The possible treatment of cancer with nanoparticles (NPs) would be carried out via inoculation into the veins; as a result, the NPs would come into contact with white blood cells (WBCs) and red blood cells (RBCs) prior to reaching the target cancerous cells. In the current study, the genotoxicity and cytotoxicity potential of silver NPs (AgNPs) against human blood lymphocytes and baby hamster kidney-21 (BHK-21) cells was tested using comet and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, respectively. First, AgNPs were created using a Heliotropium eichwaldi L. (HE) extract. These AgNPs were then confirmed by ultraviolet–visible (UV–Vis) spectroscopy, which yielded a sharp peak at 416 nm with a maximum absorbance of 1.92. Moreover, an X-ray diffraction (XRD) analysis confirmed the crystalline nature and particle size (19.79 nm) of AgNPs, whereas scanning electron microscopy (SEM) revealed their irregular morphology and size of 30 nm. In turn, an EDX analysis indicated that AgNPs had an appreciable composition of Ag ions (30.68%). According to the comet assay, the HE-AgNPs, and standard H₂O₂ caused highly significant damage to DNA compared with HE extract. The comet assay was reported in terms of the total comet score (TCS). In the case of the MTT assay, a dose-dependent cytotoxicity was noted, in which doxorubicin, and AgNPs were more potent against BHK-21 cells compared with a plant extract. From these results, it is evident that the green-synthesized AgNPs interacted with blood lymphocytes and BHK-21 cells, caused damage to DNA via oxidative stress, and finally triggered cell death (apoptosis). However, further studies aimed at reducing their potential threats are recommended.

A simple green method for the production of silver/gold bimetallic nanoparticles (Ag/Au BNPs) using a Heliotropium eichwaldi L. (HE) extract was designed in this study. The reduction of Ag/Au metals to stable Ag/Au BNPs within 24 h at pH 5 using 1 mL of HE at 40 °C signifies a greater rate of reaction compared with chemically elaborated synthesis. The confirmation of the synthesis and the examination of the size, shape, and elemental composition of these BNPs were performed using visible absorption spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). Stable, irregular-rod-shaped, and crystalline Ag/Au BNPs with a well-defined 6-nm diameter and a blue shift λ_max of 532 nm were synthesized using the HE extract. Moreover, the anti-cholinesterase (anti-AChE) potential of the Ag/Au BNPs was tested as a treatment for Alzheimer’s disease (AD). An excellent anti-AChE activity (IC₅₀, 71.2 ± 0.22 μg/mL) was observed for these biogenic-synthesized NPs. A statistical analysis revealed that Ag/Au BNPs inhibited AChE competitively, according to a Lineweaver–Burk plot, with K_m increasing from 0.019 to 0.063 (288%–1185.7%) and V_max remaining constant. The Ag/Au BNPs also caused an increase in K_Iapp, from 128 to 1184 (236%–828%), whereas they did not affect V_maxiapp. The K_m, K_I, and K_i values were also calculated to be 0.0053 mmol/L, 595.25 µg, and 80 µg, respectively. Therefore, it is concluded that small-size, stable, and potent Ag/Au BNPs were synthesized successfully from HE extracts that exhibited anti-AChE activity, which renders them a significant remedy for AD.

Green synthesis of silver nanoparticles (AgNPs) is attaining more attention from researchers over chemical fabrication due to their unique properties such as high dispersion in solution, surface-to-volume ratio, low toxicity, and easy preparation. In this paper, a biogenic synthesis of Kickxia elatine-based-silver nanoparticles (KE-AgNPs) was carried out by using K. elatine plant extract (KEE). The characterization of synthesized AgNPs was done by ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Fourier transform infrared (FTIR) analyses. XRD screening confirmed the crystalline nature of KE-AgNPs with 42.47 nm in size. SEM analysis confirmed the rounded shape AgNPs with 50 nm in size. FTIR confirmed the various functional groups that contribute to the stabilization and reduction of AgNPs. EDX displayed an intense peak (3.2 keV), presenting that Ag has a chief component with 61.67%. These AgNPs showed a potential antioxidant activity against 2,2'-azino-bis-(3-ethyl) benzothiazoline-6-sulfonic acid (ABTS, 66.9%), diphenyl-1-picrylhydrazyl (DPPH, 72.49%), H₂O₂ (69.42%), ferric-reducing antioxidant power assay (FRAP, 70.04%), and ammonium molybdenum (68.77%) at the highest concentration of 160 μg/mL. Statistical analysis showed that both KEE and their AgNPs inhibit alpha-amylase (α-amylase) in the mixed type mode, i.e., Michaelis constant (K_m) increased (16.62%–55.45% and 49.77%–134.78% for KE-AgNPs) and V_max decreased (2.68%–12.98% and 4.44%–11%), respectively. In the case of anti-acetylcholinesterase studies, both KEE and AgNPs revealed a mixed-type inhibition against acetylcholinesterase (AchE), i.e., K_m increased (13.53%–101.48% and 10.10%–38.04%), while V_max decreased (12.66%–52.47% and 11.91%–41.69%) for KEE and KE-AgNPs, respectively. Therefore, the synthesized AgNPs could be used for various purposes due to their non-toxicity, eco-friendly, and compact ability for therapeutic and diagnostic applications.