Limited knowledge exists about the effects of commonly used diuretic medications on the human normal flora. Thus, we investigated potential stimulatory effects of diuretic drug furosemide on urogenital tract microbiota in women. Three strains of E. coli and C. albicans with different biofilm forming capacities were obtained from female patients diagnosed with urinary tract infections. All tested strains were treated with two different concentrations of furosemide drug, in comparison to non-treated strains as the negative control. At specific time intervals, samples were obtained from growing culture and analyzed for their proliferation rate, aspartyl proteinase excretion and biofilm formation ability. E. coli and C. albicans strains significantly increased their aspartyl proteinase excretion under furosemide treatment. This effect was frequently observed after 16 hours of incubation at 37oC. This drug has also increased the biofilm forming capacities of E. coli and C. albicans strains. Interestingly, both E. coli and C. albicans non-biofilm former strains, gained the capacity of biofilm formation when treated with furosemide at certain concentrations. E. coli control became a weak biofilm former after 48 hours of incubation, while non-biofilm former C. albicans strain became a weak biofilm former in dose-dependent fashion, after 48 hours incubation with furosemide in concentration of 0.1 mg/mL, and after 16 hours of incubation with furosemide in concentration of 0.5 mg/mL. Loop diuretic drug furosemide is able to increase the microbial virulence and turn commensal microbes into opportunistic pathogens. Additionally, the results suggest that enzyme aspartyl proteinase might act as a signal molecule for the biofilm formation, leading to the increased microbial pathogenicity.

Heavy metals, due to their inability to degrade, pose a serious environmental and nutritional problem. The accumulation of essential and non-essential heavy metals in living organisms reduces normal growth and development, resulting in acute poisoning, disease and even death of organisms. Melatonin is a very important multifunctional molecule in protecting plants from oxidative stress due to its ability to directly neutralize reactive oxygen species (ROS). Also, melatonin has a chelating property, which may contribute in reducing metal-induced toxicity. In this paper, the protective role of melatonin in counteracting metal-induced free radical generation was highlighted. Using the HPLC-FLD technique melatonin was identified and quantified in the roots and leaves of lemon balm ( Melissa officinalis L.), grown under photoperiod conditions. Furthermore, the response of plants pre-treated with exogenous 0.1 mM melatonin to the increased zinc (Zn) and cadmium (Cd) concentrations was observed, with changes in mineral (Ca, Mg), physiological and antioxidant status of the plant during heavy metals stress. The obtained melatonin concentrations were the highest published for dry plants so far. Elevated Cd and Zn levels in soil caused alternation in biochemical and physiological parameters of lemon balm leaves and roots. However, melatonin pre-treatment increased plant tolerance to heavy metals stress. Increased Cd and Zn uptake and their translocation into the leaves were also improved, indicating the possible use of melatonin in phytoremediation.

Heavy metals disturb the redox homeostasis of the plant cell. The indolamine hormone, melatonin, protects plants from oxidative damage by directly scavenging reactive oxygen species or by stimulating the activity of antioxidant enzymes. The antioxidative role of melatonin in the leaves of two medicinal plants, lemon balm (Melissa officinalis L.) and valerian (Valeriana officinalis L.) that were treated with increased concentrations of Zn and Cd 24 h after sowing at an open field, were investigated. The plants were treated with Zn, Cd, melatonin and a mixture of melatonin with the mentioned metals. Exogenously added melatonin increased the endogenous melatonin concentration in lemon balm leaves. However, in the valerian leaves, lower or the same endogenous melatonin level was detected. The significantly higher concentration of endogenous melatonin in both plants was measured after treatment with Zn. As the results showed, changes in superoxide dismutase (SOD) and peroxidase (POD) activities are species-specific and change depending on the plant development phase, and the type of treatment. Melatonin pretreatment induced alternation in SOD isoenzyme profiles and activities as well as POD activity in both plant species treated with heavy metals.

Black cumin (Nigella sativa L. [N.sativa]) seed extracts demonstrated numerous beneficial biological effects including, among others, antidiabetic, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, antihypertensive, and antioxidant activity. To better understand the phytochemical composition of N. sativa seeds, methanol seed extracts were analyzed for phenolic acid and flavonoid content. Furthermore, we tested N. sativa methanol, n-hexane, and aqueous seed extracts for their inhibitory activity against butyrylcholinesterase (BChE) and catalase (CAT) as well as for antimicrobial activity against several bacterial and a yeast strains. The phenolic content of N. sativa was analyzed using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The inhibition of BChE was assessed by modified Ellman's method, and the inhibition of CAT was determined by monitoring hydrogen peroxide consumption. The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Salmonella enterica, and Escherichia coli using the agar diffusion method. The UHPLC-MS/MS method allowed the identification and quantification of 23 phenolic compounds within 15 minutes. The major components found in N. sativa seed extract were sinapinic acid (7.22 ± 0.73 µg/mg) as a phenolic acid and kaempferol (11.74 ± 0.92 µg/mg) as a flavonoid. All extracts showed inhibitory activity against BChE, with methanol seed extract demonstrating the highest inhibitory activity (inhibitory concentration 50% [IC50] 79.11 ± 6.06 µg/ml). The methanol seed extract also showed strong inhibitory activity against CAT with an IC50 value of 6.61 ± 0.27 µg/ml. Finally, the methanol extract exhibited considerable inhibitory activity against the tested microbial strains. Overall, this is the first study to investigate the ability of black cumin seed extracts to inhibit CAT. Our results indicate that N. sativa seed can be considered as an effective inhibitor of CAT activity.

Recently research shows that horseradish peroxidase, HRP, when combined with other compounds, is highly reactive toward different human tumour cells and that better understanding of catalytic mechanism and inhibition HPR could lead to a new targeted cancer therapy. Thus, the inhibition of HRP activity by dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH] was investigated for possible explanation of previously observed antitumour activities of this promising drug. HRP activity was studied under steady-state kinetic conditions by a spectrophotometric method. In the absence of the inhibitor values of = 0.47 mM and = 0.34 mM min−1, respectively, were determined. The hydrogen peroxide H2O2 kinetic measurements show a competitive inhibition with the inhibition constant = 2.56 mM. The activation energy values were found to be very similar for both reactions; in the absence of inhibitor activation energy was 17.7 kJ mol−1 and in the presence of inhibitor activation energy was 16.3 kJ mol−1. The values of Arrhenius constants were found to be different; = 4.635 s−1 was measured in the absence of inhibitor while in the presence of inhibitor Arrhenius constant was 1.745 s−1 showing that K2[B3O3F4OH] initiates conformational change in the structure of the HRP and subsequently reduces its activity.

Globalization as a worldwide process has significant implications in the area of education. In relation to this trend, the main challenge is to prepare students for the role of competent global citizens. Thus, we tested selected group of students of chemistry in attempt to measure their understanding of global trends in education. Results show positive attitudes towards student mobility, but no vision to develop competence and capacity that will make them quality applicants for international mobility programs. Scarce examples of students engagement in global educational trends only magnifies the need for well researched and organized approach in this area.