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

Connecting the dots in the associations between diet, obesity, cancer, and microRNAs

The prevalence of obesity has reached pandemic levels worldwide, leading to a lower quality of life and higher health costs. Obesity is a major risk factor for noncommunicable diseases, including cancer, although obesity is one of the major preventable causes of cancer. Lifestyle factors, such as dietary quality and patterns, are also closely related to the onset and development of obesity and cancer. However, the mechanisms underlying the complex association between diet, obesity, and cancer remain unclear. In the past few decades, microRNAs (miRNAs), a class of small non-coding RNAs, have been demonstrated to play critical roles in biological processes such as cell differentiation, proliferation, and metabolism, highlighting their importance in disease development and suppression and as therapeutic targets. miRNA expression levels can be modulated by diet and are involved in cancer and obesity-related diseases. Circulating miRNAs can also mediate cell-to-cell communications. These multiple aspects of miRNAs present challenges in understanding and integrating their mechanism of action. Here, we introduce a general consideration of the associations between diet, obesity, and cancer and review the current knowledge of the molecular functions of miRNA in each context. A comprehensive understanding of the interplay between diet, obesity, and cancer could be valuable for the development of effective preventive and therapeutic strategies in future.

A Status Review on Health-Promoting Properties and Global Regulation of Essential Oils

Since ancient times, essential oils (EOs) have been known for their therapeutic potential against many health issues. Recent studies suggest that EOs may contribute to the regulation and modulation of various biomarkers and cellular pathways responsible for metabolic health as well as the development of many diseases, including cancer, obesity, diabetes, cardiovascular diseases, and bacterial infections. During metabolic dysfunction and even infections, the immune system becomes compromised and releases pro-inflammatory cytokines that lead to serious health consequences. The bioactive compounds present in EOs (especially terpenoids and phenylpropanoids) with different chemical compositions from fruits, vegetables, and medicinal plants confer protection against these metabolic and infectious diseases through anti-inflammatory, antioxidant, anti-cancer, and anti-microbial properties. In this review, we have highlighted some targeted physiological and cellular actions through which EOs may exhibit anti-inflammatory, anti-cancer, and anti-microbial properties. In addition, it has been observed that EOs from specific plant sources may play a significant role in the prevention of obesity, diabetes, hypertension, dyslipidemia, microbial infections, and increasing breast milk production, along with improvements in heart, liver, and brain health. The current status of the bioactive activities of EOs and their therapeutic effects are covered in this review. However, with respect to the health benefits of EOs, it is very important to regulate the dose and usage of EOs to reduce their adverse health effects. Therefore, we specified that some countries have their own regulatory bodies while others follow WHO and FAO standards and legislation for the use of EOs.

Olive juice dry extract containing hydroxytyrosol, as a nontoxic and safe substance: Results from pre-clinical studies and review of toxicological studies

Products derived from olives, such as the raw fruit and oils, are widely consumed due to their taste, and purported nutritional/health benefits. Phenolic compounds, especially hydroxytyrosol (HT), have been proposed as one of the key substances involved in these effects. An olive juice extract, standardized to contain 20% HT ("OE20HT"), was produced to investigate its health benefits. The aim of this study was to demonstrate the genotoxic safety of this ingredient based on in vitro Ames assay and in vitro micronucleus assay. Results indicated that OE20HT was not mutagenic at concentrations of up to 5000 µg/plate, with or without metabolic activation, and was neither aneugenic nor clastogenic after 3-hour exposure at concentrations of up to 60 µg/mL with or without metabolic activation, or after 24-hour exposure at concentrations of up to 40 µg/mL. To further substantiate the safety of OE20HT following ingestion without conducting additional animal studies, a comprehensive literature review was conducted. No safety concerns were identified based on acute or sub-chronic studies in animals, including reproductive and developmental studies. These results were supported by clinical studies demonstrating the absence of adverse effects after oral supplementation with olive extracts or HT. Based on in vitro data and the literature review, the OE20HT extract is therefore considered as safe for human consumption at doses up to 2.5 mg/kg body weight/day.

