Festivals following the easing of COVID-19 restrictions: Prevalence of new psychoactive substances and illicit drugs.

The market for illicit drugs and new psychoactive substances (NPS) has grown significantly and people attending festivals have been identified as being at high risk (high extent and frequency of substance use). Traditional public health surveillance data sources have limitations (high costs, long implementation times, and ethical issues) and wastewater-based epidemiology (WBE) can cost-effectively support surveillance efforts. Influent wastewater samples were analyzed for NPS and illicit drug consumption collected during New Year period (from 29-Dec-2021 to 4-Jan-2022) and a summer Festival (from 29-June-2022 to 12-July-2022) in a large city in Spain. Samples were analyzed for phenethylamines, cathinones, opioids, benzodiazepines, plant-based NPS, dissociatives, and the illicit drugs methamphetamine, MDA, MDMA, ketamine, heroin, cocaine, and pseudoephedrine by liquid chromatography mass spectrometry. High consumption rates of specific NPS and established illicit drugs were identified at the peak of each event. Furthermore, a dynamic change in NPS use (presence and absence of substances) was detected over a period of six months. Eleven NPS, including synthetic cathinones, benzodiazepines, plant-based NPS and dissociatives, and seven illicit drugs were found across both the New Year and summer Festival. Statistically significant differences (p < 0.05) were seen for 3-MMC (New Year vs summer Festival), eutylone (New Year vs summer Festival), cocaine (summer Festival vs normal week and summer Festival vs New Year), MDMA (New Year vs normal week and summer Festival vs normal week), heroin (summer Festival vs New Year) and pseudoephedrine (summer Festival vs New Year). This WBE study assessed the prevalence of NPS and illicit drugs at festivals following the reduction of the COVID-19 pandemic restrictions highlighting the high use of specific substances at the peak of each event. This approach identified in a cost-effective and timely manner without any ethical issues the most used drugs and changes in use patterns and, thus, can complement public health information.

Cytotoxicity, uptake and accumulation of selenium nanoparticles and other selenium species in neuroblastoma cell lines related to Alzheimer's disease by using cytotoxicity assays, TEM and single cell-ICP-MS.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, representing 80% of the total dementia cases. The "amyloid cascade hypothesis" stablishes that the aggregation of the beta-amyloid protein (Aß42) is the first event that subsequently triggers AD development. Selenium nanoparticles stabilized with chitosan (Ch-SeNPs) have demonstrated excellent anti-amyloidogenic properties in previous works, leading to an improvement of AD aetiology. Here, the in vitro effect of selenium species in AD model cell line has been study to obtain a better assessment of their effects in AD treatment. For this purpose, mouse neuroblastoma (Neuro-2a) and human neuroblastoma (SH-SY5Y) cell lines were used. Cytotoxicity of selenium species, such as selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys) and Ch-SeNPs, has been determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry methods. Intracellular localisation of Ch-SeNPs, and their pathway through SH-SY5Y cell line, have been evaluated by transmission electron microscopy (TEM). The uptake and accumulation of selenium species by both neuroblastoma cell lines have been quantified at single cell level by single cell- Inductively Coupled Plasma with Mass Spectrometry detection (SC-ICP-MS), with a previous optimisation of transport efficiency using gold nanoparticles (AuNPs) ((69 ± 3) %) and 2.5 mm calibration beads ((92 ± 8) %). Results showed that Ch-SeNPs would be more readily accumulated by both cell lines than organic species being accumulation ranges between 1.2 and 89.5 fg Se cell-1 for Neuro-2a and 3.1-129.8 fg Se cell-1 for SH-SY5Y exposed to 250 µM Ch-SeNPs. Data obtained were statistically treated using chemometric tools. These results provide an important insight into the interaction of Ch-SeNPs with neuronal cells, which could support their potential use in AD treatment.

Simultaneous determination of aflatoxins B1, B2, G1 and G2 in commercial rices using immunoaffinity column clean-up and HPLC-MS/MS.

Rice is frequently contaminated with aflatoxins, that are highly toxic fungal substances and strongly involved on hepatic cancer. In this work, different extraction and clean-up methods were evaluated for the simultaneous extraction and clean-up of aflatoxins B1, B2, G1 and G2 from rice. Favourable results were obtained by using methanol - water (80:20, v/v) extraction followed by immunoaffinity columns for clean-up, with recoveries of 86-92%, standard deviations between 5 and 11%, LOD ranged between 0.09 and 0.32 µg/kg, and LOQ between 0.31 and 1.06 µg/kg. Method validation and sample analysis were performed by using HPLC-MS/MS. Nine rice samples from different origin, varieties and specific characteristics, acquired in Spanish supermarkets were analysed. In two basmati samples from the same batch aflatoxin B1 was detected at (1.62 ± 0.08) µg/kg and (0.77 ± 0.03) µg/kg, both lower than the levels established by European Regulation for aflatoxin B1 in cereals.

Ability of selenium species to inhibit metal-induced Aß aggregation involved in the development of Alzheimer's disease.

Extracellular accumulation of amyloid beta peptide (Aß) is believed to be one of the main factors responsible for neurodegeneration in Alzheimer's disease (AD). Metals could induce Aß aggregation, by their redox activity or binding properties to amyloid ß fibrils, leading to their accumulation and deposition outside neurons. For this reason, metal chelation may have an acknowledged part to play in AD prevention and treatment. In the current work, the role of different selenium species, including selenium nanoparticles, in Aß aggregation, was studied by evaluating their metal-chelating properties and their ability both to inhibit metal-induced Aß1-42 aggregation fibrils and to disaggregate them once formed. Transition biometals such as Fe(II), Cu(II), and Zn(II) at 50 µM were selected to establish the in vitro models. The DPPH assay was used to determine the antioxidant capacity of the evaluated selenium species. Selenium nanoparticles stabilized with chitosan (Ch-SeNPs) and with both chitosan and chlorogenic acid polyphenol (CGA@ChSeNPs) showed the highest antioxidant properties with EC50 of 0.9 and 0.07 mM, respectively. UV-Vis and d1(UV-Vis) spectra also revealed that selenium species, in particular selenomethionine (SeMet), were able to interact with metals. Regarding Aß1-42 incubation experiments, Fe(II), Cu(II), and Zn(II) induced Aß aggregation, in a similar way to most of the evaluated selenium species. However, Ch-SeNPs produced a high inhibition of metal-induced Aß aggregation, as well as a high disaggregation capacity of Aß fibrils in both the presence and absence of biometals, in addition to reducing the length and width (20% of reduction in the presence of Zn(II)) of the generated Aß fibrils. Graphical abstract.