VARIED ANTI- INFLAMMATORY ACTIVITY OF INDOMETHACIN IN DIFFERENT EXPERIMENTAL ANIMAL MODELS

OBJECTIVE: To evaluate the anti-inflammatory activity of indomethacin in different experimental anti-inflammatory animal models

METHODS: Swiss albino rats weighing around 150 g – 250 g of either sex were randomly selected and divided into 6 groups (n=6) for 3 models, each having control and  Standard .

Materials used are Carrageenan, turpentine, Cotton pellets, Mercury and water plethysmographs. Methods adopted in this study are; (1) Carrageenan induced rat-paw edema (paw volume measured through mercury and water plethysmographs), (2) turpentine induced arthritis (by measuring lateral diameter of knee joint), as models of acute inflammation, (3) Cotton pellet induced granuloma (measured through dry weight of granulation tissue) as model of sub-acute inflammation.

RESULTS: The following observations were made. Indomethacin exhibited potent anti-inflammatory activity in Carrageenan induced edema model (83.34% inhibition in mercury plethysmograph) compared to control. But its anti-inflammatory activity is of lower order both in turpentine induced arthritis & cotton pellet granuloma model (48% & 40.16% inhibition respectively). All the results obtained were statistically significant with P< 0.001 in all four investigated methods

CONCLUSION: In the light of the above mentioned observations even an established anti-inflammatory agent (Indomethacin) has not shown considerably equal anti-inflammatory activity against all  conventional models of experimental inflammation. So, a drug capable of inhibiting only one particular model of experimental inflammation might still be an effective anti-inflammatory agent. Hence, it may be suggested that any new drug to be evaluated for anti-inflammatory activity must be screened for more than 2-3 conventional models of inflammation.