The hopeful anticancer role of oleuropein in breast cancer through histone deacetylase modulation

Anticancer Effects of Secoiridoids-A Scoping Review of the Molecular Mechanisms behind the Chemopreventive Effects of the Olive Tree Components Oleocanthal, Oleacein, and Oleuropein

The olive tree (Olea europaea) and olive oil hold significant cultural and historical importance in Europe. The health benefits associated with olive oil consumption have been well documented. This paper explores the mechanisms of the anti-cancer effects of olive oil and olive leaf, focusing on their key bioactive compounds, namely oleocanthal, oleacein, and oleuropein. The chemopreventive potential of oleocanthal, oleacein, and oleuropein is comprehensively examined through this systematic review. We conducted a systematic literature search to identify eligible articles from Scopus, PubMed, and Web of Science databases published up to 10 October 2023. Among 4037 identified articles, there were 88 eligible articles describing mechanisms of chemopreventive effects of oleocanthal, oleacein, and oleuropein. These compounds have the ability to inhibit cell proliferation, induce cell death (apoptosis, autophagy, and necrosis), inhibit angiogenesis, suppress tumor metastasis, and modulate cancer-associated signalling pathways. Additionally, oleocanthal and oleuropein were also reported to disrupt redox hemostasis. This review provides insights into the chemopreventive mechanisms of O. europaea-derived secoiridoids, shedding light on their role in chemoprevention. The bioactivities summarized in the paper support the epidemiological evidence demonstrating a negative correlation between olive oil consumption and cancer risk. Furthermore, the mapped and summarized secondary signalling pathways may provide information to elucidate new synergies with other chemopreventive agents to complement chemotherapies and develop novel nutrition-based anti-cancer approaches.

Next-generation sequencing reveals altered gene expression and enriched pathways in triple-negative breast cancer cells treated with oleuropein and oleocanthal

Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by poor prognosis and limited treatment options. Oleuropein and oleocanthal are bioactive chemicals found in extra-virgin olive oil; they have been shown to have anti-cancer potential. In this study, we examined the inhibitory effects of these two natural compounds, on MDA-MB-231 and MDA-MB-468 TNBC cell lines. The human TNBC MDA-MB-231 and MDA-MB-468 cell lines were treated with oleuropein or oleocanthal at ranging concentrations for 48 h. After determining the optimum concentration to reach IC50, using the sulforhodamine B assay, total RNA was extracted after 12, 24, and 48 h from treated and untreated cells. Poly(A)-RNA selection was conducted, followed by library construction and RNA sequencing. Differential gene expression (DEG) analysis was performed to identify DEGs between treated and untreated cells. Pathway analysis was carried out using the KEGG and GO databases. Oleuropein and oleocanthal considerably reduced the proliferation of TNBC cells, with oleocanthal having a slightly stronger effect than oleuropein. Furthermore, multi-time series RNA sequencing showed that the expression profile of TNBC cells was significantly altered after treatment with these compounds, with temporal dynamics and groups of genes consistently affected at all time points. Pathway analysis revealed several significant pathways associated with TNBC, including cell death, apoptotic process, programmed cell death, response to stress, mitotic cell cycle process, cell division, and cancer progression. Our findings suggest that oleuropein and oleocanthal have potential therapeutic benefits for TNBC and can be further investigated as alternative treatment options.

Efficient CRISPR/Cas9-Mediated BAX Gene Ablation in CHO Cells To Impair Apoptosis and Enhance Recombinant Protein Production

Background

Despite recent advances in recombinant biotherapeutics production using CHO cells, their productivity remains lower than industrial needs, mainly due to apoptosis.

Objectives

Present study aimed to exploit CRISPR/Cas9 technology to specifically disrupt the BAX gene to attenuate apoptosis in recombinant Chinese hamster's ovary cells producing erythropoietin.

