Examples of toxicity testing
1. Botox testing in mice
Thousands of mice are still being killed every year in UK laboratories, for the safety testing of botulinum toxin, which is the active ingredient in the cosmetic preparation, botox, as well as in therapeutic products used for medical conditions, such as Parkinson's disease. This use of animals is a clear breach of the 1998 government ban on cosmetic product testing. In this case, the notoriously cruel LD50 test is used, in which 50 per cent of the test animals must die before the experiment can be concluded.
The botox testing scandal is further compounded by the fact that a key government-appointed testing laboratory - the National Institute for Biological Standards and Control (NIBSC) - employs a completely non-animal testing method for botulinum that annually spares the lives of an estimated 5, 400 mice within the NIBSC alone. The test is known as the SNAP-25 method (3).
Despite the blatant flouting of the rule prohibiting animal testing of cosmetic products, the Home Office insists that no such licensing is allowed. This is technically correct ... but dishonest. While licences are granted for the testing of botulinum and, while it is claimed that all such tested botulinum is intended for medical use, the self-evident reality is that a great deal of it ends up being used for purely cosmetic purposes. The government knows this - as is made clear by answers to a series of Parliamentary Questions posed to Home Office Ministers by Michael Hancock MP in March 2005 (4).
The government made clear in its replies that it did permit botulinum tested under a therapeutic licence to be sold as a cosmetic product - but that the onus is on the doctor who prescribes its use for this purpose. This allows the government to defend itself against claims that cosmetic botox has not been tested and yet, simultaneously, can insist that it has not licensed animal tests for cosmetic botox.
2. Vomiting shrews
Researchers at St George's Hospital Medical School, London, chose the house musk shrew as a model for studying nausea and vomiting in humans (a known side effect in people undergoing chemotherapy). It was observed, by chance, that some of the shrews spontaneously ate their own vomit. This observation persuaded the researchers to study vomiting in shrews, unrelated to their chemotherapy-in-humansexperiments. Three groups of 16 shrews (specially bred at St George's) were forced to vomit, either through the effects of motion sickness, or else by being administered nicotine. The animals were subsequently killed with carbon dioxide, and then their necks were broken. This was done in order to study and weigh the stomach contents of each shrew. The researchers concluded that 'This curious behaviour observed under laboratory conditions, if replicated in the wild, may have significant ecological consequences for shrews'.
Source: Potential energetic implications of emesis in the house musk shrew (Suncus murinus). Andrews PL, Friedman MI, Liu YL, Smith JE, Sims DW. (Department of Basic Medical Sciences, St George's Hospital Medical School, London). Physiology and Behaviour 2005;84:519-524.
3. Inflamed livers in Beagles
Researchers in the Department of Pharmacology and Therapeutics at the University of Liverpool used beagle dogs and rats to study the adverse effects of an experimental anti-inflammatory drug. The drug was originally developed to treat inflammatory skin disease in humans, and appeared to work in mice. However, in subsequent (unpublished) experiments using rats and beagle dogs, the drug caused liver damage, and was therefore discontinued. The authors of the present study, nevertheless, were keen to elucidate the mechanism by which the drug caused liver damage. Healthy adult rats and beagle dogs were injected with the drug and then killed so that their livers could be used to assess the effects of the drug. It was found that the drug damaged liver cells in both the rat and the dog. However, the researchers had difficulty in understanding the mechanism of cell toxicity, and could not explain why the drug should cause liver inflammation in dogs, but not in rats.
Source: Formation and protein binding of the acyl glucuronide of a leukotriene B antagonist (SB-209247): relation to species differences in hepatotoxicity. Kenny JR, Maggs JL, Tettey JN, Harrell AW, Parker SG, Clarke SE, Park BK. (Department of Pharmacology and Therapeutics, University of Liverpool). Drug Metabolism and Disposition 2005; 33:271-281.
4. Tumours in rats
Researchers at the Institute of Occupational Medicine in Edinburgh exposed 352 rats to a cancer-causing substance. Young (9-12 week) rats were divided into groups of 50 and injected with either cellulose or asbestos fibres. Although these fibres are normally associated with lung disease in humans, the animals were injected in their abdominal cavities to observe the body's response. The authors state that such studies had already been undertaken previously in 1992, 1995, 1996 and 1997. However, in this study, the amount of fibres injected was particularly large - so large, in fact, that the fibres were administered in three doses instead of one. Even the authors voiced concern about the volume of fibres. The experiment was allowed to run its course (up to 28 months) until nearly all the animals had died from advanced abdominal cancer with blood-stained abdominal fluid.
The authors concluded by saying that the study demonstrated that high doses of fibres are capable of producing tumours when injected into the abdominal cavity of rats. Source: Tumorigenicity of cellulose fibers injected into the rat peritoneal cavity. Cullen RT, Miller BG, Clark S, Davis JM. (Institute of Occupational Medicine, Edinburgh). Inhalation Toxicology 2002; 14:685-703.
5. Chemical burns in pigs
Scientists in the Biomedical Sciences Department at the Ministry of Defence, Porton Down, used pigs to test the effects of a well-known corrosive chemical agent. Three Large White pigs were anaesthetised and then exposed to the effects of Lewisite. This chemical, known since 1918, is extremely toxic and can produce full-thickness (i.e. third-degree) burns when applied to the skin. Its effects have already been well documented in the scientific literature.
After exposure to the chemical, which produced severe skin blistering, the test animals were allowed to recover from the anaesthetic. Twenty-four hours later, all three pigs were killed by lethal injection, and tissue samples taken.
The researchers concluded that the test results were consistent with those reported by other scientists in 1994, 1989 and 2002. It was also concluded that the present study confirmed the use of the large white breed of pig as an 'appropriate model' for pursuing further such studies.
Source: Examination of Changes in Connective Tissue Macromolecular Components of Large White Pig Skin Following Application of Lewisite Vapour. Lindsay CD, Hambrook JL, Brown RF, Platt JC, Knight R, Rice P (Biomedical Sciences Department, Dstl Porton Down, Salisbury, Wiltshire) Journal of Applied Toxicology 2004;24:37-46.