Diet-Derived Antioxidants and Their Role in Inflammation, Obesity and Gut Microbiota Modulation

It is generally accepted that gut microbiota, inflammation and obesity are linked to the development of cardiovascular diseases and other chronic/non-communicable pathological conditions, including cancer, neurodegenerative diseases and ageing-related disorders. In this scenario, oxidative stress plays a pivotal role. Evidence suggests that the global dietary patterns may represent a tool in counteracting oxidative stress, thus preventing the onset of diseases related to oxidative stress. More specifically, dietary patterns based on the regular consumption of fruits and vegetables (i.e., Mediterranean diet) have been licensed by various national nutritional guidelines in many countries for their health-promoting effects. Such patterns, indeed, result in being rich in specific components, such as fiber, minerals, vitamins and antioxidants, whose beneficial effects on human health have been widely reported. This suggests a potential nutraceutical power of specific dietary components. In this manuscript, we summarize the most relevant evidence reporting the impact of dietary antioxidants on gut microbiota composition, inflammation and obesity, and we underline that antioxidants are implicated in a complex interplay between gut microbiota, inflammation and obesity, thus suggesting their possible role in the development and modulation of chronic diseases related to oxidative stress and in the maintenance of wellness. Do all roads lead to Rome

Phoenix dactylifera L. seeds: a by-product as a source of bioactive compounds with antioxidant and enzyme inhibitory properties

Date (Phoenix dactylifera L.) seeds are a valuable and abundant by-product with various potential food applications and a source of functional and bioactive ingredients. In this study, date seeds from eight cultivars (Ourous “OUR”, Tazizaout “TAZ”, Tazarzeit “TAR”, Tazoughart “TAG”, Ouaouchet “OUC”, Oukasaba “OUK”, Delat “DEL” and Tamezwertn'telet “TWT”) cultivated in the M'zab oasis (south of Algeria) were analyzed for their chemical and phytochemical compositions, antioxidant capacities and in vitro inhibition of some enzymes. Variations in chemical compositions were observed in the studied date seeds. The greatest contents of total phenolic compounds (476 mg GAE per g dw), total flavonoids (6.52 mg QE per g dw), anthocyanins (1.26 mg Q3GE per g dw), flavonols (3.36 mg Q3GE per g dw), proanthocyanidins (85.13 mg CE per g dw), and ascorbic acid were detected in the seeds of the TAG cultivar. All extracts manifested good antioxidant activities tested by ORAC and FRAP assays. The OUC and OUR extracts displayed the most potent antioxidant capacity against DPPH˙ free radicals (IC50 = 37.30 μg ml−1) and ABTS˙+ cation radicals (IC50 = 13.89 μg ml−1), respectively. The antioxidant activity evaluated through a xanthine/xanthine oxidase system demonstrated that the TAZ extract was more efficient as a superoxide radical scavenger (IC50 = 9.08 μg ml−1). Date seed extracts (DSE) exhibited inhibitory activities on enzymes, showing substantial potential as skin-whitening, neuroprotective, anti-hyperglycemic or anti-hyperlipidemic agents; the inhibitory potential was tested using tyrosinase (TYR), acetylcholinesterase (AChE), α-glucosidase (α-GLU) and lipase. All date seed cultivars were able to inhibit tyrosinase and α-glucosidase in a dose-dependent manner reaching the maximum inhibition

Promelanogenic Effects by an Annurca Apple-Based Natural Formulation in Human Primary Melanocytes

