¹Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, SAUDI ARABIA
²Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, Zagazig 44511, EGYPT
³Department of Biology, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Alkarj 11942, SAUDI ARABIA
⁴Department of Biology, College of Science, King Khalid University, Abha, 61413, SAUDI ARABIA
⁵Biological Sciences Department, College of Science & Arts, King Abdulaziz University, Rabigh, 21911, SAUDI ARABIA
⁶Faculty of Medical Laboratory Sciences, University of Shendi, Shendi P.O. Box 142, SUDAN
⁷Department of Biology, College of Science, Jouf University, Sakaka, Al-Jouf, SAUDI ARABIA
⁸Department of Chemistry, College of Science and Arts, King Abdulaziz University, Rabigh 21911, SAUDI ARABIA DOI : 10.9775/kvfd.2026.36996 The rise of colorectal cancer and multidrug-resistant infections in immunocompromised patients demands eco-friendly therapies. This study compared conventional and green silver nanoparticles (AgNPs) synthesized via Portulaca oleracea leaf extract in terms of antibacterial, antioxidant, anticancer, and in vivo physiological activities against N-methyl-N-nitrosourea (MNU)-induced colon cancer in rats. AgNPs synthesized via Portulaca oleracea leaf extract exhibited an surface plasmon resonance (SPR) at 420 nm, a spherical morphology (7-22 nm), and protein capping. Against eight pathogens (including S. aureus, E. coli, and P. aeruginosa), green AgNPs (320 μg/mL) showed larger inhibition zones (26.3 vs. 20.1 mm for S. aureus) and MIC values ranging from 12.5-20 μg/mL, representing a two-fold decrease compared to chemical nanoparticles. In HCT-116 colon cancer cells, green AgNPs had a 2.3-fold lower IC₅₀ (12.4 vs. 28.6 μg/mL), induced a 4.8-fold increase in Caspase-3 activity, and increased apoptotic cells to 42.6% (vs. 18.3%). In MNU-induced rat colon cancer, green AgNPs (320 mg/kg) restored physiological parameters i.e., body weight gain to 78.6% (vs. 15.4% in controls), reduced mortality to 0% (vs. 50%), lowered tumor incidence to 16.7% (vs. 100%), and normalized oxidative stress markers (MDA 2.5 vs. 8.4 nmol/mg). Preventive treatment completely abolished tumors. Green AgNPs consistently outperformed chemical counterparts, offering a potent, safe nanomedicine for dual antibacterial and anticancer applications against toxic carcinogens. Keywords : Green silver nanoparticles, Purslane extract, Colon cancer, Antibacterial, Apoptosis, Oxidative stress, Antioxidant, Chemoprevention, Safety