A Novel Antimicrobial Peptide Sp-LECin with Broad-Spectrum Antimicrobial Activity and Anti-Pseudomonas aeruginosa Infection in Zebrafish.

New antimicrobial agents are urgently needed to address the increasing emergence and dissemination of multidrug-resistant bacteria. In the study, a chemically synthesized truncated peptide containing 22-amino acids derived from a C-type lectin homolog SpCTL6 of Scylla paramamosain was screened and found to exhibit broad-spectrum antimicrobial activity, indicating that it is an antimicrobial peptide (AMP), named Sp-LECin. Sp-LECin possessed the basic characteristics of most cationic AMPs, such as positive charge (+4) and a relatively high hydrophobicity (45%). After treatment with Sp-LECin, the disruption of microbial membrane integrity and even leakage of cellular contents was observed by scanning electron microscopy (SEM). In addition, Sp-LECin could bind lipopolysaccharide (LPS), increase the outer and inner membrane permeability and induce reactive oxygen species (ROS) production, ultimately leading to the death of Pseudomonas aeruginosa. Furthermore, Sp-LECin exhibited potent anti-biofilm activity against P. aeruginosa during both biofilm formation and maturation. Notably, Sp-LECin had no obvious cytotoxicity and could greatly improve the survival of P. aeruginosa-infected zebrafish, by approximately 40% over the control group after 72 h of treatment. This study indicated that Sp-LECin is a promising antibacterial agent with the potential to be used against devastating global pathogen infections such as P. aeruginosa.

A truncated Sph12-38 with potent antimicrobial activity showing resistance against bacterial challenge in Oryzias melastigma.

Antimicrobial peptides (AMPs) represent an efficient part of innate immunity and are found in a variety of life. Among them Histone 2A (H2A), as a promising class of AMPs, attracts great attention, but the in vivo mechanism of H2A derived AMP is still less known. Based on the acquisition of Sphistin, a synthetic 38-amino acid H2A derived peptide from Scylla paramamosain, as reported in our previous study, was truncated into three short fragments (Sph12-38, Sph20-38 and Sph30-38) and further investigated for its possible functional domains. The antimicrobial activities of these analogs against different Gram-positive bacteria, Gram-negative bacteria and fungi were illustrated. Among the analogs, Sph12-38 showed a stronger activity with a much lower minimum inhibitory concentration (3 µM) against Staphylococcus aureus, Corynebacterium glutamicum, Micrococcus lysodeikticus Fleming, Bacillus subtilis, Pseudomonas fluorescens, Aeromonas hydrophila and A. sobria in comparison with the reported Sphistin. A leakage of intracellular content was described in E. coli treated with Sph12-38. Unlike Sphistin which mainly disrupts the membrane integrity, Sph12-38 could also combine the A. sobria genomic DNA with a minimum concentration of 6 µM and was located intracellularly in cells observed under confocal laser scanning microscope imaging. In comparison with the control group of Oryzias melastigma injected with A. sobria alone, the group treated with a mixture of Sph12-38 and A. sobria showed a higher survival rate 7 days post-injection. Furthermore, in a pretreatment assay at 6 h, a higher survival rate was observed in the group injected with the mixture of Sph12-38 and A. sobria. Taken together, the synthetic peptide of Sph12-38 had a potent antimicrobial activity against bacteria. However, Sph12-38 had no cytotoxicity towards the hemolymph of S. paramamosain. Our study suggested that, as with Sph12-38, the H2A derived peptides were more likely prone to exert their activities in vivo through the truncated fragments while defending against different species of pathogens.

Correction: Lonicera japonica Thunb. as a promising antibacterial agent for Bacillus cereus ATCC14579 based on network pharmacology, metabolomics, and in vitro experiments.

[This corrects the article DOI: 10.1039/D3RA00802A.].

Clinical efficacy of a combination treatment of traditional Chinese medicine for scalp seborrheic dermatitis.

