Researchers identify ginger-derived compound that may help fight inflammatory diseases

A group of researchers from the Nara Institute of Science and Technology in Ikoma, Japan identified antioxidant properties of a ginger-derived compound that could help fight inflammatory diseases, according to a new study published in the journal International Immunology.

Many natural compounds have various antiinflammatory and other beneficial properties, which humans have been using for medicinal purposes for hundreds of years. However, the specific molecular mechanisms behind these health-promoting effects are not always clear. One such compound is 1'-acetoxychavicol acetate (ACA), which comes from the tropical ginger Alpinia plant.

In the study, researchers found that ACA attenuates mitochondrial damage through decreasing mitochondrial reactive oxygen species (ROS), blocking activation of a crucial protein complex known as the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome. Many inflammatory diseases, like inflammatory bowel disease, display improper and chronic activation of this complex, the researchers said.

Previous work has suggested that the NLRP3 inflammasome plays a significant role in promoting inflammation by secreting a molecule called IL-1ß. This acts as a messenger that recruits various immune cells to the site of injury or infection. Additional studies described how production of ROS can help trigger activation of the NLRP3 inflammasome. Since other groups showed that ACA can reduce ROS production in certain immune cells, the researchers said they became curious how this compound would impact the NLRP3 inflammasome and its functions.

For the study, the researchers grew immune cells in culture that were obtained from mouse bone marrow and used a mouse model of colitis. ACA was added to the growing cells and the live mice were given the compound in their food. The researchers then examined the effects on ROS production, secretion of IL-1ß, and other markers of inflammation.

This work provides novel evidence for a specific molecular mechanism governing the previously observed anti-inflammatory properties of ACA. Furthermore, it highlights the potential of ACA for therapeutic use in diseases mediated by IL-1ß molecules, or associated with cytokine storm occurrence, the researchers said.

"Many disease pathogeneses involve dysregulation of the inflammasome," said Daisuke Ori, PhD, co-lead author on the study, in a statement. "Blood cells from people suffering from rheumatoid arthritis or other autoimmune disorders frequently have increased levels of inflammasome-derived IL-1ß. Therefore, targeting the NLRP3 inflammasome with a compound like ACA may be a promising therapeutic strategy."