Could This Plant Derived Compound Offer a New Way to Treat Rheumatoid Arthritis? Scientists Believe So

A natural compound extracted from a traditional medicinal plant reduced joint swelling, inflammation, and tissue damage in rats with rheumatoid arthritis, according to a study published on July 22 in the journal Engineering.

Researchers found that the compound, called obakulactone (OL), targeted a protein linked to the disease and restored healthy fat metabolism, raising hopes that it could eventually lead to a new treatment strategy. The findings are based on animal and laboratory studies, and the researchers say human studies are still needed.

Rheumatoid arthritis is a long-term autoimmune disease that affects about 1% of the global population. It develops when the immune system mistakenly attacks healthy joints, causing pain, swelling, stiffness, and gradual joint damage.

While several medicines can help control the disease, they do not work for everyone and may cause serious side effects. The new study offers fresh insight into how a plant-derived compound may tackle the disease at its source instead of simply easing symptoms.

Plant Compound Reduced Inflammation and Protected Joints

The researchers isolated obakulactone from Phellodendri cortex, a medicinal plant used in traditional herbal medicine. They tested the compound in rats with rheumatoid arthritis that had been induced using complete Freund’s adjuvant.

The animals received one of three doses of obakulactone daily for 21 days. Compared with untreated animals, those receiving the compound had significantly less joint swelling and healthier cartilage and synovial tissue, the membrane that lines the joints. The treatment also improved abnormalities in immune organs such as the thymus and spleen.

Blood tests showed that obakulactone reduced several inflammatory molecules linked to rheumatoid arthritis, including IL-1β, IL-6, IL-17, and TNF-α. It also lowered common disease markers such as rheumatoid factor (RF), cyclic citrullinated peptide antibody (CCP-Ab), C-reactive protein (CRP), and matrix metalloproteinase-3 (MMP-3).

The compound also appeared to rebalance the immune system. It reduced inflammatory immune cells while increasing cells that help limit inflammation, suggesting it may calm the immune response responsible for joint damage.

Researchers Identified a New Drug Target

Using metabolomics, proteomics, and other molecular analysis techniques, the research team found that rheumatoid arthritis disrupted the body’s metabolism of several unsaturated fatty acids, including arachidonic acid, linoleic acid, and alpha-linolenic acid. Obakulactone helped restore these pathways to a healthier state.

Laboratory experiments also showed that the compound slowed the growth of rheumatoid arthritis synovial fibroblasts, cells that contribute to chronic inflammation and the destruction of cartilage and bone. It encouraged these abnormal cells to undergo programmed cell death while reducing their release of inflammatory proteins.

Further experiments identified a protein called acyl coenzyme A thioesterase 1 (ACOT1) as the compound’s direct target. Obakulactone promoted the breakdown of ACOT1, which then reduced the activity of several signaling pathways involved in inflammation, tissue scarring, and abnormal cell growth.

The researchers said the findings identify ACOT1 as a promising target for future rheumatoid arthritis therapies and suggest that correcting disrupted fatty acid metabolism may represent a new treatment approach.

The study’s authors concluded that the findings provide preclinical evidence supporting obakulactone as a potential therapeutic compound for rheumatoid arthritis while highlighting ACOT1 and unsaturated fatty acid metabolism as promising targets for future drug development.

Because the research was conducted in rats and isolated cells, the researchers cautioned that additional studies are needed to determine whether obakulactone is safe and effective in people.