JNTU B.Pharmacy III SCREENING METHODS IN PHARMACOLOGY Previous Question Paper (July-2021 - R17)

The CPCSEA (Committee for the Purpose of Control and Supervision of Experiments on Animals) is a statutory committee under the Prevention of Cruelty to Animals Act, 1960. Its primary objective is to ensure that animals used in research are not subjected to unnecessary pain or suffering.

Key guidelines include:

• Registration of establishments conducting animal research and breeding.
• Constitution of an IAEC (Institutional Animal Ethics Committee) to review and approve research protocols.
• Strict adherence to the 3Rs principle: Replacement (using non-animal models), Reduction (using the minimum number of animals), and Refinement (minimizing pain and distress).
• Mandatory requirements for housing, including appropriate temperature, humidity, lighting, and sanitation standards.
• Requirement for veterinary supervision and proper record-keeping of all animal experiments.

Breeding techniques in laboratory animals are essential to maintain genetic purity and ensure consistent experimental results:

• Inbreeding: Mating between closely related individuals (e.g., brother-sister mating for at least 20 generations) to produce inbred strains that are genetically homozygous. This minimizes genetic variation between animals.
• Outbreeding: Mating unrelated individuals within the same breed to maintain genetic diversity and prevent the expression of deleterious recessive traits. This produces outbred stocks.
• Crossbreeding: Mating animals of two different inbred strains to produce F1 hybrids, which often exhibit hybrid vigor (heterosis) and high uniformity.
• Monogamous Mating: One male is paired with one female, allowing for clear identification of the lineage and exact birth dates.
• Polygamous Mating (Harem System): One male is housed with multiple females. This is more efficient for large-scale production but makes individual pedigree tracking more difficult.

Alternatives to animal testing are collectively known as the 3Rs: Replacement, Reduction, and Refinement. These methods aim to minimize or eliminate the use of animals in research and testing while maintaining scientific rigor.

Alternatives are classified into the following categories:

• Replacement methods: Approaches that use non-animal systems to achieve scientific results. These include in vitro models (cell/tissue cultures), in silico models (computer simulations/QSAR), and the use of lower organisms or human volunteers.
• Reduction methods: Strategies that allow researchers to obtain comparable levels of information from fewer animals or to obtain more information from the same number of animals, such as improved statistical design.
• Refinement methods: Techniques that alleviate or minimize potential pain, suffering, or distress and enhance animal welfare for those animals that must still be used.

Two detailed alternative methods are described below:

1. In Silico Models (Computer-based modeling): These methods utilize mathematical and computational models to predict the toxicity or pharmacological activity of chemical substances. Quantitative Structure-Activity Relationship (QSAR) is a primary example, where the biological activity of a molecule is predicted based on its chemical structure and physicochemical properties. By analyzing existing databases of chemical toxicity, computer algorithms can screen thousands of compounds rapidly, identifying those with high potential for success or toxicity before any physical experimentation occurs.

2. In Vitro Models (Cell and Tissue Culture): These involve conducting experiments in a controlled environment outside of a living organism, such as in test tubes, culture dishes, or bioreactors. Examples include Organ-on-a-Chip technology, which uses microfluidic devices lined with human cells to mimic the physiological functions and mechanical properties of human organs (e.g., lung-on-a-chip, liver-on-a-chip). These systems provide a more human-relevant environment than traditional animal models, allowing for the study of drug absorption, metabolism, and disease progression at the cellular level with greater precision and ethical compliance.