The antibiofilm effect of blueberry fruit cultivars against Staphylococcus epidermidis and Pseudomonas aeruginosa.

The antibiofilm and antibacterial properties against Pseudomonas aeruginosa and Staphylococcus epidermidis and chemical characterization of six hydroethanolic blueberry extracts (blueberry rabbiteye-Vaccinium virgatum) from different cultivars and means of propagation were investigated. The total flavonoid, anthocyanin, and phenolic contents were determined by specific and well-established methods. Among the cultivars, Briteblue showed the lowest content of all metabolites analyzed, while Bluegem showed the highest concentrations of these compounds. All the micropropagated cultivars presented the highest amounts of chlorogenic acid. The blueberry fruit extracts showed strong activity against S. epidermidis biofilm (up to 84% inhibition) without inhibiting bacterial growth. Likewise, Bluegem micropropagated extract, which had the highest anthocyanin, flavonoids, and phenolic compound content, demonstrated the highest S. epidermidis biofilm inhibitory effect. Finally, a linear correlation between the total phenolic content and the percentage of biofilm inhibition was observed.

Eugenol derivatives as potential anti-oxidants: is phenolic hydroxyl necessary to obtain an effect?

OBJECTIVES: Eugenol, obtained from clove oil (Eugenia caryophyllata), possess several biological activities. It is anti-inflammatory, analgesic, anaesthesic, antipyretic, antiplatelet, anti-anaphylactic, anticonvulsant, anti-oxidant, antibacterial, antidepressant, antifungal and antiviral. The anti-oxidant activity of eugenol have already been proven. From this perspective testing, a series of planned structural derivatives of eugenol were screened to perform structural optimization and consequent increase of the potency of these biological activities. METHODS: In an attempt to increase structural variability, 16 compounds were synthesized by acylation and alkylation of the phenolic hydroxyl group. Anti-oxidant activity capacity was based on the capture of DPPH radical (2,2-diphenyl-1-picryl-hydrazyl), ABTS radical 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), measure of TBARS (thiobarbituric acid-reactive species), total sulfhydryl and carbonyl content (eugenol derivatives final concentrations range from 50 to 200 µm). KEY FINDINGS: Four derivatives presented an efficient concentration to decrease 50% of the DPPH radical (EC50 ) < 100 µm, which has a good potential as a free-radical scavenger. Three of these compounds also showed reduction of ABTS radical. Eugenol derivatives presenting alkyl or aryl (alkylic or arylic) groups substituting hydroxyl 1 of eugenol were effective in reducing lipid peroxidation, protein oxidative damage by carbonyl formation and increase total thiol content in cerebral cortex homogenates. In liver, the eugenol derivatives evaluated had no effect. CONCLUSIONS: Our results suggest that these molecules are promising anti-oxidants agents.

Influence of physical exercise and gender on acetylcholinesterase and butyrylcholinesterase activity in human blood samples.

The determination of cholinesterase activity in plasma and erythrocytes serves as a useful and sensitive biomarker of exposure to organophosphorus and carbamate pesticides. However, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity may be influenced by factors such as age, gender, drugs, and physical exercise. The aim of this study was to evaluate the effects of gender and physical exercise on the activity of AChE and BuChE in healthy individuals. The values for both enzymes were lower for women. Physical exercise increased the levels of BuChE, and had no significant effect on AChE. To our knowledge, this is the first clinical study evaluating the influence of physical exercise in levels of these enzymes. Considering that cholinesterase activity is a useful parameter in assessing the exposure of individuals to pesticides, it is important to understand factors that influence the determination of the enzymes in order to avoid the erroneous interpretation of results.