Herbal Aids for Cancer
From The March 2000 Issue of Nutrition Science News
by Cindy L.A. Jones, Ph.D.
Cancer treatments are a paradox, on one hand delivering powerful toxicity to a tumor, but on the other spreading toxicity to the rest of the body. The side effects of such treatments may cause death even before the cancer does. Biological response modifiers (BRMs) are compounds that have a unique effect on physiology and can reduce the side effects of cancer treatments, while at the same time increasing their effectiveness.
A BRM repairs damage to the body rather than targeting a pathogenic agent such as cancer. It typically acts by stimulating the immune system to restore optimal function. Many diseases and infections as well as AIDS result from immune surveillance failure. Because chemotherapy compromises the immune system, people receiving cancer treatments run an especially high risk of contracting and dying of infections.
Cytokines, hormones naturally produced in the body, promote immunity and are often used clinically as BRMs--to treat disease, fight viral infections and augment chemotherapy. Three pharmaceutical cytokines currently in use include colony-stimulating factors that reduce the chance of infection and thus the need for antibiotics by stimulating bone marrow to produce more white blood cells; interferons that stimulate macrophages to ingest foreign particles and help the body produce antiviral chemicals; and interleukins that stimulate growth and activation of white blood cells. The therapeutic use of these cytokines, called immunotherapy, as a cancer treatment both with and without standard anti-cancer drugs is marginally successful. Side effects such as depression, nausea and chest pain, however, can limit the effectiveness of some pharmaceutical cytokines.
Many herbs have long been known to affect the immune system, but only recently have scientists considered them as possible BRMs and adjunct cancer therapies. Such herbs often prompt the body's cells to secrete cytokines, which then enhance the immune response. The most promising of these herbs include black cumin, mistletoe, ginseng, astragalus, green tea, echinacea and garlic.
Black cumin (Nigella sativa) is related to a common garden flower that goes by several names including cinnamon flower, nutmeg flower and love-in-a-mist. In the Mediterranean and Middle East where nigella seeds are traditionally used, it is also referred to as black seed and is used for a variety of ailments including upper respiratory conditions, headaches, cancer, stomachaches and jaundice. Nigella seeds are traditionally eaten alone or ground with honey.
Nigella is considered a BRM because studies show extracts from the seeds are toxic to cancer cells and, in mice, prevent blood cell toxicity caused by the anti-cancer drug cisplatin.1 The active components of nigella seeds are the volatile oils thymoquinoline and dithymoquinone, both of which inhibit tumor cells in laboratory experiments--even tumor cells resistant to anti-cancer drugs.2 A recent cell study conducted at the International Immuno-Biology Research Laboratory in South Carolina showed that when incubated with nigella extract, cancer cells were unable to produce fibroblast growth factor and the protein collagenase, both necessary for blood-vessel growth into the tumor.3 Without a blood supply, a tumor cannot grow.
Nigella also stimulates the immune system, as shown in an experiment conducted with human lymphocytic white blood cells. Cells treated with nigella-seed proteins produced greater amounts of cytokines, specifically interleukin-1-beta and tumor necrosis factor alpha.4 How and if this is important to treating cancer is not yet established.
Another recent experiment indicates that thymoquinone may also prevent some toxic side effects of cancer treatments. Scientists from King Saud University in Saudi Arabia found that mice pretreated with thymoquinone were protected from carbon tetrachloride-induced liver toxicity. Carbon tetrachloride is a toxin that in small amounts can kill by causing the liver and kidney to atrophy. Liver toxicity was assessed by measuring the release of liver enzymes in the blood. Thymoquinone also demonstrated antioxidant activity, which may be how it protects the liver.5
According to U.S.D.A. Phytochemical and Ethnobotanical Databases compiled by James Duke, Ph.D., nigella seed also contains limonene.6 Found in high amounts in lavender, limonene is being investigated for use as a treatment for some types of cancer.7
European mistletoe (Viscum album) is an evergreen parasite that depends on a host, often an old apple tree. It has long been considered a sacred plant, partially because of its medicinal properties.8 Historically, mistletoe was used to treat nervous disorders, but some European clinics are now using it to treat cancer.
