Assessment of the Efficacy of Olive Leaf (Olea europaea L.) Extracts in the Treatment of Colorectal Cancer and Prostate Cancer Using In Vitro Cell Models

Antioxidant and anti-cancer potentials of Ag green-synthesized and encapsulated olive leaves particles on HCT-116 cells

Water extracts (OLE), whey protein encapsulated extracts (OLE/WPNs), and silver nanoparticles (OLE/Ag-NPs) were prepared from olive leaves of Manzenllie and Picual varieties. These preparations were characterized, and their antioxidant and biological activities on Vero and HCT-116 colorectal cells were assessed. The mechanism of action of the preparations was studied through tumor necrosis factor-α (TNF-α) and cytochrome C oxidase (Cox1) gene expression. OLE/Ag-NPs showed smaller particle sizes (14.23-15.53 nm) than OLE/WPNs (229.83-310.67 nm) and demonstrated lower aggregation due to their high Ƹ-potential of -24.86 to -27.90 mV. None of the preparations affected the viability of Vero cells (IC50 = 192.19-421.01 μg/mL), but they showed cytotoxic effects on HCT-116 cells (IC50 = 50.76-196.54 μg/mL), particularly OLE/WPNs. Moreover, the preparations from the Picual variety (OLE, OLE/WPNs, and OLE/Ag-NPs) showed regulatory effects against colon cancer on treated HCT-116 cells by upregulating Cox1 expression and downregulating TNF-α expression. Consequently, OLE/WPNs and OLE/Ag-NPs could be promising for industrial applications with potential health benefits.

Olive Leaves as a Source of Anticancer Compounds: In Vitro Evidence and Mechanisms

Olive trees not only produce olives but also generate a substantial amount of waste and by-products, including leaves, pomace (the solid remains after pressing olives for oil), and wastewater from the olive oil-making process. The waste products, particularly the leaves, contain bioactive compounds, especially phenolic compounds, known for their health benefits, such as high antioxidant potential and the ability to reduce inflammation. These compounds have shown promise in preventing and treating cancer. This review, based on in vitro evidence, provides a detailed description and discussion of the mechanisms through which these compounds from olive leaves can prevent development, the ways they might act against cancer cells, and their potential to increase the sensitivity of tumor cells to conventional anticancer therapy. The possible synergistic effects of these compounds suggest that olive leaf extracts may offer a promising approach for cancer treatment, compared with isolated compounds, thus providing novel possibilities for cancer therapy.

Synergistic cytotoxicity of olive leaf extract-loaded lipid nanocarriers combined with Newcastle disease virus against cervical cancer cells

Despite recent medical progress, cervical cancer remains a major global health concern for women. Current standard treatments have limitations such as non-specific toxicity that necessitate development of safer and more effective therapeutic strategies. This research evaluated the combinatorial effects of olive leaf extract (OLE), rich in anti-cancer polyphenols, and the oncolytic Newcastle disease virus (NDV) against human cervical cancer cells. OLE was efficiently encapsulated (>94% loading) within MF59 lipid nanoparticles and nanostructured lipid carriers (NLCs; contains Precirol as NLC-P, contains Lecithin as NLC-L) to enhance stability, bioavailability, and targeted delivery. Physicochemical analysis confirmed successful encapsulation of OLE within nanoparticles smaller than 150 nm. In vitro cytotoxicity assays demonstrated significantly higher toxicity of the OLE-loaded nanoparticle formulations on HeLa cancer cells versus HDF normal cells (P<0.05). MF59 achieved the highest encapsulation efficiency, while NLC-P had the best drug release profile. NDV selectively infected and killed HeLa cells versus HDF cells. Notably, combining NDV with OLE-loaded nanoparticles led to significantly enhanced synergistic cytotoxicity against cancer cells (P<0.05), with NLC-P (OLE) and NDV producing the strongest effects. Apoptosis and cell cycle analyses confirmed the increased anti-cancer activity of the combinatorial treatment, which induced cell cycle arrest. This study provides evidence that co-delivery of OLE-loaded lipid nanoparticles and NDV potentiates anti-cancer activity against cervical cancer cells in vitro through a synergistic mechanism, warranting further development as a promising alternative cervical cancer therapy.

