Direct microwave treatment enhances antioxidant and antibacterial properties of the seed extracts of Kékfrankos grapes.

The Kékfrankos is the most frequently cultivated wine grape in Hungary, with a significant national and regional impact, resulting in considerable amounts of byproducts (e.g. pomace, seeds). To the best of our knowledge no research has been conducted on the antioxidant and antibacterial properties of its seed extracts (GSE). A novel apporach of applying direct microwave treatment on grape seeds was implemented for the first time to enhance antioxidant and antimicrobial properties of GSE. Antioxidant properties were assayed using the DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power) and TPC (Folin-Ciocâlteu's Total Polyphenol Content) methods. Profile and content of polyphenols was studied using high-performance liquid chromatography/tandem mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry. Antibacterial properties were evaluated using Gram-positive Staphylococcus aureus (SA), methicillin-resistant Staphylococcus aureus (ST239) (MRSA) and Gram-negative Escherichia coli (EC) bacteria strains. Results proved that the mild direct microwave treatment of grape seeds significantly increased total polyphenol, (+)-catechin, (-)-epicatechin as well as antioxidant capacity levels by 20-30 % compared to untreated samples and resulted the best antibacterial properties based on bacterial growth curves (SA and MRSA: 0.015625 mg/mL, EC: 0.25 mg/mL). Results justify the importance of further pharmacological investigations on Kékfrankos grape seed extracts and that the direct microwave treatment of grape seeds is an innovative approach for the fast and cost efficient improvement of the antibacterial properties of grape seed extracts.

Comparison of Dietary Oils with Different Polyunsaturated Fatty Acid n-3 and n-6 Content in the Rat Model of Cutaneous Wound Healing.

Dietary supplementation with polyunsaturated fatty acids (PUFA) n-3 can affect cutaneous wound healing; however, recent findings demonstrate the variable extent of their influence on the quality of healing. Here, we compare the effect of several dietary oils, containing different levels of PUFA n-3 and PUFA n-6, on wound healing in the rat model. Rats were fed the feed mixture with 8% palm oil (P), safflower oil (S), fish oil (F) or Schizochytrium microalga extract (Sch) and compared to the animals fed by control feed mixture (C). Dorsal full-thickness cutaneous excisions were performed after 52 days of feeding and skin was left to heal for an additional 12 days. Histopathological analysis of skin wounds was performed, including immune cells immunolabeling and the determination of hydroxyproline amount as well as gene expression analyses of molecules contributing to different steps of the healing. Matrix-assisted-laser-desorption-ionization mass-spectrometry-imaging (MALDI-MSI) was used to determine the amount of collagen α-1(III) chain fragment in healing samples. Treatment by Schizochytrium extract resulted in decrease in the total wound area, in contrast to the safflower oil group where the size of the wound was larger when comparing to control animals. Diet with Schizochytrium extract and safflower oils displayed a tendency to increase the number of new vessels. The number of MPO-positive cells was diminished following any of oil treatment in comparison to the control, but their highest amount was found in animals with a fish oil diet. On the other hand, the number of CD68-positive macrophages was increased, with the most significant enhancement in the fish oil and safflower oil group. Hydroxyproline concentration was the highest in the safflower oil group but it was also enhanced in all other analyzed treatments in comparison to the control. MALDI-MSI signal intensity of a collagen III fragment decreased in the sequence C > S > Sch > P > F treatment. In conclusion, we observed differences in tissue response during healing between dietary oils, with the activation of inflammation observed following the treatment with oil containing high eicosapentaenoic acid (EPA) level (fish oil) and enhanced healing features were induced by the diet with high content of docosahexaenoic acid (DHA, Schizochytrium extract).

Staphylococcus aureus and MRSA Growth and Biofilm Formation after Treatment with Antibiotics and SeNPs.

Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous pathogen resistant to ß-lactam antibiotics. Due to its resistance, it is difficult to manage the infections caused by this strain. We examined this issue in terms of observation of the growth properties and ability to form biofilms in sensitive S. aureus and MRSA after the application of antibiotics (ATBs)-ampicillin, oxacillin and penicillin-and complexes of selenium nanoparticles (SeNPs) with these ATBs. The results suggest the strong inhibition effect of SeNPs in complexes with conventional ATBs. Using the impedance method, a higher disruption of biofilms was observed after the application of ATB complexes with SeNPs compared to the group exposed to ATBs without SeNPs. The biofilm formation was intensely inhibited (up to 99%±7% for S. aureus and up to 94%±4% for MRSA) after application of SeNPs in comparison with bacteria without antibacterial compounds whereas ATBs without SeNPs inhibited S. aureus up to 79%±5% and MRSA up to 16%±2% only. The obtained results provide a basis for the use of SeNPs as a tool for the treatment of bacterial infections, which can be complicated because of increasing resistance of bacteria to conventional ATB drugs.