Alternatives:
Testing Without Torture
Before the end of this century, cosmetics testing laboratories might be hanging signs outside their doors saying, "No admittance to rats and rabbits." Alternatives to animal tests are efficient and reliable, both for cosmetics and household product tests and for "medical research." In most cases, non-animal methods take less time to complete, cost only a fraction of what the animal experiments they replace costs, and are not plagued with species differences that make extrapolation difficult or impossible.
Products Without Pain
Avon Products, Inc., which until June of 1989 killed about 24,000 animals a year to test its products, now uses many non-animal tests, including the Eytex method. Eytex, developed by InVitro International in Irvine, Calif., assesses irritancy with a protein alteration system. A vegetable protein from the jack bean mimics the cornea's reaction when exposed to foreign matter.
The greater the irritation, the more opaque the solution becomes. The Skintex formula, also developed by InVitro International, is made from the yellowish meat of the pumpkin rind; it mimics the reaction of human skin to foreign substances. Both Eytex and Skintex can be used to determine the toxicity of more than 5,000 different materials.
In the Neutral Red Bioassay, a product of Clonetics Corporation in San Diego, Calif., a water-soluble dye is added to normal human skin cells in a tissue culture plate with 96 "wells." A computer measures the degree to which the dye is absorbed by the cells, indicating relative toxicity and eliminating the observer bias, one of the factors that limits the effectiveness of tests
on animals. EpiPack, also made by Clonetics, is the first commercial product to contain live, normal cloned human cells, which are exposed to test substances in various dilutions.
Tissue and cell cultures can be grown in the laboratory from single cells from human or animal tissues. Three companies have developed artificial "human" skin which can be used in skin grafts for burn victims and other patients and can replace animals in product tests. (1) Marrow-Tech, headquartered in LaJolla, Calif., makes NeoDerm, which begins with the injection of skin cells into a sterile plastic bag containing a biodegradable mesh. The cells attach to the mesh and grow around it, like a vine on a garden lattice. After the segment of skin is sewn onto the patient, the mesh gradually dissolves. Biosurface Technology, of Cambridge, Mass., uses the patient's own cells to grow a skin to replace the epidermis (the top layer). Organogenesis Inc., also of Cambridge, has found customers for its Testskin in Avon, Amway, Estee Lauder, and other leading cosmetics companies.
The CAM Test uses fertilized chicken eggs to assess eye irritancy by showing the reaction of the chorioallantoic membrane to test substances. Because this membrane has no nerve fibers, the test causes no discomfort or pain. This test is intended for use by cosmetics and household product manufacturers, but egg membranes have also been used to culture viruses and vaccines. (Although we should strive to use no animals or animal byproducts in experiments, egg membranes are preferable to sentient animals.)
Medical Applications
In medicine, perhaps the most informative research takes place not in test tubes, but in hospitals and clinics and the offices of statisticians and epidemiologists. Clinical surveys, using human volunteers, case studies, autopsy reports, and statistical analyses, permit far more accurate observation and use of actual environmental factors related to human disease than is possible with animals confined in laboratories, who contract diseases
in conditions vastly different from the situations that confront humans. Long before the famous smoking beagle experiments began, statisticians and epidemiologists knew that cigarette smoking causes cancer in humans, yet programs to warn people about the hazards of smoking were delayed while more animal tests were carried out to the satisfaction of the tobacco industries,
and proved "inconclusive."
Mathematical and computer models, based on physical and chemical structures and properties of a substance, can be used to make predictions about the toxicity of a substance. TOPKAT, a software package distributed by Health Designs Inc., predicts oral toxicity and skin and eye irritation. It is "intended to be used as a personal tool by toxicologists, pharmacologists, synthetic and medicinal chemists, regulators, and industrial hygienists,
among others," according to HDI. (2) It is used by the Food and Drug Administration, the Environmental Protection Agency, and the U.S. Army.
The Ames test involves mixing the test chemical with a bacterial culture of Salmonella typhimurium and adding activating enzymes to the mixture. It was able to detect 156 out of 174 (90 percent) animal carcinogens and 96 out of 108 (88 percent) non-carcinogens. (3)
The Agarose Diffusion Method was designed in the early 1960s to determine the toxicity of plastics and other synthetic materials used in medical devices such as heart valves, intravenous lines, and artificial joints. In this test, human cells and a small amount of test material are placed in a flask, separated by a thin layer of agarose, a derivative of the seaweed agar. If
the test material is an irritant, a zone of killed cells appears around the substance.
Time and Money
Non-animal tests are generally faster and less expensive than the animal tests they replace and improve upon. Eytex testing kits can test three concentrations of a chemical for $99.50; a Draize test of comparable range would cost more than $1,000. (4)
In cancer studies, animal tests of a single substance may take four to eight years and cost $400,000 or more, whereas short-term non-animal studies like the Ames test cost only $200-4,000 and can be completed in one to four days. The dangers of waiting years for results of animal tests are apparent: in 1985, the Environmental Protection Agency determined that three animal tests had not shown a sufficient degree of danger in the pesticide Alar, and it called on the manufacturer to conduct still more cancer studies on animals. Now, years later, these studies are still incomplete. Although the EPA has pulled Alar from the market, non-animal tests would have taken a matter of
days or months, not years, and could have meant that fewer consumers would have come into contact with Alar-treated products.
For scientific, health, ethical, and economic reasons, researchers must switch their focus to non-animal tests, and the large number of animal experiments that are conducted more out of "curiosity" or habit, rather than out of a real need for information, should be eliminated at once.
References
1.Fisher, Lawrence M., "3 Companies Speed Artificial Skin," The New York Times, Sept. 12, 1990.
2."Computer Model for Toxicity," PCRM Update, July-Aug. 1988, p. 2.
3."Animal Tests for Cancer-Causing Chemicals," PCRM
Update, Nov.-Dec. 1988, p. 4.
4.Feder, Barnaby J., "Beyond White Rats and Rabbits," The New York Times, Feb. 28, 1988
Back to the The ExperimentationPage