Scientists have found a natural chemical named obakulactone (OL) that may help treat rheumatoid arthritis (RA). OL comes from the bark of a plant called Phellodendri cortex. In lab tests, OL lowered the signs of arthritis by helping the body break down a protein called ACOT1 and by fixing the balance of healthy fats.
OL Lessens Swelling and Joint Damage
Rats with arthritis were given three different doses of OL for three weeks. All doses made the swollen joints smaller and helped the cartilage and joint lining look normal again. The treatment also improved the health of immune organs such as the thymus and spleen.
Inside the joints, OL reduced the number of aggressive immune cells (CD3⁺ T cells and CD68⁺ macrophages). It also encouraged macrophages to change from a harmful “M1” type to a healing “M2” type and stopped T cells from turning into inflammation‑causing Th17 cells.
Blood tests showed lower levels of inflammatory signals like IL‑1β, IL‑6, IL‑17, and TNF‑α. Markers that doctors use to track RA—such as RF, CCP‑Ab, CRP, and MMP‑3—also went down with higher doses of OL.
Fixing Fatty‑Acid Problems
Using several advanced techniques, researchers saw that arthritis messed up the body’s production of unsaturated fatty acids. OL helped restore normal levels of important fats like arachidonic acid, linoleic acid, and α‑linolenic acid.
When they looked at arthritis‑related joint cells (synovial fibroblasts), OL slowed these cells’ rapid growth, made them die when needed, and reduced the chemicals they released that cause inflammation.
ACOT1 Is a Direct Target
Lab tests proved that OL sticks directly to the protein ACOT1. The binding strength was measured at about 6 µM. This connection caused the cell to tag ACOT1 for destruction, sending it to the proteasome—a tiny machine that recycles unwanted proteins.
When ACOT1 levels dropped, another protein called SCD1 also fell. This chain reaction lowered the activity of two important signaling pathways, JAK‑STAT and PI3K‑AKT, which control cell growth, survival, and inflammation. By dialing down these pathways, OL reduced both inflammation and tissue scarring.
A New Idea for RA Treatment
Rheumatoid arthritis is a chronic disease that hurts about 1 % of people worldwide. The immune system attacks healthy joint tissue, causing pain, stiffness, and long‑term damage. Current medicines don’t work for everyone and can cause side effects.
The new animal studies suggest that OL could become a safe, natural option for treating RA. They also highlight ACOT1 and the balance of unsaturated fatty acids as promising new drug targets.
Because the research was done in rats and isolated cells, more studies are needed to see if OL is safe and effective in humans.