Biosynthesis and characterization of gold nanoparticles from citrullus colocynthis (L.) schrad pulp ethanolic extract: Their cytotoxic, genotoxic, apoptotic, and antioxidant activities

The age-old discipline of plant therapy has gained renewed importance through the utilization of plants for the synthesis of metal nanoparticles. However, toxicity testing and characterization of the recently synthesized nanomaterials are essential to evaluating their appropriate application. <i>Citrullus colocynthis</i> is a medicinal plant with several health benefits. Herein, we used its ethanolic pulp extract (PE) to manufacture gold nanoparticles (PE-AuNPs). Various approaches were employed to assess the MTT₅₀ and NR₅₀ values of PE and PE-AuNPs at different concentrations in the human hepatocarcinoma cell line (HepG2). The study aimed to assess the genotoxic effects and in vivo toxicity of PE and PE-AuNPs at MTT₅₀ dosages. The quasi-spherical, cubic/triangular prisms, and nail-looking particles exhibited no antioxidant properties. They had an absorbance peak between 540 and 560 nm, diameters of less than 20 nm, hydrodynamic diameters of 177.9 nm, and a negative surface charge (-10.3 mV). The significant role of plant phytochemicals in the formation of metal nanoparticles is confirmed by the diminished antioxidant capacity of extract residues following PE-AuNP synthesis. PE-AuNPs exhibited in vivo and cytotoxic effects at relatively lower concentrations compared to PE. In contrast to PE, PE-AuNPs exhibited lower genotoxic at MTT₅₀ dosages. Despite having MTT₅₀ values of approximately 1.95 ± 0.06 and 0.89 ± 0.03 mg/ml, PE and PE-AuNPs can still be considered biocompatible. Nonetheless, our results suggest that the characteristics of recently produced nanoparticles can differ from those of the matching plant. Further investigation can provide a better understanding of the possible therapeutic and pharmacological impacts of PE-AuNPs.