Tongbi Huoluo Decoction alleviates cartilage degeneration in knee osteoarthritis by inhibiting degradation of extracellular matrix

Exploration of scientific connotation of "Yin-Jing" medical properties of Cyathula officinalis via potentiating therapeutic effect, guidance and targetability

ETHNIC PHARMACOLOGICAL RELEVANCE: "Cyathula officinalis Kuan (COK)" has the effect of "guiding the drug downward" and can enhance the efficacy of formula, e.g., Shentong Zhuyu Decoction (STZYD). However, there is currently no scientific basis on COK to guide drugs to target organs in STZYD.

AIM OF THE STUDY

The main objective of this study was to unclose the scientific connotations of the Yin-Jing medicinal properties of COK using molecular biology and modern chemical methods.

MATERIALS AND METHODS

A rat model of adjuvant arthritis was established. The optimal dose of STZYD was determined by observing a series of indicators, and the therapeutic effects of STZYD and [STZYD - COK] were compared. The water decoction of COK was divided into five fragments (i.e., Fr. A-E) by macroporous adsorption resin and alcohol deposition methods. The Fr. A-E were further characterized by a combination of multiple chromatographic and spectral techniques. The potentiating therapeutic effects, guidance and targetability tests were used to evaluate "Yin-Jing" function by compatible combination of other drugs using pharmacological indicators, pharmacokinetics, high-performance liquid chromatography (HPLC) and small animal live imaging (SALI) techniques.

RESULTS

The optimal dose of STZYD was confirmed to be 1 × dose and COK increased the efficacy of [STZYD - COK]. The results of chemical characterization showed that the main components of Fr. A-E were polysaccharide, fructooligosaccharide and small Mw fructan, saponins and flavonoid glycosides, steroidal ketones, organic acids esters, respectively. Pharmacological experiments showed that Fr. A, Fr. B and Fr. E were attributed to potentiate therapeutic effects. Guidance assays showed that Fr. B enhanced drug distribution and uptake in the kidneys, joints and cells. Targetability assays further confirmed that Fr. B had apparent targetability toward the joints and kidneys rather than other organs and tissues.

CONCLUSIONS

This study for the first time combined potentiating therapeutic effects, guidance and targeting evaluation system, and identified Fr. B as the pharmacodynamic material basis of COK's Yin-Jing medicinal properties.

Transcriptomic integration and ligand-receptor crosstalk reveal the underlying molecular mechanisms between hip cartilage and subchondral bone in osteonecrosis of femoral head

Osteonecrosis of femoral head (ONFH) is characterized not only by ischemic bone tissue necrosis but also by cartilage degeneration, which plays an essential role in the pathogenesis of ONFH. The molecular communication between tissues contributes to disease progression, however the communication between cartilage and subchondral bone in the progression of ONFH remains unclear. In this study, we integrated transcriptomic data from ONFH cartilage and subchondral bone, exploring common differentially expressed genes (DEGs), pathway and function enrichment analyses, the protein-protein interaction (PPI) network, and hub genes to comprehensively study molecular integration. Additionally, we explored the molecular crosstalk between and within cartilage and subchondral bone using ligand-receptor pairs and ONFH cartilage proteomic data. Finally, key genes and ligand-receptor pairs were validated by quantitative real-time PCR (qRT-PCR). There were 27 common DEGs and five hub genes in cartilage and subchondral bone. The defined hub genes included COL1A1, COLIA2, CTSK, SPARC, and MXRA5. Notably, pathways related to ossification, extracellular matrix, and collagen formation were significantly altered in ONFH. Ligand-receptor data combined with DEGs revealed 60 differentially expressed ligands and 51 differentially expressed receptors in cartilage and four ligands and three receptors in subchondral bone. In inter-tissue comparisons, ligands from chondrocytes predominantly paired with receptors on osteoblasts in the subchondral bone, such as FN1, MMP2, and FGF1. Conversely, ligands from osteoblasts and osteocytes in the subchondral bone frequently paired with chondrocyte receptors, including FN1, COL1A1, and SEMA7A. At the protein level, we identified thirteen ligands and one receptor, with COL3A1 being the most highly expressed ligand and CD82 the only differentially expressed receptor in ONFH. This study highlights common molecular mechanisms and ligand-receptor crosstalk between and within cartilage and subchondral bone in ONFH, offering new insights into the disease's pathophysiology and potential molecular targets for therapeutic intervention.

Trachelogenin alleviates osteoarthritis by inhibiting osteoclastogenesis and enhancing chondrocyte survival

BACKGROUND

Osteoarthritis (OA) is a prevalent global health concern associated with the loss of articular cartilage and subchondral bone. The lack of disease-modifying drugs for OA necessitates the exploration of novel therapeutic options. Our previous study has demonstrated that traditional Chinese medical herb Trachelospermum jasminoides (Lindl.) Lem. extract suppressed osteoclastogenesis and identified trachelogenin (TCG) as a representative compound. Here, we delved into TCG's potential to alleviate OA.

METHODS

We initially validated the in vivo efficacy of TCG in alleviating OA using a rat OA model. Subsequently, we isolated primary bone marrow-derived macrophages in vitro to investigate TCG's impact on osteoclastogenesis. We further employed a small molecule pull-down assay to verify TCG's binding target within osteoclasts. Finally, we isolated primary mouse chondrocytes in vitro to study TCG's regulatory effects and mechanisms on chondrocyte survival.

RESULTS

TCG preserved subchondral bone integrity and protected articular cartilage in a rat OA model. Subsequently, in vitro experiments unveiled TCG's capability to inhibit osteoclastogenesis and function through binding to Ras association proximate 1 (Rap1) and inhibiting its activation. Further study demonstrated that TCG inhibited Rap1/integrin αvβ3/c-Src/Pyk2 signaling cascade, and consequently led to failed F-actin ring formation. Besides, TCG promoted the proliferation of mouse primary chondrocytes while suppressing apoptosis in vitro. This is attributed to TCG's ability to upregulate HIF1α, thereby promoting glycolysis.

CONCLUSION

TCG exerted inhibitory effects on osteoclastogenesis through binding to Rap1 and inhibiting Rap1 activation, consequently preventing subchondral bone loss. Moreover, TCG enhanced chondrocyte survival by upregulating HIF1α and promoting glycolysis. These dual mechanisms collectively provide a novel approach to prevented against cartilage degradation.