Protective effects of hydroxytyrosol-supplemented refined olive oil in animal models of acute inflammation and rheumatoid arthritis

Hydroxytyrosol targets extracellular matrix remodeling by endothelial cells and inhibits both ex vivo and in vivo angiogenesis

The health benefits of olive oil are attributed to their bioactive compounds, such as hydroxytyrosol. Previously, we demonstrated that hydroxytyrosol inhibits angiogenesis in vitro. The present study aimed to: i) get further insight into the effects of hydroxytyrosol on extracellular matrix remodeling; and ii) test whether hydroxytyrosol is able to inhibit angiogenesis ex vivo and in vivo. Hydroxytyrosol induced a shift toward inhibition of proteolysis in endothelial cells, with decreased expression of extracellular matrix remodeling-enzyme coding genes and increased levels of some of their inhibitors. Furthermore, this work demonstrated that hydroxytyrosol, at concentrations within the range of its content in virgin olive oil that can be absorbed from moderate and sustained virgin olive oil consumption, is a strong inhibitor of angiogenesis ex vivo and in vivo. These results suggest the need for translational studies to evaluate the potential use of hydroxytyrosol for angio-prevention and angiogenesis inhibition in clinical setting.

Transdermal anti-inflammatory activity of bilayer film containing olive compound hydroxytyrosol: physical assessment, in vivo dermal safety and efficacy study in Freund's adjuvant-induced arthritic rat model

Previous studies have shown that hydroxytyrosol (HT) can be a potential alternative therapeutic agent for the treatment of rheumatoid arthritis (RA). However, HT is extensively metabolized following oral administration, which leads to formulating HT in a topical vehicle to prolong drug action as well as to provide a localized effect. Hidrox-6 is a freeze-dried powder derived from fresh olives and contains a high amount of HT (∼3%) and other polyphenols. Alginate bilayer films containing 5% and 10% Hidrox-6 were formulated. The films were characterized with respect to their physical, morphology, rheological properties; drug content uniformity; and in vitro drug release. Acute dermal irritancy tests and a skin sensitization study were carried out in rats. An efficacy study of the bilayer films for RA was conducted using Freund's adjuvant-induced polyarthritis rats. Animal data showed that the bilayer film formulations did not cause skin irritancy. The efficacy in vivo results showed that the Hidrox-6 bilayer films lowered the arthritic scores, paw and ankle circumference, serum IL-6 level and cumulative histological scores compared with those measured for controls. The topical Hidrox-6 bilayer films improve synovitis and inflammatory symptoms in RA and can be a potential alternative to oral RA therapy.

Protective effects of a blueberry extract in acute inflammation and collagen-induced arthritis in the rat

Here we investigated the anti-inflammatory effect of a blueberry extract in the carrageenan-induced paw edema model and collagen-induced arthritis model, both in rats. Along with the chemical characterization of the phenolic content of the fruits and extract, the antioxidant potential of the extract, the cellular antioxidant activity and the effects over neutrophils' oxidative burst, were studied in order to provide a mechanistic insight for the anti-inflammatory effects observed. The extract significantly inhibited paw edema formation in an acute model the rat. Our results also demonstrate that the standardized extract had pharmacological activity when administered orally in the collagen-induced arthritis model in the rat and was able to significantly reduce the development of clinical signs of arthritis and the degree of bone resorption, soft tissue swelling and osteophyte formation, consequently improving articular function in treated animals.

The metabolic role of the gut microbiota in health and rheumatic disease: mechanisms and interventions

The role of the gut microbiome in animal models of inflammatory and autoimmune disease is now well established. The human gut microbiome is currently being studied as a potential modulator of the immune response in rheumatic disorders. However, the vastness and complexity of this host-microorganism interaction is likely to go well beyond taxonomic, correlative observations. In fact, most advances in the field relate to the functional and metabolic capabilities of these microorganisms and their influence on mucosal immunity and systemic inflammation. An intricate relationship between the microbiome and the diet of the host is now fully recognized, with the microbiota having an important role in the degradation of polysaccharides into active metabolites. This Review summarizes the current knowledge on the metabolic role of the microbiota in health and rheumatic disease, including the advances in pharmacomicrobiomics and its potential use in diagnostics, therapeutics and personalized medicine.

Hydroxytyrosol prevents chondrocyte death under oxidative stress by inducing autophagy through sirtuin 1-dependent and -independent mechanisms

BACKGROUND

Hydroxytyrosol (HT), a major phenolic antioxidant found in olive oil, can afford protection from oxidative stress in several types of non-tumoral cells, including chondrocytes. Autophagy was recently identified as a protective process during osteoarthritis (OA) development and critical for survival of chondrocytes. Therefore we have investigated the possibility to modulate chondrocyte autophagy by HT treatment.

