Resveratrol, a natural phytoalexin found mainly in grapes, possesses a variety of beneficial activities including anticancer, antimicrobial and antiviral. However, there is no information about its effects on kinetoplastid parasites such as Leishmania. Leishmania is a human pathogen responsible for a spectrum of diseases known as leishmaniases and a significant health problem in many parts of the world. In this study, we investigated effects of resveratrol and its hydroxylated analogues on Leishmania major, a causative agent of zoonotic cutaneous leishmaniasis in the Old World. Resveratrol showed antileishmanial activity against promastigotes in vitro and, more importantly, was effective against intracellular amastigotes, a parasite life stage infectious in humans, as detected in in vitro macrophage assay. The hydroxylated stilbenes tested in this study also showed antileishmanial activity against promastigotes, the most promising being 3,4,4',5'-tetrahydroxy-trans-stilbene. This compound showed excellent antileishmanial activity against extracellular promastigotes in vitro but not intracellular amastigotes. Our results suggest that resveratrol may be useful as a therapeutic agent to treat leishmaniasis and warrant its further assessment in animal models of disease.

In this article, the properties of thermosensitive chitosan hydrogels (structural and biological) prepared using chitosan chloride and β‐glycerophosphate are presented. The porous structure of the gels was observed with a scanning electron microscopy (SEM). Rheological and other structural and morphological investigations were carried out by infrared spectroscopy and X‐ray photoelectron spectroscopy. Crystallinity of the gel was determined by X‐ray diffraction analysis. Biocompatibility of the chitosan gels was investigated by contact with bone cells (line Saos‐2) for 7 and 21 days. The cells were encapsulated and seeded onto the gel. A live/dead test showed no cytotoxic reaction. The structure of the gels, before and after the cell culture, was tested using SEM (including ESEM), to select the most suitable method of preparation and reliable visualization of the gel with cells. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46459.

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Chemical plant protection is a commonly discussed factor potentially responsible for decline in pollinators and other beneficial insect populations. Various groups of chemicals including persistent organic pollutants could impact a bee colony’s welfare and are reported to be present in bee tissue and apiary products. The aim of this work was to evaluate the presence of selected persistent organic pollutant and pesticide residues in bee pollen originating from different geographical regions of Poland. Pesticide residues were identified in 60% of tested bee pollen samples. The compounds identified were mainly active ingredients of fungicide preparations. Insecticide active ingredients were up to 30% of the identified residues. The triazole fungicide tebuconazole and the neonicotinoid insecticide thiacloprid were the most frequently found pesticides in pollen. The highest pesticide concentration was determined for prothioconazole (356 μg kg-1). Mean concentrations of chlorinated biphenyls–EC6 and EC12 were 194 pg g-1 and 74 pg g-1, respectively. CB # 28 has the greatest share in the EC6 profile (mean 61 pg g−1, 31% contribution). Relatively high contributions were also observed for CBs # 101 (35 pg g−1, 18%), # 138 (36 pg g−1, 19%) and # 153 (33 pg g−1, 17%). CB # 114 and 118 have the highest share in the dioxin-like biphenyls fraction with mean concentrations of 17.6 and 37.6 pg g−1 (respectively 23 and 50%). Mean calculated concentrations of 39 polybrominated diphenyl ether congeners (Σ39 BDE) were 20 ± 27.7 pg g−1. High variability was observed between maximal and minimal determined concentration values. Individual BDEs were found at different frequencies and varying concentration levels. BDEs # 47, 75 and 99 dominated the profile with average concentrations of 3 pg g−1, 3.1 pg g−1, and 2.9 pg g−1, respectively.