The mechanism of
Rehmanniae Radix Praeparata against
osteoarthritis was investigated based on network pharmacology, molecular docking, and in vitro experiments in the present study. Osteoclast models were established via receptor activator of nuclear factor-κB
ligand(RANKL) and
macrophage colony-stimulating factor(
M-CSF) inducing RAW264.7 cells. Further, the influence of
Rehmanniae Radix Praeparata on the activity of
tartrate-resistant acid phosphatase(TRAP) was evaluated and the efficacy of
Rehmanniae Radix Praeparata in the treatment of
osteoarthritis was verified. The active components of
Rehmanniae Radix Praeparata were obtained from
Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP) and literature, and the potential targets of the components were collected from SwissTargetPrediction.
Osteoarthritis disease targets were searched in Online Mendelian Inheritance in Man(OMIM), Therapeutic Target Database(TTD), GeneCards, and DisGeNET. The intersection targets of
Rehmanniae Radix Praeparata and
osteoarthritis were obtained by Venny platform. The
protein-
protein interaction(PPI) network was constructed by Cytoscape 3.8.2, and key targets were obtained based on topology algorithm. The Database for Annotation, Visualization and Integrated Discovery(DAVID) was used to perform Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. Finally, the
mRNA expression of the key targets was determined by RT-qPCR and the binding activity between the components and key targets was validated by molecular docking. The results showed that
Rehmanniae Radix Prae-parata inhibited the TRAP activity, thus inhibiting
bone resorption by osteoclasts and treating
osteoarthritis. By network pharmacology, 14 active components of
Rehmanniae Radix Praeparata and 126 intersection targets were obtained. The network pharmacology enrichment results revealed 432 biological processes and 139 signaling pathways. Key targets such as proto-oncogene
tyrosine-protein kinase Src(SRC),
signal transducer and activator of transcription 3(STAT3) and
transcription factor p65(RELA) were obtained according to the degree in topological analysis. SRC was highly expressed in osteoclasts, which accelerated the development of
osteoarthritis. Therefore, SRC was selected for subsequent verification, and
Rehmanniae Radix Praeparata decreased the gene expression level of SRC. The molecular docking showed that
acteoside,
isoacteoside,
raffinose had good bonding activity with SRC, suggesting that they might be the critical components in treating
osteoarthritis. In conclusion,
Rehmanniae Radix Praeparata can inhibit
bone resorption by osteoclasts and balance the metabolism of articular cartilage and subchondral bone via acting on SRC, thus playing a therapeutic role in
osteoarthritis. In addition,
Rehmanniae Radix Praeparata may exert overall efficacy on
osteoarthritis through other targets such as STAT3 and RELA, and other related pathways such as PI3 K-AKT and
IL-17 signaling pathways.