Spirulina supplementation and rheumatoid arthritis: A systematic review of current research and molecular mechanisms.

Natural products have gained popularity as adjuvant therapies for managing degenerative diseases, including rheumatoid arthritis (RA). Preclinical studies suggest the beneficial effects of Spirulina in RA; however, there no systematic review is available. To address this gap, we conducted a systematic review of the existing evidence on the role of Spirulina in RA. A comprehensive Literature search was conducted in Scopus, Web of Science, PubMed, and Google Scholar up to April 2025. Search alert services were employed to identify newly published articles after the initial search. Both MeSH terms and text words were applied, with no restrictions on language or publication date. Two independent researchers performed the search and screening. Ultimately, 13 animal studies met the inclusion criteria, while no eligible human or in vitro studies were identified. The included studies indicated that Spirulina may confer protective effects against RA through multiple mechanisms. These include inhibition of cyclooxygenase-2, lipoxygenase, and myeloperoxidase enzymes activity; suppression of pro-inflammatory cytokines production; inhibition of angiogenesis; scavenging of free radicals; and enhancement of both enzymatic and non-enzymatic antioxidant activity. Evidence from animal studies supports the potential therapeutic role of Spirulina in RA. Nonetheless, well-designed clinical trials and in vitro studies are needed to clarify its mechanisms of action, establish optimal dosing, and evaluate safety and long-term efficacy in human populations.