Green synthesis of silver nanoparticles using <i>Catharanthus roseus</i> leaf and stem extracts and their differential antibacterial activity

, compared to 14.5 ± 0.6 mm for stem-derived AgNPs. Gram-negative bacteria showed lower susceptibility, with inhibition zones ≤ 12 mm. These results indicate plant-part-dependent variation in antibacterial activity. However, further studies involving physicochemical characterization, MIC/MBC assays, and phytochemical profiling are necessary to validate and extend these findings.