract from broccoli may
function as a breast cancer preventive.(64) On the
basis of mechanisms of carcinogenic effects cigarette smoke, sulforaphane
appears to be a component in the prevention of lung cancer.
 Broccoli
contains a high percentage of D-glucarate compared to most plants studied. As
mentioned earlier in this article, D-glucarate is critical in maintaining the
important glucuronidation detoxification process.
Broccoli provides a cornucopia of carotenoids and other nutrients that provide a
wide range of health benefits. The new Life Extension Mix contains a
super-concentrated broccoli extract that is standardized to deliver precise
amounts of sulforaphane and D-glucarate in each dose.
A potent flavonoid
Apigenin is a flavonoid found in parsley, artichoke, basil, celery and other
plants. Over the last three years, a large number of published studies have
demonstrated the anti-cancer properties of apigenin.
To study the effects of various plant constituents, an examination was made of
21 different flavonoids on the growth of human breast cancer cells. Apigenin was
shown to the most effective anti-proliferative flavonoid tested.(69)
A related study showed that flavonoids such as apigenin bind to estrogen
receptor sites on cell membranes in order to prevent over-proliferation of these
cells in response to estrogen.(70)
A study assessed the antioxidant potencies of several dietary flavonoids
compared with vitamin C. Pretreatment with all flavonoids and vitamin C produced
dose-dependent reductions in oxidative DNA damage. When ranked in order of
potency, only apigenin, rutin and quercetin were more effective than vitamin C
in reducing DNA oxidative damage.(71)
Apigenin was tested to ascertain its effect on human leukemia cells. Apigenin
was shown to induce apoptosis more effectively than quercetin and other
flavonoids tested. The researchers attributed a unique mechanism of inducing
apoptosis to the cancer preventive activity of apigenin.(72)
Another study showed that apigenin and another flavonoid called luteolin
strongly inhibited the growth of human leukemia cells and induced these cells to
differentiate.(73) Topoisomerases are involved in
many aspects of leukemic cell DNA metabolism such as replication and
transcription reactions. In one study, quercetin or apigenin were shown to
inhibit topoisomerase-catalyzed DNA irregularities.(74)
In a study of various agents used to induce differentiation of human
promyelocytic leukemia cells, apigenin and luteolin were among the flavonoids
shown to cause these leukemia cells to mature into healthy moncytes and
macrophages.(75)
In studies against thyroid cancer cell lines, apigenin and luteolin were the
most effective inhibitors found. Apigenin was shown to inhibit cancer cell
signal transduction and induce apoptosis. The scientists concluded that apigenin
may provide a new approach for the treatment of human anaplastic thyroid
carcinoma for which no effective therapy is presently available.(76)
Another study compared the effects genistein, apigenin, luteolin, chrysin and
other flavonoids on human thyroid carcinoma cell lines. Among the flavonoids
tested, apigenin and luteolin were shown to be the most potent inhibitors of
these cancer cell lines. The scientists noted that because these thyroid cancer
cells lacked an anti-estrogen receptor binding site and an estrogen receptor,
that apigenin and luteolin are inhibiting these cancer cells via previously
unknown mechanisms. The scientists concluded that apigenin and luteolin may
represent a new class of therapeutic agents in the management of thyroid cancer.(77)
In a study on
colorectal cancer cell lines, apigenin or quercetin were shown to interfere with
epidermal growth factor cell stimulation. The researchers speculated that these
flavonoids could be primary components in fruits and vegetables that reduce the
risk colorectal cancer by inferring with the cancer cell growth signaling
pathway.(78)
The epidermal growth factor signal transduction pathway is an essential
component of both cancer cell growth and differentiation. Certain gelatinases
are expressed in human cancers and are thought to play a critical role in tumor
cell invasion and metastasis. Apigenin was shown to inhibit these gelatinases
and interfere with the growth factor signaling pathways. The scientists
concluded that compounds like apigenin may provide a novel means of controlling
growth and invasive potential of certain tumors via these dual mechanisms.(79)
In a related study, apigenin was shown to prevent the degradation of tissue
components by cultured human carcinoma cells, a mechanism by which cancer
spreads to other parts of the body.(80)
The soy isoflavone genistein has been shown to be a potent inhibitor of cancer
cell proliferation and in vitro angiogenesis. Moreover, the concentration of