Introduction Melanocytes are engaged in synthesis, transport, and release of pigments at the epidermal-melanin units in response to the finely regulated melanogenic pathway. A multifaceted combination of both intrinsic and extrinsic factors – from endocrine and paracrine dynamics to exogenous stimuli such as sunlight and xenobiotics – modulates expression and activity of proteins involved in pigmentation, including the rate-limiting enzyme tyrosinase. As well as playing critical physiological functions comprising skin photoprotection, melanins define hair and skin pigmentation which in turn have impacted considerably to human social communication since time immemorial. Additionally, numerous skin diseases based on pigmentation alterations can have serious public influence. While several melanogenesis inhibitors are already available, the number of melanin activators and tyrosinase stimulators as drug-like agents is still limited. Methods To explore the biological effects of an Annurca Apple-based nutraceutical preparation (AMS) on melanin production, experiments in cellular models of human skin were performed. Both primary cultures and co-cultures of epidermal melanocytes (HEMa) and follicular keratinocytes (HHFK) were used. Results We show that AMS, by now branded for its cutaneous beneficial effects, induces in total biocompatibility a significant promelanogenic effect in human primary melanocytes. In line, we found melanin cytosolic accumulation consistent with tyrosinase up-regulation. Conclusion Disposal of skin pigmenting agents would be attractive for the treatment of hypopigmentation disorders, to postpone skin photoaging or simply for fashion, so that discovery and development of melanogenesis stimulators, especially from natural sources, is nowadays a dynamic area of research

Annurca apple (M. pumila Miller cv Annurca) extracts act against stress and ageing in S. cerevisiae yeast cells

During the past years, a number of studies have demonstrated the positive effect of apple on ageing and different diseases such as cancer, degenerative and cardiovascular diseases. The unicellular yeast Saccharomyces cerevisiae represents a simple eukaryotic model to study the effects of different compounds on lifespan. We previously demonstrated that apple extracts have anti-ageing effects in this organism because of their antioxidant properties. In particular, the effect is related to the presence in this fruit of polyphenols, which give a large contribution to the antioxidant activity of apples

Nutrition, inflammation and liver-spleen axis

Chronic low-grade systemic inflammation represents a mechanism common to many diseases linked to atherosclerosis-related pathways. There is a growing body of evidence indicating that the combination of food quantity and quality along with genetic susceptibility are able to induce the aberrant activation of innate immune signalling, which initially contributes to chronic low-grade inflammation. Liver represents the central player to inflammatory response. Dietary/metabolic factors contribute to the pathogenesis of Non-alcoholic Fatty Liver Disease (NAFLD), the main causes of liver disease in the Western world. Enlargement of the spleen, central organ in regulating the inflammation-related immune response, is commonly seen in patients with of NAFLD, depicting the so called "liver-spleen axis." The aim of this review was to provide an at-a-glance overview of the possible bi-directional mechanisms linking nutrition and inflammation, particularly pinpointing the inflammatory effects stemmed by nutrition on "liver-spleen axis." In particular, the role of unhealthy diet, healthy dietary patterns, such as the Mediterranean diet style, dietary vitamins and micronutrients, such as vitamin D or Magnesium, and Glucagon-Like Peptide-1, a well-known incretin released in response to meal intake, will be discussed. The highly variability of the inflammatory response highlights the role of expert nutritionists in refining methodologies apt to assess nutritional epidemiology and to apply appropriate dietary intervention to counteract diet-induced inflammation mechanisms

Antioxidant and Antidiabetic Properties of a Thinned-Nectarine-Based Nanoformulation in a Pancreatic β-Cell Line

Pancreatic β-cells play a crucial role in maintaining glucose homeostasis, although they are susceptible to oxidative damage, which can ultimately impair their functionality. Thinned nectarines (TNs) have gained increasing interest due to their high polyphenol and abscisic acid (ABA) content, both of which possess antidiabetic properties. Nevertheless, the efficacy of these bioactive compounds may be compromised by limited stability and bioavailability in vivo. This study aimed to develop nanoformulations (NFs) containing pure ABA or a TN extract (TNE) at an equivalent ABA concentration. Subsequently, the insulinotropic and antioxidant potential of the NFs and their unformulated (free) forms were compared in MIN-6 pancreatic cells exposed to varying glucose (5.5 mM and 20 mM) and iron (100 µM) concentrations. NF-TNE treatment exhibited enhanced antioxidant activity compared to free TNE, while ABA-based groups showed no significant antioxidant activity. Moreover, MIN6 cells incubated with both high glucose and iron levels demonstrated significantly higher insulin AUC levels after treatment with all samples, with NF-TNE displaying the most pronounced effect. In conclusion, these results highlight the additional beneficial potential of TNE due to the synergistic combination of bioactive compounds and demonstrate the significant advantage of using a nanoformulation approach to further increase the benefits of this and similar phytobioactive molecules