A Comprehensive View on the Impact of Chlorogenic Acids on Colorectal Cancer

Chlorogenic acids are plant secondary metabolites, chemically-polyphenols with similar biological activity, formed through the esterification of quinic acid and hydrocinnamic acid moieties. They are best known for their high concentration in coffee and other dietary sources and the antioxidant properties that they exhibit. Both chlorogenic acids and plant extracts containing significant amounts of the compounds show promising in vitro activity against colorectal cancer. With coffee being the most popular drink in the world, and colorectal cancer at an unfortunate peak in incidence and mortality, the mechanisms through which the anti-tumorigenic effect of chlorogenic acids could be functionalized for CRC prevention seem appealing to study. Therefore, this review aims to enable a better understanding of the modes of action of chlorogenic acids in combating carcinogenesis, with a focus on cell cycle arrest, the induction of apoptosis, and the modulation of Wnt, Pi3K/Akt, and MAPK signal transduction pathways, alongside the reduction in the number of inflammatory cytokines and chemokines and the counterintuitive beneficial elevation of oxidative stress.

Comprehensive Review of Olea europaea: A Holistic Exploration into Its Botanical Marvels, Phytochemical Riches, Therapeutic Potentials, and Safety Profile

Human health is now inextricably linked to lifestyle choices, which can either protect or predispose people to serious illnesses. The Mediterranean diet, characterized by the consumption of various medicinal plants and their byproducts, plays a significant role in protecting against ailments such as oxidative stress, cancer, and diabetes. To uncover the secrets of this natural treasure, this review seeks to consolidate diverse data concerning the pharmacology, toxicology, phytochemistry, and botany of Olea europaea L. (O. europaea). Its aim is to explore the potential therapeutic applications and propose avenues for future research. Through web literature searches (using Google Scholar, PubMed, Web of Science, and Scopus), all information currently available on O. europaea was acquired. Worldwide, ethnomedical usage of O. europaea has been reported, indicating its effectiveness in treating a range of illnesses. Phytochemical studies have identified a range of compounds, including flavanones, iridoids, secoiridoids, flavonoids, triterpenes, biophenols, benzoic acid derivatives, among others. These components exhibit diverse pharmacological activities both in vitro and in vivo, such as antidiabetic, antibacterial, antifungal, antioxidant, anticancer, and wound-healing properties. O. europaea serves as a valuable source of conventional medicine for treating various conditions. The findings from pharmacological and phytochemical investigations presented in this review enhance our understanding of its therapeutic potential and support its potential future use in modern medicine.

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.

Investigation on the mechanisms by which the herbal remedies induce anti-prostate cancer activity: uncovering the most practical natural compound

Prostate cancer (PCa) is one of the most reported cancers among men worldwide. Targeting the essential proteins associated with PCa could be a promising method for cancer treatment. Traditional and herbal remedies (HRs) are the most practical approaches for PCa treatment. Here, the proteins and enzymes associated with PCa were determined based on the information obtained from the DisGeNET database. The proteins with a gene-disease association (GDA) score greater than 0.7 and the genes that have a disease specificity index (DSI) = 1 were selected as the target proteins. 28 HRs with anti-PCa activity as a traditional treatment for PCa were chosen as potential bioactive compounds. More than 500 compound-protein complexes were screened to find the top-ranked bioactives. The results were further evaluated using the molecular dynamics (MD) simulation and binding free energy calculations. The outcomes revealed that procyanidin B2 3,3'-di-O-gallate (B2G2), the most active ingredient of grape seed extract (GSE), can act as an agonist for PTEN. PTEN has a key role in suppressing PCa cells by applying phosphatase activity and inhibiting cell proliferation. B2G2 exhibited a considerable binding affinity to PTEN (11.643 kcal/mol). The MD results indicated that B2G2 could stabilize the key residues of the phosphatase domain of PTEN and increase its activity. Based on the obtained results, the active ingredient of GSE, B2G2, could play an agonist role and effectively increase the phosphatase activity of PTEN. The grape seed extract is a useful nutrition that can be used in men's diets to inhibit PCa in their bodies.Communicated by Ramaswamy H. Sarma.