Materials and Methods

The STRING database was used to identify the key pro-apoptotic genes to be modified by CRISPR/Cas9 technique. The single guide RNAs (sgRNAs) targeting identified gene (BAX) were designed, and CHO cells were then transfected with vectors. Afterward, changes in the expression of the Bax gene and consequent production rates of erythropoietin were investigated in manipulated cells, even in the presence of an apoptosis inducer agent, oleuropein.

Results

BAX disruption significantly prolonged cell viability and increased proliferation rate in manipulated clones (152%, P-value = 0.0002). This strategy reduced the levels of Bax protein expression in manipulated cells by more than 4.3-fold (P-value <0.0001). The Bax-8 manipulated cells displayed higher threshold tolerance to the stress and consequence apoptosis compared to the control group. Also, they exhibited a higher IC50 compared to the control in the presence of oleuropein (5095 µM.ml^-1 Vs. 2505 µM.ml^-1). We found a significant increase in recombinant protein production levels in manipulated cells, even in the presence of 1,000 µM oleuropein compared to the control cell line (p-value=0.0002).

Conclusions

CRISPR/Cas9 assisted BAX gene ablation is promising to improve erythropoietin production in CHO cells via engineering anti-apoptotic genes. Therefore, exploiting genome editing tools such as CRISPR/Cas9 has been proposed to develop host cells that result in a safe, feasible, and robust manufacturing operation with a yield that meets the industrial requirements.

Implication of the Mediterranean diet on the human epigenome

Epigenetics, defined as "hereditary changes in gene expression that occur without any change in the DNA sequence", consists of various epigenetic marks, including DNA methylation, histone modifications, and non-coding RNAs. The epigenome, which has a dynamic structure in response to intracellular and extracellular stimuli, has a key role in the control of gene activity, since it is located at the intersection of cellular information encoded in the genome and molecular/chemical information of extracellular origin. The focus shift of studies to epigenetic reprogramming has led to the formation and progressive importance of a concept called "nutriepigenetics", whose aim is to prevent diseases by intervening on nutrition style. Among the diet types adopted in the world, the renowned Mediterranean Diet (MD), being rich in unsaturated fatty acids and containing high levels of whole grain foods and large quantities of fruits, vegetables, and legumes, has shown numerous advantages in excluding chronic diseases. Additionally, the fact that this diet is rich in polyphenols with high antioxidant and anti-inflammatory properties has an undeniable effect in turning some cellular pathways against the disease. It is also apparent that the effects of polyphenols on the epigenome cause changes in mechanisms such as DNA methylation and histone acetylation/deacetylation, which have a regulatory effect on gene regulation. This review presents the effects of long-term consumption of nutrients from the MD on the epigenome and discusses the benefits of this diet in the treatment and even prevention of chronic diseases.

Nutri-Epigenetic Effects of Phenolic Compounds from Extra Virgin Olive Oil: A Systematic Review

Dietary components can induce epigenetic changes through DNA methylation, histone modification, and regulation of microRNAs (miRNAs). Studies of diet-induced epigenetic regulation can inform anticipatory trials and fine-tune public health guidelines. We systematically reviewed data on the effect of extra virgin olive oil (EVOO) and its phenolic compounds (OOPCs) on the epigenetic landscape. We conducted a literature search using PubMed, Scopus, and Web of Science databases and scrutinized published evidence. After applying selection criteria (e.g., inclusion of in vitro, animal, or human studies supplemented with EVOO or its OOPCs), we thoroughly reviewed 51 articles, and the quality assessment was performed using the revised Cochrane risk of bias tool. The results show that both EVOO and its OOPCs can promote epigenetic changes capable of regulating the expression of genes and molecular targets involved in different metabolic processes. For example, oleuropein (OL) may be an epigenetic regulator in cancer, and hydroxytyrosol (HT) modulates the expression of miRNAs involved in the development of cancer, cardiovascular, and neurodegenerative diseases. We conclude that EVOO and its OOPCs can regulate gene expression by modifying epigenetic mechanisms that impact human pathophysiology. A full elucidation of the epigenetic effects of EVOO and its OOPCs may contribute to developing different pharma-nutritional strategies that exploit them as epigenetic agents. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42022320316.