Mistletoe may prove helpful for treating cancer because it stimulates the immune system, stabilizes DNA, inhibits blood vessel growth and is toxic to cancer cells.9 Many of these effects were documented in cell and animal studies in the 1970s and 1980s. Although small and poorly designed, some human studies show that mistletoe treatment also improves the quality of life and survival rates for people with cancer.
The most common preparation of mistletoe is an injectable, fermented whole-plant extract called Iscador.10 Its active components include proteins such as ML-I and viscotoxins. Recent studies show that mistletoe's viscotoxins affect the immune system. Arndt Bussing from Krebsforschung Herdecke, University Witten/Herdecke in Germany showed that crude extracts of viscotoxin stimulated human granulocyte cells (a type of white blood cell) to destroy pathogenic cells.11 This is especially important because cancer treatment stunts granuloctye activity, which in turn increases infection risk. Treatment with mistletoe must be administered only under the supervision of a health care provider.
There are two types of ginseng, Panax ginseng, also known as Oriental, Asiatic, Chinese, Korean or Japanese ginseng, and P. quinquefolius, known as American ginseng. Siberian ginseng (Eluetherococcus senticosus) is a different plant genus entirely but shares many properties with true ginseng. All of the ginsengs are adaptogenic herbs, meaning they produce nonspecific resistance for the body. Although ginseng's energy-producing properties can benefit someone with cancer, scientific evidence indicates it has more specific uses.10
A recent cell study by Tadahir Takeda from Kanazawa University in Ishikawa, Japan, showed that polysaccharides from panax boost production of the immune-stimulating cytokine interleukin-8. Both leukemic human monocytes (types of blood cells) and normal human monocytes were incubated with panax extracts for 24 hours. Researchers then measured the amount of IL-8 in the cells. The ginseng significantly increased the amount of IL-8 secreted from these cells compared to cells not incubated with ginseng.12
A purified polysaccharide of panax, called ginsan, has several immunomodulating effects on mouse cells that are similar to the effects of the naturally occurring cytokine interleukin-2. Ginsan activates T and B lymphocytes and macrophages and converts spleen cells into activated killer cells that destroy tumor cells. When ginsan was injected into mice with induced lung cancer, it significantly reduced the number of tumors--by 44 percent--compared with mice that did not receive ginsan. When mice were given ginsan in their drinking water, the tumors also decreased, but only by 15 percent. Ginsan had no detectable toxicity.13
Customers should discuss using ginseng with their physician because the herb can decrease blood platelet clotting. When taken in conjunction with chemotherapy, bleeding problems may occur.
In Chinese medicine, astragalus (Astragalus membranaceous) is considered an adaptogenic herb.14 A 1988 experiment indicated astragalus extract increased the ability of interleukin-2 to kill cultured tumor cells.15 A more recent study at the Hiroshima University School of Medicine in Japan showed that a water-based astragalus extract, when incubated with mouse spleen cells, had several immunopotentiating effects. It increased B cell growth, T cell activity, and interleukin-6, tumor necrosis factor and antibody production.16
Astragalus also protects the body against drug toxicity. In one animal study, a combination of astragalus and wintergreen (Pyrola rotundifolia) prevented damage to the kidney and to the cochlear nerves and hair cells of the inner ear caused by the antibiotic gentamicin, commonly prescribed for pneumonia and sepsis.17
Astragalus is included in a Chinese herbal medicine referred to as 10 significant tonic decoction or SQT (Shi-Quan-Da-Bu-Tang). It is a 10-herb combination recommended in conjunction with cancer therapy to protect the body from drug toxicity and increase immunity. According to Chinese research, astragalus prevents the adverse effects of the anti-cancer drugs mitomycin C and cisplatin as well as stimulates the immune system.18 The herb is more commonly used in Asia as an adjuvant to cancer treatments.
