Untapping the Potential of Astragaloside IV in the Battle Against Respiratory Diseases.

Respiratory diseases are an emerging public health concern, that pose a risk to the global community. There, it is essential to establish effective treatments to reduce the global burden of respiratory diseases. Astragaloside IV (AS-IV) is a natural saponin isolated from Radix astragali (Huangqi in Chinese) used for thousands of years in Chinese medicine. This compound has become increasingly popular due to its potential anti-inflammatory, antioxidant, and anticancer properties. In the last decade, accumulated evidence has indicated the AS-IV protective effect against respiratory diseases. This article presents a current understanding of AS-IV roles and mechanisms in combatting respiratory diseases. The ability of the agent to suppress oxidative stress, cell proliferation, and epithelial-mesenchymal transition (EMT), to attenuate inflammatory responses, and modulate programmed cell death (PCD) will be discussed. This review highlights the current challenges in respiratory diseases and recommendations to improve disease management.

Efficient Eradication of Bacterial Biofilms with Highly Specific Graphene-Based Nanocomposite Sheets.

Bacterial biofilms are usually resistant to antibiotics, thus powerful methods are required for removal. Nanomaterial involving a combination of treatment modalities recently has been recognized as an effective alternative to combat biofilm. However, its targeted and controlled release in bacterial infection is still a major challenge. Here, we present an intelligent phototherapeutic nanoplatform consisting of an aptamer (Apt), indocyanine green (ICG), and carboxyl-functionalized graphene oxide (GO-COOH), namely, ICG@GO-Apt, for targeted treatment of the biofilm formed by Salmonella Typhimurium. Since Apt-conjugated nanosheets (NSs) can specifically accumulate near abscess caused by the pathogens, they enhance greatly the local drug molecule concentration and promote their precise delivery. They can simultaneously generate heat and reactive oxygen species under near-infrared irradiation for photothermal/photodynamic therapy, thereby significantly enhancing biofilm elimination. The phototherapeutic ICG@GO-Apt also displays a good biocompatibility. More importantly, the multifunction phototherapeutic platform shows an efficient biofilm elimination with an efficiency of greater than 99.99% in an abscess formation model. Therefore, ICG@GO-Apt NSs with bacteria-targeting capability provide a reliable tool for clinical bacterial infection that circumvents antibiotic resistance.

Gold-Platinum Nanodots with High-Peroxidase-like Activity and Photothermal Conversion Efficiency for Antibacterial Therapy.

Combined therapeutic strategies for bacterial infection have attracted worldwide attention owing to their faster and more effective therapy with fewer side effects compared with monotherapy. In this work, gold-platinum nanodots (AuPtNDs) are simply and quickly synthesized by a one-step method. They not only exhibit powerful peroxidase-like activity but also confer a higher affinity for hydrogen peroxide (H2O2), which is 3.4 times that of horseradish peroxidase. Under 808 nm laser irradiation, AuPtNDs also have excellent photothermal conversion efficiency (50.53%) and strong photothermal stability. Excitingly, they can combat bacterial infection through the combination of chemodynamic and photothermal therapy. In vitro antibacterial results show that the combined antibacterial strategy has a broad-spectrum antibacterial property against both Escherichia coli (Gram negative, 97.1%) and Staphylococcus aureus (Gram positive, 99.3%). Animal experiments further show that nanodots can effectively promote the healing of bacterial infection wounds. In addition, owing to good biocompatibility and low toxicity, they are hardly traceable in the main organs of mice, which indicates that they can be well excreted through metabolism. These results reveal the application potential of AuPtNDs as a simple and magic multifunctional nanoparticle in antibacterial therapy and open up new applications for clinical anti-infective therapy in the near future.

Targeting effect of berberine on type I fimbriae of Salmonella Typhimurium and its effective inhibition of biofilm.

As a primary cause of food contamination and human diseases, Salmonella Typhimurium can easily form a biofilm that is difficult to remove from food surfaces, and often causes significant invisible threats to food safety. Although berberine has been widely used as an anti-infective drug in traditional medicine, some basic principles underlying its mechanism, especially the interaction between berberine and type I fimbriae genes, has not been verified yet. In this study, two strains of major fimbrial gene mutants (ΔfimA and ΔfimH) were constructed to demonstrate the possible action of berberine on type I fimbriae genes. The broth microdilution method was used to determine the antibacterial activity of berberine against selected strains (WT, ΔfimA, and ΔfimH). Cell agglutination experiments revealed that the number of S. Typhimurium type I fimbriae reduced after berberine treatment, which was consistent with transmission electron microscopy results. Quantitative real-time PCR experiments also confirmed that berberine reduced fimA gene expression, indicating a certain interaction between berberine and fimA gene. Furthermore, confocal laser scanning microscopy imaging of biofilm clearly revealed that berberine prevents biofilm formation by reducing the number of type I fimbriae. Overall, it is well speculated for us that berberine could be an excellent combating-biofilm drug in clinical microbiology and food preservation. KEY POINTS: • Reduce the number of fimbriae. • Berberine targeting fimA. • Effective biofilm inhibitor.