Lepidium sativum (garden cress) seed oil was examined for its antimicrobial, antioxidant, and anti-inflammatory activities. The oil was obtained by hydrodistillation, where gas chromatography coupled with mass spectrometry that utilized to study its chemical composition. Microdilution method was used to test the antimicrobial effect of oil against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Klebsiella pneumoniae, and Candida albicans. The antioxidant activity was assessed by radical scavenging activity assay using 2,2-diphenyl-1-picrylhydrazyl radical. The major constituents found in the oil were 7,10-hexadecadienoic acid, 11-octadecenoic acid, 7,10,13-hexadecatrienoic acid, and behenic acid. The minimum inhibitory concentration (MIC) against all pathogens was 47.5 mg/ml, except for Salmonella enterica, which showed MIC of 90 mg/ml. The oil demonstrated antioxidant activity in a dose dependent pattern, with a half maximal inhibitory concentration (IC50) value of 40 mg/ml, and exerted anti-inflammatory activity, wherein 21% protection was shown at a concentration of 300 μg/ml. Thus, L. sativum seed oil shows antimicrobial, antioxidant, and anti-inflammatory properties.

Background: Multidrug-resistant Klebsiella pneumoniae (MDR-KP) poses a significant global health threat due to its involvement in severe infections and high mortality rates. The emergence of MDR strains necessitates the exploration of alternative therapeutic strategies.Methods: K. pneumoniae isolates were obtained from human and animal sources. Antibacterial susceptibility testing was performed, followed by the evaluation of essential oil activity through inhibition zone, MIC, and MBC determinations. Checkerboard assays were conducted to assess synergistic effects with amikacin. Gene expression analysis and transmission electron microscopy were employed to elucidate the mechanisms of action. Molecular docking studies were performed to identify potential binding targets of bioactive compounds.Results: Klebsiella pneumoniae was isolated from 25 of the100 samples examined, representing a prevalence rate of 25%. All isolates were found to be multidrug-resistant. Tea tree and thyme essential oils exhibited potent antibacterial activity and synergistic effects with amikacin. Notably, these combinations significantly downregulated the expression of key capsule virulence genes (wcaG, rmpA, magA, uge, and wabG), suggesting a novel mechanism for enhancing amikacin efficacy. Transmission electron microscopy revealed disrupted cell integrity in MDR-KP cells treated with the combinations. Molecular docking analysis identified Terpinen-4-ol, Farnesol, 1,4-Dihydroxy-p-menth-2-ene, and 7-Oxabicyclo [4.1.0] heptane as potential bioactive compounds responsible for the observed effects.Conclusion: By effectively combating MDR-KP, this research holds promise for reducing antibiotic resistance, improving treatment outcomes, and ultimately enhancing potential care.

The purpose of this study was to study the antimicrobial activity of chitosan nanoparticles (CSNPs) on Pseudomonas aeruginosa with special emphasis on their sensitivity to pH and the effect of pH on their activity. Antimicrobial activity of CSNPs against Pseudomonas aeruginosa at different pH was tested using broth dilution method. Further assessment of antivirulence activity and sensitization of CSNPs on Pseudomonas aeruginosa were examined. Significant antimicrobial effects of CSNPs against Pseudomonas aeruginosa were detected at slightly acidic pH 5, whereas the activity was abolished at a pH of greater than 7. The antivirulence activity of CSNPs was then investigated and treatment with CSNPs (1000 ppm) resulted in a significant reduction or even complete inhibition of pyocyanin production by P. aeruginosa compared with untreated P. aeruginosa indicating the antivirulence activity of CSNPs. CSNPs also sensitized P. aeruginosa to the lytic effects of sodium dodecyl sulfate (SDS); such sensitization was not blocked by washing chitosan-treated cells prior to SDS exposure revealing that CSNPs disturb the outer membrane leading to irreversible sensitivity to detergent even at low concentration (100 ppm). These findings highlight CSNPs as potentially useful as indirect antimicrobial agents for a variety of applications.

