Anti-inflammatory and Immunomodulatory Effects of Marine n-3 Polyunsaturated Fatty Acids on Human Health and Diseases

The pharmaceutical effects of n-3 polyunsaturated fatty acids (n-3 PUFAs) as dietary nutrients on human health and diseases have gained much attention and are investigated for decades. Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) are the three major n-3 PUFAs enriched in marine organisms, such as fish, shrimp, algae, and so on. It has been well known that n-3 PUFAs, especially DHA and EPA, are beneficial in reducing the risk of cardiovascular and cerebrovascular diseases. Accumulating evidence suggests that n-3 PUFAs might cure inflammatory diseases through several mechanisms, such as plasma membrane remodeling of lymphocytes, down-regulating pro-inflammatory cytokines, and alternating adhesion molecule expressions. Several molecular targets of n-3 PUFAs on immune-regulation have also been identified, such as GPR120 (FFA4), protein kinase C (PKC), and PPAR-γ. However, it remains inconclusive if dietary n-3 PUFAs function the same both in vitro and in vivo based on cohort studies. This review will focus on the molecular targets and mechanisms of anti-inflammatory and immunomodulatory effects of n-3 PUFAs on human health and diseases, such as obesity, tumor, diabetes, and autoimmune diseases.