Analytical Profile and Antioxidant and Anti-Inflammatory Activities of the Enriched Polyphenol Fractions Isolated from Bergamot Fruit and Leave

Dramatic Suppression of Lipogenesis and No Increase in Beta-Oxidation Gene Expression Are among the Key Effects of Bergamot Flavonoids in Fatty Liver Disease

Bergamot flavonoids have been shown to prevent metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and stimulate autophagy in animal models and patients. To investigate further the mechanism of polyphenol-dependent effects, we performed a RT2-PCR array analysis on 168 metabolism, transport and autophagy-related genes expressed in rat livers exposed for 14 weeks to different diets: standard, cafeteria (CAF) and CAF diet supplemented with 50 mg/kg of bergamot polyphenol fraction (BPF). CAF diet caused a strong upregulation of gluconeogenesis pathway (Gck, Pck2) and a moderate (>1.7 fold) induction of genes regulating lipogenesis (Srebf1, Pparg, Xbp1), lipid and cholesterol transport or lipolysis (Fabp3, Apoa1, Lpl) and inflammation (Il6, Il10, Tnf). However, only one β-oxidation gene (Cpt1a) and a few autophagy genes were differentially expressed in CAF rats compared to controls. While most of these transcripts were significantly modulated by BPF, we observed a particularly potent effect on lipogenesis genes, like Acly, Acaca and Fasn, which were suppressed far below the mRNA levels of control livers as confirmed by alternative primers-based RT2-PCR analysis and western blotting. These effects were accompanied by downregulation of pro-inflammatory cytokines (Il6, Tnfa, and Il10) and diabetes-related genes. Few autophagy (Map1Lc3a, Dapk) and no β-oxidation gene expression changes were observed compared to CAF group. In conclusion, chronic BPF supplementation efficiently prevents NAFLD by modulating hepatic energy metabolism and inflammation gene expression programs, with no effect on β-oxidation, but profound suppression of de novo lipogenesis.

Extraction, purification and in vitro assessment of the antioxidant and anti-inflammatory activity of policosanols from non-psychoactive Cannabis sativa L

Policosanols (PCs) are bioactive compounds extracted from different natural waxes. In this work, the purification, characterization and assessment of the antioxidant and anti-inflammatory activity was carried out on PCs from an innovative source, i.e. a waxy material from supercritical-fluid extraction (SFE) of non-psychoactive Cannabis sativa L. (hemp) inflorescences. Starting from this material, PCs were obtained by microwave-assisted trans-esterification and hydrolysis, followed by preparative liquid chromatography under normal phase conditions. The purified product was characterized using high-performance liquid chromatography (HPLC) with an evaporative light scattering detector (ELSD). In vitro cell-free and cell-based antioxidant and anti-inflammatory assays were then performed to assess their bioactivity. HPLC-ELSED analysis of the purified mixture from hemp wax revealed C26OH and C28OH as the main compounds. In vitro assays indicated an inhibition of intracellular reactive oxygen species (ROS) production, a reduction of nuclear factor kappa B (NF-κB) activation and of the activity of the neutrophil elastase. Immunoblotting assays allowed us to hypothesize the mechanism of action of the compounds of interest, given the higher levels of MAPK-activated protein kinase 2 (MK2) and heme oxygenase-1 (HO-1) protein expression in the PC pretreated HaCaT cells. In conclusion, even if more research is needed to unveil other molecular mechanisms involved in hemp PC activity, the results of this work suggest that these compounds may have potential for use in oxinflammation processes.

Comparison of different drying methods for bergamot peel: Chemical and physicochemical properties

This study examines the effectiveness of seven drying methods applied to bergamot peels, encompassing hot air, microwave, infrared-assisted microwave, freeze, infrared, sun, and oven drying. All samples exhibited moisture content and water activity levels within the acceptable range for dry foods. All methods effectively transformed the peels into powdered form, yielding comparable results. Each method offers distinct advantages and disadvantages, and the choice of method should be based on the desired properties of the final product. The highest ascorbic acid content was found in freeze-dried and hot air-dried samples (>400 mg/100 g), whereas sun-dried samples had the lowest (89.58 mg/100 g). Infrared-dried samples exhibited the highest levels of total phenolics and flavonoids (193.40 and 530.14 mg/100 g, respectively), attributed to reactions induced by elevated temperatures. The total carotenoids were higher in freeze-dried samples (54.12 mg/100 g) compared to other drying methods (<27 mg/100 g). Microwave-dried samples had the highest 5-hydroxymethylfurfural content (73.06 mg/100 g), and freeze-dried samples had the highest naringin content (1568.70 mg/100 g). Although infrared drying had good particle density, porosity, and fluidity, freeze-drying was the most effective, retaining the highest levels of bioactive compounds. Among the methods studied, freeze-drying is recommended due to its superior ability to preserve bioactive compounds. Infrared and infrared-assisted drying methods were suitable for recovering phenolics from bergamot waste, offering lower energy consumption and practical preservation of physicochemical properties. This study emphasizes the importance of selecting the appropriate drying method to ensure high-quality dried food and producing value-added products from bergamot waste, contributing to sustainable agriculture and waste reduction. PRACTICAL APPLICATION: This study demonstrates that infrared and freeze-drying are the most effective methods for producing high-quality bergamot peel samples with enhanced antioxidant properties. These findings hold promising implications for the food industry, offering a viable approach to preserve bergamot peels and their valuable attributes.

