Role of Th17 and IL-17 Cytokines on Inflammatory and Auto-immune Diseases.

BACKGROUND: The IL-17 (interleukin 17) family consists of six structurally related pro-inflammatory cytokines, namely IL-17A to IL-17F. These cytokines have garnered significant scientific interest due to their pivotal role in the pathogenesis of various diseases. Notably, a specific subset of T-cells expresses IL-17 family members, highlighting their importance in immune responses against microbial infections. INTRODUCTION: IL-17 cytokines play a critical role in host defense mechanisms by inducing cytokines and chemokines, recruiting neutrophils, modifying T-cell differentiation, and stimulating the production of antimicrobial proteins. Maintaining an appropriate balance of IL-17 is vital for overall health. However, dysregulated production of IL-17A and other members can lead to the pathogenesis of numerous inflammatory and autoimmune diseases. METHOD: This review provides a comprehensive overview of the IL-17 family and its involvement in several inflammatory and autoimmune diseases. Relevant literature and research studies were analyzed to compile the data presented in this review. RESULTS: IL-17 cytokines, particularly IL-17A, have been implicated in the development of various inflammatory and autoimmune disorders, including multiple sclerosis, Hashimoto's thyroiditis, systemic lupus erythematosus, pyoderma gangrenosum, autoimmune hepatic disorders, rheumatoid arthritis, psoriasis, psoriatic arthritis, ankylosing spondylitis, osteoarthritis, and graft-versus-host disease. Understanding the role of IL-17 in these diseases is crucial for developing targeted therapeutic strategies. CONCLUSION: The significant involvement of IL-17 cytokines in inflammatory and autoimmune diseases underscores their potential as therapeutic targets. Current treatments utilizing antibodies against IL-17 cytokines and IL-17RA receptors have shown promise in managing these conditions. This review consolidates the understanding of IL-17 family members and their roles, providing valuable insights for the development of novel immunomodulators to effectively treat inflammatory and autoimmune diseases.

Targeting neuroinflammation by polyphenols: A promising therapeutic approach against inflammation-associated depression.

Depression is the most prevalent and debilitating mental disorder that affects a substantial number of people globally, hindering all aspects of their lives and leading to a high number of suicides each year. Despite the availability of an array of antidepressant medications, taking these medications does not relieve depressive symptoms in a considerable number of patients, implying that an incomplete understanding of the pathomechanisms involved in the development of depression. Besides that, a subset of those non-responsive patients exhibits an increased systemic and central inflammatory response, which has collectively led to the evolvement of the inflammatory theory of depression. Indeed, peripherally generated inflammatory mediators, as well as insults within the brain, can activate the brain's resident immune cells, resulting in a neuroinflammatory response that interferes with the multitude of neurobiological domains implicated in the pathogenesis of depression. Polyphenols, a group of plant-derived bioactive molecules, have been shown to exert neuroprotective functions on the brain by influencing an array of neuropathological mechanisms, including neuroinflammation. From these perspectives, this review mechanistically provides an overview of the neuropathological roles of sustained neuroinflammatory response in the development of depression and elucidates the therapeutic potential of flavonoid and nonflavonoid polyphenols in modulating inflammatory mediators and signaling cascades as well as promoting other neurophysiological and neuroprotective functions underlying inflammation-associated depressive symptoms. Therefore, given their significant anti-neuroinflammatory effects, polyphenols could be a promising and effective adjunctive therapy for the treatment of neuropsychiatric symptoms associated with inflammation-related depression.