Dried matrix spots: an evolving trend in the toxicological field.

Dried matrix spot (DMS) is a sampling technique, primarily used to analyze blood to diagnose metabolic diseases in newborns. As this technique has several advantages, DMS has started to be employed for other purposes using other biological matrices and increasingly in toxicology over the last decade. The aim of this work was to review the analytical methods using DMS which can be applied to drugs of abuse and which have been published since 2010. Three different databases were searched, using dried, spots, and drugs of abuse as the descriptors and using a snowball search. After applying the exclusion criteria, 39 papers remained. The most common publications were related to the use of blood, which corresponded to 77% of the papers, followed by urine and oral fluid, which corresponded to 13 and 10% of the papers, respectively. The selected studies covered different illicit drugs, sample sizes of 5 to 250 µL and spot sizes ranging from 3 to 18 mm in diameter. This review also examined the extraction techniques and the methods employed to analyze various biological matrices and drugs of abuse, mostly by liquid-extraction and liquid chromatography-tandem mass spectrometry. The benefits of DMS include: a simple sample pretreatment, better stability than liquid matrices, a simple extraction procedure, lower costs, and environmental benefits. DMS appears to be a promising technique in the field of toxicology and provides new perspectives for use in forensic laboratories.

Development and Validation of a Method Using Dried Oral Fluid Spot to Determine Drugs of Abuse.

A liquid chromatography-mass spectrometry method using dried oral fluid spots was developed and validated for the simultaneous quantification of cocaine, benzoylecgonine, cocaethylene, amphetamine, and 3,4-methylenedioxymethamphetamine. The oral fluid was applied to a Whatman 903 grade paper and submitted to a drying time of 2.5 h. The extraction procedure was optimized by chemometric approach using simplex centroid design. Spots were extracted with a mixture of acetonitrile, buffer, and methanol. Calibration curves covered a linear concentration range of 40-500 ng/mL. Validation parameters of linearity, precision, accuracy, selectivity, carryover, matrix effects, and stability were evaluated and showed satisfactory results. Spot homogeneity was also satisfactory, with less than 15% of deviation from nominal concentration. Spot volume did not influence accuracy when less than 100 µL of the sample was applied to the spot. The validation of the proposed method suggests a potential application in different scenarios in toxicology.

Multianalytical Method Validation for Qualitative and Quantitative Analysis of Solvents of Abuse in Oral Fluid by HS-GC/MS.

The use of oral fluid as a biological matrix to monitor the use of drugs of abuse is a global trend because it presents several advantages and good correlation to the blood level. Thus, the present work aimed to develop and validate an analytical method for quantification and detection of solvents used as inhalants of abuse in oral fluid (OF), using Quantisal™ as collector device by headspace and gas chromatography coupled with a mass detector (HS-GC/MS). Chromatographic separation was performed with a ZB-BAC1 column and the total time of analysis was 11.8 min. The method showed good linearity (correlation coefficient higher than 0.99 for all solvents). The limits of detection ranged from 0.05 to 5 mg/L, while the lower limits of quantification ranged from 2.5 to 12.5 mg/L. Accuracy, precision, matrix effect, and residual effect presented satisfactory results, meeting the criteria accepted for the validation of bioanalytical methods. The method showed good selectivity considering that, for solvents coeluting at the same retention time, resolution was performed by the mass detector. The method developed proved to be adequate when applied in OF samples from users of drugs and may be used to monitor the abuse of inhalants in routine forensic analyses.

