Guyanxiao Tincture Alleviates Frozen Shoulder via Suppressing ACTC1 Induced Fibrosis in Shoulder Capsule
- VernacularTitle:骨炎消酊通过抑制ACTC1介导的肩关节囊纤维化缓解冻结肩
- Author:
Quan SUN
1
;
Kai-Wei ZHANG
2
;
Yang LIU
2
;
Yan WANG
2
;
Rui ZHENG
2
;
Shu-Guang ZHENG
2
Author Information
- Publication Type:Journal Article
- Keywords: frozen shoulder; Guyanxiao Tincture; icariside F2; fibrosis; ACTC1
- From: Progress in Biochemistry and Biophysics 2026;53(10):2714-2732
- CountryChina
- Language:English
- Abstract: ObjectiveFrozen shoulder (FS) is a debilitating musculoskeletal disorder characterized by persistent inflammation and progressive fibrosis of the glenohumeral joint capsule, leading to pain and severely restricted range of motion. Given the limited efficacy of current pharmacotherapies, there is an urgent need for novel anti-fibrotic agents. Guyanxiao Tincture (GYX), a traditional Chinese herbal formula, has shown clinical benefits in alleviating FS symptoms. However, its bioactive constituents and the molecular mechanisms underlying its therapeutic effects remain poorly defined. This study aimed to systematically evaluate the therapeutic efficacy of GYX against FS and to elucidate the mechanisms by which GYX attenuates capsular fibrosis. MethodsA Sprague-Dawley (SD) rat model of FS was established by immobilizing the unilateral shoulder with a plaster cast for 21 d. Following model induction, animals were administered with GYX or its serum-identified bioactive component, icariside F2. The absorbed prototype compounds of GYX in FS rat serum were profiled using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Therapeutic effects were assessed by measuring shoulder range of motion (ROM), histopathological evaluation of the capsule via hematoxylin-eosin staining, and quantification of transforming growth factor‑β1 (TGF-β1) content by ELISA. To explore the underlying mechanisms, transcriptomic profiling of the shoulder capsule was performed using RNA sequencing, and differentially expressed genes were validated by real-time quantitative PCR. Protein expression and localization were examined through immunohistochemistry, immunofluorescence, and Western blot. Protein-protein interaction networks were constructed to identify key regulatory hubs. In vitro, primary shoulder capsule fibroblasts were stimulated with TGF‑β1 to induce a fibrotic phenotype and then treated with icariside F2. The expression of alpha cardiac muscle 1 (ACTC1), α‑smooth muscle actin, and collagen I was subsequently measured. ResultsSerum pharmacochemistry analysis identified icariside F2 as the predominant circulating bioactive component of GYX in FS rats. Both GYX and icariside F2 treatment significantly improved the ROM and ameliorated histopathological lesions, including the attenuation of synovial hyperplasia, inflammatory infiltration, and excessive collagen deposition in the shoulder capsule. Consistently, elevated TGF‑β1 levels in the model group were markedly reduced after the interventions. RNA sequencing revealed that actin ACTC1 was dramatically upregulated in the fibrotic capsule, accompanied by the enrichment of fibrosis-associated pathways such as TGF‑β signaling, focal adhesion, and ECM-receptor interaction. Protein-protein interaction network analysis demonstrated that ACTC1 directly interacts with core fibrotic genes, including Col1a1, Col1a2, Thbs2, and Fn1. Critically, icariside F2 administration significantly reversed the aberrant overexpression of ACTC1 and suppressed the activation of the aforementioned fibrosis-related pathways in vivo. In TGF‑β1-stimulated fibroblasts, icariside F2 dose-dependently downregulated ACTC1 at both the mRNA and protein levels and concurrently decreased the expression of the fibrotic markers α‑smooth muscle actin and collagen I. Immunofluorescence and Western blot further confirmed that icariside F2 attenuated stress fiber formation and collagen production in vitro. ConclusionGYX and its bioactive component icariside F2 effectively alleviate the progression of frozen shoulder by inhibiting capsular fibrosis. Mechanistically, the therapeutic action is functionally linked to the suppression of ACTC1 and its downstream profibrotic signaling cascade, highlighting ACTC1 as a promising therapeutic target for the management of frozen shoulder.
