Novel carbon nanozymes with enhanced phosphatase-like catalytic activity for antimicrobial applications.

In this work, Sulfur and Nitrogen co-doped carbon nanoparticles (SN-CNPs) were synthesized by hydrothermal method using dried beet powder as the carbon source. TEM and AFM images indicated that these SN-CNPs form a round-shape ball with an approximate diameter of 50 nm. The presence of Sulfur and Nitrogen in these carbon-based nanoparticles was confirmed by FTIR and XPS analyses. These SN-CNPs were found to have strong phosphatase-like enzymatic activity. The enzymatic behavior of SN-CNPs follows the Michaelis-Menten mechanism with greater vmax and much lower Km values compared to alkaline phosphatase. Their antimicrobial properties were tested on E. coli and L. lactis, with MIC values of 63 µg mL-1 and 250 µg mL-1, respectively. SEM and AFM images of fixed and live E. coli cells revealed that SN-CNPs strongly interacted with the outer membranes of bacterial cells, significantly increasing the cell surface roughness. The chemical interaction between SN-CNPs and phospholipid modeled using quantum mechanical calculations further support our hypothesis that the phosphatase and antimicrobial properties of SN-CNPs are due to the thiol group on the SN-CNPs, which is a mimic of the cysteine-based protein phosphatase. The present work is the first to report carbon-based nanoparticles with strong phosphatase activity and propose a phosphatase natured antimicrobial mechanism. This novel class of carbon nanozymes has the potential to be used for effective catalytic and antibacterial applications.

Potential antifibrotic effect of blueberry and grape polyphenol extracts in acute and subacute bleomycin-induced lung tissue injury models in mice / Potencial efecto antifibrótico de los extractos de polifenoles de arándano y uva en modelos de lesión tisular pulmonar aguda y subaguda inducida por bleomicina en ratones

SUMMARY: An experimental morphological and morphometric study of the antifibrotic function of blueberry and grape extracts was carried out on a model of lung injury in mice induced by intraperitoneal administration of bleomycin. During intraperitoneal administration of bleomycin to mice, acute and subacute damage to the pulmonary system was noted. Both patterns had the same prevalence and severity. The administration of polyphenolic extracts of blueberry and grape to mice showed a significant reduction in the severity of the acute and subacute pattern of lung injury. Blueberry and grape extracts reduce the acute phase of damage to the microvasculature, enhance phagocytic function, have an anti-inflammatory effect, reducing the degree of lymphohistiocytic infiltration and locoregional foci of residual inflammatory effects.

Se realizó un estudio experimental morfológico y morfométrico de la función antifibrótica de extractos de arándano y uva en un modelo de lesión pulmonar en ratones inducida por la administración intraperitoneal de bleomicina. Durante la administración intraperitoneal de bleomicina a ratones, se observaron daños agudos y subagudos en el sistema pulmonar. Ambos patrones tuvieron la misma prevalencia y severidad. La administración de extractos polifenólicos de arándano y uva a ratones mostró una reducción significativa en la severidad del patrón agudo y subagudo de lesión pulmonar. Los extractos de arándano y uva reducen la fase aguda del daño a la microvasculatura, mejoran la función fagocítica, tienen un efecto antiinflamatorio, reducen el grado de infiltración linfohistiocítica y los focos locorregionales de efectos inflamatorios residuales.

Design, synthesis, spectroscopic characterization, computational analysis, and in vitro α-amylase and α-glucosidase evaluation of 3-aminopyridin-2(1H)-one based novel monothiooxamides and 1,3,4-thiadiazoles.

Due to the growth in the incidence of diabetes mellitus throughout the world, the urgency in the search for new safe and effective inhibitors of α-amylase and α-glucosidase is increasing. In this work, we attempted to carry out studies on the synthesis, modification and comprehensive computer and biological research of new derivatives of monothiooxamides. It was shown that monothiooxamides based on 3-aminopyridin-2(1H)-ones enter into transamidation reactions with hydrazine hydrate to form the corresponding thiohydrazides. Furthermore, under the action of chloroacetyl chloride and succinic anhydride, these thiohydrazides are cyclized into conjugated 1,3,4-thiadiazole derivatives. The possible biological activity of the obtained products was evaluated by molecular docking using the AutoDock Vina program. Compounds 7a and 8b showed higher binding affinities for selected target proteins compared to the known anti-diabetic drugs acarbose and TAK-875. The obtained new derivatives of 1,3,4-thiadiazole showed sufficiently high values of inhibitory activity in the in vitro test against the enzymes α-amylase and α-glucosidase as well as sufficiently low IC50 values (for 8b 122.2 µM), which is 8 times less than the value for the reference drug acarbose (998.3 µM). All synthesized derivatives of monothiooxamides 5-8(a-c) showed no cytotoxic properties at physiological concentrations in the MTT test in human neonatal dermal fibroblasts. Moreover, some compounds (6a-c, 7a-c, 8b,c) showed pronounced cytoprotective activity. Thus, the compounds 5-8(a-c) synthesized by us, both according to the results of computer calculations and in vitro biological screening, showed their potential antidiabetic activity and high prospects for further in-depth studies, including in vivo studies.

Generation of particle assemblies mimicking enzymatic activity by processing of herbal food: the case of rhizoma polygonati and other natural ingredients in traditional Chinese medicine.

Processed herbs have been widely used in eastern and western medicine; however, the mechanism of their medicinal effects has not yet been revealed. It is commonly believed that a central role is played by chemically active molecules produced by the herbs' metabolism. In this work, processed rhizoma polygonati (RP) and other herbal foods are shown to exhibit intrinsic phosphatase-like (PL) activity bounded with the formation of nano-size flower-shaped assembly. Via quantum mechanical calculations, an enzymatic mechanism is proposed. The enzymatic activity may be induced by the interaction between the sugar molecules distributed on the surface of the nanoassemblies and the phosphatase substrate via either a hydroxyl group or the deprotonated hydroxyl group. Meanwhile, the investigation was further extended by processing some fresh herbs and herbal food through a similar protocol, wherein other enzymatic activities (such as protease, and amylase) were observed. The PL activity exhibited by the processed natural herbs was found to be able to effectively inhibit cancer cell growth via phosphatase signaling, possibly by crosstalk with kinase signaling or DNA damage by either directly binding or unwinding of DNA, as evidenced by high-resolution atomic-force microscopy (HR-AFM). In this work, the neologism herbzyme (herb + enzyme) is proposed. This study represents the first case of scientific literature introducing this new term. Besides the well-known pharmacological properties of the natural molecules contained in herbs and herbal food, there exists an enzymatic/co-enzymatic activity attributed to the nanosized assemblies.