Cycloastragenol improves tolerance to acute hypoxic exhaustive exercise stress in mice: integrated network pharmacology and experimental evidence.

BACKGROUND: Acute hypoxic exposure combined with exhaustive exercise can impair exercise performance and induce metabolic, inflammatory, oxidative, and tissue stress. Cycloastragenol, a bioactive constituent of Astragalus membranaceus, has shown antioxidant and tissue-protective potential, but its role in acute hypoxic exercise stress remains unclear. This study investigated whether cycloastragenol pretreatment attenuates fatigue- and injury-related responses in mice. METHODS: A combined exploratory network pharmacology and animal experimental approach was used. Eighty-four male C57BL/6 J mice were randomly assigned to seven groups: blank control, model control (MC), normoxic exercise, Rhodiola rosea positive control (300 mg/kg/day), and low-, medium-, and high-dose cycloastragenol groups (25, 50, and 100 mg/kg/day). Pretreatments were administered by oral gavage once daily for 40 days. The MC, positive-control, and cycloastragenol groups then underwent continuous 24-h simulated hypobaric hypoxia equivalent to 5,000 m, followed by treadmill running to exhaustion. Outcomes included exhaustion time, serum biochemical and inflammatory markers, gastrocnemius ATPase activities, representative histopathology, and selected protein-expression endpoints. Data were analyzed using one-way ANOVA with Dunnett's test, eta squared, and Cohen's d. RESULTS: Network pharmacology identified 116 overlapping targets and suggested HIF-1, PI3K-Akt, FoxO, and IL-17 signaling as hypothesis-generating pathways. Compared with MC, high-dose cycloastragenol prolonged exhaustion time (133.67 ± 7.45 vs. 96.92 ± 9.42 min; d = +4.33; p < 0.001), reduced BUN (16.14 ± 1.21 vs. 23.38 ± 1.61 mmol/L; d = -5.09; p < 0.001), lactate (7.72 ± 1.77 vs. 16.27 ± 2.62 mmol/L; d = -3.82; p < 0.001), MDA (1.08 ± 0.07 vs. 1.20 ± 0.10 nmol/mg; d = -1.41; p < 0.01), IL-6 (14.92 ± 1.00 vs. 28.69 ± 1.41 pg./mL; p < 0.001), and TNF-α (51.31 ± 2.18 vs. 114.93 ± 1.84 ng/mL; p < 0.001), while increasing T-SOD activity and Na + -K + -ATPase activity. Representative HE images and Western blot results suggested qualitative tissue protection and modulation of HIF-1alpha, FoxO1, Nrf2, and HO-1 expression. CONCLUSION: Cycloastragenol pretreatment was associated with improved tolerance to acute hypoxic exhaustive exercise and attenuation of metabolic, inflammatory, oxidative, and tissue-related responses in mice. Direct hepatic glycogen, muscle glycogen, and blood glucose endpoints were not measured; further mechanistic and translational studies are needed.