ObjectivesIn our previous research, we have developed a new combination disinfectant, glutaraldehyde‐didecyldimethylammonium bromide (GD). It was verified that GD had a strong effect on both Escherichia coli and Staphylococcus aureus. In this work, Candida albicans was selected as an object, and it could be killed by GD. We aimed to investigate the cellular and molecular mechanism of GD effecting on C. albicans.Methods and ResultsThe results of sterilization experiment indicated that GD was effective on C. albicans. Flow cytometry and atomic absorption spectrometry were applied to detect cell membrane damage of C. albicans. Luciferase reaction and Bradford method were carried out to detect ATP content and protein quantitation. Transmission electron microscopy was used for intracellular organelles morphological observation. In order to study changes in mitochondrial membrane potential, Rh 123 was used as an indicator. DNA conformation analysis was performed by molecular modelling and circular dichroism. The results indicated that membrane permeability was increased rapidly owing to GD effect, and the leaked K+ and Mg2+ were about 12·1 and 12·4 times those of the control, respectively, at 10 min after GD treatment. Simultaneously, ATP and protein also leaked rapidly out of the cell. Mitochondrial membrane potential was destroyed, succinic dehydrogenase activity was significantly decreased and DNA conformation was changed because of GD action.ConclusionsGlutaraldehyde‐didecyldimethylammonium bromide disinfected C. albicans through distorting cell membrane integrity and permeability, disturbing the intracellular homeostasis by intracellular substances leakage, especially K+, Mg2+, ATP and protein, causing electrolyte imbalance of mitochondria, changing DNA structure, which finally led to cell death.Significance and Impact of the StudyThis study focused on the cellular and molecular mechanism of GD as a disinfectant against C. albicans. It is important to provide theoretical support to GD against Candida albicans in practical application.
The preparation of cellular metabolomics samples and how to achieve comprehensive coverage of different polar metabolites in cell samples in the analysis pose a challenge for cellular metabolomics. In this study, we optimized a metabolomics protocol based on ultra-high-performance liquid chromatography high-resolution mass spectrometry (UPLC/HRMS) for the extraction and detection of metabolites in A549 cells and exploration of the intervention effect of Qi-Yu-San-Long decoction (QYSLD) on A549 cells. The results indicate that the lowest level of ATP leakage was observed when A549 cells were quenched under liquid nitrogen. MeOH/chloroform/H 2 O (1:2:1) extraction yielded more chromatographic peaks and excellent reproducibility, and the relative extraction efficiency of most target metabolites was also high. And we optimized the chromatographic separation conditions in both HILIC and RPLC modes, enabling comprehensive detection and analysis of metabolites with varying polarities. Then, we applied the optimized method to UPLC-Q-TOF/MS-based metabolomics of A549 cells to study the mechanism of QYSLD intervention in non-small cell lung cancer (NSCLC). The CCK-8, EdU staining, and cell cycle assay showed that QYSLD inhibited the proliferation of A549 cells by interfering with the cell cycle and blocking them in the G1 phase. A total of 36 differential metabolites associated with the antitumor effects of QYSLD on NSCLC were identified, mainly involving nicotinate and nicotinamide metabolism, sphingolipid metabolism, and glycerophospholipid metabolism. And western blotting confirmed that the change in 1-methylnicotinamide levels after QYSLD intervention was associated with the inhibition of nicotinamide N-methyltransferase expression in A549 cells. Graphical Abstract