In vitro is an expression of Latin which means "in glass" and refers to the technique of performing a certain procedure in a controlled environment outside a living organism.
In vitro tests can be performed on a wide range of human or animal tissue cells, and the biological material that best suits the purpose of the test must be selected.
Cell viability and / or proliferation can be assessed by counting the number of cells, using vital dyes, incorporating radioisotopes, forming colonies, cell adhesion, metabolism products, among other parameters.
Currently, this type of test is often used in the development of medicines, nutraceuticals, functional foods and cosmetics as it allows:
• detect toxic properties and their mechanisms
• incorporation of human material in tests
• identify and quantify bioactive components and their metabolites
• recognize mechanisms of action, absorption, bioavailability, metabolism and biological activity
In vitro studies are fundamental to the development process of this type of products due to its ability to provide a basis for predicting the clinical results of the product (or its component), including its success or failure in vivo.
The analyzes are carried out in the early stages of the discovery process, when the selectivity and possible interactions of the studied compound in relation to the desired therapeutic target are established.
These studies analyze the absorption, distribution, metabolism and excretion of drugs, which allows an assessment of their performance, toxicity, efficacy and side effects.
Laboratories preferentially use in vitro tests due to the following advantages:
- Does not require animals or humans
- Absence of ethical restrictions
- Avoid the need to submit animal protocols
- Avoid / reduce the need for laboratory personnel with experience in handling animals
- Less security concerns
- Lower cost
- Faster
In vitro tests do not completely replace animal testing, but they do contribute to reducing the number of animals used in screening new products.
The problem with the in vitro study is that it is not a complete representation of the response of an animal or human being to the product.
The human body is much more complex than a simple cell culture, so there is a big difference between a compound injected into a cell and the same compound administered to a human being. In addition, in vitro studies cannot fully predict the influence that this component will have on organs and systems, or the interaction with others. For this, in vivo studies are necessary in order to clarify all this missing information before conducting clinical trials.