Analysis of the In Vitro Antioxidant Activity of Drugs Used in the Treatment of Rheumatoid Arthritis

Abstract

Rheumatoid arthrits (RA) is an autoimune disease that affects diarthrodial joints. It is believed that interactions between various factors lead to improper immunomodulation, resulting in an inflammatory process that demages synovial structures. Regardless of the exact trigger, reactive oxygen species (ROS) have been implicated in playing a key role in this process. RA is one of the conditions that induce oxidative stress (OS), showing a fivefold increase in ROS production compared to healthy individuals, suggesting tha OS is a pathogenic hallmark in RA. In this context, the presente study evaluated the in vitro antioxidante acticity of drugs commonly used in the treatment of RA to control symptoms and others used to modulate the course of the disease, including: Sulfasalazine 500mg, Hydroxychloroquine 400mg, and Leflunomide 20mg. The study analyzed the ability of these drugs to scavenge the 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and determined which exhibited the best antioxidante performance, contributing to therapeutic choices among theses drugs. According to the data obtained, all the drugs demonstrated antioxidante activity, with Hydroxychloroquine being the most effective, presenting na IC50 of 35.921mg/ml. Sulfassalazine showed na IC50 of 0,783mg/ml, and Leflunomide an IC50 of 35.921mg/ml. Although some Studies had previously pointed in this direction, the literature lakced a comparative study among these RA drugs as well as a discussion on hypotheses that could explain the antioxidante mechanisms of these medications.