In vivo, in vitro, in silico ... the right variation towards stopping animal testing.

Studying animals is often essential to understand the origin of human pathologies and to develop new therapies.

Even today, researchers do not always know how to replicate the complexity of living things for certain study subjects that require the observation of sophisticated and fine interactions between organs. However, many factors, such as stress and physiological differences between animals and humans, are liable to distort the results obtained in experiments carried out on animals.

It was in 1959 that an ethical approach applied to animal experimentation saw the light of day in Europe and North America. Commonly called the 3R rule: Reduce - Refine - Replace.

• Reduce the number of animals, and unnecessary repetitions,
• Refining, in other words optimizing the experiment by reducing, eliminating or relieving the discomfort, pain, distress or anguish suffered by the animals,
• Replace , whenever possible, the in vivo model by in vitro or "in silico" models (mathematical models, bioinformatics).

It goes without saying that for us the only really valid R is the R of the replacement. And this one is slow in coming ...

The development of products not tested on animals has become a commercial argument for manufacturers.

Under pressure from consumers and animal rights associations, a first European amendment bans the testing of finished products on animals. The European Union represents the world's largest cosmetics and skincare market. A pioneer at the global level, the European Union, in 2013 banned animal testing for this industry. India, Israel, and Norway followed suit the following year. Then in 2015, New Zealand, Argentina, Turkey, the State of São Paulo, Russia, South Korea, Canada and Taiwan introduced new laws and made proposals to ban these practices.

In 2016, the Court of Justice of the European Union also banned the import of cosmetics tested on animals. Outside of Europe, the majority of developed countries also follow this orientation.

There is consensus on the use of alternative methods and the need for their development, whether in the private or public sphere.

Scientific advances in alternative methods to animal testing could save many human lives and spare millions of animals worldwide torture and unnecessary suffering. Especially since it has been shown that animal research is not useful since it does not provide relevant or predictive data for humans. According to Professor Béquain: “ No living species can be the biological model of another. This scientific truth is universally accepted: transposing the results of one species to another is an empirical method. To persevere with this process is to deny the progress of science. "

Dazzling progress has appeared in the field of research on alternative methods:

The in vitro culture method replaces that in vivo. In vitro experimentation applies to activities carried out on human cells previously cultured in the laboratory. In fact, it is possible to carry out tests under physiologically similar conditions which make it possible to carry out the necessary investigations and to provide more precise results than tests on living animals. In particular with regard to eye and skin tissues. This, moreover, has enabled cosmetic firms to do without prior work on animals. They include in particular the culture of specialized cells, also called “differentiated”, such as that of a neuron or an epidermal cell, but also that of stem cells , called “undifferentiated”, they can generally give several types of cells.
These cell cultures make it possible to create organoids, clusters of differentiated cells, which organize themselves like a mini-organ while reproducing only certain functions. These 3 D cultures are of great interest for research because they react like the organ they mimic.

The toxicological and ecotoxicological program Valitox makes it possible for its part to detect the possible acute toxicity of a substance on human cells in culture and no longer on animals. This program uses the fluorescence technique which screens human cells with light rays. After multiple manipulations, only threatened cells react by reflecting light while healthy cells absorb it. This method can replace some tests in the fields of pharmaceuticals, cosmetics, food, agrochemicals and chemicals.

In 2008, the proof of the concept was finally made and the predictivity was successfully assured since the reliability of Valitox was 82% against only 65% for the tests on mice and 61% on rats.

In 2020, the Valitox cell test is scientifically validated as an alternative method to predict acute oral toxicity in humans with a rate of 69%. For comparison, animal tests (rodents) show a much lower rate, from 50 to 57%.

For example, the highly regulated pharmaceutical industry performs quality animal tests for both drugs and vaccines. This experiment is not only very expensive but also requires very long manufacturing times. For each batch of vaccines from the laboratories, quality controls are carried out on 100 to 200 mice. The alternative of In vitro tests makes it possible to check the level of antigens thanks to chemical processes and to have more precise results. More and more laboratories now prefer to use this method.

However, it should be remembered that in vitro methods are not exempt from the extraction of animal cells for the cultivation of cell lines. Tissues and organs are recovered in slaughterhouses but also fetal calf serum. Alternatives, here too, are trying to emerge with human platelet lysate from blood donation.

In addition, researchers from the ECVAM laboratory have developed 5 different tests that use human blood cells to detect substances that would cause potentially dangerous reactions in drugs.

