# Shengyu decoction ameliorates knee osteoarthritis by inhibiting endoplasmic reticulum stress via Piezo1 channels

## TL;DR

Shengyu decoction helps treat knee osteoarthritis by reducing stress in cells through a protein called Piezo1.

## Contribution

Identifies the mechanism by which Shengyu decoction protects cartilage via Piezo1-mediated endoplasmic reticulum stress inhibition.

## Key findings

- SYD reduces cartilage damage and inflammation in knee osteoarthritis.
- SYD downregulates Piezo1, Xbp1, and Atf6 expressions linked to endoplasmic reticulum stress.
- Four active compounds in SYD interact with Piezo1, confirmed by molecular docking and SPR.

## Abstract

Shengyu decoction (SYD) is a classic and excellent prescription of traditional Chinese medicine (TCM). The innovative use of SYD by Chinese medical master Prof. Qi Shi in the treatment of knee osteoarthritis (KOA) has achieved considerable clinical outcomes. However, the current weakness is the lack of studies on the active ingredients and mechanisms of SYD.

To evaluate the role of SYD in reducing KOA cartilage damage as well as to explore the active ingredients and mechanisms of SYD.

The KOA rat model and chondrocyte model were established. This study employed various molecular biology techniques to clarify the role of SYD in vivo and in vitro. The active ingredients and mechanisms of SYD were analyzed through ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), RNA sequencing, molecular docking, and surface plasmon resonance (SPR). Finally, rescue experiments were conducted to verify the mechanisms.

The results revealed that SYD could significantly reduce cartilage tissue lesions, inhibit inflammation, and regulate proliferation–apoptosis balance. Transcriptome analysis showed an increase in the expressions of Piezo1, Xbp1, and Atf6 in KOA, and SYD downregulated them. UPLC-Q-TOF-MS analysis revealed four bioactive compounds of SYD, which were further confirmed to directly interact with Piezo1 through molecular docking and SPR assays. Furthermore, SYD downregulated the calcium ion concentration and the intensity of Piezo1 and ERS. Meanwhile, in the rescue experiment, Yoda1, the agonist of Piezo1, antagonized the pharmacological effects of SYD.

The present results provide strong evidence that SYD protected articular cartilage via inhibiting the Piezo1-mediated ERS signaling pathway. Overall, our work emphasizes the pivotal role of TCM in addressing medical challenges and provides new ideas for the treatment of KOA.