Catharanthus roseus L. plant is highly beneficial as chemotherapy drugs due to its rich alkaloids. Nanoparticles (NPs) have served as an abiotic elicitor; therefore, these chemical inputs stimulate various secondary metabolites. The present-day study sought to develop a callus culture and its utilization by applying the NPs to enhance the alkaloids in C. roseus. For callus induction, in vivo, leaves’ inoculation on MS medium had different concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D), Naphthaleneacetic acid (NAA), and Benzylaminopurine (BAP). After this stage, the induced callus culture gained stimulating by different rates (0, 1, and 2 mg L^-1) of silver nanoparticles (Ag-NPs) and titanium dioxide nanoparticles (TiO₂-NPs). The highest fresh and dry weights of calluses resulted in a combination of 0.5 mg L^-1 BAP and 0.5 mg L^-1 2,4-D, regarded as the best treatments for callus induction. The study showed no significant effect of NPs on callus growth compared with control. HPLC analysis revealed that field-grown plant leaves had the lowest alkaloid levels compared with elicitor-free callus cultures. However, all NP treatments significantly increased alkaloid contents versus the control. Ag-NPs were more effective than TiO₂-NPs in enhancing alkaloid biosynthesis. The highest range of vincristine and catharanthine (0.736 and 1.378 mg g^-1, respectively) emerged with 1 mg L^-1 Ag-NPs, while 2 mg L^-1 Ag-NPs increased vindoline and vinblastine contents (1.30 and 0.949 mg g^-1, respectively). The control exhibited lower alkaloid contents of vindoline, vincristine, catharanthine, and vinblastine (0.891, 0.492, 0.974, and 0.307 mg g^-1, respectively).

Keywords: C. roseus, nanoparticles, plant growth regulators, vincristine, vinblastine, MS medium, callus culture

Key findings: The presented trial provides a basis for how plant biotechnology contributes to pharmaceutical industry advancement, specifically how to use medicinal plants’ compounds for cancer treatment. The study confirmed that low doses of exact nanoparticles can enhance the production of essential alkaloids in the C. roseus callus culture.