Anti-inflammatory Response and Detection of Pharmacologically Active Components in Serum of Rats with Carrageenan-Induced Paw Swelling Treated with Phellodendron chinense

Phellodendron chinense C.K.Schneid., Rutaceae, is a traditional Chinese medicine that is considered to have heat-clearing and detoxifying actions and is widely used for bacteriostatic and anti-inflammatory effects in clinical treatment and healthcare products. The aim of this study was to discover the pharmacological activity of P. chinense against inflammation. A rat model with carrageenan-induced inflammation model was used to systematically evaluate the anti-inflammatory effect of P. chinense extract on the degree of foot swelling and expression of NF-kB and myeloperoxidase. HPLC-QTOF/MS/MS was used to identify the components in the P. chinense extract. A bivariate correlation analysis was performed on the relative contents of components of serum from P. chinense–treated rats and the rates of inhibition of paw edema and COX-2 levels at different time points, and their correlation coefficients were calculated. The results showed that P. chinense significantly reduced the carrageenan-induced paw edema at 0.5 to 8 h and the levels of NF-κB and myeloperoxidase at 0.5 h, and the anti-inflammatory effects were similar to those of indomethacin. A total of 19 peaks were identified in total ion current chromatograms of the P. chinense extract, including 6 alkaloids, 11 phenolic acids, and 2 flavonoids. A total of 13 peaks were identified in the total ion current chromatograms of the serum of the rats with carrageenan-induced inflammation, including 3 alkaloids and 10 phenolic acids. Correlation coefficients above 0.5 with COX-2 or inhibitory actions on paw edema were found for phellodendrine, palmatine, berberine, quinic acid, caffeic acid, dihydrocaffeic acid sulphate, 3-O-feruloylquinic acid, 4-O-feruloylquinic acid, and 5-O-feruloylquinic acid. This result suggests that the main active components from P. chinense for anti-inflammation are alkaloids and phenolic acids such as quinic acid, caffeic acid, and their metabolites.