Bergaptol, a Major Furocoumarin in Citrus: Pharmacological Properties and Toxicity

Bergaptol (5-hydroxypsoralen or 5-hydroxyfuranocoumarin) is a naturally occurring furanocoumarin widely found in citrus fruits, which has multiple health benefits. Nonetheless, no specific review articles on bergaptol have been published. Compiling updated information on bergaptol is crucial in guiding future research direction and application. The present review focuses on the research evidence related to the pharmacological properties and toxicity of bergaptol. Bergaptol has anti-inflammatory, antioxidant, anti-cancer, anti-osteoporosis, anti-microbial, and anti-lipidemic effects. It can inhibit the activities of cytochrome P450s (CYP), especially CYP2C9 and CYP3A4, thereby affecting the metabolism and concentrations of some drugs and toxins. Compared with other coumarins, bergaptol has the least potency to inhibit CYP3A4 in cancer cells. Instead, it can suppress drug efflux transporters, such as P-glycoprotein, thereby overcoming chemotherapeutic drug resistance. Furthermore, bergaptol has antimicrobial effects with a high potential for inhibition of quorum sensing. In vivo, bergaptol can be retained in plasma for longer than other coumarins. Nevertheless, its toxicity has not been clearly reported. In vitro study suggests that, unlike most furocoumarins, bergaptol is not phototoxic or photomutagenic. Existing research on bergaptol has mostly been conducted in vitro. Further in vivo and clinical studies are warranted to identify the safe and effective doses of bergaptol for its multimodal application.

Bergamot Byproducts: A Sustainable Source to Counteract Inflammation

Chronic inflammation is the result of an acute inflammatory response that fails to eliminate the pathogenic agent or heal the tissue injury. The consequence of this failure lays the foundations to the onset of several chronic ailments, including skin disorders, respiratory and neurodegenerative diseases, metabolic syndrome, and, eventually, cancer. In this context, the long-term use of synthetic anti-inflammatory drugs to treat chronic illnesses cannot be tolerated by patients owing to the severe side effects. Based on this, the need for novel agents endowed with anti-inflammatory effects prompted to search potential candidates also within the plant kingdom, being recognized as a source of molecules currently employed in several therapeutical areas. Indeed, the ever-growing evidence on the anti-inflammatory properties of dietary polyphenols traced the route towards the study of flavonoid-rich sources, such as Citrus bergamia (bergamot) and its derivatives. Interestingly, the recent paradigm of the circular economy has promoted the valorization of Citrus fruit waste and, in regard to bergamot, it brought to light new evidence corroborating the anti-inflammatory potential of bergamot byproducts, thus increasing the scientific knowledge in this field. Therefore, this review aims to gather the latest literature supporting the beneficial role of both bergamot derivatives and waste products in different models of inflammatory-based diseases, thus highlighting the great potentiality of a waste re-evaluation perspective.

Protective Role of an Extract Waste Product from Citrus bergamia in an In Vitro Model of Neurodegeneration

