Rat gingival model for testing drugs influencing inflammation

Abstract

Preclinical drug testing is an important area in new drug development where animals are used. An ideal animal model for this is one which is simple, reliable and can be extrapolated to humans. Topical drugs for inflammation are conventionally tested on the skin of animals after induction of inflammation. A gingival model would be simple as inflammation can be induced naturally by the action of plaque. Rats are a popular animal model for testing drugs as well as to study various diseases of the periodontium. Periodontal disease including gingival inflammation develops in rats in relation to indigenous plaque or experimentally induced bacterial products. A number of features of rats ranging from anatomy, histology and response to bacterial insult can be seen mirrored to a great extent in humans. There is a lot similarity in the development and resolution of inflammation as well as the gingival wound healing of rats and humans. This paper tries to explore the feasibility of using the rat gingival model for preclinical testing of drugs acting on or influencing inflammation and concludes by identifying potential areas of research using this model. The addition of such a simple and inexpensive model for preclinical testing of drugs will be welcomed by the drug developers.

A Reappraisal of Various Animal Models used in Periodontology with Future Perspectives and Alternatives

“…The incisor has no roots. With a shallow gingival sulcus and attachment of the junctional epithelium to the tooth surface, the dental gingival region of rats is fairly comparable to that of humans [12,49]. "However, there are some differences: crevicular epithelium keratinization and gingival and junctional epithelium relationship with the contact of desmosomes between superficial cells of the gingival epithelium and non-keratinized cells present in the junctional epithelium, the first is crevicular epithelium keratinization in rats; the second is gingival and junctional epithelium relationship with desmosomal contact between the most superficial cells of gingival Despite the anatomical differences, the junctional epithelium seems to function as a conduit for foreign chemicals, bacterial endotoxins, and inflammatory cell exudations, similar to what happens in humans".…”

“…Wistar and Sprague-Dawley are the strains that are used the vast majority of the time. Experimental periodontitis may be induced in periodontal disease-resistant strains of mice, such as germ-free Spraque-Dawley or white Lobund, either by the application of silk ligatures that are wrapped around the molars or through the administration of particular bacterial inoculations [12,49,50,51].…”