Physico-chemical, antioxidant and antimicrobial properties of three different types of honey from Central Serbia

There are many studies dealing with the comparison of the quality and biological characteristics of honey of distinct geographical and botanical origins. However, there is scarce literary data on the physico-chemical and biological properties of different types of honey from the same production regions. Honey samples used in this study were from the following botanical origins: forest honey (honeydew), polyfloral honey and monofloral acacia honey. All samples were provided by a local beekeeper from Šumadija district (Central Serbia) and produced during the flowering season in 2018. Spectrophotometric determination of phenolic compounds in honey samples showed that the forest honey contained the highest total phenolics (806.10 mg GAE/kg) and flavonoids (146.27 mg QU/kg) contents, more than ten times higher than acacia honey (68.48 mg GAE/kg and 18.59 mg QU/kg, respectively). Antioxidant activity was determined by DPPH· and ABTS·+ assays. Forest honey showed better antioxidant activity than the other examined honey samples (594.77 mg Trolox/kg for ABTS assay and 260.77 mg Trolox/kg for DPPH assay). The minimal inhibitory concentrations (MICs) of honey samples against a panel of eleven bacterial and eight fungal species, along with yeast Candida albicans, showed that forest honey was the most effective in inhibition of their growth. These results suggest that forest honey has the best potential, among studied honey samples, for use in the human diet as food with valuable biological properties.Publishe

Antimikrobna aktivnost i fenolni sastav ekstrakta biljke Salvia Verticillata L.

The aim of this study was to investigatethe total content of phenolic compounds, flavonoids and phenolic acids,examine the antimicrobial activity of the methanolic extract of S. verticillata aerial part, and demonstrate the presence of rosmarinic acid. The extract was rich in total phenolic content, especially in the total flavonoids content. Using the thin layer chromatography method, rosmarinic acid was identified in the extract.The extract showed moderate to weak antibacterial activity with MIC values of 1.25 to 20 mg/mL and significantly lower antifungal activity. The obtained results suggest that S. verticillata could be subjected to further studies of its pharmacological potential.Cilj ovog rada je bio određivanje ukupne količine fenolnih jedinjenja, flavonoida i fenolnih kiselina, ispitivanje antimikrobne aktivnosti metanolnog ekstrakta nadzemnog dela biljke S. verticillata, kao i dokazivanje prisustva ruzmarinske kiseline. Ekstrakt je sadržao značajnu količinu ukupnih fenolnih jedinjenja, pri čemu se izdvojio po visokom sadržaju flavonoida.TLC hromatografijom pokazano je prisustvo ruzmarinske kiseline u ovom ekstraktu. Ekstrakt je pokazao umerenu do slabu antibakterijsku aktivnost sa MIK vrednostima od 1,25 do 20 mg/mLi znatno slabiju antifungalnu aktivnost. Dobijeni rezultati sugerišu da se mogu nastaviti dalja ispitivanja farmakološkog potncijala biljkeS. verticillata

Exercise Attenuates Anabolic Steroids-Induced Anxiety via Hippocampal NPY and MC4 Receptor in Rats

The aim of our study was to evaluate the effects of chronic administration of nandrolone-decanoate (ND) or testosterone-enanthate (TE) in supraphysiological doses and a prolonged swimming protocol, alone and in combination with ND or TE, on anxiety-like behavior in rats. We investigated the immunohistochemical alterations of the hippocampal neuropeptide Y (NPY) and melanocortin 4 receptor (MC4R) neurons, as a possible underlying mechanism in a modulation of anxiety-like behavior in rats. Both applied anabolic androgenic steroids (AASs) induced anxiogenic effect accompanied with decreased serum and hippocampal NPY. The exercise-induced anxiolytic effect was associated with increased hippocampal NPY expression. ND and TE increased the number of MC4R, while the swimming protocol was followed by the reduction of MC4R in the CA1 region of the hippocampus. However, NPY/MC4R ratio in hippocampus was lowered by AASs and elevated by exercise in all hippocampal regions. An augmentation of this ratio strongly and positively correlated to increased time in open arms of elevated plus maze, in the context that indicates anxiolytic effect. Our findings support the conclusion that alterations in both hippocampal NPY and MC4R expression are involved in anxiety level changes in rats, while their quantitative relationship (NPY/MC4R ratio) is even more valuable in the estimation of anxiety regulation than individual alterations for both NPY and MC4R expression in the hippocampus

