Background: Osteoarthritis is a difficult disease but the clinic lacks effective therapy. As a classic formula of traditional Chinese medicine (TCM), Fu Zi Tang has been clinically applied for treating osteoarthirtis-related syndromes, but its anti-oesteoarthirtis efficacy and mechanism remain unclear.
Purpose: To experimentally and clinically determine the anti-osteoarthritis efficacy of Fu Zi Tang and clarify the underlying mechanism.
Methods: UPLC/MS/MS was applied to identify the main components of Fu Zi Tang. A monoiodoacetate (MIA)-induced osteoarthritis rat model was employed to evaluate the in vivo efficacy of Fu Zi Tang against osteoarthritis, by using pain behavior assessment, histopathological observation, and immunohistochemical analysis. Primary rat chondrocytes were isolated to determine the in vitro effects of Fu Zi Tang by using cell viability assay, wound healing assay, and real-time PCR (qPCR) analysis on anabolic/catabolic mRNA expressions.
RNA sequencing (RNA-seq) and network pharmacology analysis were conducted and the overlapping data were used to predict the mechanism of Fu Zi Tang, followed by verification with qPCR and Western blot assays. Finally, a retrospective analysis was performed to confirm Fu Zi Tang‘s efficacy and safety in osteoarthritis patients.
Results: The UPLC/MS/MS result showed that Fu Zi Tang contained atractylenolide I, benzoylhypaconitine, benzoylmesaconitine, benzoylaconitine, hypaconitine, mesaconitine, aconitine, lobetyolin, paeoniflorin, and pachymic acid. The in vivo data showed that Fu Zi Tang restored the cartilage degeneration in MIA-induced osteoarthritis rats by ameliorating pain behavior parameters, recovering histopathological alterations, benefitting cartilage anabolism (up-regulating Col2 expression), and suppressing catabolism (down-regulating MMP13 and Col10 expressions).
The in vitro data showed that Fu Zi Tang increased cell viability and wound healing capacity of chondrocytes, and restored the altered expressions of anabolic and catabolic genes of chondrocytes. The overlapping results of RNA-seq and network pharmacology analysis suggested that PI3K/Akt signaling mediated the anti-oesteoarthirtis mechanism of Fu Zi Tang, which was verified by qPCR and Western blot experiments. Clinically, the anti-oesteoarthirtis efficacy and safety of Fu Zi Tang were confirmed by the retrospective analysis on osteoarthritis patients.
Conclusion: The scientific innovation of this study was the determination of anti-osteoarthritis efficacy of Fu Zi Tang by experimental and clinical evidence and the discovery of its mechanism by integrated RNA-seq, network pharmacology, and molecular experiments, which suggests Fu Zi Tang as a promising TCM agency for osteoarthritis treatment.