Eating to beat cancers
AS the quest for a cure continues, researchers have enlisted tadpoles, olive oil, citrus fruits, beans, nuts, cereals, corn, bitter leaf, India almond, among other plant based foods in the war. CHUKWUMA MUANYA reports.
IN recent times, more Nigerians appear to have died of cancer or living with the disease. Though the disease has not proven cure, experts suggest that early detection and eating plant-based diets could prevent the onset and spread of cancers.
Also, researchers at the Nigeria Institute of Pharmaceutical Research and Development (NIPRD), Abuja, have developed a candidate cure from local herbs, presently undergoing clinical trials for the treatment of diabetes.
A Nigerian scientist has also developed a herbal cure for diabetes, which has been hailed in medical quarters.
Besides plant-based diets such as Bitter leaf, citrus fruits, beans, cereals, among others, researchers at the University of East Anglia, United Kingdom, suggest that tadpoles could hold the key to developing effective skin cancer drugs. The study is published in the journal, Chemistry & Biology.
The scientists have identified a compound, which blocks the movement of the pigment cells that give the tadpoles their distinctive markings.
It has been shown that uncontrolled movement of pigment cells causes skin cancer in both humans and frogs. The researchers say the next step is to test the compound in other animals.
The man-made compound, NSC 84093, was chosen out of a list of 3,000, which were screened to see if they affected the pigment cells.
According to the researchers, it produced a distinct change in the colour markings on the tadpoles at very low concentrations. The continuous stripe along the back of a wild tadpole was replaced by a pattern of individual blocks of colour.
Grant Wheeler, a developmental biologist and lead researcher at the University of East Anglia, UK said: "Forty of the compounds gave us an interesting difference which we wanted to follow up. The reason we were able to look at so many compounds was because it's very easy to look at the embryos and see the colour change. The pigment cells are interesting for a number of reasons. The first is that the place where they develop is not where they end up - they move through the embryo in a process called cell migration."
It been shown that it is when melanoma cells migrate through the body to the organs and cause secondary tumours that the disease becomes deadly. Melanomas are one of the most dangerous forms of skin cancer because they are highly invasive and resistant to treatment.
Scientists hope that if they can block this process they can halt the cancer. The compound in this study works by inhibiting matrix metaloproteinases (MMP), which are expressed by melanoma tumours in both humans and frogs.
Wheeler said that a chemist at the university recognised the structure of their compound and realised that part of it had known properties that meant it should bind to a zinc molecule.
MMPs are zinc-dependant enzymes and the researchers observed varying changes to the patterning on the tadpoles according to the strength of dose they were receiving. Wheeler added: "It's a long shot. We are quite far away from a cure for melanoma."
In another new study published recently, researchers have shown that olive oil is effective against HER-2 positive breast cancer, a form of breast cancer for which the medical establishment offers little in the way of tolerable treatment.
The December 8 issue of the journal BMC Cancer reports researchers hypothesising that the effects of the olive oil rich Mediterranean diet on breast cancer risk might be underestimated when it comes to HER-2 breast carcinomas.
They investigated the anti HER-2 effects of phenolic fractions directly extracted from commercial extra virgin olive oil (EVOO) in cultured human breast cancer cell lines. They tested for the ability to kill both HER-2 positive and negative tumours. The effects of the EVOO fractions on the expression and activation status of HER-2 oncoprotein were evaluated.
They found that all the major EVOO polyphenols (that is, secoiridoids and lignans) induced strong tumour killing effects by selectively triggering high levels of apoptotic cell death (programmed cell death) in cells over expressing HER-2. The EVOO polyphenols drastically depleted HER-2 protein and reduced autophosphorylation in a dose and time dependent manner. EVOO polyphenols induced HER-2 downregulation regardless of the molecular mechanism contributing to HER-2 over-expression. (that is naturally by gene amplification and ectopically driven by a viral promoter).
The researchers concluded that the ability of EVOO derived polyphenols to inhibit HER-2 activity by promoting the degradation of the HER-2 protein itself, together with the fact that humans have safely been ingesting polyphenols from olive oil for as long as they have been consuming olives and olive oil, support the notion that EVOO is an excellent and safe treatment targeting HER-2.
Indeed, researchers suggest that eating lots of fruit and vegetables and limited amounts of red meat and sugary foods is the way to protect against cancer.
Three separate studies in the Journal of the American Medical Association (JAMA) show the benefits of a Mediterranean-style diet.
Experts say as well as protecting against bowel cancer, eating a plant-based diet is good for the heart. Such diets offered no extra protection against breast cancer, however.
