Anti-inflammatory Mechanisms of Curcumin
Extensive research has demonstrated the mechanism by which persistent oxidative stress can lead to chronic inflammation, which in turn could cause many chronic diseases including cardiovascular diseases, neurological diseases, pulmonary diseases, diabetes and cancers [9]. Oxidative stress is defined as a disturbance in the balance between the production of reactive oxygen species (free radicals and reactive metabolites) and antioxidant defenses as their elimination by protective mechanisms. This imbalance causes the damage of important biomolecules and cells, as well as potential impacts on the organisms [10]. ROS play a central role both upstream and downstream of NF-κB and TNF-α pathways, which are located at the center of the inflammatory response. The hydroxyl radical is the most harmful of all the ROS. A schematic representation indicates the three loops involved in amplification of inflammation where loop 1 demonstrates the NF-κB-TNF-α positive feedback loop and loop 2 shows the redox sensing loop by ROS-NF-κB-TNF-α. Both loops can be blocked by using antioxidant like H2 that scavenges hydroxyl radicals directly or via NF-κB pathways. ROS are generated by Nox system and amplified through these loops. In addition, the modified proteins by ROS may generate a loop 3 which may promote the autoimmune response by feeding back into loops 1 and 2