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The increasing need for new treatments for obesity and diabetes has led to the development of new drugs and food supplements that could reduce carbohydrate absorption. Many starch blockers, based on common bean proteinaceous inhibitors against α-amylase (α-AI), are already present on the market. The extraction and purification of α-amylase inhibitor from a promising common bean cultivar from Sardinia (Nieddone) is described, highlighting the unique value of the Nieddone cultivar, particularly for its inhibitory activity on digestive enzymes and its complete lack of a hemagglutination effect on human red blood cells. The purification of α-AI involved two chromatographic steps (IEC and SEC) and was essential for revealing certain properties of the inhibitor. The purified inhibitor has a tetrameric structure (α2β2) and a molecular weight of approximately 42 kDa, as determined by SEC and SDS-PAGE, confirming it as a lectin-like inhibitor. The identification of the α-AI sequence was obtained by bottom-up high-resolution mass spectrometry, which allowed us to identify a unique peptide from the α chain and six unique peptides from the β chains. α-AI exhibited an optimum temperature of around 40 °C and two pH optima at 5 and 6.5, respectively. Its remarkable stability at high temperatures was measured (approximately 25% of activity retained even after 5 h at 100 °C), whereas the raw extract lost its activity entirely after just 10 min at 90 °C. Thus, the purification process significantly enhances the thermal stability of α-AI. The demonstrated effectiveness of the purified α-AI against the α-amylase enzyme in pigs, humans and insects underscores the protein's potential for treating obesity and diabetes, as well as for managing insect pests. [ABSTRACT FROM AUTHOR]

Maltese Mushroom (Cynomorium coccineum L.) is a non-photosynthetic plant that has been used in traditional medicine for many centuries. In this paper, water extracts from the whole plant, external layer and peeled plant were studied to determine the main components responsible for its biological activities, i.e., its antimicrobial, antioxidant, and anti-tyrosinase activities; its cytotoxicity against mouse melanoma B16F10 cells; and its pro-erectile activity in adult male rats. The results of electron transfer and hydrogen transfer assays showed that the antioxidant activity was mainly due to anthocyanins in the external layer, whereas the external layer and peeled plant extracts both inhibited the microbial growth of several Gram-positive strains. In contrast, the whole plant extract had the highest anti-tyrosinase activity and exhibited pro-erectile activity when administered subcutaneously. Overall, this study elucidated which parts of Maltese Mushroom are responsible for its antimicrobial, antioxidant, and anti-tyrosinase activities and thus which extracts have potential for use in nutraceutical formulations.

Phaseolus vulgaris α-amylase inhibitor (α-AI) is a protein that has recently gained commercial interest, as it inhibits mammalian α-amylase activity, reducing the absorption of dietary carbohydrates. Numerous studies have reported the efficacy of preparations based on this protein on the control of glycaemic peaks in type-2 diabetes patients and in overweight subjects. A positive influence on microbiota regulation has also been described. In this work, ten insufficiently studied Italian P. vulgaris cultivars were screened for α-amylase- and α-glucosidase-inhibiting activity, as well as for the absence of antinutritional compounds, such as phytohemagglutinin (PHA). All the cultivars presented α-glucosidase-inhibitor activity, while α-AI was missing in two of them. Only the Nieddone cultivar (ACC177) had no haemagglutination activity. In addition, the partial nucleotide sequence of the α-AI gene was identified with the degenerate hybrid oligonucleotide primer (CODEHOP) strategy to identify genetic variability, possibly linked to functional α-AI differences, expression of the α-AI gene, and phylogenetic relationships. Molecular studies showed that α-AI was expressed in all the cultivars, and a close similarity between the Pisu Grogu and Fasolu cultivars' α-AI and α-AI-4 isoform emerged from the comparison of the partially reconstructed primary structures. Moreover, mechanistic models revealed the interaction network that connects α-AI with the α-amylase enzyme characterized by two interaction hotspots (Asp38 and Tyr186), providing some insights for the analysis of the α-AI primary structure from the different cultivars, particularly regarding the structure–activity relationship. This study can broaden the knowledge about this class of proteins, fuelling the valorisation of Italian agronomic biodiversity through the development of commercial preparations from legume cultivars. [ABSTRACT FROM AUTHOR]

