Epigenetic Modulation by Luteolin, Quercetin and Apigenin in Systemic Lupus Erythematosus and Rheumatoid Arthritis: Mechanisms and Therapeutic Perspectives

For many years, plants have long served as sources of potential therapeutic agents. Recently, there has been a growing interest in investigating the effects of plant bio-active compounds on epigenetic modulation of several processes—among them, modifications of DNA, histones, and microRNAs that influence gene expression. Aberrant epigenetic changes can affect key cellular processes by altering the expression of many important genes, leading to disturbances in human cells, and consequently, to various diseases including systemic autoimmune diseases. However, these modifications are reversible, offering a unique way for therapeutic intervention. Many plant-derived compounds possess the potential to modify these abnormal epigenetic modifications. Among these are apigenin, quercetin and luteolin, which can alter the level of histone acetylation, DNA methylation and miRs in cells. This review highlights these abnormal epigenetic alterations in two important autoimmune diseases in humans, i.e., lupus erythematosus and rheumatoid arthritis, and discusses the promising efficacy of these bio-active compounds in mitigating these deleterious epigenetic signatures. Furthermore, this review addresses ongoing clinical investigations to evaluate the therapeutic potential of these plant-derived compounds in the treatment of both systemic lupus erythematosus and rheumatoid arthritis, along with their limitations and challenges.