Phytochemicals as a Promising Approach to Rheumatoid Arthritis: Current Perspectives

In recent years, phytochemicals and medicinal plants have increasingly been used to treat autoimmune diseases, such as rheumatoid arthritis (RA). RA, a systemic inflammatory disease, is a chronic condition that affects primarily the joints, which are lined by synovial membranes, and leads to pain, diminished mobility, and joint deterioration. Oxidative stress, synovial hyperplasia, immune cell infiltration, and the production of pro-inflammatory cytokines, such as TNF-α and IL-6, are key factors in RA development. Herbal medicine is an effective alternative to conventional treatments, such as biologics, nonsteroidal anti-inflammatory drugs, and disease-modifying antirheumatic drugs, which are commonly used but can lose effectiveness or cause adverse effects. Phytotherapy therefore provides a promising complementary approach. This review provides an in-depth analysis of the pathophysiology of RA, therapeutic targets, drug resistance, and current therapeutic boundaries, with a focus on the roles of phytochemicals such as lignans, flavonoids, alkaloids, terpenoids, and phenolic compounds. By targeting key pro-inflammatory cytokines such as TNF-α and IL-6, and reformed molecular pathways such as those involving NF-κB, MAPK, and Nrf2/HO-1, these phytochemicals have potent anti-inflammatory and anti-rheumatoid arthritis properties.