In this study, a polar extract of Aconitum lycoctonum L. was used for the synthesis of silver nanoparticles (AgNPs), followed by their characterization using different techniques and evaluation of their potential as antioxidants, amylase inhibitors, anti-inflammatory and antibacterial agents. The formation of AgNPs was detected by a color change, from transparent to dark brown, within 15 min and a surface resonance peak at 460 nm in the UV–visible spectrum. The FTIR spectra confirmed the involvement of various biomolecules in the synthesis of AgNPs. The average diameter of these spherical AgNPs was 67 nm, as shown by the scanning electron micrograph. The inhibition zones showed that the synthesized nanoparticles inhibited the growth of Gram-positive and negative bacteria. FRAP and DPPH assays were used to demonstrate the antioxidant potential of AgNPs. The highest value of FRAP (50.47% AAE/mL) was detected at a concentration of 90 ppm and a DPPH scavenging activity of 69.63% GAE was detected at a concentration of 20 µg/mL of the synthesized AgNPs. 500 µg/mL of the synthesized AgNPs were quite efficient in causing 91.78% denaturation of ovalbumin. The AgNPs mediated by A. lycoctonum also showed an inhibitory effect on α-amylase. Therefore, AgNPs synthesized from A. lycoctonum may serve as potential candidates for antibacterial, antioxidant, anti-inflammatory, and antidiabetic agents.

Recent advances in nanoscience and nanotechnology have revolutionized the medical field, particularly in the treatment and prevention of disease. Silver nanoparticles (AgNPs) are considered one of the best supreme and most important nanomaterials with a variety of compulsive nanomaterial having diverse array of multifunctional bioapplications. The current study focuses on the green biosynthesis of AgNPs using polysaccharides extracted from Olea europaea leaves. The synthesized AgNPs were thoroughly analyzed and characterized using various spectroscopic and microscopic techniques including, UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, Energy dispersive X-ray (EDX), and Scanning electron microscopy (SEM). The absorption peak at 440 nm showed a high plasmon resonance band, confirming the formation of green AgNPs by the reduction of Ag⁺ ions to Ag⁰. FTIR analysis showed the appearance and extension of different functional groups. The results of EDX and SEM confirmed the synthesis of AgNPs with spherical shape, crystalline structure, and an average size of 64.42 nm. The biosynthesized AgNPs possessed improved antimicrobial activities, indicating the importance of biosynthesized NPs in the pharmaceutical industry. In addition, the biosynthesized AgNPs were biocompatible and exhibited anti-inflammatory activity (86.29%), almost similar to that of a standard drug (87.78%) at a concentration of 500 µL/mL. The polysaccharides obtained from O. europaea could be considered as effective reducing agent, leading to an environmentally friendly synthesis of stable and biologically important AgNPs with a wide range of applications.

Plants are sessile and mostly exposed to various environmental stresses which hamper plant growth, development, and significantly decline its production. Drought stress is considered to be one of the most significant limiting factors for crop plants, notably in arid and semi-arid parts the world. Therefore, the present study aimed to evaluate the potential impact of different concentrations (10, 100, and 200 µg/mL) of kinetin capped zinc oxide nanoparticles (Kn-ZnONPs) on Vigna radiata (L.) R. Wilczek under varying levels (5%, 10%, 15%) of PEG-induced drought stress. ZnONPs were synthesized by a co-precipitation method using Zinc acetate as a precursor at pH-12, incinerated to 500 °C, and kinetin was used as a surface functionalizing agent. The resulting Kn-ZnONPs were characterized by various contemporary analytical techniques, including SEM, SEM-EDS, XRD, DLS, and Zeta potential and IR spectroscopy. Crystalline Kn-ZnONPs, with a zeta potential of 27.8 mV and a size of 67.78 nm, of hexagonal wurtzite structure and vibrational stretches associated with N-H, C-O, C-N, etc., were confirmed. PEG-induced drought stress significantly reduced the growth of V. radiata by declining the chlorophyll and carotenoid contents. Moreover, a significant decrease in the levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), soluble sugar contents, proline, protein contents, phenol, and tannin were observed compared to the control. However, the exogenous application of Kn-ZnONPs ameliorated all photosynthetic parameters by up-regulating the antioxidant defense system through the promotion of SOD, POD, CAT, and lipid peroxidation levels. The biochemical parameters, such as proteins, soluble sugars, and proline, were observed to be maximum in plants treated with 200 µg/mL Kn-ZnONPs under 5% drought stress. The application of Kn-ZnONPs also enhanced the total phenol contents, flavonoid, and tannin contents. In conclusion, the findings of this study demonstrate that the exogenous application of Kn-ZnONPs provides beneficial effects to V. radiata by attenuating the damaging effects of drought stress through the up-regulation of the antioxidant defense system and osmolytes. These results suggest that Kn-ZnONPs have potential as a novel approach to improve crop productivity under drought stress conditions.