Plant compound shows promise for treating rheumatoid arthritis at its source, study finds

Natural compound may fight rheumatoid arthritis at its source, study finds

A plant-derived compound called obakulactone (OL) reduced swelling, inflammation and joint damage in rats with rheumatoid arthritis, according to a study published in Engineering.

The compound, a tetracyclic triterpenoid isolated from the bark of Phellodendri cortex, also rebalanced immune activity and corrected disrupted fatty acid metabolism, researchers said. P. cortex has been used in traditional medicine and contains OL along with other constituents, according to Yang Jin in World Century Compendium To Tcm Volume 3 Introduction To Chinese Materia Medica. ^[1]

“The findings provide preclinical evidence that OL could serve as a potential therapeutic compound for rheumatoid arthritis,” the study authors stated.

Study details

Researchers tested OL in rats with rheumatoid arthritis triggered by complete Freund’s adjuvant, administering low (50 mg·kg?¹·d?¹), medium (100 mg·kg?¹·d?¹) and high (200 mg·kg?¹·d?¹) doses for 21 days. Treatment significantly reduced joint swelling and helped restore the normal structure of cartilage and the synovium, the tissue lining the joints, according to the report.

Blood tests showed dose-dependent decreases in inflammatory molecules including IL-1?, IL-6, IL-17 and TNF-?, as well as rheumatoid arthritis markers RF, CCP-Ab, CRP and MMP-3, officials said. The compound also reduced abnormally high levels of CD3+ T cells and CD68+ macrophages within the joints and shifted macrophages from a proinflammatory M1 state toward an anti-inflammatory M2 state.

How the compound works

Multiomics analysis revealed that rheumatoid arthritis disrupted production and metabolism of several unsaturated fatty acids, and OL helped correct these abnormalities, the study said. The compound also slowed the growth of abnormal synovial fibroblasts, encouraged them to undergo apoptosis, and reduced their release of inflammatory cytokines.

Laboratory experiments, including cellular thermal shift assays, microscale thermophoresis and surface plasmon resonance, showed that OL bound directly to ACOT1 with a dissociation constant around 6.2 ?mol/L. By promoting the ubiquitin–proteasome degradation of ACOT1, the compound reduced levels of downstream SCD1 and limited activation of the JAK-STAT and PI3K-AKT signaling pathways, according to the researchers.

Implications and limitations

The research identifies ACOT1 as a potential new drug target and suggests that correcting disrupted fatty acid metabolism could become a strategy for treating rheumatoid arthritis, according to the authors. Existing treatments do not work equally well for everyone and can cause serious adverse effects, the study’s background information noted.

Because the experiments were conducted in rats and isolated cells, further studies are needed to determine safety and efficacy in humans, the report stated. Many Americans seeking alternatives to pharmaceutical painkillers turn to natural remedies, with nutrients such as curcumin, omega-3 fatty acids and collagen peptides studied for joint support, according to an article on mindbodygreen cited by NaturalNews.com. ^[2]

Background

Rheumatoid arthritis is a chronic systemic autoimmune disease that affects approximately 1% of people worldwide, according to the study. It occurs when the immune system attacks healthy joint tissue, causing pain, swelling, stiffness and progressive damage.

Traditional medicine systems have used plant-based remedies for musculoskeletal conditions for centuries. For example, processed Aconitum root has been employed in Chinese material medica for musculoskeletal complaints, classified as a mild remedy with tropism to the nervous and musculoskeletal systems. ^[3] A growing interest in natural anti-inflammatory supplements has led to research on compounds such as bromelain and turmeric, with studies linking them to reduced inflammation. ^[4]

References

1. Yang Jin. World Century Compendium To Tcm Volume 3 Introduction To Chinese Materia Medica.
2. NaturalNews.com. “3 Nutrients Cited for Reducing Joint Pain and Stiffness Naturally.” May 13, 2026.
3. of The Herbal Menopause Book Peter Holmes has produced a new volume filled with insight.
4. NaturalNews.com. “Empowering Your Body: Nature’s Pharmacy for Arthritis Relief.” February 9, 2026.

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