"The best advice is still as it stands to eat lots of fruit and vegetables," said Dr. Steve Heggie, a scientist at World Cancer Research Fund
Also, a collaborative study led by University College, London (UCL) shows that the compound - inositol pentakisphosphate - found in beans, nuts and cereals inhibits a key enzyme (phosphoinositide 3-kinase) involved in tumour growth.
The findings, published in Cancer Research, suggest that a diet enriched in such foods could help prevent cancer, while the inhibitor offers a new tool for anti-cancer therapy.
Phosphoinositide 3-kinase is a key player in the development and progression of human tumours. Scientists have been exploring phosphoinositide 3-kinase as a target for cancer treatment but inhibitors have been difficult to develop because of problems with the chemical stability and toxicity of the inhibiting substances.
Now, a team of scientists led by Dr. Marco Falasca of the UCL Sackler Institute has discovered that a natural compound, inositol pentakisphosphate, inhibits the activity of the enzyme, suggesting it could be used to develop new treatments for cancer.
In the study, the compound was tested in mouse models and on cancer cells. Not only was it found to inhibit the growth of tumours in mice, but the phosphate also enhanced the effect of cytotoxic drugs in ovarian and lung cancer cells. The findings suggest that inositol pentakisphosphate could be used to sensitise cancer cells to the action of commonly used anti-cancer drugs.
Inositol pentakisphosphate is a non-toxic, water-soluble compound found in most legumes (such as lentils, peas and beans) and in wheat bran and nuts. These properties make the compound a promising therapeutic agent since conventional chemotherapy agents can be toxic to different degrees, whereas in the study, the inositol phosphate agent was found to be non-toxic even at higher concentrations.
Falasca of the UCL Sackler Institute says: "Our study suggests the importance of a diet enriched in food such as beans, nuts and cereals which could help prevent cancer. Our work will now focus on establishing whether the phosphate inhibitor can be developed into an anti-cancer agent for human therapy. We believe that inositol pentakisphosphate is a promising anti-cancer tool and we hope to bring it to clinical testing soon."
Dietary fibre, also known as roughage or bulk, includes all parts of plant foods that the body cannot digest or absorb. Unlike other food components such as fats, proteins or carbohydrates, which the body breaks down and absorbs - the body does not digest fibre. Therefore, it passes virtually unchanged through your stomach and small intestine and into the colon.
Insoluble fibre promotes the movement of material through the digestive system and increases stool bulk, so it can be of benefit to those who struggle with constipation or irregular stools. Whole-wheat flour, wheat bran, nuts and many vegetables are good sources of insoluble fiber.
Soluble fibre dissolves in water to form a gel-like material. It can help lower blood cholesterol and glucose levels. Generous quantities of soluble fiber can be found in oats, peas, beans, apples, citrus fruits, carrots, and barley.
Using a new method, researchers say they have discovered that whole grains like corn, whole wheat, oats and brown rice exhibit a level of anti-cancer activity that is equal to, and sometimes greater than the level known to occur in vegetables and fruits.
In findings reported at the American Institute for Cancer Research (AICR) International Conference on Food, Nutrition and Cancer, researcher, Dr. Rui Hai Liu, and his colleagues at Cornell University say they have found that whole grains contain many potent antioxidants that have gone undocumented for years because researchers have not known how to look for them.
The findings may begin to clear up one of the most controversial and confusing questions in contemporary diet-cancer science; the role of high-fibre diets in lowering colon cancer risk.
New research published in the journal Breast Cancer Research suggests that Omega-3, the fatty acid found in oily fish, could be combined with a commonly used anesthetic to develop drugs to treat breast cancer.
According to the study, compounds of Omega-3 fatty acids and propofol reduce the ability of breast cancer cells to develop into malignant tumours, inhibiting cancer cell migration by 50 per cent and significantly reducing their metastatic activity. These new compounds could be developed into a new family of anti-cancer drugs.
Meanwhile, another research results indicated that soy that contains isoflavone improves menopausal symptoms and related quality of life when given in adequate doses to postmenopausal women.
Dr. Rafat Siddiqui, from the Methodist Research Institute and Indiana University in Indianapolis, United States and his colleagues studied the effect of two Omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), combined with propofol on a breast cancer cell line in vitro. Omega-3 fatty acids such as DHA and EPA have a minimal effect on cancer cells when applied alone. Propofol is a potent anti-oxidant known to inhibit cancer cell migration by only five-10 per cent.
The results of the study show that propofol and DHA or EPA have a much more significant effect on cancer cells when used in combination, as conjugates, than when used alone. The conjugates inhibit cancer cell adhesion by 15 per cent and 30 per cent respectively, reduce cell migration by 50 per cent and increase apoptosis by 40 per cent.
A recent study published recently shows that incorporating plenty of citrus fruits such as oranges, tangerine and grapefruit in the daily diet plan may help fight cancers of the mouth, skin, lung, breast, stomach and colon in laboratory tests with animals and with human cells.
