Animalioinfo

1. Introduction

The use of animals for various purposes such as food, transportation, pets, sport, recreation and companionship is as old as human beings themselves. The use of animals for research purposes is one of the widespread uses. Various animals such as mice, rats, hamsters, rabbits, fish (examples - zebra, trout), birds (mainly chickens), guinea pigs, amphibians (xenopus frogs), primates, dogs, cats, etc. long-term (CULABBR , 1988). The main purpose of these studies is drug testing and toxicology screenings, which are useful in the development of new treatments for infectious and non-infectious diseases.

2. The three R's: reduction, improvement and replacement

Alternatives to animal testing have been proposed to overcome some of the disadvantages associated with animal testing and to avoid unethical practices. The 3 R strategy is applied, which means reducing, refining and replacing the use of laboratory animals (Ranganatha and Kuppast, 2012). Different methods and alternative organisms are used to implement this strategy. The concept of animal replacement was first discussed in 1957 by Charles Hume and William Russell at the University Federation for Animal Welfare (UFAW) (
Balls, 1994). Russell and Burch (1959) proposed some ways to make animal experiments more humane, which were later called the 3 R's. This approach encourages the use of a minimum number of animals, thus "reducing" the total number of animals used in an experiment. The use of animals must be carefully planned and "tuned" to minimize the pain and fear caused during the experiment. Additionally, whenever possible, higher animals should be “replaced” with alternative methodologies and lower organisms (Ranganatha and Kuppast, 2012, Zurlo et al., 1996). Animal replacement is defined as "any scientific method using non-sentient material that can replace the use of conscious living vertebrates in animal experiments". Two kinds of compensation were distinguished as "relative" and "absolute" compensation. Animals are used as a relative surrogate, but are not exposed to any stress during the experiment. No use of animals at any stage of the experiment is identified as an absolute replacement strategy (Balls, 1994).

2.2. Replacement

Various alternatives to the use of animals have been proposed, such as in vitro models, cell cultures, computational models and new imaging/analysis techniques (Balls, 2002). In vitro models provide an opportunity to study the cellular response in a closed system where experimental conditions are maintained. Such models provide preliminary information for the outcome of an in vivo experiment. For example, computer models have been used to study cardiac function and to select potential drug candidates (Gipson and Sugrue, 1994). In many countries, in vitro cell cultures have replaced the Draize skin and eye irritation test and the use of animals in these tests. Another example is the extraction of insulin from the pancreas of pigs and cows, but now it is obtained from bacterial cultures, which are life-saving drugs for diabetes patients. This extracted insulin must be checked for purity, potency and dose. The use of animals was routine for such control, but now chromatographic techniques are used to check purity, potency, and calculate drug doses (Foreman et al., 1996). Overall, this replacement substantially reduces the use of animals in various processes.

3. Computer models

Computers can help understand various basic principles of biology. Specialized computer models and software programs help design new drugs. Computer-generated simulations are used to predict various possible biological and toxic effects of a chemical or potential drug candidate without the need to dissect animals. Only the most promising molecules obtained from the primary screening are used for in vivo experiments. For example, to know the receptor binding site of a drug, in vivo experimentation is necessary. Software known as Computer Aided Drug Design (CADD) is used to predict the receptor binding site for a potential drug molecule. CADD works to identify the likely binding site, thereby avoiding testing unwanted chemicals that have no biological activity. With the help of these software programs we can also make a new drug tailored for a specific binding site and then at the final stage animal testing is done to get confirmatory results (Vedani, 1991). This will reduce the total number of experimental animals and achieve the objectives of Russell and Burch's 3 R's.