Detection of the Anticancer and Genotoxic Activities of Heliotropium eichwaldi L.-fabricated Silver Nanoparticles on BHK-21 Cells and Human Blood Lymphocytes Using MTT and Comet Assays

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.