Influence of Olive Oil and Its Components on Breast Cancer: Molecular Mechanisms

Breast cancer is the most frequent malignant neoplasia and a leading cause of mortality in women worldwide. The Mediterranean diet has been proposed as a healthy dietary pattern with protective effects in several chronic diseases, including breast cancer. This diet is characterized by the consumption of abundant plant foods and olive oil as the principal source of fat, which is considered one of the main components with potential antioxidant, anti-inflammatory and anticancer effects. Extra-virgin olive oil (EVOO) has several bioactive compounds, mainly including monounsaturated fatty acids, triterpenes and polyphenols, such as phenolic alcohols (e.g., hydroxytyrosol), secoiridoids (e.g., oleuropein and oleocanthal), lignans (e.g., pinoresinol) or flavonoids (e.g., luteolin). While epidemiological evidence is still limited, experimental in vivo and in vitro data have shown a protective effect of this oil and its compounds on mammary carcinogenesis. Such effects account through complex and multiple mechanisms, including changes in epigenetics, transcriptome and protein expression that modulate several signaling pathways. Molecular targets of EVOO compounds have a role in the acquisition of cancer hallmarks. Although further research is needed to elucidate their beneficial effects on human prevention and progression of the disease, evidence points to EVOO in the context of the Mediterranean diet as a heathy choice, while EVOO components may be promising adjuvants in anticancer strategies.

Protective Effects and Benefits of Olive Oil and Its Extracts on Women's Health

Women and men share similar diseases; however, women have unique issues, including gynecologic diseases and diseases related to menstruation, menopause, and post menopause. In recent decades, scientists paid more attention to natural products and their derivatives because of their good tolerability and effectiveness in disease prevention and treatment. Olive oil is an essential component in the Mediterranean diet, a diet well known for its protective impact on human well-being. Investigation of the active components in olive oil, such as oleuropein and hydroxytyrosol, showed positive effects in various diseases. Their effects have been clarified in many suggested mechanisms and have shown promising results in animal and human studies, especially in breast cancer, ovarian cancer, postmenopausal osteoporosis, and other disorders. This review summarizes the current evidence of the role of olives and olive polyphenols in women's health issues and their potential implications in the treatment and prevention of health problems in women.

An updated review on the potential antineoplastic actions of oleuropein

Oleuropein is an ester of elenolic acid and hydroxytyrosol (3, 4-dihydroxyphenylethanol). It is a phenolic compound and the most luxuriant in olives. The detailed information related to the anticancer effects of oleuropein was collected from the internet database PubMed/Medline, ResearchGate, Web of Science, Wiley Online Library, and Cnki using appropriate keywords until the end of October 2021. Oleuropein has been shown to have antioxidant, anticancer, antiinflammatory, cardioprotective, neuroprotective, and hepatoprotective effects. Previous studies also revealed that oleuropein could effectively inhibit the malignant progression of esophageal cancer, gastric cancer, breast cancer, lung cancer, liver cancer, pancreatic cancer, ovarian cancer, prostate cancer, and cervical cancer. Recently, the role of oleuropein in inhibiting tumor cell proliferation, invasion, and migration and inducing tumor cell apoptosis has gained extensive attention. In this review, we have summarized the latest research progress related to the antioncogenic mechanisms and the potential role of oleuropein in targeting different human malignancies. Based on these findings, it can be concluded that oleuropein can function as a promising chemopreventive and chemotherapeutic agent against cancer, but its more detailed anticancer effects and underlying mechanisms need to be further validated in future preclinical as well as clinical studies.

