An exploration into the therapeutic effects and molecular mechanisms of paeoniflorin in the treatment of adjuvant-induced arthritis rats by a network pharmacology-based research strategy / 药学学报

ABSTRACT

Paeoniflorin (PAE), the major active compounds of Chinese herbs Radix Paeoniae Alba andChinese patent drug "Total Glucosides of Paeony Capsules", which is effective in the treatment of rheumatoid arthritis (RA), exerted multi-pharmacological activities, such as anti-inflammatory, immune-regulatory, etc. However, its potential action mechanisms remain unclear. Herein, we predicted the putative targets of Radix Paeoniae Alba and constructed an interaction network of putative targets of Radix Paeoniae Alba and known RA-related genes. A list of key putative targets was identified by calculating their topological features (degree, node betweenness and closeness) in the above pharmacological network. Importantly, pathway enrichment analysis revealed that these key putative targets were significantly enriched in several RA-related pathways, including cartilage damage-related IL1B-TNF-TLR2-JUN-MMP1-MMP3 signaling pathway. Further molecular docking simulation showed that PAE, the major active compounds of Radix Paeoniae Alba, has strong binding affinity with MMP1 and MMP3 proteins. Next, in vivo experiments based on the adjuvant-induced arthritis (AIA) animal models showed that PAE significantly alleviated the disease severity and the syndromes of severe redness or swelling in hind limbs of AIA rats, including decreasing the arthritis score, the diameter of the limbs, and elevating body weight and pain thresholds (all P<0.05). ELISA assay indicated that PAE obviously suppressed the abnormal up-regulation of serum inflammatory factors including IL-1β, TNF-α, IL-6, IL-17 and IFN-γ in AIA rats (all P<0.001). Western blot analysis found that PAE simultaneously modulated the abnormal up-regulation of MMP1 and MMP3 proteins in the ankle tissues of AIA rats (all P<0.001) (all procedures in the current study were performed in accordance with the ethical standards of the Center for Laboratory Animal Care, China Academy of Chinese Medical Sciences). In conclusion, PAE alleviated the cartilage damage and disease severity in the progressive process of RA via regulating the IL1B-TNF-TLR2-JUN-MMP1-MMP3 pathway. This study provided the theoretical basis of the PAE for its immune-regulatory effects, and as well provided references for the action mechanism study of extract compounds of Chinese herbs.