Wuhan Polytechnic University

Hyperuricemic nephropathy (HN) is a serious kidney complication of hyperuricemia, yet effective treatments are lacking. Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has been implicated in renal tubular injury, but its regulatory mechanisms in HN remain unclear. This study investigated the protective effects of diosmetin (DIOS), a natural flavonoid with antioxidant properties, against monosodium urate (MSU)-induced damage in HK-2 human renal tubular cells. We confirmed that MSU-induced cell death was characteristic of ferroptosis. Through a combination of transcriptomic analysis and network pharmacology, we identified the BNIP3/Nrf2/GPX4 pathway as the primary potential target of DIOS. Molecular docking and subsequent experimental validation demonstrated that DIOS directly interacts with and modulates BNIP3, leading to the activation of Nrf2 and the upregulation of its downstream target, GPX4. This cascade enhanced the cellular antioxidant defense system, effectively suppressing lipid peroxidation and ferroptosis. Our findings reveal a novel mechanism by which DIOS protects against MSU-induced renal tubular injury and highlight the BNIP3/Nrf2/GPX4 axis as a promising therapeutic target for mitigating ferroptosis in HN.

The intake of selenium (Se) is beneficial only in a small range of concentrations, so there is an urgent need for rapid and accurate detection of selenium-enriched agricultural products. The detection of Se by conventional laser-induced breakdown spectroscopy (LIBS) is challenging due to its difficulty to excite and observe. In this work, a method was proposed by integrating a chopper with the photomultiplier tube (PMT), utilizing delayed triggering to achieve precise time control of the signals. This method not only could selectively detect the signals from the plasma, but also could avoid the interference of bremsstrahlung and interfering elements under wide bandpass conditions. The signal with no delay time was determined based on the kurtosis of the output signal from PMT. The ratio of the signal of Se to that of other interfering elements was improved by adjusting the delay time. The quantitative results and stability were greatly improved, with an R² of 0.991 and an average relative standard deviation (ARSD) of 14.2 %. For the first time, the limit of detection (LOD) of solid samples was improved to less than 2 ppm, providing a reliable and advanced method for the detection of selenium-enriched agricultural products.