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Alzheimer's disease (AD) is an age-associated neurodegenerative amyloid disease and is considered a social and clinical problem the last decades, particularly in the Western countries. Amyloid diseases are characterized by the deposition of typically aggregated protein/peptides in tissues that are associated with brain degeneration and progressive cognitive impairment. The amyloid plaques and neurofibrillary tangles arise as a result of self-assembly into fibrillar material of amyloid-β protein and hyperphosphorylated tau, respectively. Moreover, mounting evidence shows that oxidative and nitrosative stress plays a central role in the pathogenesis of neurodegenerative disorders such as AD. Oleuropein belongs to a specific group of polyphenols, the secoiridoids, which are abundant in Oleaceae. Oleuropein aglycone is abundant in extra virgin olive oil and it is generated as a product of a glucosidase released when olive fruits are crushed. This secoiridoid compound has radical-scavenging activity and antioxidative effects and it is considered a promising target to prevent amyloid toxicity as an inhibitor of the oligomer nucleation and growth. The neuroprotective and antioxidant effects of flavonoids have been found to strongly depend on their structure and functional groups. Oleuropein aglycone counteracts amyloid aggregation and toxicity affecting different pathways: amyloid precursor protein processing, amyloid-β peptide and tau aggregation, autophagy impairment, and neuroinflammation. In the current work, available literature on oleuropein aglycone effects as antioxidant and inhibitor of amyloid deposits in AD is reviewed. Moreover, we discuss the chemistry, food sources and bioavailability of oleuropein aglycone.

Wound healing is a complex process that consists of several phases that range from coagulation, inflammation, accumulation of radical substances, to proliferation, formation of fibrous tissues and collagen, contraction of wound with formation of granulation tissue and scar. Since antiquity, vegetable substances have been used as phytotherapeutic agents for wound healing, and more recently natural substances of vegetable origin have been studied with the attempt to show their beneficial effect on wound treatment. Curcumin, the most active component of rhizome of Curcuma longa L. (common name: turmeric), has been studied for many years due to its bio-functional properties, especially antioxidant, radical scavenger, antimicrobial and anti-inflammatory activities, which play a crucial role in the wound healing process. Moreover, curcumin stimulated the production of the growth factors involved in the wound healing process, and so curcumin also accelerated the management of wound restoration. The aim of the present review is collecting and evaluating the literature data regarding curcumin properties potentially relevant for wound healing. Moreover, the investigations on the wound healing effects of curcumin are reported. In order to produce a more complete picture, the chemistry and sources of curcumin are also discussed.

Background Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease mainly caused by high-fat diets and sudden feed changes, vitamin and energy deficiency, and inflammatory processes. Fatty liver leads to cirrhosis, hepatocellular carcinoma as well as liver failure. Lifestyle-modifying such as weight loss and a healthy diet have an inverse correlation with the risk of fatty liver. The promising effect of a diet rich in vegetables and fruits against fatty liver has been evidenced by several empirical studies focused on flavonoids. Among naturally occurring flavonoids, naringenin is one of the most important flavonoids which can be isolated from some edible fruits, especially citrus species. Methods In the present review, we discuss the effects of naringenin and its nano-formulations against fatty liver disease and the proposed molecular mechanism of action. A large number of studies attributed to naringenin anti-inflammatory, antioxidant and insulin-like actions, as well as different types of effects on sex hormone metabolism and lipid metabolism. Naringenin-loaded nanoparticles have been used to solve the limited stability, solubility, bioavailability and pharmacological activity of naringenin and, consequently, to improve its therapeutic effects. Results and discussion Naringenin exerts diverse biological actions including the decrease of biomarkers of lipid peroxidation and protein carbonylation, increase of antioxidant defenses, scavenging of reactive oxygen species and modulation of signaling pathways related to fatty acid metabolism which can favor the oxidation of fatty acid, lower lipid accumulation in the liver and thereby prevent fatty liver.

Moderate physical exercise leads the organism to adapt to this stressful situation. However, when exercise is exhaustive, it is also known to induce an overproduction of reactive species which can result in oxidative damage to macromolecules and tissues. Many studies have been carried out to evaluate the validity of dietary strategies or micronutrients in order to attenuate exercise-induced oxidative stress. Polyphenols are a large group of compounds widely distributed throughout the plant kingdom. This review summarizes recent evidence in relation to the effects of polyphenols as antioxidant and anti-inflammatory agents, using exercise as a model of study.

Wound healing is a complex process that consists of several phases that range from coagulation, inflammation, accumulation of radical substances, to proliferation, formation of fibrous tissues and collagen, contraction of wound with formation of granulation tissue and scar. Since antiquity, vegetable substances have been used as phytotherapeutic agents for wound healing, and more recently natural substances of vegetable origin have been studied with the attempt to show their beneficial effect on wound treatment. Curcumin, the most active component of rhizome of Curcuma longa L. (common name: turmeric), has been studied for many years due to its bio-functional properties, especially antioxidant, radical scavenger, antimicrobial and anti-inflammatory activities, which play a crucial role in the wound healing process. Moreover, curcumin stimulated the production of the growth factors involved in the wound healing process, and so curcumin also accelerated the management of wound restoration. The aim of the present review is collecting and evaluating the literature data regarding curcumin properties potentially relevant for wound healing. Moreover, the investigations on the wound healing effects of curcumin are reported. In order to produce a more complete picture, the chemistry and sources of curcumin are also discussed.

Oxidative stress plays a key role in the pathogenesis of different serious chronic diseases such as cancer, diabetes, cardiovascular and neurodegenerative disorders, etc. Recent research has been focused on the beneficial role of dietary antioxidants against oxidative stress both under in vitro and in vivo conditions. Theobroma cacao L. (cacao tree) is an evergreen tree which is native to South America. It is a plant of great economic importance and its seeds are commonly used to produce cocoa powder and chocolate. In addition to its uses in food industry, cocoa is a rich source of polyphenolic antioxidants. There is a plethora of in vitro and in vivo studies that report cocoa antioxidant capacity. The protective activity of cocoa seems to be due to its phytochemical constituents, especially catechins. However, bioavailability of cocoa polyphenolic constituents following oral administration is very low (nanomolar concentrations). In the present paper, we critically reviewed the available literature on the antioxidant and free radical scavenging activities of cocoa and its polyphenolic constituents. In addition to these, we provide brief information about cultivation, phytochemistry, bioavailability and clinical impacts of cocoa.

In the last decades epidemiological studies and associated meta-analyses have strongly suggested that long term consumption of plant foods (fruits, vegetables, cereals, dry legumes, and beverages like wine, coffee and tea) offers protection against development of oxidative stress related pathologies, such as cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases [1, 2]. These results have prompted research to study polyphenols, following the discovery of their antioxidant and radical scavenger activities [3]. So, the antioxidant properties of polyphenols have been widely studied from the mid- 1990s, but the latest research indicates that the mechanisms of action of polyphenols go beyond the modulation of oxidative stress [3]. Polyphenols protective activity can be ascribed to their capacity of interact with cellular functions at different levels, such as affecting gene expression, protein synthesis and enzyme activities, binding to membrane or nuclear receptors as either an elective ligand or a ligand mimic. Recently, it has been also demonstrated the antibacterial activity of some polyphenols against multidrug-resistant bacteria [4]. The goal of this special issue is to present novel results about dietary polyphenols healthy properties, with particular attention to their mechanisms of action. On behalf of all authors, we hope that this issue of Current Pharmaceutical Biotechnology will promote novel ideas and provide prospects for theirs scientific activity. Finally, we would like to thanks all the contributors and reviewer for their precious and valuable contribution in this issue.