Antioxidant, Nutraceutical Properties, and Fluorescence Spectral Profiles of Bee Pollen Samples from Different Botanical Origins.

Bee pollen is made by honey bees (Apis Mellifera) from the pollen of plants and flowers and represents an apiary product enriched in essential amino acids, polyphenols, omega-3, and omega-6 fatty acids. This study investigated the botanical origin, micronutrient profile, and antioxidant activity of bee pollen samples (n = 10) harvested in Lucca and Massa Carrara (Tuscany, Italy) between 2016 and 2017. The palynological analysis showed that bee pollen samples were composed of nine botanical families. Front-face fluorescence spectroscopy was performed on bee pollen samples in bulk, without any treatment, and in ethanol extracts to determine the characteristic fluorescent profile and, to identify the main chemical compounds with biological activity. The main chemical compounds detected were polyphenols (mainly flavonoids and phenolic acids), hydro-soluble vitamins (B2, B3, B6, and B9), amino acids, and pigments. Furthermore, the antioxidant activity was investigated, and one of the two Viburnum pollens resulted in the highest polyphenols and flavonoids content (20.15 ± 0.15 mg GAE/g fw and 23.46 ± 0.08 mg CE/g fw, respectively). However, Prunus and Eucalyptus families showed the highest in vitro (190.27 ± 8.30 µmol Fe2+/g) and ex vivo (54.61 ± 8.51 CAA unit) antioxidant capacity, respectively. These results suggested that Tuscan bee pollen, depending on the botanical family, is rich in essential nutrients and potential nutraceutical product.

Lifestyle of a Roman Imperial community: ethnobotanical evidence from dental calculus of the Ager Curensis inhabitants.

BACKGROUND: The analysis of ancient calcified dental plaque is a powerful archaeobotanical method to elucidate the key role of the plants in human history. METHODS: In this research, by applying both optic microscopy and gas chromatography mass spectrometry on this matrix, a detailed qualitative investigation for reconstructing the lifestyle of a Roman imperial community of the Ager Curensis (Sabina Tiberina, Central Italy) was performed. RESULTS: The detection of animal micro-remains and molecules (e.g., hairs, feather barbules, markers of dairy products), starch granules of several cereals and legumes, pollen (e.g., Juglans regia L., Hedera sp. L.) and other plant micro-debris (e.g., trichome of Olea sp., hemp fibers), and phytochemicals (e.g., Brassicaceae, Lamiaceae herbs, Ferula sp., Trigonella foenum-graecum L., wine, and Humulus lupulus L.) in the dental calculus sample demonstrated that plant-derived foods were regularly consumed together with animal resources. CONCLUSIONS: This nutritional plan, consistent with the information reported in ancient written texts, suggested that the studied population based its own subsistence on both agriculture and husbandry, probably also including beekeeping and hunting activities. All together, these results represent proofs for the comprehension of food habits, phytotherapeutic practices, and cultural traditions of one of the first Roman settlements in the Sabina Tiberina area.

Contamination of honey by oxytetracycline from pig manure.

Although the use of antimicrobial is not allowed in bee industry according to current EU legislation, antimicrobial residues are often detected in honey doomed to human consumption. This study aims to investigate if bees living in hives located nearby tanks filled with pig manure containing residues of oxytetracycline, would naturally harvest water from it, thus contaminating their honey. Data from this experiment were compared with those originating from direct contamination with oxytetracycline through the beehive feeders. Bees did not harvest water from manure, even during the warmest days of summer. Instead, antimicrobial residues were evidenced and quantified in honey from hives directly contaminated with oxytetracycline. Interestingly, antimicrobial residues were also observed in honey from untreated hives thus suggesting that illegal treatments can cause contamination, albeit at low levels, of honey produced in legally-untreated neighboring hives.

Antibacterial Activity of Different Blossom Honeys: New Findings.

Antibacterial activity is the most investigated biological property of honey. The goal of this study was to evaluate the antibacterial activity of 57 Slovak blossom honeys against Staphylococcus aureus and Pseudomonas aeruginosa and investigate the role of several bioactive substances in antibacterial action of honeys. Inhibitory and bactericidal activities of honeys were studied to determine the minimum inhibitory and bactericidal concentrations. The contents of glucose oxidase (GOX) enzyme, hydrogen peroxide (H2O2), and total polyphenols (TP) were determined in honeys. We found that honey samples showed different antibacterial efficacy against the tested bacteria as follows: wildflower honeys > acacia honeys > rapeseed honeys. Overall antibacterial activity of the honeys was statistically-significantly correlated with the contents of H2O2 and TP in honeys. A strong correlation was found between the H2O2 and TP content. On the other hand, no correlation was found between the content of GOX and level of H2O2. Antibacterial activity of 12 selected honeys was markedly reduced by treatment with catalase, but it remained relatively stable after inactivation of GOX with proteinase-K digestion. Obtained results suggest that the antibacterial activity of blossom honeys is mainly mediated by H2O2 levels present in honeys which are affected mainly by polyphenolic substances and not directly by GOX content.

Botanical influence on phenolic profile and antioxidant level of Italian honeys.

