CoO/Co-graphene quantum dots as an oxidative mimetic nanozyme for the colorimetric detection of L-cysteine.

The preparation of cobalt-based nanozymes with high oxidase-like activity still needs more efforts. In this paper, we report the synthesis of a CoO/Co-tryptophan-functional graphene quantum dot hybrid (CoO/Co-Try-GQD). Firstly, cobalt ions coordinate with the indole nitrogen on Try-GQD to form a complex, followed by thermal reduction and oxidation. The resulting hybrid presents a three-dimensional network structure, and CoO/Co nanoparticles are uniformly dispersed on the graphene sheet with an average size of 10 ± 0.24 nm. This unique structure improved the oxidase-like activity of the hybrid, enabling it to catalyze the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to rapidly produce deep blue ox-TMB with a strong absorbance at 652 nm (A652). A colorimetric method was developed for the highly sensitive determination of L-cysteine (L-cys) based on the inhibition of the hybrid's oxidase-like activity and low A652 caused by the binding of L-cys with Co atoms on CoO/Co via the Co-S bond. The A652 linearly decreased with increasing L-cys concentration in the range of 0.05-2 µM, and the detection limit was 0.032 µM. Further, the established method has been successfully applied to the determination of L-cys in milk.

Molecular and morphological data reveal two new species of Tropicoporus (Hymenochaetaceae, Basidiomycota) from Australia and tropical Asia.

Phylogenetic analyses and morphological examination confirmed two new species in the tropical polypore genus Tropicoporus, T.oceanianus and T.zuzaneae, from Australia and tropical Asia, respectively. A phylogenetic analysis based on the two DNA markers including the nuclear ribosomal internal transcribed spacer (ITS) region and the large subunit (nLSU) gene shows that these two new species form two independent lineages nested in the genus Tropicoporus. T.oceanianus is characterized by perennial and ungulate basidiomata, the occasional presence of hymenial setae, a trimitic hyphal structure in the context and a dimitic hyphal system in the trama, and broadly ellipsoid to subglobose basidiospores measuring 5.2-6 × 4-5 µm. T.zuzaneae is characterized by perennial and resupinate basidiomata with distinct receding margin, glancing pores, very thin to almost lacking subiculum, a dimitic hyphal structure, the absence of any setal elements, broadly ellipsoid to subglobose basidiospores measuring 3.8-4.9 × 3-4.2 µm. The differences among the new species and their phylogenetically related and morphologically similar species are discussed.

Indole-3-carboxaldehyde regulates RSV-induced inflammatory response in RAW264.7 cells by moderate inhibition of the TLR7 signaling pathway.

Human respiratory syncytial virus (RSV) is highly contagious and the leading cause of severe respiratory tract illness in infants, elderly, and immunocompromised individuals. Toll-like receptor 7 (TLR7), a pattern recognition receptor recognising the ssRNA of RSV, activates proinflammatory pathways and triggers secretion of interferons (IFNs). On the one hand, the inflammatory responses help clear out virus. On the other hand, they lead to severe lung damage. Banlangen is a traditional Chinese herbal medicine commonly prescribed for respiratory virus infection treatment, but the mechanisms of action and active components remain largely unknown. In the present study, we investigated the effects of the main active components of total alkaloids from banlangen (epigoitrin, indole-3-carboxaldehyde, indole-3-acetonitrile and 4-methoxyindole-3-acetonitrile) on the RSV-induced inflammatory responses in mouse macrophage cells (RAW264.7). Our results demonstrated that RSV-induced IFN-α excessive secretion was moderately inhibited by indole-3-carboxaldehyde through downregulation of mRNA expression in a dose-dependent manner, in comparison, the inhibitory effects of ribavirin were too strong. Furthermore, we revealed that indole-3-carboxaldehyde suppressed transcription of IFN-α by inhibiting RSV-induced TLR7 expression in RAW264.7 cells. Additionally, indole-3-carboxaldehyde inhibited RSV-induced NF-κB signalling activation in a TLR7-MyD88-dependent manner. Together, our findings suggest that indole-3-carboxaldehyde inhibited RSV-induced inflammatory injury by moderate regulation of TLR7 signaling pathway and did not significantly affect the viral clearance competence of the innate immune system.

Deoxyelephantopin decreases the release of inflammatory cytokines in macrophage associated with attenuation of aerobic glycolysis via modulation of PKM2.

Growing evidence suggests that activated immune cells undergo metabolic reprogramming in the regulation of the innate inflammatory response. Remarkably, macrophages activated by lipopolysaccharide (LPS) induce a switch from oxidative phosphorylation to aerobic glycolysis, and consequently results in release of proinflammatory cytokines. Pyruvate Kinase M2 (PKM2) plays a vital role in the process of macrophage activation, promoting the inflammatory response in sepsis and septic shock. Deoxyelephantopin (DET), a naturally occurring sesquiterpene lactone from Elephantopus scaber, has been shown to counteracts inflammation during fulminant hepatitis progression, but the underlying mechanism remains unclear. Here, we studied the function of the DET on macrophage activation and investigated the anti-inflammatory effects of DET associated with interfering with glycolysis in macrophage. Our results first demonstrated that DET attenuates LPS-induced interleukin-1ß (IL-1ß) and high-mobility group box 1 (HMGB1) release in vitro and in vivo and protected mice against lethal endotoxemia. Furthermore, DET decreased the expression of pyruvate dehydrogenase kinase 1 (PDK1), glucose transporter 1(GLUT1), lactate dehydrogenase A (LDHA), and reduced lactate production dose-dependently in macrophages. Moreover, we further revealed that DET attenuates aerobic glycolysis in macrophages associated with regulating the nuclear localization of PKM2. Our results provided a novel mechanism for DET suppression of macrophages activation implicated in anti-inflammatory therapy.