A balanced diet, rich in fruits and vegetables and ensuring the intake of natural products, has been shown to reduce or prevent the occurrence of many chronic diseases. However, the choice to consume large quantities of fruits and vegetables leads to an increase in the amount of waste, which can cause an alteration in environmental sustainability. To date, the concept of a "byproduct" has evolved, now being understood as a waste product from which it is still possible obtain useful compounds. Byproducts in the agricultural sector are a rich source of bioactive compounds, capable of possessing a second life, decreasing the amount of waste products, the disposal costs, and environmental pollution. A promising and well-known citrus of the Mediterranean diet is the bergamot (Citrus bergamia, Risso et Poiteau). The composition of bergamot is known, and the rich presence of phenolic compounds and essential oils has justified the countless beneficial properties found, including anti-inflammatory, antioxidant, anti-cholesterolemic, and protective activity for the immune system, heart failure, and coronary heart diseases. The industrial processing of bergamot fruits leads to the formation of bergamot juice and bergamot oil. The solid residues, referred to as "pastazzo", are normally used as feed for livestock or pectin production. The fiber of bergamot (BF) can be obtained from pastazzo and could exert an interesting effect thanks to its content of polyphenols. The aims of this work were twofold: (a) to have more information (composition, polyphenol and flavonoid content, antioxidant activity, etc.) on BF powder and (b) to verify the effects of BF on an in vitro model of neurotoxicity induced by treatment with amyloid beta protein (Aβ). In particular, a study of cell lines was carried out on both neurons and oligodendrocytes, to measure the involvement of the glia and compare it with that of the neurons. The results obtained showed that BF powder contains polyphenols and flavonoids and that it is able to exercise an antioxidant property. Moreover, BF exerts a protective action on the damage induced by treatment with Aβ, and this defense is found in experiments on the cell viability, on the accumulation of reactive oxygen species, on the involvement of the expression of caspase-3, and on necrotic or apoptotic death. In all these results, oligodendrocytes were always more sensitive and fragile than neurons. Further experiments are needed, and if this trend is confirmed, BF could be used in AD; at the same time, it could help to avoid the accumulation of waste products.

Chemical, Nutritional and Biological Evaluation of a Sustainable and Scalable Complex of Phytochemicals from Bergamot By-Products

The present paper reports a sustainable raw material obtained from the by-products derived from the industrial production of bergamot (Citrus × Bergamia Risso & Poiteau) essential oils. The procedure to obtain the raw material is designed to maintain as much of the bioactive components as possible and to avoid expensive chemical purification. It consists of spray-drying the fruit juice obtained by squeezing the fruits, which is mixed with the aqueous extract of the pulp, i.e., the solid residue remained after fruit pressing. The resulting powder bergamot juice (PBJ) contains multiple bioactive components, in particular, among others, soluble fibers, polyphenols and amino-acid betaines, such as stachydrine and betonicine. LC-MS analysis identified 86 compounds, with hesperetin, naringenin, apigenin and eridictyol glucosides being the main components. In the second part of the paper, dose-dependent anti-inflammatory activity of PBJ and of stachydrine was found, but neither of the compounds were effective in activating Nrf2. PBJ was then found to be effective in an in vivo model of a metabolic syndrome induced by a high-sugar, high-fat (HSF) diet and evidenced by a significant increase of the values related to a set of parameters: blood glucose, triglycerides, insulin resistance, systolic blood pressure, visceral adipose tissue and adiposity index. PBJ, when given to control rats, did not significantly change these values; in contrast, they were found to be greatly affected in rats receiving an HSF diet. The in vivo effect of PBJ can be ascribed not only to bergamot polyphenols with well-known anti-inflammatory, antioxidant and lipid-regulating effects, but also to the dietary fibers and to the non-phenolic constituents, such as stachydrine. Moreover, since PBJ was found to affect energy homeostasis and to regulate food intake, a mechanism on the regulation of energy homeostasis through leptin networking should also be considered and deserves further investigation.

Treatment with bergamot (Citrus bergamia) leaves extract attenuates leptin resistance in obese rats

Low-grade chronic inflammation in obesity is associated with leptin resistance. In order to alleviate this pathological condition, bioactive compounds capable of attenuating oxidative stress and inflammation have been researched, and bergamot (Citrus bergamia) presents these properties. The aim was to evaluate the effect of bergamot leaves extract on leptin resistance in obese rats. Animals were divided into 2 groups: control diet (C, n = 10) and high sugar-fat diet (HSF, n = 20) for 20 weeks. After detecting hyperleptinemia, animals were divided to begin the treatment with bergamot leaves extract (BLE) for 10 weeks: C + placebo (n = 7), HSF + placebo (n = 7), and HSF + BLE (n = 7) by gavage (50 mg/kg). Evaluations included nutritional, hormonal and metabolic parameters; adipose tissue dysfunction; inflammatory, oxidative markers and hypothalamic leptin pathway. HSF group presented obesity, metabolic syndrome, adipose tissue dysfunction, hyperleptinemia and leptin resistance compared to control group. However, the treated group showed a decrease in caloric consumption and attenuation of insulin resistance. Moreover, dyslipidemia, adipose tissue function, and leptin levels showed an improvement. At the level of the hypothalamus, the treated group showed a reduction of oxidative stress, inflammation and modulation of leptin signaling. In conclusion, BLE properties were able to improve leptin resistance through recovery of the hypothalamic pathway.