OBJECTIVE: To evaluate the clinical efficacy of a combination treatment of traditional Chinese medicine (TCM) in scalp seborrheic dermatitis (SSD) of differing severity. METHODS: Our study included patients with typical SSD who visited the Medical Research Center for Hair and Skin at our hospital. Symptoms were evaluated using a "16-point scale" developed at the center. Patients who had mild SSD were treated with Pi Fu Kang Xi Ye (PFKXY), those with moderate SSD were treated with PFKXY combined with Run Zao Zhi Yang Jiao Nang (RZZYJN), and those with severe dermatitis were treated with PFKXY and RZZYJN along with garlicin enteric-coated tablets. Patients were asked to revisit 4 weeks later to evaluate the efficacy. RESULTS: Symptom scores of all patients decreased by (5.48 ± 2.51) after treatment as compared with before treatment, and the results of t-test and correlation test were significant (p < 0.01). The scores of patients with mild, moderate and severe SSD decreased by 3.14 ± 1.83, 4.90 ± 1.77, and 8.05 ± 2.21, respectively, after treatment as compared with before treatment. Among them, the changes in scores of patients with moderate dermatitis before and after treatment were significant in the t-test and correlation test (p < 0.01). CONCLUSION: In this study, the combination treatment of TCM showed significant efficacy in the treatment of mild, moderate, and severe SSD, and the efficacy was stable, especially for patients with moderate SSD.

Lonicera japonica Thunb. as a promising antibacterial agent for Bacillus cereus ATCC14579 based on network pharmacology, metabolomics, and in vitro experiments.

Lonicera japonica Thunb. has attracted much attention for its treatment of bacterial and viral infectious diseases, while its active ingredients and potential mechanisms of action have not been fully elucidated. Here, we combined metabolomics, and network pharmacology to explore the molecular mechanism of Bacillus cereus ATCC14579 inhibition by Lonicera japonica Thunb. In vitro inhibition experiments showed that the Lonicera japonica Thunb.'s water extracts, ethanolic extract, luteolin, quercetin, and kaempferol strongly inhibited Bacillus cereus ATCC14579. In contrast, chlorogenic acid and macranthoidin B had no inhibitory effect on Bacillus cereus ATCC14579. Meanwhile, the minimum inhibitory concentrations of luteolin, quercetin, and kaempferol against Bacillus cereus ATCC14579 were 15.625 µg mL-1, 31.25 µg mL-1, and 15.625 µg mL-1. Based on the previous experimental basis, the metabolomic analysis showed the presence of 16 active ingredients in Lonicera japonica Thunb.'s water extracts and ethanol extracts, with differences in the luteolin, quercetin, and kaempferol contents between the water extracts and ethanol extracts. Network pharmacology studies indicated that fabZ, tig, glmU, secA, deoD, nagB, pgi, rpmB, recA, and upp were potential key targets. Active ingredients of Lonicera japonica Thunb. may exert their inhibitory effects by inhibiting ribosome assembly, the peptidoglycan biosynthesis process, and the phospholipid biosynthesis process of Bacillus cereus ATCC14579. An alkaline phosphatase activity assay, peptidoglycan concentration assay, and protein concentration assay showed that luteolin, quercetin, and kaempferol disrupted the Bacillus cereus ATCC14579 cell wall and cell membrane integrity. Transmission electron microscopy results showed significant changes in the morphology and ultrastructure of the cell wall and cell membrane of Bacillus cereus ATCC14579, further confirming the disruption of the cell wall and cell membrane integrity of Bacillus cereus ATCC14579 by luteolin, quercetin, and kaempferol. In conclusion, Lonicera japonica Thunb. can be used as a potential antibacterial agent for Bacillus cereus ATCC14579, which may exert its antibacterial activity by destroying the integrity of the cell wall and membrane.

A Novel Antimicrobial Peptide Sparamosin26-54 From the Mud Crab Scylla paramamosain Showing Potent Antifungal Activity Against Cryptococcus neoformans.

