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

Aim of the studyThis study examined the modulating effects of Clematis chinensis Osbeck (Ranunculaeae) on pro-inflammatory and degradative mediators associated with inflammatory arthritis.Materials and methodsPrimary human chondrocytes (PHC) were stimulated with IL-1β or lipopolysaccharide (LPS) to induce the enhanced release of prostaglandin E2 (PGE2), metalloproteinase (MMP-3 and -13), and cyclooxygenase-2 (COX-2) protein expression. The 18F-FDG microPET imaging system was used to evaluate the anti-arthritic effects of Clematis chinensisin vivo.ResultsThe 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 PGE2, MMP-3, -13, and COX-2 productions by LPS-stimulated PHC. Furthermore, CC6 also exerted inhibitory effects on 2-18F-fluoro-2-deoxy-d-glucose (18F-FDG) uptake when assessed by positron emission tomography (PET) uptake in the joints and serum PGE2 of rabbits with knee joints injected with LPS.ConclusionThe 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.

Graphical abstractThe dry root of Clematis chinensis Osbeck, Wei-Ling-Xian (A), is one of tradition Chinese herbs and the acetone extract showed significantly chondroprotective effects on inflammatory arthritis.Figure optionsDownload full-size imageDownload as PowerPoint slide