Honeybees directly transfer plant compounds from nectar into honey. Each plant species possesses a specific metabolic profile, the amount and the typology of plant molecules that may be detected in honey vary according to their botanical origin. Aim of the present work was the spectrophotometrical determination of concentration ranges of simple phenols and flavonoids in 460 several Italian monofloral honeys, in order to individuate specific intervals of plant metabolites for each typology of honey. Moreover, an LC-MS analysis was performed to determine amount of various secondary metabolites in the samples, with the purpose to use them as potential molecular markers in support to honey melissopalynological classification. As plant molecules have a strong reducing power, the antioxidant activity of the honeys was evaluated by two antiradical assays, DPPH and FRAP. The free radical scavenging effect of each monofloral group was correlated to the concentration of simple phenols and flavonoids, with the aim to deduce the existence of possible relationships between these parameters. In conclusion, dark honeys (Castanea sativa, honeydew, Erica sp. and Eucalyptus sp.) appeared to be the richest in secondary metabolites and, consequently, showed higher antioxidant activity. However, all analyzed monofloral honeys showed to be good sources of antioxidants.

Effect of thermal liquefying of crystallised honeys on their antibacterial activities.

Thermal liquefying of crystallised honey is the most convenient option for beekeepers to fully liquefy honey. A controlled mild thermal treatment is widely used for effective and safe liquefying of crystallised honey. In this study, we demonstrated that thermal liquefying at different temperatures of 45, 55 and 65 °C does not affect the overall honey antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus, and, in some cases, it may even increase the antibacterial potential of honey. A mild thermal treatment of crystallised honey was able to significantly increase its glucose oxidase (GOX) enzyme activity. On the other hand, the increased GOX activity in treated honey samples did not affect levels of accumulated H2O2, suggesting that some phytochemicals may contribute to or modulate antibacterial activity. Taken together, a mild thermal liquefaction of crystallised honey may increase the potential bioactivity of this matrix, which is also affected by the botanical origin.

Identification of ancient Olea europaea L. and Cornus mas L. seeds by DNA barcoding.

The analysis of ancient DNA (aDNA) provides archaeologists and anthropologists with innovative, scientific and accurate data to study and understand the past. In this work, ancient seeds, found in the "Mora Cavorso" archaeological site (Latium, Central Italy), were analyzed to increase information about Italian Neolithic populations (plant use, agriculture, diet, trades, customs and ecology). We performed morphological and genetic techniques to identify fossil botanical species. In particular, this study also suggests and emphasizes the use of DNA barcode method for ancient plant sample analysis. Scanning electron microscope (SEM) observations showed seed compact structure and irregular surface but they did not permit a precise nor empirical classification: so, a molecular approach was necessary. DNA was extracted from ancient seeds and then it was used, as template, for PCR amplifications of standardized barcode genes. Although aDNA could be highly degraded by the time, successful PCR products were obtained, sequenced and compared to nucleotide sequence databases. Positive outcomes (supported by morphological comparison with modern seeds, geographical distribution and historical data) indicated that seeds could be identified as belonging to two plant species: Olea europaea L. and Cornus mas L.

Characterization of Phaseolus vulgaris L. landraces cultivated in central Italy.

Eight Phaseolus vulgaris L. landraces cultivated on farm in marginal areas of Central Italy (Lazio region) were investigated in order to evaluate chemical composition of storage proteins and secondary metabolites fractions. The total protein content showed some differences among landraces; the maximum value was next to 30 g for 100 g of dry weight. The seed storage proteins were screened by polyacrylamide gel electrophoresis (SDS/PAGE): seven landraces exhibited phaseolin patterns type S, one landrace showed a phaseolin pattern type T. A morphological analysis of cotyledon parenchyma performed by scanning electron microscopy (SEM) revealed differences in size of starch granules. Moreover the polyphenolic composition was investigated using HPLC-APCI; from the methanol extracts a flavonoid, kaempferol, and a coumarin, 5,7-dimethoxycoumarin, were identified. To our knowledge, this is the first time that 5,7-dimethoxycoumarin has been reported in P. vulgaris seeds.

Superoxide dismutase activity in the cyanobacterium Microcystis aeruginosa after surface bloom formation.

• The presence of superoxide dismutase (SOD) enzymes and the response of SOD after in vitro induction and decay of a surface bloom are shown in cultures of the cyanobacterium Microcystis aeruginosa. • The SOD enzymes of surface blooms, early degenerate and completely degenerate cultures were assayed by staining for SOD activity, immunoblotting and immunogold labelling. • One band of Mn- and three bands of Fe-SOD were detected in cell extracts. During surface bloom formation, Fe-SOD activity increased fivefold compared with that in control cells; no variation was detected in Mn-SOD activity. However, in early degenerate cultures, Fe-SOD activity decreased to that seen in control cultures, while activity disappeared in completely degenerate cultures. Immunogold labelling showed that Fe-SOD was localized in the cytoplasmic and thylakoid membranes of Microcystis. The extent of labelling paralleled the course of Fe-SOD activity with an increase in particles in surface blooming cells. • The results suggest Fe-SOD increased due to photooxidative stress. However, under prolonged photooxidative stress, high concentrations of active oxygen species could directly, or indirectly, inactivate and degrade Fe-SOD.