Efficacy of Telmisartan in Pristane Induced Arthritis Rat Model

Introduction: Rheumatoid arthritis is one of the most common systemic inflammatory diseases characterized by progressive damage to the joints. There is rising evidence that Renin Angiotensin Aldosterone System signaling is also involved in the inflammatory response in rheumatoid arthritis and its blockers possess anti-arthritic properties. Telmisartan is an angiotensin receptor blocker and PPAR-? agonist and its anti-arthritic effects were evaluated. Aims & Objectives: This experimental study was designed to evaluate the anti-arthritic efficacy of telmisartan in pristane induced rat model of arthritis in adult female rats. Place and duration of study: The study was conducted in the Department of Pharmacology, Army Medical College, Rawalpindi, in collaboration with National Institute of Health and Armed Forces Institute of Pathology from July 2020 to August 2020. Material & Methods: Twenty four (24) adult non-pregnant female Sprague Dawley rats were divided in three groups (n=8) designated as Group A (normal control), Group B (arthritic control) and Group C (telmisartan group) & maintained on standard diet and water adlibitum. Rheumatoid arthritis was induced in each rat of Groups B &C by a single intradermal injection of 0.5ml pristane at the base of its tail on day 0 and the disease developed in two weeks. All 3 groups were given distilled water 2.5 ml/kg from 2-4 weeks and Group C was additionally given dissolved telmisartan orally at 2 mg/kg/day. Anti-arthritic efficacy was determined by assessing arthrogram score and total leukocyte count on day 0, 14 and 28 along with histological examination done at the end of the study. Data analysis was done using SPSS version 25. Results: Healthy rats in group A maintained a unremarkable arthogram & histogram score & TLC count of 6675±350/?l during the entire study period. Telmisartan administration in Group C for two weeks after pristane induction resulted in significant reduction in arthrogram score (AS) 9.5±3.66, total leukocyte count (TLC) 7350±550/?l and histological score (HS) to 6.88±1.24 as compared to (AS) 14.50±2.07, WBC 10150±350/?L & (HS) 10.75±2.05 in Group B, left untreated with pristane alone. The intergroup comparison showed significant p value < 0.05 respectively. Conclusion: Anti-arthritic effect was shown by telmisartan as it was able to ameliorate the changes induced by pristane.