Due to the increasing prevalence of drug-resistant fungi and the limitations of current treatment strategies to fungal infections, exploration and development of new antifungal drugs or substituents are necessary. In the study, a novel antimicrobial peptide, named Sparamosin, was identified in the mud crab Scylla paramamosain, which contains a signal peptide of 22 amino acids and a mature peptide of 54 amino acids. The antimicrobial activity of its synthetic mature peptide and two truncated peptides (Sparamosin1-25 and Sparamosin26-54) were determined. The results showed that Sparamosin26-54 had the strongest activity against a variety of Gram-negative bacteria, Gram-positive bacteria and fungi, in particular had rapid fungicidal kinetics (killed 99% Cryptococcus neoformans within 10 min) and had potent anti-biofilm activity against C. neoformans, but had no cytotoxic effect on mammalian cells. The RNA-seq results showed that after Sparamosin26-54 treatment, the expression of genes involved in cell wall component biosynthesis, cell wall integrity signaling pathway, anti-oxidative stress, apoptosis and DNA repair were significantly up-regulated, indicating that Sparamosin26-54 might disrupt the cell wall of C. neoformans, causing oxidative stress, DNA damage and cell apoptosis. The underlying mechanism was further confirmed. Sparamosin26-54 could bind to several phospholipids in the cell membrane and effectively killed C. neoformans through disrupting the integrity of the cell wall and cell membrane observed by electron microscope and staining assay. In addition, it was found that the accumulation of reactive oxygen species (ROS) increased, the mitochondrial membrane potential (MMP) was disrupted, and DNA fragmentation was induced after Sparamosin26-54 treatment, which are all hallmarks of apoptosis. Taken together, Sparamosin26-54 has a good application prospect as an effective antimicrobial agent, especially for C. neoformans infections.

The Long-Term Effect of a Nine Amino-Acid Antimicrobial Peptide AS-hepc3(48-56) Against Pseudomonas aeruginosa With No Detectable Resistance.

The emergence of multidrug-resistant (MDR) pathogens has become a global public health crisis. Among them, MDR Pseudomonas aeruginosa is the main cause of nosocomial infections and deaths. Antimicrobial peptides (AMPs) are considered as competitive drug candidates to address this threat. In the study, we characterized two AMPs (AS-hepc3(41-71) and AS-hepc3(48-56)) that had potent activity against 5 new clinical isolates of MDR P. aeruginosa. Both AMPs destroyed the integrity of the cell membrane, induced leakage of intracellular components, and ultimately led to cell death. A long-term comparative study on the bacterial resistance treated with AS-hepc3(41-71), AS-hepc3(48-56) and 12 commonly used antibiotics showed that P. aeruginosa quickly developed resistance to the nine antibiotics tested (including aztreonam, ceftazidime, cefepime, imipenem, meropenem, ciprofloxacin, levofloxacin, gentamicin, and piperacillin) as early as 12 days after 150 days of successive culture generations. The initial effective concentration of 9 antibiotics against P. aeruginosa was greatly increased to a different high level at 150 days, however, both AS-hepc3(41-71) and AS-hepc3(48-56) maintained their initial MIC unchangeable through 150 days, indicating that P. aeruginosa did not produce any significant resistance to both AMPs. Furthermore, AS-hepc3(48-56) did not show any toxic effect on mammalian cells in vitro and mice in vivo. AS-hepc3(48-56) had a therapeutic effect on MDR P. aeruginosa infection using a mouse lung infection model and could effectively increase the survival rate of mice by inhibiting bacterial proliferation and attenuating lung inflammation. Taken together, the short peptide AS-hepc3(48-56) would be a promising agent for clinical treatment of MDR P. aeruginosa infections.

Association between asymptomatic carotid stenosis and cognitive function: a systematic review.

BACKGROUND: Asymptomatic carotid stenosis (CS), traditionally considered clinically silent, may be an independent risk factor for a cognitive impairment. METHODS: To determine whether an association exists between asymptomatic CS and cognitive function, we systematically reviewed the literature in the Cochrane Library, MEDLINE, EMBASE and the China National Knowledge Infrastructure databases. RESULTS: A total of 8 cross-sectional studies and 2 community-based cohort studies were included, comprising 763 participants in the CS group and 6308 participants in the non-CS group. All but one study supported the association between asymptomatic CS and cognitive impairment. Pooled analysis identified older age (2 studies) and cerebral hypoperfusion (2 studies) as additional factors in patients with asymptomatic CS that may linked to cognitive decline. CONCLUSIONS: These results suggest that rather than being clinically silent, asymptomatic CS may be associated with cognitive impairment, and this should be further investigated in high-quality studies.