Total Flavonoids of Rhizoma Drynariae Treat Osteoarthritis by Inhibiting Arachidonic Acid Metabolites Through AMPK/NFκB Pathway

Abstract

Guang-Yao Chen,1,2,* Xiao-Yu Liu,3,* Xue-Er Yan,4,* XinBo Yu,1,2 Yi Liu,5 Jing Luo,1,2 Qing-Wen Tao1,2 1Department of TCM Rheumatology, China-Japan Friendship Hospital, Beijing, People’s Republic of China; 2Beijing Key Laboratory for Immune-Mediated Inflammatory Diseases, China-Japan Friendship Hospital, Beijing, People’s Republic of China; 3School of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, People’s Republic of China; 4Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, People’s Republic of China; 5Humanities School, Beijing University of Chinese Medicine, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qing-Wen Tao, Email [email protected]: Previous clinical studies have found that total flavonoids of Rhizoma Drynariae (TFRD) have a good therapeutic effect on osteoarthritis (OA), but its therapeutic mechanism needs further research.Methods: OA rat model was established by Hulth method and was intervened by TFRD. Pathological assessments were conducted to assess the protective effect of TFRD on cartilage. Serum metabolomics and network pharmacology were detected to predict the mechanism of TFRD treating OA. In further experiments, molecular biology experiment was carried out to confirm the predicted mechanisms in vivo and in vitro.Results: TFRD can effectively reduce chondrocyte apoptosis and cartilage degeneration in OA model rats. Serum metabolomics revealed that the intervention effect may be closely related to arachidonic acid metabolism pathway. Network pharmacologic prediction showed that COX-2 was the key target of TFRD in treating OA, and its mechanism might be related with NFκB, apoptosis, AMPK and arachidonic acid metabolism pathway. In vivo experiments indicated that TFRD can inhibit the abnormal expression of COX-2 mRNA in OA model rats. In the in vitro studies, the expression of COX-2 mRNA and protein increased, AMPK phosphorylation was inhibited, and NFκB signaling pathway was activated in IL-1β-induced chondrocytes, and these changes can be reversed by TFRD. After the activation of AMPK signaling pathway or the block-down of NFκB signaling pathway, the effect of TFRD on COX-2 mRNA expression was significantly weakened.Conclusion: TFRD can inhibit COX-2-mediated arachidonic acid metabolites, and its mechanism is closely related to AMPK/NFκB pathway, which may be a key mechanism in the treatment of OA.Keywords: total flavonoids of Rhizoma Drynariae, osteoarthritis, network pharmacology, serum metabolomics, cyclooxygenase-2, AMPK/NFκB pathway

Keywords

• total flavonoids of rhizoma drynariae
• osteoarthritis
• network pharmacology
• serum metabolomics
• cyclooxygenase-2
• ampk/nfκb pathway.