Drying methodology effect on the phenolic content, antioxidant activity of Myrtus communis L. leaves ethanol extracts and soybean oil oxidative stability

In this study, different drying methodologies (convective air, oven and microwave) of Myrtus communis L. (M. communis L.) leaves were conducted to investigate their effects on the levels of phenolic compounds, antioxidant capacity of ethanolic extracts (EEs) as well as the soybean oil oxidative stability. Drying methodology significantly influenced the extractability of phenolic compounds. Microwave drying led to an increase in the amounts of total phenols, flavonoids and proanthocyanidins followed by oven drying at 70 °C. Higher temperature of drying (100 and 120 °C) led to a significant reduction of their amounts (p < 0.05). An ultra-performance liquid chromatography method combined with high resolution mass spectroscopic detection was used to analyze the phenolic fraction of extracts. Higher amounts of the identified compounds were observed when leaves were heat treated. Furthermore, the evaluation of the antioxidant activity showed that the studied extracts possess in general high antioxidant capacities, significantly dependent on the employed drying methodology. The incorporation of the different extracts at 200 ppm in soybean oil showed that its oxidative stability was significantly improved. Extracts from leaves treated with microwave (EE_MW) and at 70 °C (EE_70) have better effect than BHT. The results of the present study suggest that microwave drying could be useful to enhance the extractability of phenolic compounds and the antioxidant capacity of M. communis L. leaf extract

The qualitative composition and comparative biological potential of Lunaria annua L. (Brassicaceae) extracts

Lunaria annua L. (Brassicaceae) in contrast to its name is a biennial plant native to the Balkans and southwest Asia. This research aimed to evaluate the composition of phenolic compounds (total phenolics, phenolic acids, flavonoids, flavonols, and gallotannins) of methanolic extracts of the aboveground parts (LAA) and roots (LAR) of L. annua, as well as antioxidant, antigenotoxic and anti-inflammatory properties of the extracts in vitro. LAA was richer in all groups of phenolics in comparison to LAR. LAA also had higher antioxidant potential except for the inhibition of lipid peroxidation. LAA and LAR showed inhibition of cyclooxygenase-1 and -2 (COX-1 and -2) enzymatic activities. The anti-inflammatory potential of L. annua extracts was outstanding, especially regarding COX-2 inhibition. Presented findings can lead to the isolation of compounds in L. annua responsible for this plant's remarkable anti-inflammatory properties.Publishe

The Impact of Hippocampal Sex Hormones Receptors in Modulation of Depressive-Like Behavior Following Chronic Anabolic Androgenic Steroids and Exercise Protocols in Rats

