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Do herbal remedies interfere with conventional breast cancer drugs?


The turmeric powder

There have been claims and counter claims of the effect of herbal remedies on breast cancer treatments. Doctors have in recent studies warned that skin creams and herbal remedies may interfere with breast cancer treatments.At an advanced stage of breast cancer lesions often spread to the skin – and many patients attempt to sooth these with topical creams and herbal treatments.

But researchers from Nova Medical School in Portugal said these delay wound healing and interfere with hormone therapy or chemotherapy.
According to the report first published by DailyMailUK Online, the doctors said herbal treatments such as turmeric or ginseng can stop blood from clotting as well as it should and worsen scarring.A breast surgeon, Prof. Maria Joao Cardoso, presenting at the Advanced Breast Cancer conference in Lisbon, Portugal, said treatments including garlic and ginger remedies are among those that can do more harm than good.She said while there is a long list of complementary products that patients can try, there is no evidence they treat skin lesions effectively.

Cardoso further explained: “Many patients do not check and do not tell their doctors that they are using complementary therapies. There are many of these therapies, especially herbal products and topical creams, that can have a negative impact in cancer treatment. Many compounds are complex and some ingredients can delay healing and interfere with the efficacy of ongoing systemic treatments.

“Laboratory studies have shown that certain products can reduce the blood clotting process required for a wound to heal. If a patient has a bleeding wound, these compounds can have a strong, adverse impact on scarring and how well wound dressings work. In as many as a fifth of cases, breast cancer spreads to the skin.She said the resulting lesions are difficult to treat and can cause physical discomfort and distress.

The professor said topical treatments, which have become more popular, are only successful in healing or controlling the wound in 50 per cent of cases and activities such as yoga, acupuncture and Reiki may help patients manage their stress.

Also, another study published last year in Oncology Journal, Integrative Oncology titled “Herb-Drug Interactions in Cancer Care” highlighted four popular herbs and a medicinal mushroom commonly used by cancer patients—turmeric, green tea, ginger, ashwagandha, and reishi mushroom—along with reports of their interactions with standard drugs.

The researchers concluded: “We conclude by emphasizing the need to inform patients and physicians about herb-drug interactions and how to advise patients on appropriate use of herbal supplements to minimize the risk for interactions.”They explained: “Herbs have served as medicine throughout human history. Since the passage of the Dietary Supplement Health and Education Act (DSHEA), inconsistent regulatory practices have resulted in widespread, indiscriminate use of herbal supplements. Available data indicate that cancer patients use these products (along with standard treatments) more often than the general population. The reasons cited for such use include improving health, reducing the risk of recurrence, and reducing the side effects of cancer treatments. Herbs, however, contain biologically active compounds and can potentially interact with prescription medications, including chemotherapy drugs…”

But, a study published earlier this year in the Saudi Pharmaceutical Journal had validated among others garlic, ginger, turmeric and green tea as natural cures for breast cancer.

The study was conducted by researchers from the Institute of Pharmacy, Physiology & Pharmacology, University of Agriculture, 38000 Faisalabad, Pakistan; Department of Environmental Science and Engineering, School of Environmental Studies, China University of Geosciences, 430074 Wuhan, PR China; Faculty of Science and Natural Resources, University Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia; and Institute of Pharmacy, Physiology & Pharmacology, University of Agriculture, 38000 Faisalabad, Pakistan.

The study reviewed different types of plants that retain the immune stimulating and anti-tumor properties. Large variety of active phytochemicals such as carotenoids, flavonoids, ligands, polyphenolics, terpenoids, sulphides, lignans and plant sterols has been identified in different types of herbs.

These phytochemicals have different mechanisms of action. They either stimulate the protective enzyme like glutathione transferase or prevent the cell proliferation.The review centered on the biochemical properties of Allium sativum (garlic), Echinacea, Curcuma longa (turmeric), Arctium lappa (Burdock), Camellia sinensis (green tea), ginseng (Panax ginseng) and Flax seed. Extracts and juices of Withania somnifera, Amoora rohituka, Dysoxylum binectariferum and Vaccinium macrocarpon, respectively also used as anti-breast cancer.

The volatile oils and extracts of these herbs and plants inhibit the synthesis of mevalonate that lessen the tumor growth and cholesterol synthesis.The researchers concluded: “Multi-factorial factors are involved for breast cancer; many factors act independently or may be in combination, especially in high risk individuals. It is important to know the pathogenesis of this common disease, which is associated with high mortality and morbidity especially if not detected early.

“So the role of early screening in high risk individuals as well as proper surveillance of treated case in order to detect recurrence at early stages has been advocated.”

Garlic (Allium sativum), for hundreds of years it has been used for treating many illnesses. It involves hundred or more than hundred therapeutically useful secondary metabolites, for example, alliin, alliinase, and allicin. Alliin, an amino acid, is present in garlic oil that is transformed to allicin after its rhizomes are crumpled.

