Scientists have identified a natural plant compound that could offer a surprising new approach to fighting rheumatoid arthritis. In experiments with rats, the substance reduced joint swelling, protected cartilage, and calmed harmful immune activity. Researchers also discovered that it works through an unexpected mechanism involving the way the body processes fats.

The findings, published in the journal Engineering , center on a compound called obakulactone (OL), a naturally occurring tetracyclic triterpenoid extracted from Phellodendri cortex , a type of plant bark. Tetracyclic triterpenoids are plant chemicals characterized by a structure containing four interconnected rings.

The researchers found that obakulactone helps restore balance to unsaturated fatty acids, which play important roles in cellular function and inflammation.…