The aim of this study was to evaluate alterations in depressive-like behaviors in rats following chronic administration of a supraphysiological dose of anabolic androgenic steroids (AASs) as well as exposure to a prolonged exercise protocol. The role of hippocampal sex hormones receptors in the modulation of depressive-like behavior was also assessed. A total of 48 male Wistar albino rats were divided into six groups: control, exercise (1 h/day, five consecutive days), nandrolone-decanoate (ND, 20 mg/kg/week, in a single dose), exercise plus ND, testosterone-enanthate (TE, 20 mg/kg/week, in a single dose), and exercise plus TE. After the 6-week protocols were complete, the rats underwent behavioral testing in the tail suspension test (TST). Rats were sacrificed for the collection of blood samples, to determine sex hormones levels, and isolation of the hippocampus, to determine [androgen receptors (AR) and estrogen receptors α (ERα)] expression. ND and TE treatment induced significant depressive-like behavior, opposing the antidepressant effect of exercise. Chronic TE administration elevated testosterone (T) and dihydrotestosterone (DHT) serum levels, and this was augmented by exercise. In contrast, ND and exercise alone did not alter T or DHT levels. There were no changes in serum estradiol levels in any of the groups. Immunohistochemical analysis showed that exercise reduced AR immunoreactivity in all hippocampal regions and increased the ERα expression in the CA1, dentate gyrus (DG), and total hippocampal sections, but not in the CA2/3 region. AASs administration increased AR expression in all hippocampal regions, although not the total hippocampal section in the TE group and did not significantly decrease ERα. The hippocampal AR/ERα expression index was lowered while parvalbumin (PV)-immunoreactivity was enhanced by exercise. AASs administration increased the AR/ERα index and reduced PV-immunoreactivity in the hippocampus. The number of PV-immunoreactive neurons negatively correlated with the antidepressant effects and the AR/ERα ratio. Our results suggest a potential role of the numerical relationship between two sex hormones receptors (stronger correlation than for each individual receptor) in the regulation of depressive-like behavior via the hippocampal GABAergic system in rats, which allow better understanding of the hippocampal sex hormones receptors role in modulation of depressive-like behavior

TET-mediated DNA hydroxymethylation is negatively influenced by the PARP-dependent PARylation

Background Poly(ADP-ribosyl)ation (PARylation), a posttranslational modification introduced by PARP-1 and PARP-2, has first been implicated in DNA demethylation due to its role in base excision repair. Recent evidence indicates a direct influence of PARP-dependent PARylation on TET enzymes which catalyse hydroxymethylation of DNA—the first step in DNA demethylation. However, the exact nature of influence that PARylation exerts on TET activity is still ambiguous. In our recent study, we have observed a negative influence of PARP-1 on local TET-mediated DNA demethylation of a single gene and in this study, we further explore PARP–TET interplay. Results Expanding on our previous work, we show that both TET1 and TET2 can be in vitro PARylated by PARP-1 and PARP-2 enzymes and that TET1 PARylation negatively affects the TET1 catalytic activity in vitro. Furthermore, we show that PARylation inhibits TET-mediated DNA demethylation at the global genome level in cellulo. Conclusions According to our findings, PARP inhibition can positively influence TET activity and therefore affect global levels of DNA methylation and hydroxymethylation. This gives a strong rationale for future examination of PARP inhibitors' potential use in the therapy of cancers characterised by loss of 5-hydroxymethylcytosine

EpiCRISPR targeted methylation of Arx gene initiates transient switch of mouse pancreatic alpha to insulin-producing cells

Introduction: Beta cell dysfunction by loss of beta cell identity, dedifferentiation, and the presence of polyhormonal cells are main characteristics of diabetes. The straightforward strategy for curing diabetes implies reestablishment of pancreatic beta cell function by beta cell replacement therapy. Aristaless-related homeobox (Arx) gene encodes protein which plays an important role in the development of pancreatic alpha cells and is a main target for changing alpha cell identity. Results: In this study we used CRISPR/dCas9-based epigenetic tools for targeted hypermethylation of Arx gene promoter and its subsequent suppression in mouse pancreatic αTC1-6 cell line. Bisulfite sequencing and methylation profiling revealed that the dCas9-Dnmt3a3L-KRAB single chain fusion constructs (EpiCRISPR) was the most efficient. Epigenetic silencing of Arx expression was accompanied by an increase in transcription of the insulin gene (Ins2) mRNA on 5th and 7th post-transfection day, quantified by both RT-qPCR and RNA-seq. Insulin production and secretion was determined by immunocytochemistry and ELISA assay, respectively. Eventually, we were able to induce switch of approximately 1% of transiently transfected cells which were able to produce 35% more insulin than Mock transfected alpha cells. Conclusion: In conclusion, we successfully triggered a direct, transient switch of pancreatic alpha to insulin-producing cells opening a future research on promising therapeutic avenue for diabetes management. 1 Introductio