ABSTRACT This study reports the green synthesis and characterization of silver (0)/silver (I) oxide nanoparticles (St‐Ag/Ag 2 O‐NPs) using ethanolic leaf extract of Senna tora L., a medicinal plant known for its traditional therapeutic applications. The extract served as a bioreductant and capping agent in the synthesis with silver nitrate (AgNO 3 ). UV‐visible spectroscopy ( λ max = 435 nm) confirmed nanoparticle formation, while powder X‐ray diffraction (PXRD) revealed the coexistence of Ag 0 and Ag 2 O nanocrystals. Transmission electron microscopy (TEM) showed well‐defined morphology, and Fourier‐transform infrared (FT‐IR) spectroscopy identified phytochemicals involved in surface stabilization. Zeta potential (−17.9 mV) and Brunauer–Emmett–Teller (BET) surface area (10.74 m 2 g −1 ) indicated moderate colloidal stability and porosity. Anti‐amoebic activity against Entamoeba histolytica was significantly enhanced by St‐Ag/Ag 2 O‐NPs (IC 50 = 0.707 ± 0.034 µg mL −1 ) compared to the crude extract (IC 50 = 1.096 µg mL −1 ). Cytotoxicity assays against HEK‐293 cells demonstrated a high IC 50 of 100.13 µg mL −1 , resulting in a remarkable Selectivity Index (SI) of 141.6, which confirms the safety and high specificity of these nanoparticles toward protozoal cells. Notably, this is the first report that demonstrate the anti‐amoebic efficacy of silver/silver oxide nanoparticles synthesized from Senna tora L., underscoring their therapeutic potential. Antioxidant assays further revealed superior radical scavenging by nanoparticles in ABTS (IC 50 = 56.20 µg mL −1 ), DPPH (IC 50 = 78.22 µg mL −1 ), and superoxide radical scavenging (IC 50 = 92.01 µg mL −1 ) assays. These findings highlight the dual bio‐functional potential of St‐Ag/Ag 2 O‐NPs as anti‐amoebic and antioxidant agents.
Sarkar et al. (2026) studied this question.