Objective:To investigate the role and mechanism of molecular hydrogen in lipopolysaccharide (LPS)-induced acute lung injury (ALI).Methods:Balb/c male mice were randomly(random number) divided into control group, control+H 2, LPS and LPS+H 2 group with 6 mice in each group. The levels of malondialdehyde (MDA) and Fe 2+ in lung tissue were detected by kits. The lung tissue morphology was observed. The infiltration levels of F4/80 positive macrophages in lung tissue were detected by immunofluorescence staining. A549 cells were divided into control, control+H 2, erastin and erastin+H 2 group. The reactive oxygen species (ROS), malondialdehyde, (MDA), lactate dehydrogenase (GSH), number of cell death and lactate dehydrogenase (LDH) release in each group were detected by kits. Nrf2, GPX4, and HO-1mRNA were quantified by real-time PCR, the protein expression level of Nrf2 was detected by western blot, and the nuclear translocation level of Nrf2 was observed by immunofluorescence. The chi-square test was performed before the measurement data were counted. One-way analysis of variance was used to compare differences between multiple groups. Results:Compared with the control group, the histopathological damage was aggravated, and the levels of MDA, Fe 2+ significantly increased in the LPS group, and F4/80 positive immune cells infiltration significantly increased (all P<0.05). Compared with LPS group, the degree of lung injury in LPS+H 2 group significantly reduced (all P<0.05). In vitro experiments, compared with the control group, the ROS, MDA levels, number of cell death and LDH release significantly increased in erastin group (all P<0.05), while GSH, and GPX4 mRNA levels decreased (all P<0.05). HO-1mRNA and Nrf2 nuclear translocation levels increased (all P<0.05). Compared with erastin group, ROS, MDA levels, cell death number and LDH release decreased in earstin+H 2 group (all P<0.05). The levels of GSH, GPX4 mRNA, Nrf2 mRNA, HO-1 mRNA and Nrf2 nuclear translocation levels increased (all P<0.05). Conclusions:Molecular hydrogen attenuates LPS-induced ALI by promoting Nrf2 nuclear translocation to inhibit ferroptosis of alveolar epithelial cells.

Background::Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography (ERCP), the benefits and safety of high-carbohydrate fluid diet (CFD) intake 2 h before ERCP remain unclear. This study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients’ recovery.Methods::This prospective, multicenter, randomized controlled trial involved 15 tertiary ERCP centers. A total of 1330 patients were randomized into CFD group ( n = 665) and fasting group ( n = 665). The CFD group received 400 mL of maltodextrin orally 2 h before ERCP, while the control group abstained from food/water overnight (>6 h) before ERCP. All ERCP procedures were performed using deep sedation with intravenous propofol. The investigators were blinded but not the patients. The primary outcomes included postoperative fatigue and abdominal pain score, and the secondary outcomes included complications and changes in metabolic indicators. The outcomes were analyzed according to a modified intention-to-treat principle. Results::The post-ERCP fatigue scores were significantly lower at 4 h (4.1 ± 2.6 vs. 4.8 ± 2.8, t = 4.23, P <0.001) and 20 h (2.4 ± 2.1 vs. 3.4 ± 2.4, t= 7.94, P <0.001) in the CFD group, with least-squares mean differences of 0.48 (95% confidence interval [CI]: 0.26–0.71, P <0.001) and 0.76 (95% CI: 0.57–0.95, P <0.001), respectively. The 4-h pain scores (2.1 ± 1.7 vs. 2.2 ± 1.7, t = 2.60, P = 0.009, with a least-squares mean difference of 0.21 [95% CI: 0.05–0.37]) and positive urine ketone levels (7.7% [39/509] vs. 15.4% [82/533], χ2 = 15.13, P <0.001) were lower in the CFD group. The CFD group had significantly less cholangitis (2.1% [13/634] vs. 4.0% [26/658], χ2 = 3.99, P = 0.046) but not pancreatitis (5.5% [35/634] vs. 6.5% [43/658], χ2 = 0.59, P = 0.444). Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla (odds ratio [OR]: 0.61, 95% CI: 0.39–0.95, P = 0.028) in the multivariable models. Conclusion::Ingesting 400 mL of CFD 2 h before ERCP is safe, with a reduction in post-ERCP fatigue, abdominal pain, and cholangitis during recovery.Trail Registration::ClinicalTrials.gov, No. NCT03075280.