Finally, the progress of research has made it possible to highlight the In silico method, which is among the most promising. Thanks to the creation of sophisticated computer models, scientists hope to simulate the evolution of a pathology or the action of a molecule. This method is particularly useful in the educational environment in which the manipulations do not result in the death of an animal.

Today, there are many alternatives to avoid these practices. More than 200 alternative methods to international research have been developed and validated by the OECD (Organization for Economic Cooperation and Development). These include microdosing (humans are given very small amounts of a substance to check its effects on the body at the cellular level), also non-invasive imaging techniques - such as MRIs and X-rays.

According to the general manager of Kréatis (company marketing in silico alternatives to animal models) Carole Charmeau " if the animal model remains the" least worse "when it comes to studying the fate of a chemical substance in an entire organism, it should be kept in mind that in vitro methods generally use animal biological products while most in silico methods are based on all the in vivo and in vitro results available in the literature to develop predictive models ”.

To date, there are platforms and networks made up of researchers from all over the world who bring together datasets on alternative methods in animal experimentation. This allows everyone, large companies and governments to be able to consult experimental data so as not to have to reproduce it.

Among others we can quote:

QSAR : ( Quantitative structure-activity relationship ) It is a process by which a chemical structure is correlated with a well-defined effect such as biological activity or chemical reactivity. These computer techniques are based on the similarities of experiences with existing substances and on our knowledge of human biology.

FRANCOPA : French platform for the development, validation and dissemination of alternative methods in animal experimentation. Its very comprehensive website offers information files, a Frequently Asked Questions section, a forum, an information letter and links to other European counterparts.

JaCVAM : ( Japan Animal Experiment Alternative Evaluation Center) The policy and mission of JaCVAM is to promote the 3Rs in animal experimentation for the safety assessment of chemicals and other materials in Japan and to establish guidelines guidelines for new alternative experimental methods through international collaboration.

OECD : ( Organization for Economic Co-operation and Development) This international organization's Guidelines for the Testing of Chemicals is a collection of approximately 150 of the most relevant internationally approved test methods used by governments, industry and independent laboratories to identify and characterize the potential hazards of chemicals.

KoCVAM : (Korean Center for the Validation of Alternative Methods) Its mission is to formulate and promote policies concerning the development and adoption of alternatives to animal testing. Provide information on alternative testing methods and educational programs for industry, academia and research institutes.
Coordinate the validation and peer review process of alternative test methods and propose validated test methods to the OECD for testing guidelines. And finally, to conduct research in collaboration with Canadian and foreign institutions.

ICCVAM : (Interagency Coordinating Committee on Validation of Alternative Methods) This committee is made up of representatives from 17 US federal regulatory and research agencies. Each of these regulatory and research organizations requires, uses, generates or disseminates information on toxicology and safety testing. ICCVAM facilitates international collaboration on the development of alternative test methods by joining the International Cooperation on Alternative Test Methods.

ANTIOPES : European network made up of nearly 300 researchers, spread over 11 French research organizations. It connects the various research centers and acts mainly in the field of systemic analysis for applications in predictive toxicology in the health environment. It makes it possible to increase knowledge of existing and new substances, to entrust the industry with the responsibility of assessing the risk for the user and finally to reduce animal testing.

ANTIDOTE EUROPE is a Scientific Committee which fights against animal experimentation on the grounds of the danger it represents for society. In particular in terms of public health insofar as it considers that the observations made on animals cannot be transposed to human subjects. Their goal is to ignore any ethical argument and rely solely on scientific arguments proving the ineffectiveness of animal testing.

The big brands are also developing alternatives:

The L'Oréal group (with its L'Oréal Paris, Maybelline and Lancôme brands), has been carrying out research on the creation of artificial skin to test its products for several years. The French cosmetics giant has a large laboratory in Lyon, where the EpiSkin is manufactured, a model of human epithelium reconstructed from skin cells incubated from surgical residues. This alternative method to animal research, which involves using a structure similar to the human epidermis to measure skin irritation caused by chemicals in cosmetics. Garnier , has just been labeled CRUELTY FREE by PETA.

The more countries that end animal testing, the more pressure will increase on those who delay doing so. Wanting to test molecules intended for humans on animal species is an aberration which amounts to denying the fundamental barrier existing between each species.

The end goal must be the total replacement of any tests on live animals for scientific and educational purposes.