The Double-Edged Sword of Oleuropein in Ovarian Cancer Cells: From Antioxidant Functions to Cytotoxic Effects

Oleuropein plays a key role as a pro-oxidant as well as an antioxidant in cancer. In this study, the activity of oleuropein, in an in vitro model of ovarian (OCCs) and breast cancer cells (BCCs) was investigated. Cell viability and cell death were analyzed. Oxidative stress was measured by CM-H2DCFDA flow cytometry assay. Mitochondrial dysfunction was evaluated based on mitochondrial reactive oxygen species (ROS) and GPX4 protein levels. Further, the effects on iron metabolism were analyzed by measuring the intracellular labile iron pool (LIP). We confirmed that high doses of oleuropein show anti-proliferative and pro-apoptotic activity on HEY and MCF-7 cells. Moreover, our results indicate that low doses of oleuropein impair cell viability without affecting the mortality of cells, and also decrease the LIP and ROS levels, keeping them unchanged in MCF-7 cells. For the first time, our data show that low doses of oleuropein reduce erastin-mediated cell death. Interestingly, oleuropein decreases the levels of intracellular ROS and LIP in OCCs treated with erastin. Noteworthily, we observed an increased amount of ROS scavenging enzyme GPX4 together with a consistent reduction in mitochondrial ROS, confirming a reduction in oxidative stress in this model.

Update on Anti-Inflammatory Molecular Mechanisms Induced by Oleic Acid

In 2010, the Mediterranean diet was recognized by UNESCO as an Intangible Cultural Heritage of Humanity. Olive oil is the most characteristic food of this diet due to its high nutraceutical value. The positive effects of olive oil have often been attributed to its minor components; however, its oleic acid (OA) content (70-80%) is responsible for its many health properties. OA is an effective biomolecule, although the mechanism by which OA mediates beneficial physiological effects is not fully understood. OA influences cell membrane fluidity, receptors, intracellular signaling pathways, and gene expression. OA may directly regulate both the synthesis and activities of antioxidant enzymes. The anti-inflammatory effect may be related to the inhibition of proinflammatory cytokines and the activation of anti-inflammatory ones. The best-characterized mechanism highlights OA as a natural activator of sirtuin 1 (SIRT1). Oleoylethanolamide (OEA), derived from OA, is an endogenous ligand of the peroxisome proliferator-activated receptor alpha (PPARα) nuclear receptor. OEA regulates dietary fat intake and energy homeostasis and has therefore been suggested to be a potential therapeutic agent for the treatment of obesity. OEA has anti-inflammatory and antioxidant effects. The beneficial effects of olive oil may be related to the actions of OEA. New evidence suggests that oleic acid may influence epigenetic mechanisms, opening a new avenue in the exploration of therapies based on these mechanisms. OA can exert beneficial anti-inflammatory effects by regulating microRNA expression. In this review, we examine the cellular reactions and intracellular processes triggered by OA in T cells, macrophages, and neutrophils in order to better understand the immune modulation exerted by OA.

In Vitro Study of the Potential Role of Olive Oil Oleuropein in Modulating the 5-FU Cytotoxic Efficacy against the Tongue Squamous Cell Carcinoma

BACKGROUND: 5-fluorouracil (5-FU) is an anticancer drug used to inhibit the proliferation of many different tumor cells. Since severe side effects are associated with this drug, its combination with different natural compounds would allow the use of a significantly lower dose of 5-FU. Oleuropein (OLEU), has been shown to have inhibitory effects on various types of cancers. AIM: The main objective of the current study was to assess the cytotoxic effect of OLEU and the chemotherapeutic drug 5-FU on Human Tongue Carcinoma Cancer Cell Line (HNO-97) and Human Normal Oral Epithelial Cell Line (OEC) either independently or combinatory effect. MATERIALS AND METHODS: 3-(4,5- dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cell viability, and half-maximal inhibitory concentration (IC50) was calculated. Flowcytometry for cell cycle analysis was performed. Also, in vitro scratch assay was done to assess the inhibitory effects of OLEU on the migration of cells.RESULTS: MTT assay study demonstrated that OLEU and 5-FU alone or in combinations have produced a significant inhibitory effect on both normal and cancer cell lines with a favorable impact for OLEU on cancer cell lines rather than the normal one. A significant increase in the cell inhibitory % was reported between the single and the combinations treated groups as compared to the non-treated control group. Cell cycle analysis via flowcytometry showed that OLEU had induced cell cycle arrest at G0/1 phase, decreased S phase and G2/M phase either independently or in combination for 24h and 48h when compared with a non-treated control group. A Scratch assay test showed that OLEU could induce delayed wound healing. CONCLUSIONS: The findings of the present study suggest that OLEU can exert an anti-cancer effect on HNO-97 and may have the potential for potentiation of 5-FU cytotoxic effects and reduction of its adverse effects. In addition, OLEU could inhibit cancer progression and expansion from the initial tumor.