The regulation of cellular growth, proliferation, and other related processes is influenced by the hyperactivation of the mechanistic target of the rapamycin (mTOR) signaling pathway, which is commonly observed in various types of cancers. Nanoparticles green-formulated by plants have been utilized in the treatment of multiple types of cancers by regulating the signaling pathways. This research presents a straightforward and environmentally friendly chemical research method, along with a bio-inspired approach, to fabricate copper nanoparticles using Acroptilon repens leaf extract. Advanced physicochemical techniques such as FE-SEM, EDX, TEM, and XRD study were employed to characterize the prepared copper nanoparticles. The results revealed that the Cu NPs exhibited a spherical shape, with an average diameter ranging from 10 to 60 nm. The impact of copper nanoparticles on normal (HUVEC) and PC14 cell was evaluated through a 48-hour MTT assay to determine their anticancer efficacies. During the antioxidant test, copper nanoparticles and BHT exhibited IC 50 values of 69 and 25 mu g/mL, respectively, against DPPH free radicals. The IC 50 of copper nanoparticles against PC14 was measured at 315 mu g/ mL. The presence of copper nanoparticles led to a dose-dependent reduction in the viability of the malignant lung cell line. The examination of gene expression levels of PIK3, AKT, and mTOR, which are associated with the mTOR pathway, along with Bax, Bcl2, and Caspase-3, reveals that copper nanoparticles effectively regulate PC14 cell apoptosis and proliferation through the PI3K-Akt-mTOR signaling pathway regulation. The inhibition of the cell cycle and the induction of apoptosis caused by copper nanoparticles may be linked to the mTOR pathway. Consequently, copper nanoparticles can serve as a promising natural anti-cancer drug for aiding in lung adenocarcinoma treatment.