Cotton Pellet-Induced Granuloma

The method previously used by Afsar et al³⁰ was used to evaluate the transudative and proliferative components of chronic inflammation. Male albino Wistar rats (200–250 g) were fasted overnight with free access to water until the commencement of the experiment. The control, standard and test groups of rats received 2% Tween 80, indomethacin and fractions, respectively, as mentioned in Grouping and Dosing of Animals.

Cotton pellets weighing 10±1 mg were sterilized in an autoclave for 30 min at 120 °C under 15Ib pressure. Twenty minutes after treatment with the standard drug and fractions, the rats were anesthetized with ketamine hydrochloride (50 mg/kg, i.p) and the subcutaneous tunnel was made aseptically using blunted forceps in both sides of the previously shaved groin region of each rat. Two sterilized cotton pellets weighing 10±1 mg each were then implanted bilaterally in the subcutaneous tunnel and stitched with chromic catgut (2/0 metric-1/2 circle). Treatment with 2% Tween 80, indomethacin and fractions continued for a total of seven consecutive days (p.o., once a day). On day 8, the rats were sacrificed with ether anesthesia and the pellets surrounded by granuloma tissue were dissected out carefully and freed from extraneous tissue. The wet weight of the cotton was taken immediately after removal and then dried up to a constant weight at 60 °C for 24 hrs and the net dry weight, that is, after subtracting the weight of the cotton pellets, was determined.

The measure of exudate formation = Immediate wet weight of pellet – Constant dry weight of the pellet

The measure of granuloma tissue formation = Constant dry weight – Initial weight of the cotton pellet

The exudate amount (mg), granulation tissue formation (mg), the percentage inhibition of exudate and granuloma tissue formation were calculated according to the formula described below.³¹