An originator of Sulfur comprising compound is allicin, which is responsible for odor and its therapeutic properties. Garlic oil contains another Sulfur holding substance, Ajoene. Ajoene delays the cancer production while selenium as antioxidant.Bioflavonoids, cyanidin and quercetin, are also found in garlic with antioxidant properties. Anti-cancer activity of garlic is due to high amount of organic sulfides and polysulfide’s.

Mechanism behind anti-tumour activity stimulating the lymphocytes and macrophages is that they kill the cancerous cells and interferes with tumor cells metabolism.Studies have shown that the number of suppressor T cells is increased by garlic and converts the lymphocytes in that form which is cytotoxic to cancerous cells. Metastases are prevented by altering the adhesion and attachment of cancerous cells, circulating in the blood vessels.Harmful effects of carcinogens to DNA are prevented by ripened garlic extract; it improves the immune system of the body, increases the removal of carcinogens from the body, and enhances the detoxifying enzyme’s activity.

Researchers have found that the ripened extract of garlic is also helpful to shield the propagation of several types of cancers such as colon, stomach, breast, lungs and bladder.Complications of chemotherapy and radiotherapy could be lessen with garlic extract.

Scientific name of turmeric is Curcuma longa. Turmeric gives dark yellow color to food.Curcumin, the active ingredient of turmeric, is present in its rhizome and rootstock. Curcumin is known to have anticancerous activity due to its phenolic substances.Propagation of lung, breast, skin and stomach cancer is limited by turmeric. Eicosanoids, for example prostaglandin E-2 (PGE-2), production is altered by curcumin, an antioxidant agent. It has also anti-inflammatory action in human.

Curcumin has been revealed to have inhibitory action in all phases of cancer growth, which are initiation, promotion, and propagation.Nitrosamine production is inhibited by turmeric; it results in increase natural antioxidant action of the body. Amount of glutathione and other non-protein sulphahydryls is increased by curcumin, and they act directly on different enzymes.

Curcumin has been reported to be safe, but due to its antioxidant properties, it can interact with chemotherapy drugs such as cyclophosphamide and doxorubicin. It is also known to interfere with CYP450 enzymes and may interact with substrate drugs. In addition, because of its antiplatelet property, curcumin can increase the risk of bleeding when used with anticoagulants.

Green tea
The leaves of green tea (Camellia sinensis) are used to prepare tea. With origins in Asia and now consumed worldwide, green tea and its extracts have been used to prevent and treat hyperlipidemia, hypertension, atherosclerosis, and cancer. The active constituent of green tea extract is epigallocatechin-3-gallate (EGCG).

Green tea extract has demonstrated chemopreventive activity by preventing formation of precancerous polyps, inhibiting proliferation of breast cancer cells, and by inducing apoptosis in bladder cancer cells. A large case-control study reported a reduction in the risk of breast cancer following intake of mushrooms (both fresh and dried forms) and green tea in premenopausal and postmenopausal women. It may also reduce the risk of myelodysplastic syndromes. A meta-analysis, however, failed to find any benefits for prevention of gastric cancer.

Topical application of green tea extract has been shown to be effective against external genital and perianal warts. One such extract, sinecatechins, is approved by the FDA. Preclinical studies, however, have shown that the polyphenolic constituents in green tea can negate the therapeutic effect of bortezomib, an anticancer drug, while increasing the risk of toxicity when used with tamoxifen and irinotecan. Elevated risk of hepatotoxicity has also been reported when used with acetaminophen and when consumed on an empty stomach.

A clinical study showed that taking 800-mg EGCG is associated with elevated liver enzymes, which was reversible following cessation of consumption. According to an observational study, intake may enhance the risk of breast cancer in postmenopausal women. Daily consumption of green tea varied between one and three cups. The risk appears to be modified by the age at onset of tea drinking, with a protective effect for women who started before age 20 years and an increased risk for those who started after age 50 years. Green tea extract is also known to interfere with the CYP450 3A4 enzyme and may affect the intracellular concentration of drugs metabolized by this enzyme.

Ginger, the rhizome of the plant Zingiber officinale, has long been used as a culinary spice and medicine in Asian and Arabic traditions to treat the common cold, headache, and fevers, as well as gastrointestinal and inflammatory disorders. Clinical trials indicate that ginger can effectively reduce nausea and vomiting due to pregnancy, motion sickness, and following surgery. Findings of its efficacy in preventing chemotherapy-induced nausea are also promising. A systematic review of randomized, controlled, and crossover trials, however, found that data are inconclusive to recommend clinical use.

A longitudinal study reported that in patients receiving warfarin, concomitant use of ginger elevated the risk of bleeding. A common warning is to discontinue use of ginger supplements in the perioperative setting due to the potential risk for increased bleeding. According to a recent systematic review, findings of platelet aggregation and coagulation properties of ginger are equivocal. Future studies are needed for definitive data.