Overweight and obesity are constantly increasing, not only in Western countries but also in low‐middle‐income ones. The decrease of both the intake of carbohydrates and their assimilation are among the main dietary strategies to counter these conditions. α‐Amylase, a key enzyme involved in the digestion of carbohydrates, is the target enzyme to reduce the absorption rate of carbohydrates. α‐Amylase inhibitors (α‐AIs) can be found in plants. The common bean, Phaseolus vulgaris is of particular interest due to the presence of protein‐based α‐AIs which, through a protein–protein interaction, reduce the activity of this enzyme. Here we describe the nature of the various types of common bean seed extracts, the type of protein inhibitors they contain, reviewing the recent Literature about their molecular structure and mechanism of action. We also explore the existing evidence (clinical trials conducted on both animals and humans) supporting the potential benefits of this protein inhibitors from P. vulgaris, also highlighting the urgent need of further studies to confirm the clinical efficacy of the commercial products. This work could contribute to summarize the knowledge and application of P. vulgaris extract as a nutraceutical strategy for controlling unwanted weight gains, also highlighting the current limitations. [ABSTRACT FROM AUTHOR]

Cynomorium coccineum is a non-photosynthetic plant that grows in Mediterranean countries and that is amply used in the traditional medicine. The aim of this study was to extend previous studies on the chemical and biological properties of C. coccineum, evaluating the potential antiviral and antiproliferative activity of the methanolic extract. The MTT assay was used for the in vitro cytotoxic studies against human cancer-derived cell lines, while both MTT and plaque reduction (PRT) methods were used to evaluate the potential inhibitory effect of the extract against a panel of mammal viruses. The results obtained showed no selective activity against any DNA and RNA virus but revealed an interesting antiproliferative activity against human leukaemia-derived cell lines. [ABSTRACT FROM AUTHOR]

Oxidative stress is the imbalance between reactive oxygen species (ROS) production, and accumulation and the ability of a biological system to clear these reactive products. This imbalance leads to cell and tissue damage causing several disorders in human body, such as neurodegeneration, metabolic problems, cardiovascular diseases, and cancer. Cucurbitaceae family consists of about 100 genera and 1,000 species of plants including mostly tropical, annual or perennial, monoecious, and dioecious herbs. The plants from Cucurbita species are rich sources of phytochemicals and act as a rich source of antioxidants. The most important phytochemicals present in the cucurbits are cucurbitacins, saponins, carotenoids, phytosterols, and polyphenols. These bioactive phyto‐constituents are responsible for the pharmacological effects including antioxidant, antitumor, antidiabetic, hepatoprotective, antimicrobial, anti‐obesity, diuretic, anti‐ulcer activity, and antigenotoxic. A wide number of in vitro and in vivo studies have ascribed these health‐promoting effects of Cucurbita genus. Results of clinical trials suggest that Cucurbita provides health benefits for diabetic patients, patients with benign prostate hyperplasia, infertile women, postmenopausal women, and stress urinary incontinence in women. The intend of the present review is to focus on the protective role of Cucurbita spp. phytochemicals on oxidative stress‐related disorders on the basis of preclinical and human studies. The review will also give insights on the in vitro and in vivo antioxidant potential of the Cucurbitaceae family as a whole. [ABSTRACT FROM AUTHOR]

