[MODELING INFLAMMATORY EDEMA: ARE THE MODELS INTERCHANGEABLE].

Area of Science:

• Pharmacology
• Inflammation Research
• Drug Discovery

Background:

• Sub-plantar injection of carrageenan and formalin in rodents is a common method for modeling inflammatory edema.
• These models are utilized to assess the anti-inflammatory and analgesic potential of novel therapeutic agents.
• Published literature indicates distinct patterns in the application of these models across different species and for varied pharmacological endpoints.

Purpose of the Study:

• To systematically analyze the published data on carrageenan and formalin induced paw edema models.
• To determine the primary uses and species-specific applications of these inflammation models.
• To provide evidence-based recommendations for the optimal use of these experimental models in drug evaluation.

Main Methods:

• Systematic review of published literature on experimental edema models.
• Analysis of data concerning the induction agents (carrageenan, formalin), animal species (mice, rats), and evaluated pharmacological activities (anti-inflammatory, analgesic).

Main Results:

• The carrageenan-induced paw edema model is predominantly employed in rats for assessing anti-inflammatory activity.
• The formalin-induced paw edema model is primarily utilized in both rats and mice for evaluating analgesic activity.
• A clear distinction exists in the application of these models based on the intended pharmacological outcome and the animal species used.

Conclusions:

• Carrageenan paw edema in rats and formalin paw edema in mice are recommended as distinct yet complementary models for inflammation research.
• These models should not be considered interchangeable due to species-specific and endpoint-specific variations in their application.
• The findings support the judicious selection of edema models to accurately evaluate drug efficacy in preclinical studies.