Redox State Modulatory Activity and Cytotoxicity of Olea europaea L. (Oleaceae) Leaves Extract Enriched in Polyphenols Using Macroporous Resin

The food products derived from Olea europaea are a fundamental part of the Mediterranean diet, and their health-promoting effects are well known. In this study, we analyzed the phytochemical characteristics, the redox state modulatory activity, and the cytotoxic effect of an olive leaf aqueous extract enriched by macroporous resin on different tumor and normal cell lines (LNCaP, PC3, HFF-1). HPLC-DAD analysis, the Folin-Ciocalteu and aluminum chloride methods confirmed the qualitatively and quantitatively high content of phenolic compounds (130.02 ± 2.3 mg GAE/g extract), and a DPPH assay (IC50 = 100.00 ± 1.8 μg/mL), the related antioxidant activity. The biological investigation showed a significant cytotoxic effect, highlighted by an MTT test and the evident cellular morphological changes, on two prostate cancer cell lines. Remarkably, the extract was practically non-toxic on HFF-1 at the concentrations (100, 150, 300 µg/mL) and exposure times tested. Hence, the results are selective for tumor cells. The underlying cytotoxicity was associated with the decrease in ROS production (55% PC3, 42% LNCaP) and the increase in RSH levels (>50% PC3) and an LDH release assay (50% PC3, 40% LNCaP, established necrosis as the main cell death mechanism.

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.

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

Alginate microcapsules are a talented means for the delivery of broad curative biomacromolecules. In this study, we immobilized olive leaf extract (OLE) by calcium alginate (CA) and chitosan-coated CA (CCA) and characterized the OLE-loaded CA and CCA. The cytotoxic effect, the cell cycle arrest, and the apoptotic effect of OLE and its microcapsules were investigated against breast adenocarcinoma (MCF-7) and lung carcinoma (A549). As a result, the loading capacity of OLE-CA and OLE-CCA was found to be 80 and 99%, respectively, in optimal conditions. Also, OLE-CA and OLE-CCA were characterized by unique FTIR peaks and morphological display relative to the empty CCA microcapsules. The cytotoxicity analysis showed that the IC50 values of OLE-CA and OLE-CCA were determined to be 312 and 0.94 μg mL-1 against A549, respectively, whereas these were found to be 865.4 and 425.5 μg mL-1 for MCF-7 cells. On the other hand, the OLE microcapsules did not possess in any concentration of cytotoxic influence on the BEAS 2B healthy cell line. Also, the exposure of OLE-CCA to MCF-7 and A549 resulted in the arrest of more MCF-7 and A549 cells at the G0/G1 phase compared to the OLE. A549 and MCF-7 cells were predominantly found in the late apoptosis phase and necrosis phase, respectively. Optical microscopy images confirmed that OLE microcapsules were more effective against MCF-7 and A549 than free OLE. The present work suggested that the OLE microcapsules might be administered as nutrition supplements for cancer therapy.