Although it is better known as a cancer preventive, preliminary studies suggest green tea (Camellia sinensis) also may be a useful treatment for cancer or an adjuvant to chemotherapy.19 Green tea contains catechins, antioxidantlike polyphenolic compounds, that can inhibit the spread of cancer.20
A recent animal study by Sadao Hirota from the University of Shizuoka in Japan showed that, when taken with chemotherapy, steeped green tea also enhanced the therapeutic effects of the drugs. Mice with cancer were treated with the widely used anti-tumor drug doxorubicin and given green tea orally. After 18 days, tumor size in the green tea plus doxorubicin-group decreased 37 percent compared with 25 percent in the mice given only doxorubicin. Researchers found that the concentration of doxorubicin increased in the tumors of animals receiving the green tea but not in normal tissue, which may explain the drug's increased effectiveness.21
Many laboratory studies document echinacea's (Echinacea spp.) traditional use as an immune stimulator. The active polysaccharide fraction of echinacea increases phagocytosis, or ingestion of foreign particles, and stimulates production of the cytokines interleukin-1, interleukin-6 and tumor necrosis factor.22
One human study by Wolfram Grimm of Philipps University in Marburg, Germany, showed that echinacea had some ability to prevent upper respiratory tract infections and shorten their duration. His double-blind study of 109 people showed that taking 4 mL of E. purpurea extract twice daily for eight weeks decreased the risk of infection by 22 percent and shortened the duration of colds by two days.23 Although the improvement is modest, it may have important implications to someone on chemotherapy. Some herbalists, however, warn that using echinacea for long periods can decrease immunity. Herbalist Christopher Hobbs suggests using echinacea for only a week or 10 days at a time.24
Another study using cells from healthy volunteers, chronic fatigue syndrome patients and AIDS patients, showed that combined extracts of panax and echinacea enhanced natural killer cell function, an important component of cellular immunity. This was true for all the cells.25
Although echinacea is usually recommended for upper respiratory tract infections and there is little data on its use as an adjuvant to chemotherapy, it is reasonable to expect its immune-enhancing effects to decrease the risk of infection in people receiving cancer treatments.
Garlic (Allium sativum) may be an effective adjuvant treatment for cancer because of its effects on the liver, tumor cells and the immune system.10
Its ability to reduce the side effects of cancer treatment was demonstrated in an animal study in which garlic given orally to rats significantly reduced liver damage caused by the cancer-causing aflatoxins found in molds.26 Researchers speculate that because garlic enhances the activity of glutathione S-transferase, a liver enzyme that helps detoxify and remove toxins from the body, it may detoxify aflatoxins before they cause damage.
A more recent study by Dale Riggs at West Virginia University in Morgantown indicated aged garlic extracts are effective against bladder cancer. Garlic extracts were injected four times during a one-week period into mice with bladder cancer. The mice showed significant reduction in tumor growth compared with mice that did not receive injections. Garlic extract was also effective when given orally. High doses of garlic (greater than 12.5 mL per injection) caused toxicity, but effective doses (6.3 mL) did not cause side effects.27 When garlic extracts were given orally in the animals' drinking water (29 mL/day), tumors decreased significantly with no side effects.
In another experiment, a water-soluble extract of fresh garlic given orally to mice for five days prior to gamma-radiation treatment protected against the chromosomal damage caused by treatment.28
With luck, researchers will continue to find inexpensive and nontoxic BRMs. In addition to their usefulness as adjuvants to chemotherapy, such herbs may also help treat AIDS, chronic fatigue syndrome and other immune-depressing diseases. Although inferring meaningful effects for humans from laboratory and animal studies is not easy, in most cases these herbs have few side effects when compared to pharmaceuticals and are generally safe to use. Advise customers to talk to their doctors before pursuing supplemental cancer treatments so that potential side effects, as well as therapeutic effects, can be monitored. Many of these treatments require injections that should be administered only by a qualified medical professional.
Cindy L.A. Jones, Ph. D., is a freelance writer and author of The Antibiotic Alternative due out soon from Healing Arts Press. She lives in Colorado where she teaches and writes.
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