A ratiometric water-soluble fluorescent probe for the detection of sulfur dioxide derivative in sinusitis mice model.

Sulfur dioxide (SO2) plays an extremely important role in the basic processes of physiology and pathology. As an antioxidant, SO2 can maintain the redox homeostasis in the cell. Excessive inhalation of SO2 would lead to irreparable respiratory damage, resulting in respiratory diseases, neurological disorders, and even cardiovascular disease. Thus, it is urgent to exploit an excellent way to monitor SO2 derivatives in biological system. Herein, we design a water-soluble ratiometric fluorescent probe to fast detect the level of SO2 derivatives in living cells in vivo. The probe displays obvious fluorescence signal at long wavelength, which is helpful for imaging of biological system. After respond to SO2 derivatives, the fluorescence signal at 465 nm increases rapidly due to the Michael addition reaction is triggered, further causing the disruption of large conjugated system. The probe exhibits high selectivity and fast respond to SO2 derivatives, which can be able to sensitive and real-time monitoring of SO2 derivatives level in living cells. Moreover, the probe reveals a low detection limit and a great linear relationship to SO2 derivatives. Based on the negligible cytotoxicity and good biocompatibility of the probe, which is employed to detect exogenous and endogenous SO2 derivatives in living cells. In addition, it is also served as a potential chemical tool to detect SO2 derivatives in mice model of sinusitis.

Genistein and beta-carotene enhance the growth-inhibitory effect of trichostatin A in A549 cells.

BACKGROUND: The combination of anti-cancer drugs with nutritional factors is a potential strategy for improving the efficacy and decreasing the toxicity of chemotherapy. However, whether nutritional factors enhance the effect of trichostatin A (TSA), a novel anti-cancer drug, is unclear. AIM: We investigated the individual enhancing effect and its possible mechanisms of genistein, daidzein, beta-carotene, retinoic acid, and alpha-tocopherol on the cell-growth-inhibitory effect of TSA in a human lung carcinoma cell line, A549. METHODS: A549 cells were incubated with TSA (50 ng/mL) alone or in combination with the various nutritional factors for various times, and cell growth was measured. IMR90 cells, human lung fibroblasts, were also incubated with TSA alone or in combination with genistein or beta-carotene to determine the selectivity of these treatments. In addition, we studied effects on the cell cycle, caspase-3 activity, and DNA damage (by comet assay) in A549 cells. RESULTS: After treatment for 72 h, 10-microM genistein or beta-carotene significantly enhanced the growth-inhibitory effect of TSA in A549 cells. Daidzein, retinoic acid, and alpha-tocopherol at the same concentration had no significant effect. However, genistein and beta-carotene failed to enhance the cell-growth-arrest effect of TSA in IMR90 cells. Flow cytometric analysis showed that both genistein and beta-carotene significantly increased the TSA-induced apoptosis in A549 cells. Genistein significantly enhanced TSA-induced caspase-3 activity in A549 cells by 34% at 24 h, and the caspase-3 inhibitor partly inhibited the enhancing effect of genistein on TSA-induced apoptosis. beta-Carotene did not significantly affect TSA-induced caspase-3 activity. However, beta-carotene rather than genistein enhanced TSA-induced DNA damage. CONCLUSIONS: Genistein and beta-carotene enhance the cell-growth-arrest effect of TSA on A549 cells. Genistein exerts its effect, at least partly, by increasing caspase-3 activity; whereas beta-carotene may enhance TSA-induced cell death mainly through a caspase-3-independent pathway.