Therapeutic Potential of Phytochemicals in Autoimmune Diseases: A Systematic Review

Autoimmune diseases are a significant clinical challenge worldwide. Traditional treatments often have adverse effects, leading to a growing interest in alternative therapies. This systematic review attempts a qualitatively synthesize of current evidence on the therapeutic potential of phytochemicals in autoimmune diseases. The review includes randomized controlled trials (RCTs), clinical trials (CTs) and observational studies published between 2013 to 2023. Databases searched include PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL). A total of 676 studies were retrieved from various databases. We followed the PICO framework to develop the review protocol and registered on the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY) with registration number INPLASY202460031.

In the context of rheumatoid arthritis, eight potential phytochemicals have been identified, including sinomenine, curcumin, flavonol quercetin, eichhornia crassipes, apocynin, β-sitosterol, tanshinone IIA, and 3′3-diindolylmethane (DIM). For multiple sclerosis, five phytochemicals - berberine, 23-Hydroxy Ursolic Acid (23-OH UA), forskolin, sulforaphane (SFN), and moringin - have shown effectiveness. Flavonol quercetin and portulaca oleracea exhibit potential for treating type 1 diabetes. Furthermore, curcumin and quercetin have demonstrated potential activity against oral lichen planus (OLP). Anatabine has shown effectiveness against Hashimoto's Thyroiditis, while thuja occidentalis is a potential option for the treatment of Inflammatory Bowel Disease (IBD). Additionally, agave tequilana shows potential efficacy against Systemic Lupus Erythematosus (SLE). These natural compounds offer promising alternative or adjunctive treatments with fewer adverse effects compared to conventional therapies. Nevertheless, rigorous clinical validation is necessary to translate these findings into clinical practice and establish standardized guidelines for their use in autoimmune disease management.