Curcumin in Redox and Inflammatory Signaling: Mechanistic Insights into NF-κB and Nrf2 Pathway Regulation

Curcumin demonstrates its anti-inflammatory properties via a multitude of molecular pathways. It effectively prevents the activation of nuclear factor-kappa B (NF-κB), a vital transcription factor responsible for the production of modifiable pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6. Additionally, curcumin downregulates the expression of cyclooxygenase-2 (COX-2) and lipoxygenase (LOX), thereby reducing the production of pro-inflammatory eicosanoids. Furthermore, it suppresses the activity of inducible nitric oxide synthase (iNOS), resulting in reduced nitric oxide synthesis and disrupting the expression of chemokines and adhesion molecules. Moreover, curcumin modulates immune responses by influencing the functionality of various immune cell types ultimately leading to a reduction in inflammation. These diverse actions render curcumin a promising candidate for the therapeutic management of chronic inflammatory disorders. Beyond its anti-inflammatory effects, curcumin possesses significant antioxidant capabilities. It directly scavenges reactive oxygen species (ROS), counting the superoxide anion, hydroxyl radical, and nitrogen dioxide. Indirectly, curcumin augments endogenous antioxidant defenses. Additionally, curcumin inhibits lipid peroxidation, thereby preserving the integrity of cellular membranes and mitigating oxidative damage. To surmount these challenges, various methodologies have been devised, including the application of nanoparticles, liposomes, phospholipid complexes, and co-administration with bioavailability accompaniments. Due to its capacity to concurrently target inflammatory and oxidative stress pathways, curcumin exhibits significant potential as an adjunctive therapeutic agent in a range of diseases considered by these pathological mechanisms. Ongoing clinical trials are actively assessing its efficacy and safety within human populations.