The rapid development of nanotechnology and its applications in medicine has provided the perfect solution against a wide range of different microbes, especially antibiotic-resistant ones. In this study, a one-step approach was used in preparing silver nanoparticles (AgNPs) by mixing silver nitrate with hot Hypericum perforatum (St. John’s wort) aqueous extract under high stirring to prevent agglomeration. The formation of silver nanoparticles was monitored by continuous measurement of the surface plasma resonance spectra (UV-VIS). The effect of St. John’s wort aqueous extract on the formation of silver nanoparticles was evaluated and fully characterized by using different physicochemical techniques. The obtained silver nanoparticles were spherical, monodisperse, face-centered cubic (fcc) crystal structures, and the size ranges between 20 to 40 nm. They were covered with a capping layer of organic compounds considered as a nano dimension protective layer that prevents agglomeration and sedimentation. AgNPs revealed antibacterial activity against both tested Gram-positive and Gram-negative bacterial strains causing the formation of 13–32 mm inhibition zones with MIC 6.25–12.5 µg/mL; Escherichia coli strains were resistant to tested AgNPs. The specific growth rate of S. aureus was significantly reduced due to tested AgNPs at concentrations ≥½ MIC. AgNPs did not affect wound migration in fibroblast cell lines compared to control. Our results highlighted the potential use of AgNPs capped with plant extracts in the pharmaceutical and food industries to control bacterial pathogens’ growth; however, further studies are required to confirm their wound healing capability and their health impact must be critically evaluated.

The accumulation of polyaromatic hydrocarbons in plants is considered one of the most serious threats faced by mankind because of their persistence in the environment and their carcinogenic and teratogenic effect on human health. The concentrations of sixteen priority polycyclic aromatic hydrocarbons (16 PAHs) were determined in four types of edible vegetables (tomatoes, zucchini, eggplants, and cucumbers), irrigation water, and agriculture soil, where samples were collected from the Jordan Valley, Jordan. The mean total concentration of 16 PAHs (∑16PAHs) ranged from 10.649 to 21.774 µg kg⁻¹ in vegetables, 28.72 µg kg⁻¹ in soil, and 0.218 µg L⁻¹ in the water samples. The tomato samples posed the highest ∑16PAH concentration level in the vegetables, whereas the zucchini samples had the lowest. Generally, the PAHs with a high molecular weight and four or more benzene rings prevailed among the studied samples. The diagnostic ratios and the principal component analysis (PCA) revealed that the PAH contamination sources in soil and vegetables mainly originated from a pyrogenic origin, traffic emission sources, and biomass combustion. The bioconcentration factors (BCF) for ∑16PAHs have been observed in the order of tomatoes > cucumbers and eggplants > zucchini. A potential cancer risk related to lifetime consumption was revealed based on calculating the incremental lifetime cancer risk of PAHs (ILCR). Therefore, sustainable agricultural practices and avoiding biomass combusting would greatly help in minimizing the potential health risk from dietary exposure to PAHs.

Drought is a major abiotic stressor that severely limits plant growth and development. In response, plants often enhance the biosynthesis of flavonoids, key secondary metabolites that contribute to growth regulation and stress adaptation. This study investigated the drought tolerance mechanisms of cress (Lepidium sativum) by examining the effects of varying drought durations on growth parameters, stress severity and associated metabolic responses. The results showed that drought stress significantly impaired plant growth, with shoot and root lengths reduced to 0.7- and 0.8-fold of control levels, respectively, after 4 days of water deficit. Prolonged drought (12 days) further decreased relative water content (RWC), reaching 0.8-fold in shoots and 0.6-fold in roots. Stress severity, assessed by relative electrolyte conductivity, exhibited a nine-fold increase after 12 days, indicating considerable membrane damage. Biochemical analyses revealed a time-dependent increase in total flavonoid content, which rose by 1.3-, 1.6- and 1.4-fold after 4, 8 and 12 days of drought exposure, respectively. Anthocyanin content increased modestly by 1.6-fold after 12 days of drought. Chalcone synthase (CHS) activity increased markedly, by 1.9- and 2.7-fold after 4 and 8 days, respectively, indicating its early induction as a critical drought response. Overall, these findings underscore the importance of CHS activation and flavonoid accumulation in enhancing drought resilience in cress. Further studies should focus on identifying individual flavonoid compounds and clarifying their role in maintaining membrane integrity under prolonged drought conditions.