METHODS

DNA damage and cell death were estimated in human C-28/I2 and primary OA chondrocytes exposed to hydrogen peroxide. Autophagic flux and mitophagy were monitored by measuring levels and location of autophagy markers through western blot, immunostaining and confocal laser microscopy. Late autophagic vacuoles were stained with monodansylcadaverine. The involvement of sirtuin 1 (SIRT-1) was evaluated by immunohistochemistry, western blot and gene silencing with specific siRNA.

RESULTS

HT increases markers of autophagy and protects chondrocytes from DNA damage and cell death induced by oxidative stress. The protective effect requires the deacetylase SIRT-1, which accumulated in the nucleus following HT treatment. In fact silencing of this enzyme prevented HT from promoting the autophagic process and cell survival. Furthermore HT supports autophagy even in a SIRT-1-independent manner, by increasing p62 transcription, required for autophagic degradation of polyubiquitin-containing bodies.

CONCLUSIONS

These results support the potential of HT as a chondroprotective nutraceutical compound against OA, not merely for its antioxidant ability, but as an autophagy and SIRT-1 inducer as well.

GENERAL SIGNIFICANCE

HT may exert a cytoprotective action by promoting autophagy in cell types that may be damaged in degenerative diseases by oxidative and other stress stimuli.

Olive Oil and the Hallmarks of Aging

Aging is a multifactorial and tissue-specific process involving diverse alterations regarded as the "hallmarks of aging", which include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion and altered intracellular communication. Virtually all these hallmarks are targeted by dietary olive oil, particularly by virgin olive oil, since many of its beneficial effects can be accounted not only for the monounsaturated nature of its predominant fatty acid (oleic acid), but also for the bioactivity of its minor compounds, which can act on cells though both direct and indirect mechanisms due to their ability to modulate gene expression. Among the minor constituents of virgin olive oil, secoiridoids stand out for their capacity to modulate many pathways that are relevant for the aging process. Attenuation of aging-related alterations by olive oil or its minor compounds has been observed in cellular, animal and human models. How olive oil targets the hallmarks of aging could explain the improvement of health, reduced risk of aging-associated diseases, and increased longevity which have been associated with consumption of a typical Mediterranean diet containing this edible oil as the predominant fat source.

An update on dietary phenolic compounds in the prevention and management of rheumatoid arthritis

Certain nutritional components influence the cellular metabolism and interfere in the pathological inflammatory process, so that they may act as a coadjuvant in the treatment of many chronic inflammatory diseases, including rheumatoid arthritis (RA).

Development and in vitro assessment of alginate bilayer films containing the olive compound hydroxytyrosol as an alternative for topical chemotherapy

Topical chemotherapy is the application of cancer drugs directly onto the skin, which has become a standard treatment for basal cell carcinoma. Due to the promising results in the treatment of skin cancer, topical chemotherapy has recently been applied to breast cancer patients because some breast cancer tissues are only superficial. Hydroxytyrosol, a phenolic compound from olives that is present in high amounts in Hidrox(®) olive extract, has been shown to have a protective effect on normal cells and selective antitumor activities on cancerous cells. The aims of the present study were to develop an alginate bilayer film containing Hidrox(®) and to investigate its potential use as a topical chemotherapeutic agent. Alginate films were characterized for swelling and for physical, thermal, rheological, and mechanical properties. Drug content uniformity and in vitro drug release tests were also investigated. The alginate bilayer films containing Hidrox(®), HB2, showed controlled release of hydroxytyrosol at a flux of 0.094±0.009 mg/cm(2)/h. The results of the cytotoxic assay showed that the HB2 films were dose-dependent and could significantly reduce the growth of breast cancer cells (MCF-7) at 150 μg/mL for a cell viability of 29.34±4.64%. In conclusion, an alginate bilayer film containing Hidrox(®) can be a potential alternative for topical chemotherapeutic agent for skin and breast cancer treatment.

New perspectives on bioactivity of olive oil: evidence from animal models, human interventions and the use of urinary proteomic biomarkers

Olive oil (OO) is the primary source of fat in the Mediterranean diet and has been associated with longevity and a lower incidence of chronic diseases, particularly CHD. Cardioprotective effects of OO consumption have been widely related with improved lipoprotein profile, endothelial function and inflammation, linked to health claims of oleic acid and phenolic content of OO. With CVD being a leading cause of death worldwide, a review of the potential mechanisms underpinning the impact of OO in the prevention of disease is warranted. The current body of evidence relies on mechanistic studies involving animal and cell-based models, epidemiological studies of OO intake and risk factor, small- and large-scale human interventions, and the emerging use of novel biomarker techniques associated with disease risk. Although model systems are important for mechanistic research nutrition, methodologies and experimental designs with strong translational value are still lacking. The present review critically appraises the available evidence to date, with particular focus on emerging novel biomarkers for disease risk assessment. New perspectives on OO research are outlined, especially those with scope to clarify key mechanisms by which OO consumption exerts health benefits. The use of urinary proteomic biomarkers, as highly specific disease biomarkers, is highlighted towards a higher translational approach involving OO in nutritional recommendations.