UPLC profiling of matcha extract capping biosynthesized copper oxide nanoparticles and their antimicrobial and cytotoxic potentials

This research demonstrates a green synthesis and subsequent functionalization process of copper oxide nanoparticles (CuO NPs) utilizing matcha green tea extract as a sustainable reducing and functionalizing agent. UPLC-MS analysis revealed the presence of significant bioactive phytochemicals, notably epigallocatechin gallate (EGCG), which is implicated in the reduction process. Thorough characterisation (XRD, FT-IR, SEM) verified the synthesis of pure, crystalline, monoclinic CuO NPs with an average size of 16-24 nm. The nanoparticles had considerable antibacterial activity, exhibiting robust efficacy against Escherichia coli and Staphylococcus aureus, with a minimum inhibitory concentration of 250 µg/ml. CuO NPs-matcha exhibited significant, dose-dependent cytotoxicity against MCF-7 and Caco-2 carcinoma cells, with IC₅₀ values of 122.1 and 161.9 µg/ml, respectively. Crucially, they demonstrated markedly reduced toxicity towards non-cancerous Vero cells (IC₅₀ = 333.2 µg/ml), yielding selectivity indices of 2.73 and 2.06, which confirms a favorable selective profile. Although the positive control doxorubicin showed greater potency (lower IC₅₀), the CuO NPs-Matcha demonstrated significantly higher selectivity for cancer cells, suggesting a potentially improved safety profile despite its lower efficacy. These findings underscore the matcha-synthesized CuO NPs as a highly promising and biocompatible nanomaterial for specific medicinal applications, particularly in antibacterial and anticancer therapies.