Uncovering the Mechanism of Chinese Hawthorn Leaf on Myocardial Ischemia Based on Network Pharmacology, Molecular Docking Verification, and In Vitro Studies.

Hawthorn leaf has shown therapeutic effects in the patients with myocardial ischemia. Our study combines network pharmacology, molecular docking techniques, and in vitro experiment with the aim of revealing the mechanism of hawthorn leaves in the treatment of myocardial ischemia. The active ingredients and corresponding targets of hawthorn leaf through Traditional Chinese Medicine System Pharmacology and Swiss Target Prediction databases. Targets related to myocardial ischemia were retrieved by Gene Card, Online Mendelian Inheritance in Man, Disgenet, and Therapeutic Targets Database databases. Cytoscape software was used to construct an ingredient-target-organ network and enrichment analysis of common targets was analyzed. Molecular docking verification of the core compound and target interactions was performed using MOE software. In vitro cell experiment was performed to verify the findings from bioinformatics analysis. Six active components and 107 potential therapeutic targets were screened. The protein-protein interaction network analysis indicated that 10 targets, including AKT1 and EGFR, were hub genes. Quercetin, kaempferol and isorhamnetin were taken as core active components. Through pathway enrichment analysis, nearly 455 Gene Ontology entries and 77 Kyoto Encyclopedia of Genes and Genomes pathways were obtained, mainly including PI3K/Akt, estrogen and other signaling pathways. Molecular docking prediction showed that three main active ingredients were firmly combined with the core targets. Cellular experiments showed that quercetin alleviated oxidative damage in cells and regulated the expression of PI3K, P-AKT/AKT and Bax/Bcl-2 proteins. This study identified the potential targets of Hawthorn leaf against myocardial ischemia using network pharmacology and in vitro verification, which provided a new understanding of the pharmacological mechanisms of Hawthorn leaf in treatment of myocardial ischemia.

Electrochemical aptasensor based on DNA-templated copper nanoparticles and RecJf exonuclease-assisted target recycling for lipopolysaccharide detection.

An electrochemical aptasensor for detecting lipopolysaccharides (LPS) was fabricated based on DNA-templated copper nanoparticles (DNA-CuNPs) and RecJf exonuclease-assisted target recycling. The DNA-CuNPs were synthesized on a double-stranded DNA template generated through the hybridization of the LPS aptamer and its complementary chain (cDNA). In the absence of LPS, the CuNPs were synthesized on DNA double-strands, and a strong readout corresponding to the CuNPs was achieved at 0.10 V (vs. SCE). In the presence of LPS, the fabricated aptamer could detach from the DNA double-strand to form a complex with LPS, disrupting the template for the synthesis of CuNPs on the electrode. Meanwhile, RecJf exonuclease could hydrolyze the cDNA together with this single-stranded aptamer, releasing the LPS for the next round of aptamer binding, thereby enabling target recycling amplification. As a result, the electrochemical signal decreased and could be used to indicate the LPS content. The fabricated electrochemical aptasensor exhibited an extensive dynamic working range of 0.01 pg mL-1 to 100 ng mL-1, and its detection limit was 6.8 fg mL-1. The aptasensor also exhibited high selectivity and excellent reproducibility. Moreover, the proposed aptasensor could be used in practical applications for the detection of LPS in human serum samples.