Gender differences in biochemical markers and oxidative stress of rats after 28 days oral exposure to a mixture used for weight loss containing p-synephrine, ephedrine, salicin, and caffeine

ABSTRACT The association of p-synephrine, ephedrine, salicin, and caffeine in dietary supplements and weight loss products is very common worldwide, even though ephedrine has been prohibited in many countries. The aim of this study was to evaluate a 28-day oral exposure toxicity profile of p-synephrine, ephedrine, salicin, and caffeine mixture (10:4:6:80 w/w respectively) in male and female Wistar rats. Body weight and signs of toxicity, morbidity, and mortality were observed daily. After 28 days, animals were euthanized and blood collected for hematological, biochemical, and oxidative stress evaluation. No clinical signs of toxicity, significant weight loss or deaths occurred, nor were there any significant alterations in hematological parameters. Biochemical and oxidative stress biomarkers showed lipid peroxidation, and hepatic and renal damage (p < 0.05; ANOVA/Bonferroni) in male rats (100 and 150 mg/kg) and a reduction (p < 0.05; ANOVA/Bonferroni) in glutathione (GSH) levels in all male groups. Female groups displayed no indications of oxidative stress or biochemical alterations. The different toxicity profile displayed by male and female rats suggests a hormonal influence on mixture effects. Results demonstrated that the tested mixture can alter oxidative status and promote renal and hepatic damages.

RESUMO A associação de p-sinefrina, efedrina, salicina, e cafeína em suplementos alimentares e produtos para perda de peso é muito utilizada em todo o mundo, embora a efedrina tenha sido proibida em muitos países. O objetivo deste estudo foi avaliar o perfil de toxicidade à exposição oral de 28 dias à associação de p-sinefrina, efedrina, salicina e cafeína (na proporção de 10:4:6:80 m/m respectivamente) em ratos Wistar machos e fêmeas. Diariamente, os animais foram observados quanto ao peso corporal, sinais de toxicidade, morbidade e mortalidade. Após 28 dias, os animais foram sacrificados e o sangue coletado para avaliações hematológicas, bioquímicas e de estresse oxidativo. Não se observaram sinais clínicos de toxicidade, tampouco perda significativa de peso, mortes, ou quaisquer alterações significativas nos parâmetros hematológicos. Biomarcadores do estresse oxidativo e bioquímicos mostraram peroxidação lipídica, danos renais e hepáticos (p < 0,05; ANOVA/Bonferroni) em ratos machos (100 e 150 mg/kg) e a redução (p < 0,05; ANOVA/Bonferroni) nos níveis de glutationa reduzida (GSH) em todos os grupos de machos tratados. Nas fêmeas, não houve indícios de estresse oxidativo, nem alterações bioquímicas. O diferente perfil de toxicidade entre os gêneros sugere influência hormonal nos efeitos de mistura administrada. A associação testada pode alterar o estado oxidativo e promover danos renais e hepáticos.

Biological assessment (antiviral and antioxidant) and acute toxicity of essential oils from Drimys angustifolia and D. brasiliensis

The genus Drimys presents the widest geographical distribution of the Winteraceae family, which comprises seven genera and about 120 species. In Brazil, the genus is found from Bahia to Rio Grande do Sul and occur in two species, Drimys angustifolia Miers, and D. brasiliensis Miers, Winteraceae, popularly known as "casca-de-anta", characterized by the presence of flavonoids and essential oils. It is used in folk medicine as an antiscorbutic, stimulant, antispasmodic, anti-diarrheal, antipyretic, antibacterial, and against asthma and bronchitis, besides having insecticidal properties. In addition to the known biological activities, it is very important to explore new applications in the treatment of physiological disorders or diseases caused by parasites. Based on this information, in this study we propose to evaluate volatile oils of the species D. brasiliensis and D. angustifolia, as an antioxidant, using the model of the DPPH radical as an antiviral against human herpes virus type 1 (HSV-1) and acute toxicity in vivo. The two species were not able to reduce the DPPH radical and showed interesting antiviral activity, significantly reducing the virus titers in vitro assays. Regarding the in vivo toxicity in female Wistar rats, treatment with the two species showed interesting signs in animals such as salivation, ptosis, tremor, decreased motor activity. In addition the oils of D. brasiliensis to other signs, some animals showed increased urination and diarrhea.