Hunan Agricultural University

Electrocatalytic nitrate reduction reaction (NO3RR) represents a sustainable and environmentally benign route for ammonia (NH3) synthesis. However, NO3RR is still limited by the competition from hydrogen evolution reaction (HER) and the high energy barrier in the hydrogenation step of nitrogen-containing intermediates. Here, we report a selective etching strategy to construct RuM nanoalloys (M = Fe, Co, Ni, Cu) uniformly dispersed on porous nitrogen-doped carbon substrates for efficient neutral NH3 electrosynthesis. Density functional theory calculations confirm that the synergic effect between Ru and transition metal M modulates the electronic structure of the alloy, significantly lowering the energy barrier for the conversion of *NO2 to *HNO2. Experimentally, the optimized RuFe-NC catalyst achieves 100% Faraday efficiency with a high yield rate of 0.83 mg h−1 mgcat−1 at a low potential of − 0.1 V vs. RHE, outperforming most reported catalysts. In situ spectroscopic analyses further demonstrate that the RuM-NC effectively promotes the hydrogenation of nitrogen intermediates while inhibiting the formation of hydrogen radicals, thereby reducing HER competition. The RuFe-NC assembled Zn-NO3− battery achieved a high open-circuit voltage and an outstanding power density and capacity, which drive selective NO3− conversion to NH3. This work provides a powerful synergistic design strategy for efficient NH3 electrosynthesis and a general framework for the development of advanced multi-component catalysts for sustainable nitrogen conversion.

Employing antioxidant nanozymes to eliminate reactive oxygen species (ROS) is a promising strategy for alleviating oxidative stress. However, most current nanozymes struggle to balance catalytic efficacy with biosafety, limiting their clinical applicability. In this study, we introduce a novel platform: DNA nanoribbon-templated copper nanoclusters (DNR/Cu NCs), which harness dual antioxidative mechanisms (direct ROS scavenging and activation of nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) pathway) to synergistically mitigate oxidative stress. Unlike conventional nanozymes that rely on a single mechanism, DNR/Cu NCs exhibit combined superoxide dismutase (SOD)/catalase (CAT)/glutathione peroxidase (GPx), thereby enhancing overall ROS elimination. The biocompatible DNR scaffold facilitates the formation of ultrasmall Cu NCs with high catalytic activity and promotes NRF2 nuclear translocation to transcriptionally upregulate HO-1, amplifying endogenous antioxidant defenses. In both hepatocyte and zebrafish models of oxidative injury, the DNR/Cu NCs effectively suppressed ROS accumulation, suppressed apoptosis, and restored redox balance while mitigating tissue damage in vivo. This study highlights a paradigm-shifting approach in nanozyme design, offering a promising therapeutic avenue for oxidative stress-related diseases.

Corus officinalis Siebold & Zucc belongs to the genus Cornus in the Cornaceae family, and was first recorded in the "Shennong Herbal Classic", now has been included in "according to the tradition of both food and Chinese herbal medicines", consist of kidney and liver tonifying, antioxidant substances including cycloid glycosides, flavonoids, polyphenols, organic acids, etc. AIM OF THE STUDY: This study was aimed at discovering the mechanism underlying the anti-hyperemia effect of Cor in rats, particularly its protective effect against liver and kidney dysfunction caused by HUA.

In this study, the effect of Cor extract against HUA was verified in rats, subsequently, network pharmacology combined with non-targeted metabolomic were performed to investigate its composition characteristics, and further multi-omics studies and molecular validation were performed to reveal molecular mechanism both in vivo and in vitro.

The results demonstrated that cornuside, hydroxygenkwanin and tetrahydroalstonine were the main bioactive compounds in Cor extract, which protected intestinal metabolism disorder by increasing relative abundances of Bacteroides, Lactobacillus Roseburia and Akkermansia, alleviated liver oxidative damage by activation of the Nrf2/HO-1(NQO1) antioxidant pathway, and reduced liver UA synthesis by inhibiting the expression of UA synthesis protein XOD in rat model. In addition, tetrahydroalstonine alleviated inflammation via inhibiting PI3K/Akt/NF-κB signaling pathway, with cornuside and hydroxygenkwanin enhanced renal tubule UA transport capacity by regulating the translations of XDH and HRP genes, all of which protected HUA-rat kidney from inflammatory infiltration damage, and reduced serum urea nitrogen (BUN), creatinine (CRE) and UA levels.

These findings indicates that Cor can alleviate HUA by enhancing liver-renal-intestine UA metabolism, inhibiting inflammatory responses of liver-renal-intestine as well as providing hepatorenal protection.