successful treatment of x-ray and radium burns. Today, aloe is also commonly found in commercial shampoos and skin lotions. Aloe is generally considered safe for use in humans, both topically and orally and is reported to be non-toxic even when injected in high doses. Aloe Vera is also approved by the FDA as a natural flavoring. But side effects from the use of aloe have also been reported. A bitter yellow substance in the bundle sheath is a purgative and laxative, and must be removed in processing--skin and intestinal irritation can also result from applying or ingesting the raw juice. Aloe has been studied extensively in Russia, as well as in Madagascar and Japan. There is considerable research evidence for aloe's usefulness as a non-specific immune stimulator and immune modulator. These findings point not only to aloe's potential role as
adjuvant therapy for cancer, but also to its value for patients whose immune function has been compromised as a side effect of mainstream therapy. Most studies, however, examined the effects of aloe or its constituents when injected; it is unclear, therefore what results might be expected from the use of aloe taken orally. In 1976, guided by assays for tumor-inhibitory activity, researchers examined an extract of the seeds of the aloe species Rhamnus frangula L. and isolated aloe emodin, compound that showed significant antileukemic activity against the P-388 lymphocytic leukemia in mice. In a pair of studies carried out at the Pasteur Institute in Madagascar in 1980 and 1981, researchers found that mice given a hypodermic injection of unrefined Aloe vahombe extract were protected against infection caused by the bacteria Klebsiella pneumoniae, Listeria monocytogenes and Yersinia pestis, Plasmodium berghei parasites, and Candida
albicans fungus. In a third study in 1983, the researchers examined the effect of a polysaccharide fraction of
aloe on the development of experimental fibrosarcoma and melanoma in mice.
Polysaccharides are large a class of carbohydrate molecules that include the common
sugars. They administered the fraction intravenously.
According to the authors:
“In the case of the McC3-1 tumor, but it is encouraging to note that under different experimental conditions the rate of growth of tumors in animals, which were treated, is slower than in those not treated. Preliminary studies of its action seem to indicate that the fraction acts upon non-specific [immune] response and could possibly stimulate the phagocyte [foreign body ingesting] activity of the peritoneal macrophagus [immune
cells].” In their 1988 review of aloe research, Klein and Penneys cite in vitro studies in which aloe inhibited the metabolism of arachidonic acid. One product of arachidonic acid suppresses the activity of immune cells that are part of the body's surveillance against cancer cells. Aloe also decreases thromboxane production by platelets in vitro. Thromboxane is produced by platelets and enhances platelet aggregation, which under normal circumstances is the process by which blood clots and wounds begin to heal. But this same coagulation process can also thicken the blood and promote the arrest of cancer cells that have broken loose from tumors to become lodged at distant sites, which is a critical step in the metastatic process. As an anticoagulant, aloe might inhibit tumor cell arrest at potential metastatic sites. Two Russian researchers carried out an evaluation of antimetastatic properties of aloe and of its usefulness in potentiating the effectiveness of chemotherapy. Using three types of experimental tumors in mice and rats, they found that aloe treatment contributed to a reduction of tumor mass, metastatic foci and metastasis frequency at different stages of tumor progress without affecting major tumor growth. They concluded: "Succus Aloes potentiates the antitumor effect of 5-fluorouracil and cyclophosphamide as components of combination chemotherapy."
In another animal study, S.Y. Peng found that acemannan increased survival of sarcomabearing mice: Acemannan, in both enriched and highly purified forms, was administered intraperitoneally to female CFW mice into which murine sarcoma cells had been subcutaneously implanted. The rapidly growing, highly malignant, and invasive sarcoma grew in 100% of implanted control animals, resulting in mortality in 20 to 46 days, dependent on the number of cells implanted. Approximately 40% of animals treated with acemannan at the time of tumor cell implantation (1.5 x 10(6) cells) survived. Roberts and Travis tested whether a wound dressing gel that contained acemannan extracted from aloe leaves might affect the severity of radiation-induced acute skin reactions in C3H mice and compared the effect to other commercially available gels such as a personal lubricating jelly and a healing ointment. They found that the average peak skin reactions of the acemannan-treated mice were lower than those of the untreated mice at all radiation doses tested. The average peak skin reactions for mice treated with personal lubricating jelly or healing ointment were similar to irradiated control values. Reduction in the percentage of mice with severe skin reactions
was greatest in the groups that received wound dressing gel containing acemannan for at least 2 weeks beginning immediately after irradiation. There was no effect if gel was applied only before irradiation or beginning 1 week after irradiation. Sato and colleagues also examined the protective effects of Aloe arborescens on mouse skin injury induced by x-rays and also concluded that there was a significant protective effect from skin injury.
