Silver-loaded Nepeta glomerulosa nanoemulsion boosts cytotoxicity, induces apoptosis in A549 and AGS cancer cells

The global rise in cancer incidence and the pervasive issue of multidrug resistance (MDR) underscore an urgent need for innovative therapeutic strategies. Current standard-of-care often faces limitations due to systemic toxicity and poor bioavailability. Nano-delivery systems, such as nanoemulsions, offer a promising avenue to overcome these challenges by improving drug solubility, enhancing targeted delivery, and optimizing pharmacokinetics, thereby maximizing therapeutic efficacy while minimizing off-target effects.

Researchers prepared a hydroalcoholic extract from Nepeta glomerulosa via maceration. Subsequently, Ag-N.g.Ext. NEs were formulated using high-energy emulsification, characterized by FTIR, SEM, DLS, ZP, and XRD for physical properties. The anticancer efficacy was evaluated in human lung (A549) and gastric (AGS) cancer cell lines. Cytotoxicity was assessed using MTT assay, while apoptosis induction was confirmed via DAPI staining and Real-time PCR quantifying TP53 and BAX gene expression.

The Ag-N.g.Ext. NEs were characterized as spherical nanoparticles with a mean size of 269.5 nm and a negative zeta potential of -23.1 mV, indicating good stability. The nanoemulsion exhibited a non-crystalline structure. > Notably, the nanoemulsion significantly enhanced cytotoxicity, achieving an IC₅₀ of 125 µg/mL across both A549 and AGS cancer cells, a substantial improvement compared to the raw extract's IC₅₀ values of 500 µg/mL (A549) and 250 µg/mL (AGS). Apoptosis induction was significantly higher in cells treated with Ag-N.g.Ext. NEs (p ≤ 0.05). Specifically, TP53 gene expression increased 3.317-fold in A549 cells and 8.027-fold in AGS cells. Similarly, BAX gene expression saw increases of 3.877-fold in A549 cells and 2.351-fold in AGS cells, confirming a robust pro-apoptotic mechanism.