A novel fluorimetric method to evaluate red wine antioxidant activity

In the light of the increasing use of red wine in the diet, due to its antioxidant properties, the availability of a simple and fast method to assay the antioxidant activity of this beverage is needed. Here we measured wine antioxidant capacity (WAC) via "crocin bleaching test", wine polyphenol content (WPC), via Folin Ciocalteu method, and fluorimetric response (WF) of 13 Italian red wines. A fairly good correlation between WAC and WF (R = 0.82) was found, thus validating the fluorimetric method as a simple, fast and cheap method to evaluate the antioxidant activity of red wines

Poly(Lactic-co-glycolic) Acid and Phospholipids Hybrid Nanoparticles for Regeneration of Biological Tissue

In tissue regeneration, biomaterials facilitate biological processes. However, a treatment with biomaterials will be successful only if supported by simple and inexpensive technologies which stimulate the regenerative processes. The present study focused on the possibility of creating formulations from which then to obtain suitable materials for the regeneration of heart tissue. The experimental procedure for precipitation of polymer- nanoparticles was modified ad hoc to obtain hybrid poly lactic-co-glycolic acid (PLGA)-phospholipid nanoparticles. The properties of the formulations produced by direct PLGA-phospholipid co-precipitation depend on the mass ratio R= polymer mass/phospholipid mass. The value of this parameter allows us to modulate the properties of the formulations. Formulations with R = 1.5, 2.3, 4, and 9 were prepared, and for each of them the particle-size distribution obtained by dynamic light scattering was studied. All samples showed that the hydrodynamic diameter decreases with increasing R value. This behavior is interpreted as polymer coil shrinkage due to contacts with the non-solvent. The spreadability and ease of obtaining thin sheets were evaluated for each formulation. The formulation with R=4 resulted in a homogeneous and easily workable material in thin sheets

Bioactivity of Wild Hop Extracts against the Granary Weevil, Sitophilus granarius (L.)

The use of bioinsecticides, rather than synthetic compounds, appears a goal to be pursued in pest control, especially for species such as Sitophilus granarius (L.) which attack stored products. Since Humulus lupulus (L.) is a remarkable source of bioactive compounds, this study investigated the bioactivity of hop flower extracts against S. granarius adults by evaluating toxic (contact, inhalation, and ingestion), repellent, antifeedant, and nutritional effects as well as their anticholinesterase activity and olfactory sensitivity. Hop extracts were obtained by soaking dried and ground hop cones in solvents of decreasing polarity: methanol, acetone, and n-hexane. Dried crude extracts were resuspended in each solvent, and used in topical application, ingestion, and fumigation toxicity assays, as well as in contact and short-range repellency tests, in vitro anticholinesterase activity evaluation, and electroantennographic tests. No inhalation toxicity for the extracts was found. On the contrary, all extracts showed adult contact toxicity 24 h after treatment (LD50/LD90 16.17/33.20, 25.77/42.64, and 31.07/49.48 µg/adult for acetone, n-hexane, and methanol extracts, respectively); negligible variations for these values at 48 h were found. The anticholinesterase activity shown by all extracts suggested that the inhibition of this enzyme was one of the mechanisms of action. Interestingly, flour disk bioassays revealed a significant ingestion toxicity for the acetone extract and a lower toxicity for the other two extracts. Moreover, all extracts affected insect nutritional parameters, at the highest dose checked. Filter paper and two-choice pitfall bioassays showed repellent activity and a strong reduction of insect orientation to a highly attractive food odor source, with minor differences among extracts, respectively. Finally, the presence of volatile compounds in the different extracts that are perceived by insect antennae was confirmed by electroantennography. All these findings strongly suggest a possible use of hop cone extracts against S. granarius, thus further confirming this plant as an interesting species for pest control