The emergence of antibiotic resistance poses a serious threat to humankind, emphasizing the need for alternative antimicrobial agents. This study focuses on investigating the antibacterial, antibiofilm, and anti-quorum-sensing (anti-QS) activities of saponin-derived silver nanoparticles (AgNPs-S) obtained from Ajwa dates (Phoenix dactylifera L.). The design and synthesis of these novel nanoparticles were explored in the context of developing alternative strategies to combat bacterial infections. The Ajwa date saponin extract was used as a reducing and stabilizing agent to synthesize AgNPs-S, which was characterized using various analytical techniques, including UV–Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The biosynthesized AgNPs-S exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria due to their capability to disrupt bacterial cell membranes and the leakage of nucleic acid and protein contents. The AgNPs-S effectively inhibited biofilm formation and quorum-sensing (QS) activity by interfering with QS signaling molecules, which play a pivotal role in bacterial virulence and pathogenicity. Furthermore, the AgNPs-S demonstrated significant antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and cytotoxicity against small lung cancer cells (A549 cells). Overall, the findings of the present study provide valuable insights into the potential use of these nanoparticles as alternative therapeutic agents for the design and development of novel antibiotics. Further investigations are warranted to elucidate the possible mechanism involved and safety concerns when it is used in vivo, paving the way for future therapeutic applications in combating bacterial infections and overcoming antibiotic resistance.

Whole-genome doubling or polyploidy increases plants' tolerance to biotic and abiotic stress. Cadmium (Cd) damages the plant's metabolic system, leading to decreased plant development. The role of tetraploidy and iron nanoparticles (Fe NPs) in minimizing Cd toxicity in rice was investigated in this work. Diploid (E285) and tetraploid (T485) rice lines were treated with Cd (100 μM) and different doses of Fe NPs (0, 10, 25, and 50 mg L⁻¹). The Cd exposure substantially decreased agronomic traits (root and shoot length, shoot and root fresh weight), chlorophyll contents, and antioxidant enzyme activity and increased reactive oxygen species (ROS). The Cd toxicity effect was more pronounced in diploid rice than in tetraploid rice. The application of Fe NPs to Cd-contaminated rice plants reversed the detrimental consequences of Cd in tetraploid and diploid rice cultivars, verified by the substantial upturn in plant growth parameters, chlorophyll contents, decreased ROS, and increased levels of antioxidant enzymes. The Cd uptake was significantly reduced by tetraploidy and Fe NPs, which negatively controlled the expression patterns of Cd transporter genes (like OsNRAMP2 and OsHMA2). The strongest association was seen between diploid rice and cadmium levels in seedlings. Transmission electron microscopy revealed that Cd, especially in diploid rice, caused cell structure damage that Fe NPs and tetraploidy almost repaired. This study demonstrated that tetraploidy and Fe NPs could alleviate Cd toxicity by lowering Cd accumulation, ROS, and cell damage.