Scientific name of ginseng is Panax ginseng. It is lasting plant mainly grows in China, Korea, Japan and Russia. Part used of this plant is dried root. It has many therapeutic uses including cancer. Active substances of ginseng have shown that it reduces or blocks the development of tumor necrosis factor in the skin of mouse, blocks the propagation and metastases of cancerous cells, stimulate cell differentiation, and level of interferon.Other types of cancerous cells stages may also hindered by ginseng’s ingredients.

An investigation was also carried out in Korea, recommended that ginseng reduces the cancer risk in human.As related to fresh sliced ginseng, its juice or tea, the most potent and active type of ginseng is its extract and dried powder for prevention of cancer threat.By interrupting the DNA synthesis ginseng retains the tumor development.Beneficial effects of active compound of P. ginseng include restart of natural killer cells impaired during chemotherapy and radiotherapy, induces macrophages and enhances antibodies formation.

What is breast cancer?
Breast cancer develops from a cancerous cell, which develops in the lining of a duct or lobule in one of the breasts.When the breast cancer has spread into surrounding breast tissue it is called an “invasive” breast cancer. Some people are diagnosed with “carcinoma in situ”, where no cancer cells have grown beyond the duct or lobule.Most cases develop in women over the age of 50 but younger women are sometimes affected. Breast cancer can develop in men though this is rare.The cancerous cells are graded from stage one, which means a slow growth, up to stage four, which is the most aggressive.


What causes breast cancer?
A cancerous tumour starts from one abnormal cell. The exact reason why a cell becomes cancerous is unclear. It is thought that something damages or alters certain genes in the cell. This makes the cell abnormal and multiply ‘out of control’.Although breast cancer can develop for no apparent reason, there are some risk factors that can increase the chance of developing breast cancer, such as genetics.

What are the symptoms of breast cancer?
The usual first symptom is a painless lump in the breast, although most breast lumps are not cancerous and are fluid filled cysts, which are benign. The first place that breast cancer usually spreads to is the lymph nodes in the armpit. If this occurs you will develop a swelling or lump in an armpit.

How is breast cancer diagnosed?
Initial assessment: A doctor examines the breasts and armpits. They may do tests such as a mammography, a special x-ray of the breast tissue, which can indicate the possibility of tumours.Biopsy: A biopsy is when a small sample of tissue is removed from a part of the body. The sample is then examined under the microscope to look for abnormal cells. The sample can confirm or rule out cancer.If you are confirmed to have breast cancer, further tests may be needed to assess if it has spread. For example, blood tests, an ultrasound scan of the liver or a chest x-ray.

How is breast cancer treated?
Treatment options, which may be considered, include surgery, chemotherapy, radiotherapy and hormone treatment. Often a combination of two or more of these treatments is used.Surgery: Breast-conserving surgery or the removal of the affected breast depending on the size of the tumour.

Radiotherapy: A treatment, which uses high-energy beams of radiation focused on cancerous tissue. This kills cancer cells, or stops cancer cells from multiplying. It is mainly used in addition to surgery. Chemotherapy: A treatment of cancer by using anti-cancer drugs, which kill cancer cells, or stop them from multiplying Hormone treatments: Some types of breast cancer are affected by the ‘female’ hormone oestrogen, which can stimulate the cancer cells to divide and multiply. Treatments, which reduce the level of these hormones, or prevent them from working, are commonly used in people with breast cancer.

How successful is treatment?
The outlook is best in those who are diagnosed when the cancer is still small and has not spread. Surgical removal of a tumour in an early stage may then give a good chance of cure.The routine mammography offered to women between the ages of 50 and 70 mean more breast cancers are being diagnosed and treated at an early stage.

Advising patients
Research suggests that patient–provider communication about herbal use is very rare in the oncology setting. Although many oncologists are not trained in the use of herbs, they have an important role in advising and guiding patients as part of the overall treatment plan. Where scientific evidence is lacking, physicians often advise against supplementation by erring on the safe side. But such a conservative approach can also discourage communication about dietary supplement use.


For many oncologists, finding credible information about dietary supplements, especially herbs, can also be tricky. Standard drug databases (example, Lexicomp) have comprehensive information on prescription drugs, but the entries on herbal supplements are often limited. On commercial websites that promote herbal products, information about potential adverse effects or interactions is often minimized or ignored.

To address this issue, the Integrative Medicine Service at Memorial Sloan Kettering Cancer Center has developed the “About Herbs” website: It contains objective information on more than 280 dietary supplements and bogus treatments used by cancer patients. Mechanisms of action underlying the effects of these products and the drugs with which they can potentially interact are listed. This award-winning site, which has both healthcare professional and consumer versions, is available free of charge to clinicians and patients. Other databases that provide reliable information include the National Institutes of Health’s Office of Dietary Supplements (, which is free to access, and and the Natural Medicines Comprehensive Database (, both of which charge for their services.

Herbal product use by cancer patients has significantly risen in the last few decades. However, these agents lack governmental oversight and are biologically active, with a potential for interactions with chemotherapy and other cancer drugs. Fostering open communication on herbal product use between patients and physicians is therefore important. Physicians should discuss expectations with their patients, clearly communicating the potential benefits and risks involved.


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