Atractylenolide III attenuates acute kidney injury through phosphorylation of PIK3CA: Functional activation and molecular interaction analysis.

Acute kidney injury (AKI) is a clinical syndrome characterized by high morbidity and mortality, with currently limited effective therapeutic strategies available. Atractylodes macrocephala Koidz is a key tonic herb in Traditional Chinese Medicine (TCM), historically used to treat conditions such as spleen deficiency, edema, and oliguria. These traditional indications align closely with clinical manifestations of AKI, including fluid retention and impaired urination. Modern pharmacological studies have revealed that its major active compound, Atractylenolide III (ATL-III), possesses anti-inflammatory and antioxidant properties. However, the underlying mechanisms by which ATL-III alleviates AKI remain poorly understood. This study aimed to investigate the therapeutic potential of ATL-III in AKI and delineate the molecular mechanisms underlying its protective effects. To assess the in vivo renoprotective effects of ATL-III, mouse models of AKI were established using cisplatin and ischemia-reperfusion injury (IRI). ATL-III was administered at 10, 20, and 40 mg/kg, and curcumin was used as a positive control. Renal function and injury were assessed by measuring serum creatinine and blood urea nitrogen levels, performing histological staining, ELISA, and analyzing the expression of kidney injury molecule-1 (KIM-1). In parallel, HK-2 cell models treated with cisplatin or subjected to hypoxia/reoxygenation (H/R) were used to further assess the protective effects of ATL-III in vitro. To explore the potential molecular mechanisms, network pharmacology and molecular docking analyses were conducted to predict candidate targets of ATL-III, followed by molecular dynamics (MD) simulations to evaluate the binding stability between ATL-III and key target proteins. Finally, cellular thermal shift assays (CETSA) and siRNA-mediated knockdown of PIK3CA were performed to confirm that ATL-III exerts its renoprotective effects through activation of the PIK3CA/AKT signaling pathway. ATL-III exhibited significant renoprotective effects in both in vivo and in vitro models of AKI in a dose-dependent manner. Compared with the positive control group curcumin, ATL-III demonstrated superior efficacy by effectively reversing the elevated levels of inflammatory cytokines and oxidative stress markers. Network pharmacology analysis suggested that ATL-III may inhibit the onset and progression of AKI by modulating the AKT signaling pathway and exerting anti-inflammatory effects. Molecular dynamics simulations demonstrated favorable binding stability between ATL-III and PIK3CA. In the cisplatin-induced HK-2 cell model, ATL-III directly binds to PIK3CA and promotes its phosphorylation. This interaction enhances activation of the PIK3CA/AKT pathway, which subsequently suppresses inflammation, reduces oxidative stress, and alleviates AKI-associated cellular injury. ATL-III offers kidney protection through a PIK3CA/AKT-dependent mechanism, underscoring its viability as a potential treatment for AKI.