Development of Pegylated Nano-Phytosome Formulation with Oleuropein and Rutin to Compare Anti-Colonic Cancer Activity with Olea Europaea Leaves Extract

Olive leaf extract is a valuable source of phenolic compounds; primarily, oleuropein (major component) and rutin. This natural olive leaf extract has potential use as a therapeutic agent for cancer treatment. However, its clinical application is hindered by poor pharmacokinetics and low stability. To overcome these limitations, this study aimed to enhance the anticancer activity and stability of oleuropein and rutin by loading them into PEGylated Nano-phytosomes. The developed PEGylated Nano-phytosomes exhibited favorable characteristics in terms of size, charge, and stability. Notably, the anticolonic cancer activity of the Pegylated Nano-phytosomes loaded with oleuropein (IC50=0.14 μM) and rutin (IC50=0.44 μM) surpassed that of pure oleuropein and rutin alone. This outcome highlights the advantageous impact of Nano-phytosomes to augment the anticancer potential of oleuropein and rutin. These results present a promising pathway for the future development of oleuropein and rutin Nano-phytosomes as effective options for passive tumor-targeted therapy, given their improved stability and efficacy.

[Progress on three-dimensional cell culture technology and their application]

Three-dimensional (3D) cell culture model is a system that co-culture carriers with 3D structural materials and different types of cells in vitro to simulate the microenvironment in vivo. This novel cell culture model has been proved to be close to the natural system in vivo. In the process of cell attachment, migration, mitosis and apoptosis, it could produce biological reactions different from that of monolayer cell culture. Therefore, it can be used as an ideal model to evaluate the dynamic pharmacological effects of active substances and the metastasis process of cancer cells. This paper compared and analyzed the different characteristics of cell growth and development under two-dimensional (2D) and 3D model culture and introduced the establishment method of 3D cell model. The application progress of 3D cell culture technology in tumor model and intestinal absorption model was summarized. Finally, the application prospect of 3D cell model in the evaluation and screening of active substance was revealed. This review is expected to provide reference for the development and application of new 3D cell culture models.

Updated Organic Composition and Potential Therapeutic Properties of Different Varieties of Olive Leaves from Olea europaea

Olea europaea L. folium merits further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of Madural, Verdeal, and Cobrançosa elementary leaves and leaf sprouts (mamões) collected in the region of Valpaços, Portugal. Organic analysis assessed the moisture content, total carbohydrates, ash, protein, and fat contents, total phenolic content (TPC), vitamin E, and fatty acid (FA) profiles. Moisture content was determined through infrared hygrometry and TPC was determined by a spectrophotometric method. Concerning organic analysis, all leaf samples showed similar moisture content, though Cobrançosa's leaf sprouts and Verdeal's elementary leaves had slightly lower contents. Meanwhile, these cultivars also showed a higher TPC, α-tocopherol isomer, and fatty acid composition (FAC). FAC in all samples exhibited higher contents of PUFA and SFA than MUFA, with a predominance of linolenic and palmitic acids. Organic analyses of Cobrançosa's leaf sprouts and Verdeal's elementary leaf extracts allow for the prediction of adequate physiological properties regarding neuroinflammatory, neurobehavioral, metabolic, cardiovascular, osteo-degenerative, anti-ageing, pulmonary, and immunological defense disorders. These physiological changes observed in our preliminary in silico studies suggest an excellent nutraceutical, which should be borne in mind during severe pandemic situations.

Dietary Polyphenols: Extraction, Identification, Bioavailability, and Role for Prevention and Treatment of Colorectal and Prostate Cancers

Fruits, vegetables, and other edible plants in our diet have numerous health benefits, due to the bioactive compounds in these food items, including polyphenols. These plants are a rich and promising source of natural products and phytochemicals that can be used to treat and prevent numerous diseases and prevent the progression of cancer. Dietary polyphenols exhibit chemo-preventive and therapeutic effects against various ailments, including several types of cancer. The current study focuses on polyphenol’s traditional and advanced extraction methods, with supercritical extraction as a novel approach. It also deals with their identification, bioavailability, and role in preventing and treating colorectal and prostate cancers. Additionally, the article covers the literature that deals with the anticancer activities of polyphenols, as well as their potential use as anticancer agents.