An Insight into Anticancer Bioactives from Punica granatum (Pomegranate)

Cancer is one of the major reasons for mortality across the globe. Side effects that are observed with the pharmacological medications present in the market majorly affect the quality of life of patients. This has caused the researchers to find an alternative source of medications such as herbal medicine which has shown a promising effect in anticancer treatment, one such source is Pomegranate, which belongs to the family Punicaceae. Several polyphenols are present in Punica granatum which exhibits properties ranging from antioxidant effect, antidiabetic effect, beneficial impact in treatment, and management of metabolic and cardiovascular disorders to advantageous impact in anticancer treatment. Polyphenols like punicalin, punicalagin, and ellagic acid are a few of the many compounds responsible for the anticancer activity of pomegranate. Many preparations of pomegranate such as Pomegranate Juice (PJ), Pomegranate seed oil (PSO), Pomegranate peel extract (PoPx) etc. are used in various clinical studies. These polyphenols show anticancer activity by either arresting the cell cycle in the G2/M phase, inducing apoptosis, or by damaging the DNA of tumor cells. This review explicitly discusses the role and mechanism of bioactives obtained from the pomegranate in the treatment and management of cancer. The chemical structure, properties and role of pomegranate in the treatment of breast, lung, thyroid, colon, and prostate cancer has been focused in detail. This review also discusses various drug delivery approaches for targeted delivery on tumors as well as patented preparation of pomegranate compounds along with the ongoing clinical trials.

Epigenetic Modifications Induced by Olive Oil and Its Phenolic Compounds: A Systematic Review

Many studies demonstrated that olive oil (especially extra virgin olive oil: EVOO) phenolic compounds are bioactive molecules with anti-cancer, anti-inflammatory, anti-aging and neuroprotective activities. These effects have been recently attributed to the ability of these compounds to induce epigenetics modifications such as miRNAs expression, DNA methylation and histone modifications. In this study, we systematically review and discuss, following the PRISMA statements, the epigenetic modifications induced by EVOO and its phenols in different experimental systems. At the end of literature search through “PubMed”, “Web of Science” and “Scopus”, 43 studies were selected.Among them, 22 studies reported data on miRNAs, 15 on DNA methylation and 13 on histone modification. Most of the “epigenomic” changes observed in response to olive oil phenols’ exposure were mechanistically associated with the cancer preventive and anti-inflammatory effects. In many cases, the epigenetics effects regarding the DNA methylation were demonstrated for olive oil but without any indication regarding the presence or not of phenols. Overall, the findings of the present systematic review may have important implications for understanding the epigenetic mechanisms behind the health effects of olive oil. However, generally no direct evidence was provided for the causal relationships between epigenetics modification and EVOO health related effects. Further studies are necessary to demonstrate the real physiological consequences of the epigenetics modification induced by EVOO and its phenolic compounds.

Gene Expression Alterations Associated with Oleuropein-Induced Antiproliferative Effects and S-Phase Cell Cycle Arrest in Triple-Negative Breast Cancer Cells