Onion peels are often discarded, representing an unlimited amount of food by-products; however, they are a valuable source of bioactive phenolics. Thus, we utilized UPLC-MS/MS to analyze the metabolomic profiles of red (RO) and yellow (YO) onion peel extracts. The cytotoxic (SRB assay), anti-inflammatory (Griess assay), and antimicrobial (sensitivity test, MIC, antibiofilm, and SP-SDS tests) properties were assessed in vitro. Additionally, histological analysis, immunohistochemistry, and ELISA tests were conducted to investigate the healing potential in excisional skin wound injury and Candida albicans infection in vivo. RO extract demonstrated antibacterial activity, limited skin infection with C. albicans, and improved the skin’s appearance due to the abundance of quercetin and anthocyanin derivatives. Both extracts reduced lipopolysaccharide-induced nitric oxide release in vitro and showed a negligible cytotoxic effect on MCF-7 and HT29 cells. When extracts were tested in vivo for their ability to promote tissue regeneration, it was found that YO peel extract had the greatest impact. Further biochemical analysis revealed that YO extract suppressed NLRP3/caspase-1 signaling and decreased inflammatory cytokines. Furthermore, YO extract decreased Notch-1 levels and boosted VEGF-mediated angiogenesis. Our findings imply that onion peel extract can effectively treat wounds by reducing microbial infection, reducing inflammation, and promoting tissue regeneration.

Background/Objectives: Atorvastatin (ATR), an antihyperlipidemic drug with a potential antibacterial effect, was investigated in this study. Like other statins, ATR has been repurposed for several uses, ranging from anti-inflammatory to antimicrobial applications, and has demonstrated successful results. However, the efficacy of ATR is limited by its low solubility, indicating an opportunity for its encapsulation in a nanotechnology-based drug delivery system. Methods: Nanostructured lipid carrier (NLC) formulations were prepared using high-pressure homogenization and ultrasonication. The formulations were characterized, including their particle size, polydispersity index, zeta potential, encapsulation efficiency, and in vitro release. Antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus) was evaluated using the growth curve (bacterial growth over time) and well diffusion methods (zone of inhibition and minimum inhibitory concentration (MIC) determination). The crystal violet assay was employed to assess biofilm inhibition. Results: The NLC formulations were optimized, and the size and zeta potential of the blank nanoparticles were 130 ± 8.39 nm and −35 ± 0.5 mV, respectively. In comparison, the encapsulated NLCs had a size of 142 ± 52.20 nm and a zeta potential of −31 ± 1.41 mV. The average encapsulation efficiency was 94%, and 70% of the drug was released after 24 h. The ATR-loaded NLCs showed significantly enhanced antibacterial activity by reducing the minimum inhibitory concentration by 2.5-fold for E. coli, 1.8-fold for S. aureus, and 1.4-fold for MRSA, and promoting more effective bacterial growth inhibition. Notably, biofilm inhibition was significantly improved with ATR-NLCs, achieving 80% inhibition for S. aureus, 40% for E. coli, and 30% for MRSA, compared to free ATR (p < 0.001). These findings suggest that NLC encapsulation enhances ATR’s antimicrobial efficacy and biofilm suppression. Conclusions: This study identified NLCs as successful carriers of ATR, significantly enhancing its antibacterial efficacy and biofilm inhibition capabilities. This formulation, which shows antimicrobial potential against both Gram-positive and Gram-negative bacteria, should be further studied and developed against different resistant microbial strains.

Pseudomonas aeruginosa contributes to many chronic infections and has been found to be resistant to multiple antibiotics. Pseudomonas use a quorum sensing system (QS) to control biofilm establishment and virulence factors, and, thus, quorum sensing inhibitors (QSIs), such as meta-bromo-thiolactone (mBTL), are promising anti-infective agents. Accordingly, this study intended to investigate the antibacterial and anti-virulence activity of mBTL-loaded calcium alginate nanoparticles (CANPs) against Pseudomonas aeruginosa and different QS mutants. The results show that the mBTL-CANPs had higher antibacterial activity, which was made evident by decreases in all tested strains except the ∆lasR/∆rhlR double mutant, with MIC₅₀ (0.5 mg/mL) of mBTL-CANPs compared with free mBTL at MIC₅₀ (˃1 mg/mL). The biofilm formation of P. aeruginosa and some QS-deficient mutants were reduced in response to 0.5–0.125 mg/mL of mBTL-encapsulating CANPs. The pyocyanin production of the tested strains except ∆lasA and ∆rhlR decreased when challenged with 0.5 mg/mL of mBTL-loaded NPs. The subsequent characterization of the cytotoxic effect of these NPs on human lung epithelial cells (A549) and cystic fibrosis fibroblast cells (LL 29) demonstrated that synthesized NPs were cytocompatible at MIC₅₀ in both cell lines and markedly reduced the cytotoxic effect observed with mBTL alone on these cells. The resulting formulation reduced the P. aeruginosa strains’ adhesion to A549 comparably with mBTL, suggesting their potential anti-adhesive effect. Given the virulence suppressing action, cytocompatibility, and enhanced anti-biofilm effect of mBTL-CANPs, and the advantage of alginate-based NPs as an antimicrobial delivery system these nanoparticles have great potential in the prophylaxis and treatment of infection caused by Pseudomonas aeruginosa.