Activity

ERβ agonist also increased cell survival, but the antagonist had no effect on cell survival. Transfection of the cells with the small interfering RNAs (si-RNAs) to ERα or ERβ diminished the protective effect of silibinin on UVB-irradiated cells. In UVB-treated HaCaT cells, both ERα and ERβ were increased by silibinin treatment. Inhibition of activation and expression of ERα or ERβ by specific antagonists and si-RNAs, respectively, reduced cell survival in UVB-treated HaCaT cells regardless of silibinin treatment. Taken together, it is summarized that silibinin up-regulates both ERα and ERβ pathways in UVB-treated dermal HFF cells and epidermal HaCaT cells, leading to protection of skin from UVB-damage.Ultraviolet B (UVB) light corresponds to 5% of ultraviolet radiation. It is more genotoxic and mutagenic than UVA and causes direct and indirect cellular damage through the generation of reactive oxygen species (ROS). Even after radiation, ROS generation may continue through activation of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) enzyme. Long-term exposure can progress to premature skin aging and photocarcinogenesis. To prevent damage that is caused by UVB radiation, several studies have focused on the topical administration of compounds that have antioxidant properties. 2-Acetylphenothiazine (ML171) is a potent and selective inhibitor of NOX1. The present study investigated the antioxidant potential and photoprotective ability of ML171 in UVB-irradiated L929 fibroblasts. ML171 had considerable antioxidant activity in both the DPPH• and xanthine/luminol/xanthine oxidase assays. ML171 did not induce cytotoxicity in L929 fibroblasts and increased the viability of UVB-irradiated cells. ML171 also inhibited ROS production, the enzymatic activity of NOX, depolarization of the mitochondrial membrane, and DNA damage. Additionally, ML171 protected cell membrane integrity and induced fibroblast migration. These results suggest that the incorporation of ML171 in topical administration systems may be a promising strategy to mitigate UVB-induced oxidative damage in L929 fibroblasts.Herein, a new “turn on” fluorescent probe C-1 is developed to specifically detect hydrazine using coumarin nucleus as the fluorophore and β-diketone as the recognition group. The probe shows high selectivity towards hydrazine over other common ions and amine-containing species, as well as good water solubility and quantitative detectability of hydrazine in concentration range of 1-200 μM. The detection limit is as low as 1.89 ppb, which is lower than the threshold set by EPA (10 ppb). Probe-coated filter papers are confirmed to detect gaseous hydrazine successfully through obvious fluorescence color changes. In addition, the probe has been verified to detect hydrazine in actual water environment and living cells.The plant popularly known as “negramina” (Siparuna guianensis Aubl.), member of the family Siparunaceae produces an essential oil that presents several biological activities reported in literature. Here, the essential oil was obtained by hydrodistillation from fresh leaves collected in the state of Roraima, far north of the Amazon. Chemical composition of the essential oil was characterized by gas chromatography coupled to mass spectrometry (GC-MS) and flame ionization detector (GC-FID). The sesquiterpenoid shyobunone and its derivatives were identified as major compounds in the oil (>40%). The effect of S. guianensis essential oil on the acetylcholinesterase (AChE) activity from Crassostrea rhizophorae, Litopenaeus vannamei and Electrophorus electricus was tested by spectrophotometric assays. The essential oil has been identified as an AChE inhibitor. The mechanism of inhibition was investigated as well as spectrofluorimetric interactions between the essential oil and the enzyme. 1H NMR titration and molecular docking were also investigated. The spectrophotometric results revealed that shyobunone and its derivatives strongly interact with AChE with a kind of non-competitive inhibition. Interaction studies support the results of enzyme inhibition. Molecular coupling predicted that iso-shyobunone is the strongest ligand, corroborated by fluorescence suppression and 1H NMR titration results. In conclusion, Siparuna guianensis essential oil can be a new source of shyobunone and derivatives capable to reversibly inhibit AChE showing potential neuroprotective properties to be applied in the treatment of Alzheimer’s disease.The synthesis of new fluorescent polymers based on π-conjugated chains is a major challenge for organic electronic. The materials must be soluble, stable over long periods and able to be produced with a high yield. In particular, poly (vinylcarbazole), poly (fluorenes), and poly (thiophene) partially meet these criteria. In this study, new soluble copolymers PVK-F8T2 was synthesized from poly(9-vinylcarbazole) (PVK) and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(bithiophène)] (F8T2). As these materials are highly luminescent and green-emitting, they have good chemical and thermal stability and can be easily functionalized. Here, the vibrational and optical properties of PVK-F8T2 was studied using several different techniques, including Infrared absorption, Raman scattering, thermogravimetric analysis (TGA), UV-visible optical absorption, and both stationary and transient photoluminescence. The novel copolymer shows an increase of thermal stability compared to the two original polymers (PVK and F8T2). The stationary and transient photoluminescence reveal an energy transfer from PVK to F8T2. This study indicates that these copolymers are good candidates for photophysical applications.Azithromycin (AZM)1 is one of the most widely used antibiotics. AZM abuse is easy to cause great harm to human body, so developing a rapid and sensitive method to detect AZM is of great importance. Kinase Inhibitor Library Herein, 3-aminothiophenol as only reaction precursor, nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs)2 were fabricated by one-step hydrothermal carbonization method. All characteristics demonstrate that N,S-CQDs possess good water solubility, high fluorescence stability and low cytotoxicity. Without being disturbed by amino acids and drugs, the most interesting finding is that AZM can efficiently quench the fluorescence of N,S-CQDs by a synergistic effect of electrostatic interaction and static quenching. A fluorescent probe for the detection of AZM was constructed with high selectivity and good sensitivity, achieving two linear ranges of 2.5-32.3 μM and 37.2-110 μM and a limit of detection of 0.76 µM. The proposed fluorescent method was used for the detection of AZM in cells with fulfilling results. More importantly, the fluorescent probe was successfully used to the detection of AZM in tablets and human urine with recovery rate and relative standard deviations of 98.