ABSTRACT
Traditional fluorogens with aggregation-induced emission (AIEgens) generally exhibit strong luminescence with monotonous wavelengths in the aggregated state, whereas apparent solvatochromic emission intensities and wavelengths (shift) are observed in molecules with twisted intramolecular charge transfer (TICT) characteristic molecules. Herein, we develop a platform to construct strong luminescent nanoparticles with tunable emission colors based on a TICT-AIEgen, 3,6-divinylaryl-substituted carbazole (C12P). Also based on the same molecule, through different nanoparticle fabrication approaches, fluorescent nanoparticles with different emission colors were obtained. A detailed analysis reveals that AIE and TICT characteristics play different roles in nanoparticle emission, with AIE primarily controlling the emission intensity while TICT is more involved in manipulating the emission wavelengths. Applications of the as-prepared nanoparticles in cell imaging were preliminarily demonstrated.
ABSTRACT
This manuscript describes the preparation of water soluble aggregation-induced emission enhancement (AIEE)-based fluorescent organic nanoparticles (FONs). The fluorescence diversity of the FONs was investigated in the presence of silver nanowires. We observed that the emission of the FONs can be enhanced by mixing with the nanowires, which is believed to originate from resonance between the emission of the FONs and the surface plasmon resonances of the metal surface. That is, the AIEE phenomenon was promoted according to the metal-enhanced fluorescence (MEF) mechanism that can be used to build up a novel double emission enhancement (DEE) platform and to extend the range of AIEE applications. The systemic fluorescence enhancement, lifetime and photostability were measured and the AIEE-MEF evaluation and the interaction between the FONs and nanowires were discussed based on the obtained spectral data and SEM and fluorescent microscopy images.
ABSTRACT
The hepatoprotective potential of Crossostephium chinensis (L.) Makino water extract (CCW) on carbon tetrachloride (CCl(4)) induced liver damage was evaluated in preventive and curative rat models. Not only were indicators of hepatic damage including GPT, GOT, lipid peroxides and TBARS were examined, the activities of antioxidant enzymes (SOD, CAT, GPx) and GSH were examined as well. The results showed that CCW (0.1, 0.5 and 1.0 g/kg) significantly reduced the elevated levels of GPT and GOT by CCl(4) administration (p < 0.05). TBARS level was dramatically reduced, and SOD, CAT, GPx and GSH activities were significantly increased. In addition, CCW decreased NO production and TNF-α activation in CCl(4)-treated rats. Therefore, we speculate that CCW protects against acute liver damage through its radical scavenging ability. CCW inhibited the expression of MMP-9 protein, indicating that MMP-9 played an important role in the development of CCl(4)-induced chronic liver damage in rats. In LC-MS-MS analysis, the chromatograms of CCW with good hepatoprotective activities were established. Scopoletin may be an important bioactive compound in CCW.
Subject(s)
Antioxidants/therapeutic use , Asteraceae/chemistry , Chemical and Drug Induced Liver Injury/prevention & control , Matrix Metalloproteinase Inhibitors , Phytotherapy , Plant Extracts/therapeutic use , Scopoletin/therapeutic use , Alanine Transaminase/blood , Animals , Antioxidants/metabolism , Antioxidants/pharmacology , Aspartate Aminotransferases/blood , Carbon Tetrachloride , Chemical and Drug Induced Liver Injury/blood , Male , Nitric Oxide/biosynthesis , Plant Extracts/pharmacology , Rats , Rats, Sprague-Dawley , Scopoletin/pharmacology , Thiobarbituric Acid Reactive Substances/metabolism , Tumor Necrosis Factor-alpha/metabolismABSTRACT
This study investigated the protective effect of the aqueous extract of Flemingia macrophylla (AFM) against hepatic injury induced by CCl(4). Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected as biomarkers in the blood to indicate hepatic injury. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and reduced glutathione (GSH) contents were evaluated for oxidative stress in hepatic injury. Moreover, histopathological observation was assayed for the degree of hepatic injury. After oral administration of AFM, 0.5 g/kg and 1.0 g/kg doses significantly decreased ALT and AST, attenuated the histopathology of hepatic injury, ameliorated oxidative stress in hepatic tissue, and increased the activities of CAT, SOD and GSH-Px. The hepatoprotective effect of daidzein and genistein were consistent to that of AFM. This study demonstrated for the first time that AFM has hepatoprotective effect on acute liver injuries induced by CCl(4), and the results suggested that the effect of AFM against CCl(4)-induced liver damage was related to antioxidant properties.
