Objective To investigate the mechanisms of 6-hydroxygenistein(6-OHG)in the treatment of high-altitude hypoxia-induced lung injury.Methods The intersection targets of 6-OHG and high-altitude hypoxia-induced lung injury were identified using databases,including Swiss Target Prediction,SuperPred,GeneCards,and OMIM.The STRING database and Cytoscape software were used to construct a protein interaction network for the intersection targets of drugs and diseases,and targets with degree values greater than the median were identified as key targets.GO and KEGG enrichment analyses of key targets were performed using the DAVID database to identify relevant signaling pathways.The Maestro 13.7 software was used for molecular docking validation.A large hypobaric hypoxic chamber was used to establish a high-altitude lung injury model in mice.A total of 42 male BALB/c mice were randomly assigned to 3 groups(n=14 in each group),including a normal control group,which was exposed to the environmental conditions at the altitude of 1400 m and received a single intraperitoneal injection of normal saline,a model group,which received a single intraperitoneal injection of normal saline,and a 6-OHG group,which received a single intraperitoneal injection of 6-OHG at 100 mg/kg.Then,1 h after drug administration,mice in the model and 6-OHG groups were placed in a large hypobaric hypoxic simulation chamber for animal experiments.Then,they ascended to an altitude of 8 000 m at a speed of 10 m/s,remained in that environment for 24 h,and then descended to an altitude of 3500 m.Mice in the three groups were sacrificed,and their lung tissues were extracted to measure the water content in the lungs.Pathological changes were observed using HE staining,and the levels of malondialdehyde(MDA),H2O2,total superoxide dismutase(T-SOD),and glutathione(GSH)were measured.Western blot was performed to determine the expression levles of p-PI3K/PI3K,p-AKT/AKT,hypoxia-inducible factor 1α(HIF-1α),and vascular endothelial growth factor(VEGF)proteins.Results Key targets such as serine/threonine protein kinase 1(AKT1),HIF-1α,epidermal growth factor receptor(EGFR),matrix metalloproteinase 9(MMP9),and peroxisome proliferator-activated receptor A(PPARA)were identified.GO and KEGG enrichment analyses showed that the targets of 6-OHG in the treatment of high altitude hypoxia-induced lung injury were mainly involved in PI3K/AKT,HIF-1α/VEGF,tumor necrosis factor(TNF),and other signaling pathways.The results of animal experiments demonstrated that compared with the model group,the 6-OHG group showed significant improvement in the pathological damage of lung tissues induced by high altitude hypoxia,presenting statistically significant differences in the levels of MDA,H2O2,GSH,and T-SOD(P＜0.01).The results of Western blot assay revealed statistically significant differences in the p-PI3K/PI3K,p-AKT/AKT,HIF-1α,and VEGF levels in the lung tissues of the 6-OHG group compared with those of the model group(P＜0.01).The molecular docking results showed that 6-OHG could form stable binding with PI3K,AKT,HIF-1α,and VEGF.Conclusion 6-OHG may alleviate lung injury induced by high altitude hypoxia in mice by activating the PI3K/AKT signaling pathway and inhibiting the HIF/VEGF signaling pathway.

Objective:To prepare 7-hydroxyethyl chrysin(7-HEC)loaded poly(lactic-co-glycolic acid)(PLGA)nanoparticles and to detect the in vitro release.Methods:The 7-HEC/PLGA nanoparticles were prepared by emulsification solvent volatilization method.The particle size,polydispersity index(PDI),encapsulation rate,drug loading and zeta potential were measured.The prescription was optimized by single factor investigation combined with Box-Behnken response surface method.Mannitol was used as protectant to prepare lyophilized powder,and the optimal formulation was characterized and studied for the in vitro release.Results:The optimal formulation of 7-HEC/PLGA nanoparticles was as follows:drug loading ratio of 2.12∶20,oil-water volume ratio of 1∶14.7,and 2.72%soybean phospholipid as emulsifier.With the optimal formulation,the average particle size of 7-HEC/PLGA nanoparticles was(240.28±0.96)nm,the PDI was 0.25±0.69,the encapsulation rate was(75.74±0.80)%,the drug loading capacity was(6.98±0.83)%,and the potentiostatic potential was(-18.17±0.17)mV.The cumulative in vitro release reached more than 50%within 48 h.Conclusions:The optimized formulation is stable and easy to operate.The prepared 7-HEC/PLGA nanoparticles have uniform particle size,high encapsulation rate and significantly higher dissolution rate than 7-HEC.