Network pharmacology and experimental validation reveal that polydatin attenuates glucocorticoid-induced growth retardation via the AMPK/mTOR axis and autophagy

Background: Glucocorticoid-induced growth retardation (GIGR) is a frequent adverse effect of long-term glucocorticoid therapy in children, with few effective pharmacological interventions available. Polydatin (PD), a natural polyphenol known for modulating metabolism and oxidative stress, has not yet been explored in GIGR. This study investigates the protective effects and mechanisms of PD on GIGR, emphasizing the AMPK/mTOR signaling axis and Autophagy.

Methods: A combined approach of network pharmacology and in vitro experimental validation was employed. PD targets were predicted via SwissTargetPrediction, SEA, and TargetNet, while GIGR-related genes were collected from GeneCards, OMIM. Hub genes and pathways were identified via PPI networks, GO/KEGG enrichment, and molecular docking. Subsequently, a GIGR model was established by treating primary rat epiphyseal chondrocytes with dexamethasone, followed by PD intervention. To assess the robustness of the findings, the protective effects of PD were further examined in a Dex-treated human chondrocyte cell line (C-28/I2). In vitro assays included cellular viability (CCK-8), Apoptosis (TUNEL), gene expression (qRT-PCR), autophagosome formation (immunofluorescence), and protein expression analysis by Western blot.

Results: Network analysis indicated that PD potentially targets the AMPK/mTOR-autophagy axis. In vitro, PD significantly improved cell viability in Dex-treated chondrocytes (P < 0.001), reduced Apoptosis levels (P < 0.001), and restored expression of chondrogenic markers COL2A1, SOX9, and ACAN (P < 0.05). Consistently across both primary epiphyseal chondrocytes and C-28/I2 cells, PD increased the p-AMPK/AMPK and LC3-II/LC3-I ratios while reducing p-mTOR and p62 protein levels in a dose-dependent manner (P < 0.01), indicating activation of Autophagy through AMPK/mTOR modulation.

Conclusion: PD mitigates glucocorticoid-induced damage in epiphyseal chondrocytes by activating Autophagy via the AMPK/mTOR signaling pathway. These findings suggest that PD may serve as a promising therapeutic candidate for the treatment of GIGR.

AMPK/mTOR signaling; Autophagy; Epiphyseal chondrocytes; Glucocorticoid-induced growth retardation; Network pharmacology; Polydatin.