UPLC-MS/MS profiling, antioxidant and anti-inflammatory activities, and potential health benefits prediction of phenolic compounds in hazel leaf

Hazel leaf, one of the by-products of hazelnut, which is widely used in traditional folk medicine around the world. In the present study, the profile of free, conjugated, and bound phenolic compounds from hazel leaf was detected and their antioxidant and anti-inflammatory activities were investigated. The potential health benefits of different phenolic compounds were also predicted. The results showed that the 35 phenolic substances of free, conjugated and bound forms were identified including phenolic acids, flavonoids and catechins. Most of the hazel leaf phenolics were presented in free form, followed by conjugated and bound form. All the fractions effectively inhibited the production of reactive oxygen species and malondialdehyde in TBHP-stimulated human umbilical vein endothelial cells by enhancing endogenous superoxide dismutase, and accordingly alleviated inflammatory cytokines (NO, IL-1β, TNF-α, and IL-6) in LPS-stimulated RAW264.7 cells, showing obvious antioxidant and anti-inflammatory capacity. Moreover, combined with network pharmacology, the potential therapeutic effects and functional pathways of hazel leaf phenolics were predicted, which provided value basis for exploring their treatment on diseases and developing health products in the future.

Nano-Based Drug Delivery of Polyphenolic Compounds for Cancer Treatment: Progress, Opportunities, and Challenges

Polyphenols and their derivates, a kind of natural product distributed in herb plants, vegetables, and fruits, are the most abundant antioxidants in the human diet and have been found to display cancer-preventative effects in several epidemiological studies. The scientific community has also validated the anti-cancer bioactivities and low toxicities of polyphenolic compounds, including flavones, tannins, phenolic acids, and anthocyanins, through in vitro and in vivo studies. However, the low stability, weak targeting ability, poor solubility, and low bioavailability of pure polyphenolic agents have significantly impaired their treatment efficacy. Nowadays, nano-based technology has been applied to surmount these restrictions and maximize the treatment efficacy of polyphenols. In this review, we summarize the advantages and related mechanisms of polyphenols in cancer treatment. Moreover, aiming at the poor solubility and low bioavailability of pure polyphenols in vivo, the advantages of nano-based delivery systems and recent research developments are highlighted. Herein, particular emphasis is mainly placed on the most widely used nanomaterials in the delivery of natural products, including liposomes, micelles, and nanogels. Finally, we present an overview and the challenges of future implementations of nano-based delivery systems of polyphenolic compounds in the cancer therapeutic field.

An integrated metabolomic and proteomic approach for the identification of covalent inhibitors of the main protease (Mpro) of SARS-COV-2 from crude natural extracts

M^pro represents one of the most promising drug targets for SARS-Cov-2, as it plays a crucial role in the maturation of viral polyproteins into functional proteins. HTS methods are currently used to screen M^pro inhibitors, and rely on searching chemical databases and compound libraries, meaning that they only consider previously structurally clarified and isolated molecules. A great advancement in the hit identification strategy would be to set-up an approach aimed at exploring un-deconvoluted mixtures of compounds such as plant extracts. Hence, the aim of the present study is to set-up an analytical platform able to fish-out bioactive molecules from complex natural matrices even where there is no knowledge on the constituents. The proposed approach begins with a metabolomic step aimed at annotating the MW of the matrix constituents. A further metabolomic step is based on identifying those natural electrophilic compounds able to form a Michael adduct with thiols, a peculiar chemical feature of many M^pro inhibitors that covalently bind the catalytic Cys145 in the active site, thus stabilizing the complex. A final step consists of incubating recombinant M^pro with natural extracts and identifying compounds adducted to the residues within the M^pro active site by bottom-up proteomic analysis (nano-LC-HRMS). Data analysis is based on two complementary strategies: (i) a targeted search applied by setting the adducted moieties identified as Michael acceptors of Cys as variable modifications; (ii) an untargeted approach aimed at identifying the whole range of adducted peptides containing Cys145 on the basis of the characteristic b and y fragment ions independent of the adduct. The method was set-up and then successfully tested to fish-out bioactive compounds from the crude extract of Scutellaria baicalensis, a Chinese plant containing the catechol-like flavonoid baicalin and its corresponding aglycone baicalein which are well-established inhibitors of M^pro. Molecular dynamics (MD) simulations were carried out in order to explore the binding mode of baicalin and baicalein, within the SARS-CoV-2 M^pro active site, allowing a better understanding of the role of the nucleophilic residues (i.e. His41, Cys145, His163 and His164) in the protein-ligand recognition process.