This research on aloe's usefulness with skin irritation and radiation burns coincides with its traditional use in this regard and is significant for patients undergoing radiation therapy. Some practitioners also advise patients to take aloe orally for mouth and gastrointestinal damage from radiation, a practice considered safe because of its lack of toxicity. Research also indicates that aloe may be of use to the significant minority of cancer
patients experiencing cachexia, or wasting.
Further Reading
• Aloe Vera, Jojoba and Yucca by John Heinerman
• Aloe Vera the New Millennium: The Future of Wellness in the 21st Century by Bill C. Coats, Robert
Ahola
References
• A.D. Klein and N.S. Penneys, "Aloe Vera," Journal of the American Academy of Dermatology
18(4):714-20 (1988).
• Ralph W. Moss, Ph.D., Cancer Therapy: The Independent Consumer's Guide to Non-Toxic Treatment
and Prevention (New York: Equinox Press, 1992), 126-7.
• S.M. Kupchan and A. Karim, "Tumor Inhibitors. 114. Aloe Emodin: Antileukemic Principle Isolated
from Rhamnus frangula L.," Lloydia 39(4):223-4 (1976 July-August).
• J.Y. Brossat et al., "Immunostimulating Properties of an Extract Isolated from Aloe Vahombe. 2.
Protection in Mice by Fraction F1 Against Infections by Listeria, Monocytogenes, Yersinia Pestis,
Candida Albicans and Plasmodium Berghei," Archives de l Institut Pasteur de Madagascar 48(1):11-
34 (1981).
• S. Solar et al., "Immunostimulant Properties of an Extract Isolated and Partially Purified from Aloe
Vahombe," Archives de l Institut Pasteur de Madagascar 47(1):9-39 (1980).
• L. Ralamboranto et al., "Immunomodulating Properties of an Extract Isolated and Partially Purified
from Aloe Vahombe," Archives de l Institut Pasteur de Madagascar 50(1):227-56 (1982).
• N.S. Penneys, "Inhibition of Arachidonic Acid Oxidation In Vitro by Vehicle Components," Acta Derm
Venereol (Stockholm) 62:59-61 (1981). Cited Klein and Penneys, "Aloe Vera."
• R.H. Davis, G.H. Stewart and P.J. Bregman, "Aloe Vera and the Inflamed Synovial Pouch Model,"
Journal of the American Podiatric Medical Association 82(3):140-8 (1992).
• Klein and Penneys, "Aloe Vera."
• N.V. Gribel and V.G. Pashinskii, "Antimetastatic Properties of Aloe Juice," Voprosy Onkologii
32(12):38-40 (1986).
• S.Y. Peng et al., "Decreased Mortality of Norman Murine Sarcoma in Mice Treated with the
Immunomodulator, Acemannan," Molecular Biotherapy 3(2):79-87, 1991.
• E.E. Collins, C. Collins and C. Roentgen, "Dermatitis Treated with Fresh Whole Leaf of Aloe Vera,
AJR 33:396-7 (1935). Cited in Klein and Penneys, "Aloe Vera," 714.
• C.C. Lushbaugh and D.S. Hale, "Experimental Radiodermatitis Following Beta Irradiation," Cancer
6:690-7 (1953). Cited in Klein and Penneys, "Aloe Vera," 715.
• D.B. Roberts and E.L. Travis, "Acemannan-containing Wound Dressing Gel Reduces Radiationinduced
Skin Reactions in C3H Mice," International Journal of Radiation Oncology, Biology, Physics
32(4):1047 52 (1995).
• Y. Sato et al., "Studies on Chemical Protectors Against Radiation. XXXI. Protection Effects of Aloe
Arborescens on Skin Injury Induced by X irradiation," Yakugaku Zasshi - Journal of the
Pharmaceutical Society of Japan 110(11):876-84 (November 1990).
• Boik, Cancer and Natural Medicine, 136.
