Antioxidant and Anti-Inflammatory Effects of Turmeric Fermentation Liquid in Knee Osteoarthritis

Background: Curcuma longa L. (turmeric) is a widely used medicinal plant with potent antioxidant and anti-inflammatory properties. It has been traditionally employed to manage inflammatory diseases such as osteoarthritis. This study explored the therapeutic potential of turmeric fermentation liquid (TF) in reducing oxidative stress, inflammation, and cartilage degradation in a monosodium iodoacetate-induced rat model of knee osteoarthritis (KOA). Methods: Fresh turmeric was washed, sliced, and fermented using Lactobacillus strains under controlled conditions to enhance its bioavailability and produce TF. Male Wistar rats were divided into four groups: Control, MIA, MIA+glucosamine hydrochloride, and MIA+TF. TF was administered orally for four weeks, and its effects were assessed through ELISA, histological staining, and immunohistochemistry to measure oxidative stress markers, inflammatory cytokines, and cartilage integrity. Results: TF enhanced antioxidant capacity and significantly reduced lipid peroxidation. It suppressed pro-inflammatory cytokines (TNF-α, IL-1β) and increased anti-inflammatory IL-10 levels. Histological analysis revealed cartilage preservation, reduced proteoglycan loss, and decreased synovitis severity. Safranin O staining confirmed higher proteoglycan retention in TF-treated cartilage, while immunohistochemistry showed reduced IL-6 and IL-1β expression. Furthermore, TF improved synovial fluid quality and decreased chondrocyte apoptosis, resulting in better joint mobility and reduced pain behavior in KOA rats. Conclusion: Turmeric fermentation liquid exhibits potential as a natural therapy for KOA by addressing oxidative stress and inflammation. The fermentation process enhances bioavailability, providing a novel approach for preserving joint health and function. Further clinical studies are needed to confirm its efficacy and safety in humans. Plain Language Summary: Why was the study done? Knee osteoarthritis is a common joint disease that causes pain and stiffness. While turmeric is a traditional remedy for inflammation, its natural compounds are hard for the body to absorb. This study investigated if fermenting turmeric could create a liquid supplement that is more effective at relieving osteoarthritis symptoms. What did the researchers do and find? Researchers gave a specially prepared turmeric fermentation liquid to rats with induced knee osteoarthritis for four weeks. They found that the liquid helped reduce markers of inflammation and cellular damage in the rats’ knee joints. The treatment also appeared to protect the joint cartilage from breaking down, which was associated with improved joint health. What do these results mean? These findings suggest that fermenting turmeric may enhance its natural anti-inflammatory and antioxidant properties, offering a promising approach for managing osteoarthritis. The turmeric fermentation liquid shows potential as a natural supplement to support joint health and alleviate symptoms associated with knee osteoarthritis. However, this is an animal study, and more research, including human clinical trials, is necessary to confirm these benefits and ensure safety. Keywords: osteoarthritis, turmeric fermentation liquid, knee osteoarthritis, antioxidant therapy, anti-inflammatory treatment, cytokine modulation, cartilage preservation, oxidative stress