The animal welfare series
Example 2
Progress in diabetes treatment
Type 1 diabetes is an autoimmune disorder in which the immune system attacks the body, impeding the production of insulin, the substance that regulates blood sugar levels. People with the condition are reliant on synthetic insulin to stay healthy. Because type 1 diabetes primarily affects children and adolescents, there is a huge need for medicines that are simple to take.
Insulin you can swallow
Nowadays, patients mainly inject or, more rarely, inhale their insulin. Until now, it has been impossible to produce insulin in tablet form because the insulin is broken down in the digestive tract before it can even start to work. A research team from the University of Sydney has developed a novel form of insulin that is made up of tiny particles known as nanoparticles. These protect the insulin from the destructive effects of stomach acid so that the active substance can subsequently be absorbed into the body in the intestines.
Source: AOK, own summary
Alternative methods play an important role in development
The new oral presentation was tested using alternative methods as well as animal testing. In the early stages of research, the scientists used in vitro models, particularly human intestinal tissue, to test how well the nanoparticles were absorbed. These tests showed a significant improvement in insulin absorption compared with conventional insulin. In addition, alternative model organisms such as Caenorhabditis elegans nematodes were used to obtain further information about the effects. However, further animal testing was still indispensable for a comprehensive assessment of the efficacy of the new insulin preparation. The research team investigated blood sugar reduction, prevention of hypoglycaemia and possible side effects in mice and baboons. These tests showed that the new presentation reliably reduced the animals’ blood sugar levels without any harmful side effects whatsoever. This is a major step forwards because up to now it was considered virtually impossible to make effective insulin in tablet form. Should further trials, including trials in humans, confirm the new dosage form’s efficacy, millions of diabetes patients worldwide could one day be spared the not unproblematic chore of injecting themselves with insulin.
A medicine that can prevent diabetes?
Moreover, a research team at Johns Hopkins University in Baltimore (USA) is working on a different approach to combating diabetes. They have developed a medicine that directly targets the cause of type 1 diabetes. The medicine in question is a monoclonal antibody, an active substance that specifically recognises and affects certain cells in the body. In this case, the antibody binds to cells known as beta cells in the pancreas. These produce insulin, but are attacked by the body’s own immune system cells in people with type 1 diabetes. The new medicine protects the beta cells against these attacks. Here again, animal testing was unavoidable for safety reasons. The efficacy of the new treatment was tested in mice with a high risk of developing type 1 diabetes. It was found that the animals who received the medicine did not develop the disease and lived longer than the untreated mice.
The as-yet indispensable tests with animals give rise to hope that the active substance may one day cure or even prevent diabetes. However, the medicine needs further development before it can be used in humans. Part of this involves developing a “humanised” version of the antibody, in other words an active substance that is specifically suitable for the human body.
Why alternative methods cannot (yet) replace animal testing
Both studies show that animal testing is still essential for progress in medicine in addition to alternative methods. It helps to determine the safety and efficacy of new treatments before they are used in the complex environment of the human biological system. In the case of both the insulin tablet and antibody-based medicine, animal testing yielded important findings that could pave the way for new forms of diabetes treatment.
Further information
- Nanotech opens door to future of insulin medication.The University of Sidney, 2 May 2024
- Oral nanotherapeutic formulation of insulin with reduced episodes of hypoglycaemia, Nature, 2 January 2024
- Experimental Type 1 Diabetes Drug Shelters Pancreas Cells from Immune System Attack, John Hopkins Medicine, 04/29/2024
- Cell-Surface ZnT8 Antibody Prevents and Reverses Autoimmune Diabetes in Mice, Diabetes Volume 73, Issue 5, May 2024
Animal testing is often indispensable in biomedical research as a way of assessing the safety and efficacy of new treatments. It provides insights into the complex interactions that take place inside a living organism in a way that is not possible using alternative methods alone. Researchers are increasingly developing alternative methods such as organoids to further reduce the use of animals.