Inhibition of Pro‐inflammatory Gene Expression in Chondrocytes, Monocytes, and Fibroblasts by the Combination of Avocado Soybean Unsaponifiables, Glucosamine, and Chondroitin Sulfate

Abstract

Recent studies have shown the benefit of the natural products: avocado soybean unsaponifiables (ASU), glucosamine (Glu), and chondroitin sulfate (CS) in alleviating pain and inflammation. Their mechanism of action is not fully understood. We tested the hypothesis that the combination of ASU, Glu, and CS down-regulates pro-inflammatory gene expression. Equine and human chondrocytes, human fibroblasts, or human monocyte/macrophage surrogate THP-1 cells were incubated for 24 hrs with: control media alone, ASU (8.3 μg/ml), Glu (11 μg/ml) and CS (20 μg/ml), or combination of ASU (8.3 μg/ml NMX1000™-ASU), Glu (11 μg/ml), and CS (20 μg/ml). Cells were activated for 1 hr with lipopolysaccharide (20 ng/ml) or IL-1β (10 ng/ml). RT-PCR analysis showed that the combination product suppressed COX-2 and chemokine (IL-8, MCP) expression in chondrocytes and fibroblasts. The combination product also suppressed cytokines (TNF-α, IL-1β) and iNOS expression in THP-1 cells. The anti-inflammatory effect of the combination product was more profound than the individual agents alone in THP-1 cells. Our study supports the potential clinical utility of the combination of ASU, Glu, and CS in suppressing inflammation. This combination product may provide an alternative treatment to patients who fail to respond to the single agents alone. Supported by Nutramax Laboratories, Inc. and Mississippi State University.