Anti-Inflammatory Effects of Nutritionally Relevant Concentrations of Oleuropein and Hydroxytyrosol on Peripheral Blood Mononuclear Cells: An Age-Related Analysis

Effect of Mediterranean Diet in Combination with Isokinetic Exercise Therapy on Body Composition and Cytokine Profile in Patients with Metabolic Syndrome

BACKGROUND

Metabolic syndrome (MS) is a combination of comorbidities that increase pro-inflammatory cytokines (PIC) production, with subsequent body composition (BC) abnormalities and high cardiovascular risk. Treatment with diet and exercise has been suggested as possible non-pharmacological adjuvant treatment.

OBJECTIVE

To determine changes in BC and PIC in patients with MS after a Mediterranean-type diet (MedDiet) and/or isokinetic exercise (IE).

METHODS

A controlled randomized clinical trial was conducted at a third-level hospital in Mexico City. Intervention groups: G1: MedDiet + IE; G2: IE; G3: MedDiet; G4: control. Anthropometry, BC, and PIC were collected from the baseline and at 12 weeks post-intervention. MedDiet was estimated from a 24-h recall record. IE consisted of a standard high-intensity anaerobic exercise program.

RESULTS

Forty-two patients with MS aged 18-65 years old were included. The most frequent comorbidities were obesity, insulin resistance, and dyslipidemia. After 6 months of intervention, a significant reduction of resistin was observed within the IE group and MedDiet + IE, whereas the former group also showed an increase in adiponectin. Interventions of MedDiet and MedDiet + IE showed a decrease in IL-10. Regarding BC, all groups increased the resistance values in relation to the baseline but were lower than the control group.

CONCLUSIONS

The results suggest that MedDiet and IE have a selective impact on pro-inflammatory mediators, while the combination of MedDiet and IE may induce only minor changes in BC.

Polyphenol Treatment of Peripheral Blood Mononuclear Cells from Individuals of Different Ages

Human peripheral blood mononuclear cells (PBMCs) have been largely utilized to assess the cytotoxic, immunomodulatory, and anti-inflammatory properties of both synthetic and natural compounds. Within the latter category, polyphenols from dietary sources have been extensively analyzed. PBMCs represent a feasible in vitro model to study polyphenol hallmarks and activity according to quantitative and qualitative differences in immune responses in individuals of different age. In this chapter, we propose a method for PBMC treatment with polyphenols and analysis designed on age-dependent qualitative and quantitative variability in immune cell performance.

Anti-Inflammatory and Neuroprotective Polyphenols Derived from the European Olive Tree, Olea europaea L., in Long COVID and Other Conditions Involving Cognitive Impairment

The European olive tree, Olea europaea L., and its polyphenols hold great therapeutic potential to treat neuroinflammation and cognitive impairment. This review examines the evidence for the anti-inflammatory and neuroprotective actions of olive polyphenols and their potential in the treatment of long COVID and neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS). Key findings suggest that olive polyphenols exhibit antioxidant, anti-inflammatory, neuroprotective, and antiviral properties, making them promising candidates for therapeutic intervention, especially when formulated in unique combinations. Recommendations for future research directions include elucidating molecular pathways through mechanistic studies, exploring the therapeutic implications of olive polyphenol supplementation, and conducting clinical trials to assess efficacy and safety. Investigating potential synergistic effects with other agents addressing different targets is suggested for further exploration. The evidence reviewed strengthens the translational value of olive polyphenols in conditions involving cognitive dysfunction and emphasizes the novelty of new formulations.

The Role of Natural Products in Immunopharmacology

The Special Issue "The Role of Natural Products in Immunopharmacology", edited by Giulia Accardi, Danila Di Majo, and Anna Aiello focuses on the crucial role of natural products and their related components in treating various disorders, emphasizing their applications in the pharmacological and nutraceutical fields [...].

Exploring the synergistic potential of wild nettle and olive oil: bioactive compounds, antioxidant capacity, and antibacterial properties

This study delved into the incorporation of wild nettle (Urtica dioica L.) leaves powder with virgin olive oil, exploring its potential to enhance nutritional value and health benefits. The antioxidant, antibacterial, and mineral-enrichment attributes of the resultant nettle-infused olive oil were investigated. Phenolic composition analysis revealed that an optimal maceration time of 30-40 minutes leads to maximal phenolic and flavonoid contents (57.66 mg GAE/100 g and 67.18 mg QE/100 g, respectively). The infused oil demonstrated superior radical scavenging activity (DPPH and ABTS assays) compared to virgin olive oil. Notably, nettle infusion significantly elevates zinc (10.12 mg/kg) and iron (13.85 mg/kg) contents. Antibacterial assays exhibited enhanced inhibition diameters and lower MIC and MBC values for nettle-infused oil against various bacterial strains. The study's findings underscore the potential of nettle infusion to enhance the nutritional and functional attributes of olive oil, holding promise for novel culinary and health applications.