Weeds thrive in agricultural environments. However, in certain areas of the world, they are consumed by humans as food, and they can represent a source of valuable active ingredients of ethnomedical interest. In this study, three North African parasitic plants of the Orobanchaceae family, Cistanche violacea, Orobanche crenata and Orobanche lavandulacea, normally considered as weeds, were studied to compare their biological activities. The antioxidant activity of hexane, ethyl acetate, acetone, methanol, and water extracts obtained by sequential maceration was estimated by DPPH, ABTS and FRAP assays. The metabolic profiles of aqueous extracts were studied by 1H NMR spectroscopy. The oils extracted using hexane as solvent were analyzed by GC-FID and HPLC-DAD to characterize the fatty acid profile. The cytotoxic effect of the oil from the parasitic plants was also studied on B16F10 melanoma cancer cells. All extracts showed antioxidant activity and differences between extracts obtained using different solvents as well as for different plants have been highlighted. The highest total phenolic content was determined in O. crenata acetone extract (3.53±0.20 mmol GAE/g) and in O. lavandulacea methanol extract (2.29±0.02 mmol GAE/g). 1H NMR spectroscopy revealed the presence of amino acids, organic acids and carbohydrates. The major fatty acids in the oils were 18:2 n-6, 16:0, 18:1 n-9, and 18:3 n-3. O. lavandulacea revealed to be a highly cytotoxic species for B16F10 melanoma cells. These data suggest that, despite the extreme climate conditions and the damage that can result, the studied desert parasitic plants can represent a novel and precious source of metabolites, with promising biological activities. [ABSTRACT FROM AUTHOR]

Avocado and soybean unsaponifiables (ASU) constitute vegetable extracts made from fruits and seeds of avocado and soybean oil. Characterized by its potent anti-inflammatory effects, this ASU mixture is recommended to act as an adjuvant treatment for osteoarthritic pain and slow-acting symptomatic treatment of hip and knee osteoarthritis; autoimmune diseases; diffuse scleroderma and scleroderma-like states (e.g., morphea, sclerodactyly, scleroderma in bands). Besides, it was reported that it can improve the mood and quality of life of postmenopausal women in reducing menopause-related symptoms. This article aims to summarize the studies on biological effects of the avocado-soybean unsaponifiable, its chemical composition, pharmacotherapy as well as applications in autoimmune, osteoarticular and menopausal disorders. Finally, we will also discuss on its safety, toxicological and regulatory practices. [ABSTRACT FROM AUTHOR]

Cynomorium coccineum L. is a non-photosynthetic plant, spread over Mediterranean countries, amply used in traditional medicine. The aim of this study was to evaluate for the first time the antifungal activity of its extracts. The antifungal activity was evaluated using the macrodilution method against Candida spp., Cryptococcus neoformans and dermatophyte strains. The methanolic extract was very active against C. neoformans, Candida guilliermondii and Candida krusei, with minimal inhibitory concentrations (MIC) values of 0.025 mg/mL. This extract is more active than fluconazole against C. krusei H9. The influence of methanolic extract on the dimorphic transition in Candida albicans was also studied through the germ tube inhibition assay. More than 60% of filamentation was inhibited at a concentration of 1/4 MIC. These results are preliminary and further studies are needed to an eventual use of C. coccineum methanolic extract in the treatments of candidiasis and cryptococcosis. [ABSTRACT FROM AUTHOR]

This paper describes the oxidation of inorganic sulfide to sulfate, minimizing the formation of elemental sulfur. The described catalytic reaction uses dilute hydrogen peroxide at nearly neutral pH values in the presence of a bioinspired, heterogenized, and commercial ferriporphin. A substantial increase of the percentage of sulfide converted to sulfate is obtained in comparison with the yields obtained when working with hydrogen peroxide alone. The biomimetic catalyst also proved to be a much more efficient catalyst than horseradish peroxidase. Accordingly, it could be suitable for large-scale applications. Further studies are in progress to drive sulfate yields up to nearly quantitative. [ABSTRACT FROM AUTHOR]