Achillea moschata Wulfen: From Ethnobotany to Phytochemistry, Morphology, and Biological Activity

A multidisciplinary investigation on Achillea moschata Wulfen (Asteraceae) is outlined herein. This work, part of the European Interreg Italy-Switzerland B-ICE project, originated from an ethnobotanical survey performed in Chiesa in Valmalenco (Sondrio, Lombardy, Northern Italy) in 2019-2021 which highlighted this species' relevance of use in folk medicine to treat gastrointestinal diseases. In addition, this contribution included analyses of the: (a) phytochemical profile of the aqueous and methanolic extracts of the dried flower heads using LC-MS/MS; (b) morpho-anatomy and histochemistry of the vegetative and reproductive organs through Light, Fluorescence, and Scanning Electron Microscopy; (c) biological activity of the aqueous extract concerning the antioxidant and anti-inflammatory potential through cell-based in vitro models. A total of 31 compounds (5 phenolic acids, 13 flavonols, and 13 flavones) were detected, 28 of which included in both extracts. Covering and secreting trichomes were observed: the biseriate 10-celled glandular trichomes prevailing on the inflorescences represented the main sites of synthesis of the polyphenols and flavonoids detected in the extracts, along with volatile terpenoids. Finally, significant antioxidant and anti-inflammatory activities of the aqueous extract were documented, even at very low concentrations; for the first time, the in vitro tests allowed us to formulate hypotheses about the mechanism of action. This work brings an element of novelty due to the faithful reproduction of the traditional aqueous preparation and the combination of phytochemical and micromorphological research approaches.

Bergamot leaf extract treats cardiorenal metabolic syndrome and associated pathophysiological factors in rats fed with a high sugar fat diet

Bergamot citrus (Citrus bergamia Risso et Poiteau), have been used as a strategy to prevent or treat comorbidities associated with metabolic syndrome parameters, such as cardiorenal metabolic syndrome (CRMS). The aim was to test the effect of bergamot leaf extract on CRMS and associated pathophysiological factors in rats fed with a high sugar-fat diet. Animals were divided into two experimental groups with control diet (Control, n = 30) and high sugar-fat diet (HSF, n = 30) for 20 weeks. Once CRMS was detected, animals were redivided to begin the treatment with Bergamot Leaf Extract (BLE) by gavage (50 mg/kg) for 10 weeks: control diet + placebo (Control, n = 09), control diet + BLE (Control + BLE, n = 09), HSF diet + placebo (HSF, n = 09), HSF + BLE (n = 09). Evaluation included nutritional, metabolic and hormonal analysis; and renal and cardiac parameters. HSF groups presented obesity, dyslipidemia, hypertension, hyperglycemia, hyperinsulinemia, insulin resistance. BLE showed protection against effects on hypertriglyceridemia, insulin resistance, renal damage, and structural and functional alterations of the heart. Conclusion: Bergamot leaf extract shows potential as a therapeutic to treat CRMS in animals fed with a high sugar-fat diet.

Polyphenols from Thinned Young Apples: HPLC-HRMS Profile and Evaluation of Their Anti-Oxidant and Anti-Inflammatory Activities by Proteomic Studies

The qualitative profile of thinned apple polyphenols (TAP) fraction (≈24% of polyphenols) obtained by purification through absorbent resin was fully investigated by LC-HRMS in positive and negative ion mode and using ESI source. A total of 68 polyphenols were identified belonging to six different classes: flavanols, flavonols, dihydrochalchones, flavanones, flavones and organic and phenolic acids. The antioxidant and anti-inflammatory activities were then investigated in cell models with gene reporter for NRF2 and NF-κB and by quantitative proteomic (label-free and SILAC) approaches. TAP dose-dependently activated NRF2 and in the same concentration range (10–250 µg/mL) inhibited NF-κB nuclear translocation induced by TNF-α and IL-1α as pro-inflammatory promoters. Proteomic studies elucidated the molecular pathways evoked by TAP treatment: activation of the NRF2 signaling pathway, which in turn up-regulates protective oxidoreductases and their nucleophilic substrates such as GSH and NADPH, the latter resulting from the up-regulation of the pentose phosphate pathway. The increase in the enzymatic antioxidant cellular activity together with the up-regulation of the heme-oxygenase would explain the anti-inflammatory effect of TAP. The results suggest that thinned apples can be considered as a valuable source of apple polyphenols to be used in health care products to prevent/treat oxidative and inflammatory chronic conditions.

Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS) Profiling of Commercial Enocianina and Evaluation of Their Antioxidant and Anti-Inflammatory Activity

Enocianina is an anthocyanin-rich extract obtained from grape pomace. It is widely used as a colorant in the food industry and, in addition to anthocyanins, it also contains a variety of polyphenols. To understand whether enocianina, besides its coloring effect, may offer potential health benefit applications, we aimed to fully characterize the profile of four commercial enocianinas and assess their radical scavenging, enzymatic, antioxidant, and anti-inflammatory activities. LC-ESI-MS/MS analysis identified 90 phytochemicals. The relative content of each anthocyanin was assessed by a semi-quantitative analysis, with malvidin derivatives being the most abundant. UV-VIS spectroscopy detected total amounts of polyphenols and anthocyanins of 23% and 3.24%, respectively, indicating that anthocyanins represent a minor fraction of total polyphenols. Multiple linear regression analysis indicated that the radical scavenging activity is related to the total polyphenol content and not to anthocyanins. All four enocianinas dose-dependently activate Nrf2, and such activity was correlated with catechol-containing polyphenol content. Finally, all enocianinas showed dose-dependent anti-inflammatory activity, which at the highest concentrations tested was closely related to the total polyphenol content and was explained by radical scavenging, Nrf2 activation, and other mechanisms related to the polyphenolic components.

Bergamot and olive extracts as beer ingredients: their influence on nutraceutical and sensory properties

Citrus bergamia and Olea europaea L. variety Carolea are accounted as niche functional food for their high content of bio active compounds. Their extracts were used as adjunct to produce two beers with different styles, Blanche and Weiss, rich in antioxidants for a pool of consumers interested in a healthy lifestyle. The nutraceutical properties of these two beers were compared to Blanche and Weiss without any addition to verify if the beers enriched with natural extracts changed their aromaticity, flavors, and functionality. The antioxidant activity changed in the order: blanche bergamot beer > Weiss olive beer > blanche basal beer > Weiss basal beer. The phenolic profile of bergamot beer was qualitatively and quantitatively the richest in bio-compounds. Pearson’s correlation evidenced that total phenols contained in bergamot and olive beers were positively and significantly correlated with the antioxidant activities and precisely, with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and total antioxidant capacity (TAC). Correlation data evidenced that the bergamot was the beer with the greatest antioxidant activity and bioactive compound amount. This study highlighted as the addition of these natural extracts together with the right productive process improved sensorial beer properties, satisfying consumer taste while potentially increasing the beneficial effects on human health.

Molecular Modeling and Experimental Evaluation of Non-Chiral Components of Bergamot Essential Oil with Inhibitory Activity against Human Monoamine Oxidases

Human monoamine oxidases (hMAOs) are well-established targets for the treatment of neurological disorders such as depression, Parkinson's disease and Alzheimer's disease. Despite the efforts carried out over the years, few selective and reversible MAO inhibitors are on the market. Thus, a continuous search for new compounds is needed. Herein, MAO inhibitors were searched among the non-chiral constituents of Bergamot Essential Oil (BEO) with the aid of computational tools. Accordingly, molecular modeling simulations were carried out on both hMAO-A and hMAO-B for the selected constituents. The theoretically predicted target recognition was then used to select the most promising compounds. Among the screened compounds, Bergamottin, a furocoumarin, showed selective hMAO-B inhibitory activity, fitting its active site well. Molecular dynamics simulations were used to deeply analyze the target recognition and to rationalize the selectivity preference. In agreement with the computational results, experimental studies confirmed both the hMAO inhibition properties of Bergamottin and its preference for the isoform B.

Artichoke and bergamot extracts: a new opportunity for the management of dyslipidemia and related risk factors

The relationship between low LDL-C (cholesterol associated with low-density lipoprotein) and a lower relative risk of developing cardiovascular disease (CVD) has been widely demonstrated. Although from a pharmacological point of view, statins, ezetimibe and PCSK inhibitors, alone or in combination are the front and center of the therapeutic approaches for reducing LDL-C and its CV consequences, in recent years nutraceuticals and functional foods have increasingly been considered as a valid support in the reduction of LDL-C, especially in patients with mild/moderate hyperlipidemia - therefore not requiring pharmacological treatment - or in patients intolerant to statins or other drugs. An approach also shared by the European Atherosclerosis Society (EAS). Of the various active ingredients with hypolipidemic properties, we include the artichoke (Cynara cardunculus, Cynara scolymus) and the bergamot (Citrus bergamia) which, thanks essentially to the significant presence of polyphenols in their extracts, can exert this action associated with a number of other complementary inflammation and oxidation benefits. In light of these evidence, this review aimed to describe the effects of artichoke and bergamot in modifying the lipid and inflammatory parameters described in in vitro, in vivo and clinical studies. The available data support the use of standardized compositions of artichoke and bergamot extracts, alone or in combination, in the treatment of mild to moderate dyslipidemia, in patients suffering from metabolic syndrome, hepatic steatosis, or intolerant to common hypolipidemic treatments.

