Using 18F-FDG microPET imaging to measure the inhibitory effects of Clematis chinensis Osbeck on the pro-inflammatory and degradative mediators associated with inflammatory arthritis

Abstract Aim of the study This study examined the modulating effects of Clematis chinensis Osbeck (Ranunculaeae) on pro-inflammatory and degradative mediators associated with inflammatory arthritis. Materials and methods Primary human chondrocytes (PHC) were stimulated with IL-1β or lipopolysaccharide (LPS) to induce the enhanced release of prostaglandin E 2 (PGE 2 ), metalloproteinase (MMP-3 and -13), and cyclooxygenase-2 (COX-2) protein expression. The 18 F-FDG microPET imaging system was used to evaluate the anti-arthritic effects of Clematis chinensis in vivo . Results The acetone extracted Clematis chinensis (CC6) contained the most total saponins compared to other solvent's extracts and showed significant and dose-dependent inhibitory effects on PGE 2 , MMP-3, -13, and COX-2 productions by LPS-stimulated PHC. Furthermore, CC6 also exerted inhibitory effects on 2- 18 F-fluoro-2-deoxy- d -glucose ( 18 F-FDG) uptake when assessed by positron emission tomography (PET) uptake in the joints and serum PGE 2 of rabbits with knee joints injected with LPS. Conclusion The results suggest the significant chondroprotective effects of Clematis chinensis are through its anti-inflammatory and MMPs inhibitory abilities. Meanwhile, we established a new analysis method to evaluate the Chinese herbal anti-arthritic effects.