It is known that the Mediterranean diet is effective in reducing the risk of several chronic diseases, including cancer. A critical component of the Mediterranean diet is olive oil, and the relationship between olive oil consumption and the reduced risk of cancer has been established. Oleuropein (OL) is the most prominent polyphenol component of olive fruits and leaves. This compound has been shown to have potent properties in various types of cancers, including breast cancer. In the present study, the molecular mechanism of OL was examined in two racially different triple-negative breast cancer (TNBC) cell lines-African American (AA, MDA-MB-468) and Caucasian American (CA, MDA-MB-231). The data obtained showed that OL effectively inhibits cell growth in both cell lines, concomitant with S-phase cell cycle arrest-mediated apoptosis. The results also showed that OL-treated MDA-MB-468 cells were two-fold more sensitive to OL antiproliferative effect than MDA-MB-231 cells were. At lower concentrations, OL modified the expression of many apoptosis-involved genes. OL was more effective in MDA-MB-468, compared to MDA-MB-231 cells, in terms of the number and the fold-change of the altered genes. In MDA-MB-468 cells, OL induced a noticeable transcription activation in fourteen genes, including two members of the caspase family: caspase 1 (CASP1) and caspase 14 (CASP14); two members of the TNF receptor superfamily: Fas-associated via death domain (FADD) and TNF receptor superfamily 21 (TNFRSF21); six other proapoptotic genes: growth arrest and DNA damage-inducible 45 alpha (GADD45A), cytochrome c somatic (CYCS), BCL-2 interacting protein 2 (BNIP2), BCL-2 interacting protein 3 (BNIP3), BH3 interacting domain death agonist (BID), and B-cell lymphoma/leukemia 10 (BCL10); and the CASP8 and FADD-like apoptosis regulator (CFLAR) gene. Moreover, in MDA-MB-468 cells, OL induced a significant upregulation in two antiapoptotic genes: bifunctional apoptosis regulator (BFAR) and B-Raf proto-oncogene (BRAF) and a baculoviral inhibitor of apoptosis (IAP) repeat-containing 3 (BIRC3). On the contrary, in MDA-MB-231 cells, OL showed mixed impacts on gene expression. OL significantly upregulated the mRNA expression of four genes: BIRC3, receptor-interacting serine/threonine kinase 2 (RIPK2), TNF receptor superfamily 10A (TNFRSF10A), and caspase 4 (CASP4). Additionally, another four genes were repressed, including caspase 6 (CASP6), pyrin domain (PYD), and caspase recruitment domain (CARD)-containing (PAYCARD), baculoviral IAP repeat-containing 5 (BIRC5), and the most downregulated TNF receptor superfamily member 11B (TNFRSF11B, 16.34-fold). In conclusion, the data obtained indicate that the two cell lines were markedly different in the anticancer effect and mechanisms of oleuropein's ability to alter apoptosis-related gene expressions. The results obtained from this study should also guide the potential utilization of oleuropein as an adjunct therapy for TNBC to increase chemotherapy effectiveness and prevent cancer progression.

Potential Protective Role Exerted by Secoiridoids from Olea europaea L. in Cancer, Cardiovascular, Neurodegenerative, Aging-Related, and Immunoinflammatory Diseases

Iridoids, which have beneficial health properties, include a wide group of cyclopentane [c] pyran monoterpenoids present in plants and insects. The cleavage of the cyclopentane ring leads to secoiridoids. Mainly, secoiridoids have shown a variety of pharmacological effects including anti-diabetic, antioxidant, anti-inflammatory, immunosuppressive, neuroprotective, anti-cancer, and anti-obesity, which increase the interest of studying these types of bioactive compounds in depth. Secoiridoids are thoroughly distributed in several families of plants such as Oleaceae, Valerianaceae, Gentianaceae and Pedialaceae, among others. Specifically, Olea europaea L. (Oleaceae) is rich in oleuropein (OL), dimethyl-OL, and ligstroside secoiridoids, and their hydrolysis derivatives are mostly OL-aglycone, oleocanthal (OLE), oleacein (OLA), elenolate, oleoside-11-methyl ester, elenoic acid, hydroxytyrosol (HTy), and tyrosol (Ty). These compounds have proved their efficacy in the management of diabetes, cardiovascular and neurodegenerative disorders, cancer, and viral and microbial infections. Particularly, the antioxidant, anti-inflammatory, and immunomodulatory properties of secoiridoids from the olive tree (Olea europaea L. (Oleaceae)) have been suggested as a potential application in a large number of inflammatory and reactive oxygen species (ROS)-mediated diseases. Thus, the purpose of this review is to summarize recent advances in the protective role of secoiridoids derived from the olive tree (preclinical studies and clinical trials) in diseases with an important pathogenic contribution of oxidative and peroxidative stress and damage, focusing on their plausible mechanisms of the action involved.