Metabolic composition and authenticity evaluation of bergamot essential oil assessed by nuclear magnetic resonance spectroscopy

In this work, a sample of pure and certified bergamot essential oil (BEO) was extensively studied for the first time directly by NMR spectroscopy with the aim of investigating its metabolic composition, quantifying the main components of this complex natural matrix and simultaneously assessing whether the NMR technique is able to highlight possible frauds to which this high-cost product may be subjected. Eleven low molecular weight compounds have been identified by using 1D ¹H and ¹³C-{¹H} NMR experiments, 2D homo- and heteronuclear correlation NMR spectra, and 2D ¹H DOSY experiments; the most abundant of them, i.e., about 90% of the sample analyzed, has been quantified by employing benzoic acid as an internal standard by ¹H NMR spectrum. Moreover, since the commercial fraud of this precious oil is often due to the addition of less expensive oils, we have simulated a possible adulteration through the preparation of BEO samples to which different percentages of orange essential oil (OEO) were added. The results, obtained by combining the ¹H NMR spectra collected on the adulterated samples and on pure BEO, with chemometric analysis, principal component analysis (PCA), indicate that it is possible to distinguish the sample of pure BEO from the adulterated ones and also, among them, to differentiate between the degrees of adulteration.

Nutraceuticals and Cancer: Potential for Natural Polyphenols

Cancer is one of the leading causes of death globally, associated with multifactorial pathophysiological components. In particular, genetic mutations, infection or inflammation, unhealthy eating habits, exposition to radiation, work stress, and/or intake of toxins have been found to contribute to the development and progression of cancer disease states. Early detection of cancer and proper treatment have been found to enhance the chances of survival and healing, but the side effects of anticancer drugs still produce detrimental responses that counteract the benefits of treatment in terms of hospitalization and survival. Recently, several natural bioactive compounds were found to possess anticancer properties, capable of killing transformed or cancerous cells without being toxic to their normal counterparts. This effect occurs when natural products are associated with conventional treatments, thereby suggesting that nutraceutical supplementation may contribute to successful anticancer therapy. This review aims to discuss the current literature on four natural bioactive extracts mostly characterized by a specific polyphenolic profile. In particular, several activities have been reported to contribute to nutraceutical support in anticancer treatment: (1) inhibition of cell proliferation, (2) antioxidant activity, and (3) anti-inflammatory activity. On the other hand, owing to their attenuation of the toxic effect of current anticancer therapies, natural antioxidants may contribute to improving the compliance of patients undergoing anticancer treatment. Thus, nutraceutical supplementation, along with current anticancer drug treatment, may be considered for better responses and compliance in patients with cancer. It should be noted, however, that when data from studies with bioactive plant preparations are discussed, it is appropriate to ensure that experiments have been conducted in accordance with accepted pharmacological research practices so as not to disclose information that is only partially correct.

Defining the Cholesterol Lowering Mechanism of Bergamot (Citrus bergamia) Extract in HepG2 and Caco-2 Cells

Bergamot, a Mediterranean citrus fruit native to southern Italy, has been reported to have cholesterol-lowering properties; however, the mechanism of action is not well understood. Due to structural similarities with 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) inhibitors, it has been proposed that the phenolic compounds in bergamot may also inhibit HMGCR. Statins are widely used for their cholesterol-lowering properties; however, they are not universally well tolerated, suggesting there is a need to identify novel cholesterol-lowering strategies. In the present study, we investigated bergamot fruit extract (BFE) and its principal components (neoeriocitrin, naringin, neohesperidin, melitidin, and brutieridin) for their ability to regulate cholesterol levels in HepG2 and Caco-2 cells. BFE at increasing concentrations decreased the levels of total and free cholesterol in HepG2 cells. BFE and its constituents did not directly inhibit HMGCR activity. However, BFE and neohesperidin decreased HMGCR levels in HepG2 cells, suggesting that neohesperidin and BFE may downregulate HMGCR expression. An increase in AMP-kinase phosphorylation was observed in BFE and neohesperidin-treated cells. In Caco-2 cells, brutieridin exhibited a significant reduction in cholesterol uptake and decreased the level of Niemann-Pick C1 Like 1, an important cholesterol transporter. Taken together, our data suggest that the cholesterol-lowering activity of bergamot is distinct from statins. We hypothesize that BFE and its principal constituents lower cholesterol by inhibiting cholesterol synthesis and absorption.

