Chondrocyte Production of Pro-Inflammatory Chemokine MCP-1 (CCL-2) and Prostaglandin E-2 Is Inhibited by Avocado/Soybean Unsaponifiables, Glucosamine, Chondroitin Sulfate Combination

Abstract

Osteoarthritis (OA) is a chronic, painful disease affecting articulating joints in man and animals. It is characterized by cartilage breakdown, bone remodeling, osteophyte formation and joint inflammation. Currently used non-steroidal anti-inflammatory drugs for the management of OA are known to have deleterious side effects. To address the need for alternatives, we evaluated the anti-inflammatory effects of a combination of avocado/soybean unsaponifiables (ASU), glucosamine (GLU) and chondroitin sulfate (CS) by measuring chemokine MCP-1 (monocyte chemoattractant protein 1, CCL2) and prostaglandin E-2 (PGE 2 ) in stimulated chondrocytes. As the only cellular constituents of cartilage, chondrocytes are the source of pro-inflammatory mediators that play critical roles in the pathogenesis of OA. Chondrocytes were incubated: with: 1) control media, 2) [ASU + GLU + CS] combination, or 3) Phenylbutazone (PBZ) for 24 hours. Cells were next stimulated with IL-1β or LPS for another 24 hrs. MCP-1 and PGE 2 from supernatants were quantitated by immunoassay. Another set of chondrocytes seeded in chamber slides were stimulated with IL-1β for 1 hour and then immunostained for NF-κB. Chondrocytes stimulated with IL-1β or LPS significantly increased MCP-1 and PGE 2 production which were significantly reduced after treatment with [ASU + GLU + CS]. In contrast, PBZ significantly reduced PGE 2 but not MCP-1 production. IL-1β stimulation induced nuclear translocation of NF-κB, which The present study provides evidence that the production of MCP-1 by chondrocytes can be inhibited by the combination of [ASU + GLU + CS] but not by PBZ. In contrast, PGE 2 production was inhibited by either treatment suggesting that the production of MCP-1 and PGE 2 could be independently regulated. The finding of distinct effects of [ASU + GLU + CS] on MCP-1 and PGE 2 synthesis supports a scientific rationale for a multimodal treatment approach in the management of OA.

Mitigation of Antibiotic-Inducted Toxicity in Equine Chondrocytes by Soybean/Glucosamine/Chondroitin Combination

“…It inhibits the expression and production of cytokines, chemokines, PGE 2 , nitric oxide and matrix metalloproteinases as well as enhances the synthesis of cartilage matrix components such as collagen and proteoglycans. 21,23,24,26,28 Glucosamine and CS have been observed to downregulate the inflammatory gene expression in monolayer chondrocyte cultures. 28,34 The combined anti-inflammatory and chondroprotective effects of ASU, GLU and CS may account for the modulation of inflammation and decreased production of PGE 2 in our study.…”

“…13 Prostaglandin E 2 was used in this study as a well-defined marker of inflammation and as a key participant in the pathogenesis of OA. [26][27][28][29][30][31] It stimulates the production of degradative enzymes and inhibits the synthesis of cartilage components particularly proteoglycans. It perpetuates the inflammatory response and damage to cartilage by inducing production of other pro-inflammatory mediators.…”

“…24,35 The concentration of ASU (8.3 μg/mL) used in the present study was selected from earlier in vitro work showing significant antiinflammatory effects. 21,23,28 Of the three compounds, ASU has more recently been studied for its anti-inflammatory, anticatabolic and anabolic effects on cartilage metabolism. It inhibits the expression and production of cytokines, chemokines, PGE 2 , nitric oxide and matrix metalloproteinases as well as enhances the synthesis of cartilage matrix components such as collagen and proteoglycans.…”

“…For the present study, we felt that the 2D monolayer culture system, which is routinely used for screening a wide variety of cell effects, would facilitate adequate assessment of chondrocyte response to test agents with ease. 23,26,28 One limitation of this study is the treatment period of the chondrocyte cell cultures (24 hours). Most RILP literature Prostaglandin E 2 (PGE 2 ) production (pg/mL) by equine chondrocytes following administration of 10 mg/mL enrofloxacin (EF) with the addition of avocado/soybean unsaponifiables þ glucosamine þ chondroitin sulphate (ASU þ GLU þ CS).…”

“…The concentrations of the nutraceuticals used in this study were previously shown to exert significant biological effects primarily as anti-inflammatory agents. 21,[23][24][25][26][27][28][29]…”