The problem of nitrate removal from agricultural and industrial wastewaters is increasingly drawing attention since contamination more and more jeopardizes drinking water resources. The yeast Sporobolomyces salmonicolor produces a constitutive nitrate reductase and can use nitrate as the sole nitrogen source. The obtained nitrite is in turn reduced and assimilated by the yeast and converted into biomass. In the present study some biological features of a S. salmonicolor strain, relevant in relation with the problem of nitrate removal, such as temperature and pH requirements, preference towards particular carbon sources, and also availability of alternative nitrogen sources, have been studied in the light of their influence towards nitrate assimilation. Both efficiency and kinetics of nitrate assimilation were also explored. Work on real wastewater samples allowed for assessing the potential of the micro-organism for bioremediation: in particular, nitrogen-rich wastewaters were shown to be substantially depleted in their total nitrogen content, whereas noticeable amounts of protein-rich biomass were formed. [ABSTRACT FROM AUTHOR]

A number of vanilloids have been tested as tyrosinase inhibitors using Ligand-Based Virtual Screening (LBVS) driven by QSAR (Quantitative Structure-Activity Relationship) models as the multi-agent classification system. A total of 81 models were used to screen this family. Then, a preliminary cluster analysis of the selected chemicals was carried out based on their bioactivity to detect possible similar substructural features among these compounds and the active database used in the QSAR model construction. The compounds identified were tested in vitro to corroborate the results obtained in silico. Among them, two chemicals, isovanillin ( K = 1.08 mM) near to kojic acid (reference drug) in one cluster and isovanillyl alcohol ( K = 0.88 mM) at the same distance as hydroquinone (reference drug) in another cluster showed inhibitory activity against tyrosinase. The algorithm proposed here could result in a suitable approach for faster and more effective identification of hit and/or lead compounds with tyrosinase inhibitory activity, helping to shorten the long pipeline in the research of novel depigmenting agents to treat skin disorders. Copyright © 2010 John Wiley & Sons, Ltd. A number of vanilloids have been tested as tyrosinase inhibitors using Ligand−Based Virtual Screening (LBVS) driven by QSAR (Quantitative Structure−Activity Relationship) models as the multi−agent classification system. The algorithm proposed here could result in a suitable approach for more effective identification of compounds with tyrosinase inhibitory activity, helping in the research of novel depigmenting agents to treat skin disorders. [ABSTRACT FROM AUTHOR]

Several Mediterranean shrubs, both autochthonous and naturalized, have been traditionally used as food, flavouring and/or spicing agents, and as phytopharmaceuticals. The interest around 'natural' and 'biological' products is steadily increasing in developed countries. Therefore, it seems reasonable to screen some shrubs with regard to the actual information about their content of phytochemicals, in relation to both real and putative beneficial properties, and with particular concern to their 'antioxidant' power. Moreover, striking molecules from the examined shrubs are compared according to their occurrence in the various genera. Also, their structures and structure/activity relationship are discussed in the light of possible practical application. [ABSTRACT FROM AUTHOR]

Melanin (eumelanin) is commonly produced in mammals starting from tyrosine and/or 3,4-dioxyphenylalanine (DOPA) under the action of tyrosinase. 3-Hydroxyanthranilic acid and 3-hydroxykynurenine are intermediates occurring in the kynurenine pathway of tryptophan catabolism. In this paper, we show that these substances can interfere in melanin formation in vitro when tyrosine or DOPA is oxidized by molecular oxygen under catalysis by tyrosinase. In particular, when 3-hydroxyanthranilic acid is present, a brown and apparently water-soluble pigment is formed, whereas the typical eumelanin granules seem to become more and more rare as the concentration of 3-hydroxyanthranilic acid increases. Also in the presence of the latter, the rate of tyrosine and/or DOPA consumption decreases. A very complicated 13C-NMR spectrum indicates the high complexity of the reaction. This involves both the true melanin precursor(s) and the tryptophan metabolite, even if with peculiar mechanism and kinetics. When 3-hydroxykynurenine is substituted for 3-hydroxyanthranilic acid the reaction leads to reddish pigments whereas xanthommatins (the typical oxidation products of 3-hydroxykynurenine) are absent. A possible relationship between some dischromic pathologies and tryptophan metabolic disorders is suggested. [ABSTRACT FROM AUTHOR]