18ß-glycyrrhetinic acid alleviates radiation-induced skin injury by activating the Nrf2/HO-1 signaling pathway.

Radiation-induced skin injury is a common side effect of radiotherapy, but there are few therapeutic drugs available for prevention or treatment. In this study, we demonstrate that 18ß-Glycyrrhetinic acid (18ß-GA), a bioactive component derived from Glycyrrhiza glabra, substantially reduces the accumulation of reactive oxygen species (ROS) and inhibits apoptosis in HaCaT cells after ionizing radiation (IR), thereby mitigating radiation-induced skin injury. Mechanistically, 18ß-GA promotes the nuclear import of Nrf2, leading to activation of the Nrf2/HO-1 signaling pathway in response to IR. Importantly, Nrf2 silencing increases cell apoptosis and reverse the protective effect of 18ß-GA on radiation-induced skin injury. Furthermore, 18ß-GA preserves skin tissue structure after irradiation, inhibits inflammatory cell infiltration, and alleviates radiation dermatitis. In conclusion, our results suggest that 18ß-GA reduces intracellular ROS production and apoptosis by activating the Nrf2/HO-1 signaling pathway, leading to amelioration of radiation dermatitis.

Characteristics of disinfection byproducts from dissolved organic matter during chlor(am)ination of source water in Tibetan Plateau, China.

The Tibetan Plateau, a typical high-altitude area, is less affected by human activities such as industrial development, and the external pollution to water sources is extremely low. Then it is also an important source of water samples for exploring the molecular characteristics of precursors in the dissolved organic matter (DOM) of disinfection byproducts (DBPs) in drinking water. Research data on DBPs in drinking water on the Tibet Plateau remains insufficient, leading to uncertainty about DBP contamination in the area. This study explores the formation potential of 35 typical DBPs, including 6 trihalomethanes (THMs), 9 haloacetic acids (HAAs), 2 halogenated ketones (HKs), 9 nitrosamines (NAs), and 9 aromatic DBPs, during chlorination and chloramination of typical source water samples in the Tibet Plateau of China. Moreover, in order to further investigate the characteristics of the generation of DBPs, the molecular composition of DOM in the collected water samples was characterized by Fourier transform ion cyclotron resonance mass spectrometry. The findings reveal that, for chlorination and chloramination, the average concentration of the five classes of DBPs was ranked as follows (chlorination, chloramination): HAAs (268.1 µg/L, 54.2 µg/L) > THMs (44.0 µg/L, 2.0 µg/L) > HKs (0.7 µg/L, 1.8 µg/L) > NAs (26.5 ng/L, 74.6 ng/L) > Aromatics (20.4 ng/L, 19.5 ng/L). The dominant compounds in THMs, HAAs, and NAs are trichloromethane, dichloroacetic acid, trichloroacetic acid, and nitrosopyrrolidine, respectively. This study highlights a significant positive correlation between DBP generation and UV254, SUV254, and the double bond equivalents of DOM in the source water. It systematically elucidates DOM molecular composition characteristics and DBP formation potential in high-altitude water sources, shedding light on key factors influencing DBP generation at the molecular level in high-altitude areas.

Design, Synthesis, and Mode of Action of Thioacetamide Derivatives as the Algicide Candidate Based on Active Substructure Splicing Strategy.

Lakes and reservoirs worldwide are experiencing a growing problem with harmful cyanobacterial blooms (HCBs), which have significant implications for ecosystem health and water quality. Algaecide is an effective way to control HCBs effectively. In this study, we applied an active substructure splicing strategy for rapid discovery of algicides. Through this strategy, we first optimized the structure of the lead compound S5, designed and synthesized three series of thioacetamide derivatives (series A, B, C), and then evaluated their algicidal activities. Finally, compound A3 with excellent performance was found, which accelerated the process of discovering and developing new algicides. The biological activity assay data showed that A3 had a significant inhibitory effect on M. aeruginosa. FACHB905 (EC50 = 0.46 µM) and Synechocystis sp. PCC6803 (EC50 = 0.95 µM), which was better than the commercial algicide prometryn (M. aeruginosa. FACHB905, EC50 = 6.52 µM; Synechocystis sp. PCC6803, EC50 = 4.64 µM) as well as better than lead compound S5 (M. aeruginosa. FACHB905, EC50 = 8.80 µM; Synechocystis sp. PCC6803, EC50 = 7.70 µM). The relationship between the surface electrostatic potential, chemical reactivity, and global electrophilicity of the compounds and their activities was discussed by density functional theory (DFT). Physiological and biochemical studies have shown that A3 might affect the photosynthesis pathway and antioxidant system in cyanobacteria, resulting in the morphological changes of cyanobacterial cells. Our work demonstrated that A3 might be a promising candidate for the development of novel algicides and provided a new active skeleton for the development of subsequent chemical algicides.