Effect of Extraction Solvent and Temperature on Polyphenol Profiles, Antioxidant and Anti-Inflammatory Effects of Red Grape Skin By-Product

A fully-detailed LC-MS qualitative profiling of red grape skin, extracted with a mixture of ethanol and water (70:30 v:v) has permitted the identification of 65 compounds which can be classified into the following chemical classes: organic and phenolic acids (14 compounds), stilbenoids (1 compound), flavanols (21 compounds), flavonols (15 compounds) and anthocyanins (14 compounds). The extraction yield obtained with water at different temperatures (100 °C, 70 °C, room temperature) was then evaluated and the overall polyphenol content indicates that EtOH:H2O solvent is the most efficient and selective for polyphenol extraction. However, by analyzing the recovery yield of each single polyphenol, we found that water extraction under heating conditions is effective (extraction yield similar or even better in respect to the binary solvent) for some polyphenolic classes, such as hydrophilic procyanidins, phenolic acids, flavonol glucosides and stilbenoids. However, according to their lipophilic character, a poor yield was found for the most lipophilic components, such as flavonol aglycones, and in general for anthocyanins. The radical scavenging activity was in accordance with the polyphenol content, and hence, much higher for the extract obtained with the binary solvent in respect to water extraction. All the tested extracts were found to have an anti-inflammatory activity in the R3/1 cell line with NF-kb reporter challenged with 0.01 µg/mL of IL-1α, in a 1 to 250 µg/mL concentration range. An intriguing result was that the EtOH:H2O extract was found to be superimposable with that obtained using water at 100 °C despite the lower polyphenol content. Taken together, the results show the bioactive potentialities of grape skin extracts and the possibility to exploit this rich industrial waste. Water extraction carried out by heating is an easy, low-cost and environmentally friendly extraction method for some polyphenol classes and may have great potential for extracts with anti-inflammatory activities.

Apigenin and Luteolin Regulate Autophagy by Targeting NRH-Quinone Oxidoreductase 2 in Liver Cells

Dietary flavonoids stimulate autophagy and prevent liver dysfunction, but the upstream signaling pathways triggered by these compounds are not well understood. Certain polyphenols bind directly to NRH-quinone oxidoreductase 2 (NQO2) and inhibit its activity. NQO2 is highly expressed in the liver, where it participates in quinone metabolism, but recent evidence indicates that it may also play a role in the regulation of oxidative stress and autophagy. Here, we addressed a potential role of NQO2 in autophagy induction by flavonoids. The pro-autophagic activity of seven flavonoid aglycons correlated perfectly with their ability to inhibit NQO2 activity, and flavones such as apigenin and luteolin showed the strongest activity in all assays. The silencing of NQO2 strongly reduced flavone-induced autophagic flux, although it increased basal LC3-II levels in HepG2 cells. Both flavones induced AMP kinase (AMPK) activation, while its reduction by AMPK beta (PRKAB1) silencing inhibited flavone-induced autophagy. Interestingly, the depletion of NQO2 levels by siRNA increased the basal AMPK phosphorylation but abrogated its further increase by apigenin. Thus, NQO2 contributes to the negative regulation of AMPK activity and autophagy, while its targeting by flavones releases pro-autophagic signals. These findings imply that NQO2 works as a flavone receptor mediating autophagy and may contribute to other hepatic effects of flavonoids.

(Z)-5-(3′,4′-Bis(benzyloxy)benzylidene)furan-2(5H)-one

Over the years secondary metabolites have been considered as lead molecules both in their natural form and as templates for medicinal chemistry. Some secondary metabolites such as polyphenols and flavan-3-ols exert beneficial effects after a modification by the microbiota. Synthetic precursors of some of these modified compounds, in turn, carried a γ-alkylidenebutenolide moiety which characterizes a large class of bioactive natural products endowed with a wide range of biological activities. For these reasons stereoselective preparation of γ-alkylidenebutenolide continues to be an important issue for organic chemists. Our objective is to synthetize the novel compound (Z)-5-(3′,4′-bis(benzyloxy)benzylidene)furan-2(5H)-one in a stereocontrolled-one-pot reaction. The product was obtained in good yield. Furthermore, the theoretical investigation of the transition states suggests a new procedure to achieve Z-isomer of β-unsubstituted γ-alkylidenebutenolide.