Aloe vera has long been known for its medicinal
properties. In a sense it formed the basis of the American pharmaceutical
industry. This year marks the bicentennial of the first medicinal patent
ever granted in the US. It went to Samuel Lee, Jr. of Windham, CT for a
preparation containing potassium nitrate, gum resin, soap, and aloe. Such
concoctions typically were used as purgatives.
In just the last few years attention has focused on aloe for a different
reason. Aloe has been found to contain a substance called acemannan (Carrosyn®).
This has shown potential as a treatment for AIDS and cancer.
In a number of studies, acemannan has had both immunostimulatory and
directly antiviral properties.
It is non-toxic even when injected at high doses, causing "no significant
signs of intoxication and no deaths." White blood cells were mobilized
with well-defined immune stimulating activity (Fogleman, RW, et al. Vet
Hum Toxicol 1992;34:201-205).
In one experiment, a group of laboratory mice were implanted with deadly
sarcoma cells. These grew rapidly, producing highly malignant and invasive
tumors in all the animals. They routinely died in 20 to 46 days.
But a similar group were treated with acemannan at the time of tumor
cell implantation. Approximately 40 percent of these animals survived their
cancer. And their tumors, scientists at Texas A&M said, were infiltrated
by immune cancer-fighting cells, had dead or dying cores, and/or had regressed
(Peng, SY, et al. Mol Biother 1991;3:79-87).
Most of the experiments with acemannan have taken place in animals, particularly
in pets. (Veterinarians have less restraints on them than people doctors
and are sometimes quite open to innovative treatments.)
In 1991, acemannan was tested as an experimental treatment for feline
leukemia.This a very tough model. Feline leukemia is a virally induced disease
that kills all of the affected cats: 40 percent of them die within 4 weeks,
and 70 percent within 8 weeks of onset.
But injections of acemannan for 6 weeks significantly improved both the
quality of life and the survival rate of the infected tabbys. A full 12
weeks after initiation of treatment, 71 percent of the treated cats were
still alive and in good health (Sheets, MA, et al., Mol Biother 1991;3:41-45).
This is pretty remarkable.
When injected in this way, acemannan was been shown to have profound
effects on the immune system, including stimulation of interleukin-1 and
tumor necrosis factor production, two cytokines which probably play an anti-cancer
role.
In another pet experiment, 43 dogs and cats which had spontaneous cancers
of various kinds were treated with acemannan. Upon microscopic inspection,
the tumors of 26 of these animals again showed immunological reactions,
with marked necrosis (death) of cancerous tissue, white-blood-cell infiltration
of the tumors, and even cocoon-like encapsulations.
Twelve of these animals also had obvious clinical improvement, i.e.,
tumor shrinkage, tumor necrosis, and/or prolonged survival; these included
five of the seven animals that had fibrosarcomas (Harris,C., et al. Mol
Biother 1991;3: 207-213).
In another study, eight dogs and five cats with fibrosarcomas were treated
with acemannan in combination with surgery and radiation therapy. All of
these animals had recurrent disease that had failed to respond to previous
treatments, a poor prognosis, or both. Veterinarians gave them four to seven
weekly injections of acemannan: tumor shrinkage occurred in four of twelve
animals whose tumors were accessible to measurement. Once again, there was
a notable increase in necrosis and inflammation. Following initiation of
acemannan therapy, complete surgical excision was performed on all the animals.
Radiation therapy was begun immediately after surgery. Acemannan treatments
were continued monthly for one year.
Seven of the thirteen animals remained alive and tumor-free up to 603
days, with a median survival time of 372 days. The "data suggests that
acemannan may be an effective adjunct to surgery and radiation therapy in
the treatment of canine and feline fibrosarcomas" (King, GK, et al.
J Am Anim Hosp Assoc 1995;31:439-447).
So, could a human cancer patient get acemannan? Not easily. This is an
experimental drug, and was injected in the above experiments. One can get
aloe, but you cannot and should not inject it, nor does one easily find
out how much acemannan is in a particular aloe product. The most likely
way of getting at least some acemannan is to buy and ingest an aloe product
made from the whole leaf (minus the purgative elements, of course).
Some companies sell a 40:1 concentrate of the plant. Each four-ounce bottle
equals a gallon and a quarter of undiluted aloe. The taste is peculiar
but can be masked with vegetable juice (such as V-8). Cancer patients
often take three teaspoons per day.