Studies have further shown that citrus fruits contain limonoids, which inhibit the development of cancer in laboratory animals and in human breast cancer cells as well as reducing cholesterol.
Researchers have also suggested that if ingested, limonoids may not be absorbed in the large intestine and, therefore, could be distributed throughout the body with beneficial effects.
Previous studies show that citrus fruits hold promise for certain childhood cancers. Experts suggest that the popular citrus drink could become a cocktail to prevent or stop the deadly diseases in humans. It has also been shown that orange and tangerine peels could be better than drugs for lowering cholesterol.
Other studies indicate that naturally occurring substances in citrus juices, called flavonoids, show promise against prostate cancer, lung cancer and melanoma in laboratory studies.
Agricultural Research Service scientists in northern California, United States, led by a chemist, Gary D. Manners, are uncovering new details about these compounds. Manners and co-investigators have reported their findings in studies published during the past several years. They have demonstrated, for example, that each time one bites into a citrus slice or drink a glass of orange juice, the body can readily access a limonoid called limonin. The team was the first to show limonin's "bio-availability."
Also, earlier studies had enlisted extract from Bitter leaf to inhibit breast cancer and lowers blood glucose levels. A phytochemotherapy (treatment based on plant chemicals) for cancer made from aqueous extracts of leaves of Bitter leaf, collected in Benin City, has received a United States Patent 6849604.
The anticancer invention provides for phytochemotherapeutic compositions produced from aqueous extracts, derived from Vernonia amygdalina leaves. These pharmaceutical compositions inhibit the growth of neoplastic cells, including human breast cancer cells.
Neoplasia (new growth in Greek) is the abnormal proliferation of cells, resulting in a neoplasm. Neoplasia is the scientific term for the group of diseases commonly called tumor or cancer.
The Inventor, Izevbigie Ernest B. claims the instant invention provides phytochemotherapeutic compositions and methods for inhibiting the growth of cancer cells, and specifically for the growth inhibition of human breast cancer cells.
According to an earlier study by Izevbigie, "discovery of water-soluble anticancer agents (Edotides) from a vegetable found in Benin City, Nigeria," published in the journal Experimental Biology and Medicine, Bitter leaf may prevent the onset of breast cancer.
The researchers led by Izevbigie wrote: "Treatment of cells with physiologically relevant concentrations of water-soluble Bitter leaf extract potently inhibited DNA synthesis in a concentration dependent fashion, both in the absence and presence of serum. Fractions of Bitter leaf extract separated using preparative reverse-phase chromatography also inhibited DNA (genetic material) synthesis."
The researchers conclude: "These results suggest that the vegetable Bitter leaf, if incorporated in the diet, may prevent or delay the onset of breast cancer."
Taiwanese researchers have also found that Indian almond stops the spread of lung cancer in animal models. Indian almond is botanically called Terminalia catappa and belongs to the plant family combretaceae. It is found in almost every town and village in southern Nigeria. It is known as Malabar Almond, Tropical Almond, fruit (by some Nigerians).
Shu-Chen Chu, Shun-Fa Yang, Shang-Jung Liu, Wu-Hsien Kuo, Yan-Zin Chang and Yih-Shou Hsieh in a study titled "In vitro and in vivo antimetastatic effects of Terminalia catappa leaves on lung cancer cells" investigated the effect of the extract of T. catappa leaves (TCE) on invasion and motility of tumour cells to find that TCE exerted a dose-dependent inhibitory effect on the invasion and motility of highly metastatic A549 and Lewis lung carcinoma (LLC) cells.
Metastasis is the spread of a disease from one organ or part to another non-adjacent organ or part. Only malignant tumour cells and infections have the capacity to metastasize. Metastatic disease is a synonym of metastasis. Cancer cells can "break away", "leak", or "spill" from a primary tumour, enter lymphatic and blood vessels, circulate through the bloodstream, and settle down to grow within normal tissues elsewhere in the body. Metastasis is one of three hallmarks of malignancy (contrast benign tumours).
According to the study published in Food and Chemical Toxicology, to further investigate the precise involvement of TCE in tumour metastasis, A549 and LLC cells were treated with TCE at various concentrations, up to 100 _g/mL, for a specified period and results from zymography and Western blotting showed that a TCE treatment may decrease the expressions of tissue inhibitors, in a concentration-dependent manner.
Zymography is used for the detection of enzyme activity. Western blot analysis can detect one protein in a mixture of any number of proteins while giving information about the size of the protein.
Furthermore, the inhibitory effect of TCE on the growth and metastasis of LLC cells in vivo was proven. These results indicated that TCE could be applied to be a potential antimetastatic agent.
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