Appraisal of disease-modifying potential of amlodipine as an anti-arthritic agent: new indication for an old drug.

Amlodipine, a second-generation calcium channel blocker, exhibits documented anti-inflammatory potential. Thereby, present investigation was accomplished with an aim to explore anti-arthritic potential of amlodipine, giving a second chance to an existing drug. For validation of anti-arthritic potential of amlodipine, some in vitro models comprised of bovine serum albumin- and egg albumin-induced protein denaturation along with membrane stabilization of red blood cell was being conducted. In vivo models comprised of formaldehyde-provoked acute arthritis and CFA-instigated chronic arthritic. Paw edema, arthritic index, body weight alterations, biochemical and hematological parameters, and ankle joint histological and radiographic investigations were appraised. Moreover, RT-PCR was conducted to evaluate the levels of several inflammatory markers. Molecular docking was being conducted targeting TNF-α, IL-1β and IL-6 to establish the correlation between experimental and theoretical results. Amlodipine provides significant protection against denaturation being provoked by heating egg albumin and BSA along with stabilizing membrane of red blood cell, thereby proving in vitro anti-arthritic effect. A significant (p < 0.001) reduction in paw swelling was being observed with amlodipine in case of formaldehyde-instigated arthritis especially at the dose of 20 mg/kg. In case of CFA-provoked arthritis, reduction in paw volume and arthritic score while preservation of body weight loss and normal hematological and biochemical parameters in comparison to arthritic control were being manifested by amlodipine at the dose of 20 mg/kg. Gene expression level of TNF-α, IL-6 and IL-1β was significantly reduced by amlodipine while an increase in expression level of IL-4 and IL-10 was evident in animals treated with piroxicam and amlodipine. Molecular docking analysis demonstrated strong binding interaction of amlodipine with TNF-α, IL-6 and IL-1β thus providing a good correlation between experimental and theoretical results. Thus, current study is suggestive that amlodipine exhibits strong anti-arthritic potential and thus can be considered as a candidate for drug repurposing as anti-arthritic agent.