The use of selenium nanoparticles (SeNPs) in the biomedical area has been increasing as an alternative to the growing bacterial resistance to antibiotics. In this research, SeNPs were synthesized by green synthesis using ascorbic acid (AsAc) as a reducing agent and methanolic extract of Calendula officinalis L. flowers as a stabilizer. Characterization of SeNPs was performed by UV-vis spectrophotometry, infrared spectrophotometry (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) techniques. SeNPs of 40–60 nm and spherical morphologies were obtained. The antibacterial activity of marigold extracts and fractions was evaluated by disk diffusion methodology. The evaluation of SeNPs at different incubation times was performed through the colony-forming unit (CFU) count, in both cases against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis bacteria. Partial antibacterial activity was observed with methanolic extracts of marigold leaves and flowers and total inhibition with SeNPs from 2 h for S. marcescens, 1 h for E. cloacae, and 30 min for A. faecalis. In addition, SeNPs were found to exhibit antioxidant activity. The results indicate that SeNPs present a potentiated effect of both antimicrobial and antioxidant activity compared to the individual use of marigold extracts or sodium selenite (Na₂SeO₃). Their application emerges as an alternative for the control of clinical pathogens.

The continuous need to satisfy world food demand has led to the search for new alternatives to combat economic losses in agriculture caused by phytopathogenic fungi. These organisms cause plant diseases, reducing their productivity and decreasing fruit quality. Among the new tools being explored is nanotechnology. Nanoparticles with antimicrobial properties could be an excellent alternative to address this problem. In this work, selenium nanoparticles (SeNPs) were obtained using plant extracts of Amphipterygium glaucum leaves (SeNPs-AGL) and Calendula officinalis flowers (SeNPs-COF). Characterization of the SeNPs was performed and their ability as antifungal agents against two commercially relevant plant pathogenic fungi, Fusarium oxysporum and Colletotrichum gloeosporioides, was evaluated. Assays were performed with different concentrations of SeNPs (0, 0.25, 0.5, 1.0, and 1.7 mg/mL). It was observed that both SeNPs had antifungal activity against both plant pathogens at concentrations of 0.25 mg/mL and above. SeNPs-AGL demonstrated better antifungal activity and smaller size (around 8.0 nm) than SeNPs-COF (134.0 nm). FTIR analysis evidenced the existence of different functional groups that constitute both types of SeNPs. There are factors that have to be considered in the antimicrobial activity of SeNPs such as nanoparticle size and phytochemical composition of the plant extracts used, as these may affect their bioavailability.

Background: In recent years, crop production has expanded due to the variety of commercially available species. This increase in production has led to global competition and the search for biostimulant products that improve crop quality and yield. At the same time, agricultural products that protect against diseases caused by phytopathogenic microorganisms are needed. Thus, the green synthesis of selenium nanoparticles (SeNPs) is a proposal for achieving these needs. In this research, SeNPs were synthesized from methanolic extract of Amphipterygium glaucum leaves, and chemically and biologically characterized. Results: The characterization of SeNPs was conducted by ultraviolet–visible spectrophotometry (UV–Vis), scanning electron microscopy (SEM), electron microscopy transmission (TEM), Dynamic Light Scattering (DLS), energy dispersion X-ray spectroscopy (EDX), and infrared spectrophotometry (FTIR) techniques. SeNPs with an average size of 40–60 nm and spherical and needle-shaped morphologies were obtained. The antibacterial activity of SeNPs against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis was evaluated. The results indicate that the methanolic extracts of A. glaucum and SeNPs presented a high antioxidant activity. The biostimulant effect of SeNPs (10, 20, 50, and 100 µM) was evaluated in vinca (Catharanthus roseus), and calendula (Calendula officinalis) plants under greenhouse conditions, and they improved growth parameters such as the height, the fresh and dry weight of roots, stems, and leaves; and the number of flowers of vinca and calendula. Conclusions: The antibacterial, antioxidant, and biostimulant properties of SeNPs synthesized from A. glaucum extract demonstrated in this study support their use as a promising tool in crop production. Graphical

In this study, the effects of different concentrations of vanadium (V), selenium (Se), cerium (Ce), and iodine (I) on the growth parameters, biomass accumulation, and content of photosynthetic pigments during the seedling stage of marigold (Calendula officinalis L.) were evaluated. The beneficial elements V (3, 5, or 10 µM), Se (5, 10, or 20 µM), Ce (25, 50, or 100 µM), and I (5 or 10 µM) were applied once a week along with 50% Hoagland nutritive solution. Four applications were applied to the roots. Doses of 5 µM V and 50 µM Ce improved plant height, while 5 µM I promoted root growth. Leaf area and number of leaves increased with the application of 20 µM Se and 5 µM I, respectively. High concentrations of Se and Ce improved leaf dry weight, while 10 µM V increased the photosynthetic pigment content. The application of these elements contributed to the development and production of marigold seedlings during nursery growth.

En la actualidad, el cáncer cervicouterino es considerado una de las principales causas de mortalidad en mujeres a nivel mundial, resaltando la necesidad urgente de desarrollar estrategias terapéuticas que actúen de manera conjunta, efectiva y selectiva. Las nanopartículas de selenio (SeNPs) y los nanocompositos (NC) podrían surgir como sistemas de liberación de quimioterapéuticos para mejorar la eficacia de los tratamientos. El objetivo de este estudio fue evaluar el efecto citotóxico de nanopartículas (NPs) de selenio (Se) sintetizadas biogénicamente con extracto de Amphipterygium glaucum sobre células HeLa (cáncer cervicouterino) en cultivo 2D. Las SeNPs obtenidas presentaron un pico de máxima absorción a 275 nm (UV-Vis), un tamaño promedio de 14 nm y morfología semiesférica (TEM). Estas SeNPs se incorporaron en un aerogel de alcohol polivinílico (PVA), resultando en un NC con un peso molecular de 130,000 (SeNPs@PVA130), cuya distribución de Se y estructura porosa se confirmó por SEM. El análisis de espectroscopía FTIR-ATR evidenció interacciones entre los grupos funcionales del extracto y el Se, sugiriendo su papel como agente reductor y estabilizante. El ensayo bromuro de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolio (MTT) demostró un efecto citotóxico dependiente de la concentración, con valores de IC₅₀ de 93.8 µg/mL para las SeNPs y de 4.5 µg/mL para SeNPs@PVA130. Además, el ensayo de anexina V- isotiocianato de fluoresceína (FITC) indicó apoptosis temprana como principal mecanismo de muerte celular y el ensayo de cierre de herida reveló una inhibición significativa de la migración celular. Estos hallazgos respaldan el potencial de estos nanomateriales como agentes citotóxicos y proapoptóticos. En el futuro, se tendrían que contemplar estudios complementarios en sistemas más complejos para ser empleados como coadyuvantes sostenibles junto con los quimioterapéuticos convencionales.