Antiproliferative and Apoptotic Effects of Olive Leaf Extract Microcapsules on MCF-7 and A549 Cancer Cells

Olive leaf extract-derived chitosan-metal nanocomposite: Green synthesis and dual antimicrobial-anticancer action

In this study, we developed a novel nanocomposite by synthesizing zinc (ZnNPs), copper (CuNPs), and silver (AgNPs) nanoparticles using olive leaf extract and incorporating them into a chitosan polymer. This approach combines the biocompatibility of chitosan with the antimicrobial and anticancer properties of metal nanoparticles, enhanced by the phytochemical richness of olive leaf extract. The significance of our research lies in its potential to offer a biodegradable and stable alternative to conventional antibiotics and cancer treatments, particularly in combating multidrug-resistant bacteria and various cancer types. Comprehensive characterization through Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Transmission Electron Microscopy (TEM) confirmed the successful synthesis of the nanocomposites, with an average size of ~22.6 nm. Phytochemical analysis highlighted the antioxidant-rich composition of both the olive leaf extract and the nanoparticles themselves. Functionally, the synthesized nanoparticles exhibited potent antimicrobial activity against multidrug-resistant bacterial strains, outperforming traditional antibiotics by inhibiting key resistance genes (ermC, tetX3-q, blaZ, and Ery-msrA). In anticancer assessments, the nanoparticles showed selective cytotoxicity towards cancer cells in a concentration-dependent manner, with CuNPs and AgNPs showing particularly strong anticancer effects, while demonstrating minimal toxicity towards normal cells. ZnNPs were noted for their low cytotoxicity, highlighting the safety profile of these nanoparticles. Further, the nanoparticles induced apoptosis in cancer cells, as evidenced by the modulation of oncogenes (P21, P53, and BCL2), suggesting their therapeutic potential. The findings of our study underscore the versatile applications of these biogenic nanoparticles in developing safer and more effective antimicrobial and anticancer therapies.

Comparative analysis of silver-nanoparticles and whey-encapsulated particles from olive leaf water extracts: Characteristics and biological activity

Nanotechnology applications have been employed to improve the stability of bioactive components and drug delivery. Natural-based extracts, especially olive leaf extracts, have been associated with the green economy not only as recycled agri-waste but also in the prevention and treatment of various non-communicable diseases (NCDs). The aim of this work was to provide a comparison between the characteristics, biological activity, and gene expression of water extract of olive leaves (OLE), green synthesized OLE silver nanoparticles (OL/Ag-NPs), and OLE whey protein capsules (OL/WPNs) of the two olive varieties, Tofahy and Shemlali. The particles were characterized by dynamic light scattering, scanning electron microscope (SEM), and Fourier transform infrared. The bioactive compounds of the preparations were evaluated for their antioxidant activity and anticancer effect on HCT-116 colorectal cells as well as for their regulatory effects on cytochrome C oxidase (Cox1) and tumor necrosis factor α (TNF-α) genes. (OL/Ag-NPs) were found to be smaller than (OL/WPNs) with sizes of (37.46±1.85 and 44.86±1.62 nm) and (227.20±2.43 and 553.02±3.60 nm) for Tofahy and Shemlali, respectively. SEM showed that Shemlali (OL/Ag-NPs) had the least aggregation due to their highest Ƹ-potential (-31.76 ± 0.87 mV). The preparations were relatively nontoxic to Vero cells (IC50 = 151.94-789.25 μg/mL), while they were cytotoxic to HCT-116 colorectal cells (IC50 = 77.54-320.64 μg/mL). Shemlali and Tofahy OLE and Tofahy OL/Ag-NPs had a higher selectivity index (2.97-7.08 μg/mL) than doxorubicin (2.36 μg/mL), indicating promising anticancer activity. Moreover, Shemlali preparations regulated the expression of Cox1 (up-regulation) and TNF-α (down-regulation) on HCT-116 cells, revealing their efficiency in suppressing the expression of genes that promote cancer cell proliferation. (OL/Ag-NPs) from Tofahy and Shemlali were found to be more stable, effective, and safe than (OL/WPNs). Consequently, OL/Ag-NPs, especially Tofahy, are the best and safest nanoscale particles that can be safely used in food and pharmaceutical applications.