Oleuropein impact on colorectal cancer

Colorectal cancer (CRC) is considered the third most common cancer in the world. In Mediterranean region, olives and olive oil play a substantial role in diet and medical traditional behaviors. They totally believe that high consumption of olive products can treat a wide range of diseases and decrease risk of illness. Oleuropein is the main active antioxidant molecule found in pre-mature olive fruit and leaves. Recently, it has been demonstrated that oleuropein is used in cancer therapy as an anti-proliferative and apoptotic agent for some cancer cells. In this review, we would like to explore the conclusive effects of oleuropein on CRC with respect to in vitro and in vivo studies.

Use of Oleuropein and Hydroxytyrosol for Cancer Prevention and Treatment: Considerations about How Bioavailability and Metabolism Impact Their Adoption in Clinical Routine

The fact that the Mediterranean diet could represent a source of natural compounds with cancer-preventive and therapeutic activity has been the object of great interest, especially with regard to the mechanisms of action of polyphenols found in olive oil and olive leaves. Secoiridoid oleuropein (OLE) and its derivative hydroxytyrosol (3,4-dihydroxyphenylethanol, HT) have demonstrated anti-proliferative properties against a variety of tumors and hematological malignancies both in vivo and in vitro, with measurable effects on cellular redox status, metabolism, and transcriptional activity. With this review, we aim to summarize the most up-to-date information on the potential use of OLE and HT for cancer treatment, making important considerations about OLE and HT bioavailability, OLE- and HT-mediated effects on drug metabolism, and OLE and HT dual activity as both pro- and antioxidants, likely hampering their use in clinical routine. Also, we focus on the details available on the effects of nutritionally relevant concentrations of OLE and HT on cell viability, redox homeostasis, and inflammation in order to evaluate if both compounds could be considered cancer-preventive agents or new potential chemotherapy drugs whenever their only source is represented by diet.

Olive Oil Waste as a Source of Functional Food Ingredients: Assessing Polyphenolic Content and Antioxidant Activity in Olive Leaves

Around two million tons of olive oil are produced in Europe annually, with Portugal being among the top five European olive oil-producing countries. Olive oil production results in a substantial amount of waste in the form of olive leaves. These discarded olive leaves contain valuable phenolic compounds with antioxidant, anti-inflammatory, hypoglycaemic, neuroprotective, and antiproliferative properties. Due to their richness in polyphenols with health-promoting properties, olive leaves can be considered a potential functional food ingredient. Thus, sustainable practices for reusing olive leaf waste are in demand. In this study, the polyphenolic content in olive leaves from different Portuguese locations was determined using HPLC-UV-Vis after defining the best fit-for-purpose liquid extraction strategy. The differences in the in vitro antioxidant activity in these samples were determined by several methodologies based on radical scavenging (against 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-2-picrylhydrazyl (DPPH), and peroxyl radical (ORAC)) and on reducing properties (cupric-reducing antioxidant capacity (CUPRAC), and Folin-Ciocalteu assay (FC)), to unveil the relationship between the profile and quantity of polyphenols with antioxidant mechanisms and their capacity. At last, the stability of extracted compounds upon lyophilization and exposition to surrogate biological fluids was assessed, envisioning the future incorporation of olive leaves extracted compounds in food products.

Anti-Inflammatory Effects of Olive Leaf Extract and Its Bioactive Compounds Oleacin and Oleuropein-Aglycone on Senescent Endothelial and Small Airway Epithelial Cells

Olive tree by-products have been deeply studied as an invaluable source of bioactive compounds. Several in vitro and in vivo studies showed that olive leaf extract (OLE) has anti-inflammatory and antioxidant properties. Here, we wanted to assess the valuable benefits of two less-studied OLE components-3,4-DHPEA-EDA (Oleacin, OC) and 3,4-DHPEA-EA (Oleuropein-Aglycone, OA)-directly purified from OLE using a cost-effective and environmentally sustainable method, in line with the principles of circular economy. OLE, OC and OA were then tested in human cellular models involved in acute and chronic inflammation and in the pathogenesis of viral infections, i.e., lipopolysaccharide (LPS)-treated monocyte/macrophages (THP-1) and endothelial cells (HUVECs), senescent HUVECs and Poly(I:C)-treated small airway epithelial cells (hSAECs). Results showed that OC and OA are efficient in ameliorating almost all of the pro-inflammatory readouts (IL-1β, TNF-α, IL-8, ICAM, VCAM) and reducing the release of IL-6 in all the cellular models. In hSAECs, they also modulate the expression of SOD2, NF-kB and also ACE2 and TMPRSS2, whose expression is required for SARS-CoV-2 virus entry. Overall, these data suggest the usefulness of OLE, OC and OA in controlling or preventing inflammatory responses, in particular those associated with viral respiratory infections and aging.