genistein in the urine of subjects consuming a plant-based diet is 30-fold
higher than that in subjects consuming a traditional Western diet. Scientists
have found in one study that apigenin and luteolin are more potent cancer
inhibitors than genistein, and suggest that these plant components may
contribute to the preventive effect of a plant-based diet on chronic diseases,
including certain cancers. The scientists noted that the consumption of a
plant-based diet can prevent the development and progression and growth of solid
malignant tumors.(81)
Protein kinase C is over-expressed in many human tumors. One group of scientists
has shown that apigenin blocks several points in the process of tumor promotion,
including inhibiting kinases, reducing transcription factors and regulating cell
cycle.(82) Another group of scientists showed that
apigenin and other flavonoids inhibit prostate cancer cell growth by blocking
tyrosine kinase activity.(83) Moreover, another
study demonstrated that apigenin blocks mammary cell proliferation induced by
several kinase-related pathways.(84)
The mutation and oxidation of estrogens is related to the development of certain
cancers. The favorable influence of apigenin, genistein and other flavonoids on
estrogen metabolism led researchers in one study to speculate that these plant
extracts could be used in the prevention or treatment of estrogen-related
diseases.(85)
Another mechanism by which cells mutate into malignancies involves a process
known as sulfation. One study showed that apigenin and ellagic acid were potent
inhibitors of sulfation compared to quercetin.(86)
In a study on human promyelocytic leukemia cells, genistein, followed by
apigenin and daidzein, were the most potent inhibitors of toxic free radical
byproducts generated by these leukemia cells. Other flavonoids showed no effect.
The scientists stated that the antioxidant effects of these flavonoids may
contribute to their chemopreventive potentials against human cancers.(87)
Seven men and seven women participated in a randomized crossover trial to study
the effect of intake of parsley, containing high levels of apigenin, on
biomarkers for oxidative stress. This basic diet was supplemented with parsley
providing 3.73-4.49 mg apigenin in one of the intervention weeks. The scientists
observed increased activity of the natural antioxidants glutathione reductase
and superoxide dismutase in red blood cells during intervention with parsley as
compared to people taking the basic diet without added parsley.(88)
A group of scientists studied the potential preventive effects of skin tumor
promotion by apigenin. When topically applied, apigenin was shown to inhibit
UV-induced skin tumorigenesis in mice. The scientists observed that apigenin
facilitated several tumor suppressor factors including the important p53 binding
activity.(89)
Grape skin and red wine contain resveratrol, which has been shown to inhibit
platelet aggregation both in vivo and in vitro. One study showed that genistein,
daidzein or apigenin produced inhibitory effects against an underlying cause of
abnormal platelet aggregation similar to those seen with resveratrol.(90)
 In
order to better understand the mechanisms by which apigenin may prevent cancer,
scientists looked at the effects this flavonoid would have on new blood vessel
growth. Apigenin was shown to inhibit some factors involved in the process of
tumor angiogenesis (new blood vessel growth that feeds rapidly dividing cells).(91)
Many types of cancer cells use cyclooxygenase-2 (COX-2) to propagate. COX-2
inhibiting drugs are being prescribed to cancer patients to slow the growth of
existing tumors. One study showed that apigenin or genistein also suppresses
formation of COX-2. The scientists conducting this study suggest that apigenin
and related flavonoids may be important in the prevention of cancer and
inflammation, partly via their COX-2 inhibiting properties.(92)
These studies as a whole provide a basis for cancer patients to consume a diet
rich in certain fruits and vegetables as an adjunctive treatment for their
disease. Apigenin is an antioxidant flavonoid with chemopreventive properties.
It has been shown to arrest the growth of cancer cells, with concomitant
inhibition of intracellular signaling cascades and decreased oncogene
expression.
The Life Extension Foundation first introduced apigenin in 1985, but was unable
to find a standardized plant extract that could consistently provide a specific
number of milligrams per dose. The new Life Extension Mix contains a plant
concentrate that provides 10 to 18 mg of apigenin and apigenin 7-glucoside per
daily dose. Apigenin 7-glucoside is broken down into apigenin in the small
intestine where it is absorbed.
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