Mariana Bortholazzi Almeida

In vitro and in vivo antileishmania activity of sesquiterpene lactone-rich dichloromethane fraction obtained from Tanacetum parthenium (L.) Schultz-Bip

The discovery of new treatments for neglected diseases, including leishmaniasis, is a substantial challenge for scientific research. Plant extracts have shown potential in the selective treatment of tropical diseases. The present study evaluated the in vitro and in vivo antileishmania effects of a sesquiterpene lactone-rich dichloromethane fraction (DF) obtained from the aerial parts of Tanacetum parthenium (L.) Schultz-Bip. In vitro studies of the DF indicated an IC50 of 2.40±0.76 μg mL(-1) against the promastigote form and 1.76±0.25 μg mL(-1) against the axenic amastigote form of Leishmania amazonensis. In vivo intramuscular treatment with DF decreased the growth and size of footpad lesions in mice. The DF also significantly decreased the parasite population compared with animals that were treated with the reference drug. Plasma malondialdehyde levels were increased slightly by the DF, attributable to its parthenolide-rich composition that causes cellular apoptosis, compared with the control group, demonstrating treatment efficacy without toxicity or genotoxicity. Because the isolation and purification of plant compounds are costly and time-consuming and generate low yields, extract fractions, such as the DF studied herein, represent a promising alternative for the treatment of leishmaniasis.

TEORES DE TRIGONELINA, ÁCIDO 5-CAFEOILQUÍNICO, CAFEÍNA E MELANOIDINAS EM CAFÉS SOLÚVEIS COMERCIAIS BRASILEIROS

Commercial Brazilian regular and decaffeinated instant coffees (33 brands) were studied. The levels ranged from 0.47 to 2.15 g 100 g-1 for trigonelline, 0.38 to 2.66 g 100 g-1 for 5-caffeoylquinic acid (5-CQA), 0.24 to 4.08 g 100 g-1 for caffeine, and 0.253 to 0.476 (420 nm) for melanoidins. Variations in bioactive compound levels among batches were observed. There was no relationship between the drying process and the composition of the products. In general, Gourmet and decaffeinated coffees had higher trigonelline and 5-CQA but lower caffeine and melanoidin content than regular products.

Development and validation of a method for simultaneous determination of bioactive compounds of Tanacetum parthenium (L.) Schultz-Bip

of parthenolide in the dichloromethane fraction of the hydroalcoholic extract of Tanacetum parthenium. The method presents potential use in quality control and development of new phytochemicals, a promising alternative in the treatment of leishmaniasis.

Optimization and validation of an SBSE-HPLC-FD method using laboratory-made stir bars for fluoxetine determination in human plasma

Depression is the largest cause of disability worldwide, affecting 350 million people. Notwithstanding that clinical trials demonstrate antidepressants efficacy, the efficient response can vary individually concerning therapeutic dosage. Although important, plasma levels monitoring remains an analytical challenge whereas clean-up and pre-concentration represent critical steps. Therefore, this study aims to develop, optimize and validate a method for fluoxetine determination in human plasma, employing a laboratory-made device consisting of a PDMS stir bar sorptive for extraction, coupled with high-performance liquid chromatography-fluorescence detection (SBSE-HPLC-FD). Optimization involved sorption-desorption steps. For sorption, temperature and time were assessed by factorial and central composite design approaches, taking into account the desirability and the response surface results, with stirring speed also examined. For desorption kinetics and ultrasonic and magnetic stirring mode were evaluated. The proposed method after validation was robust, linear (25.00-1000.00 ng mL-1 , R2  > 0.98) and presented good intra- (RSD 4.18%) and inter-day-assay (RSD 11.60%) precision and accuracy (recovery 109.60%), allowing reliable quantitation without interference. The method was successfully applied to real samples. SBSE-HPLC-FD could represent a feasible alternative with good cost-benefit for low-volume samples and therapeutic drug monitoring, as well as contributing to correlation studies between plasma fluoxetine levels and clinical response, which is still little studied.

Evaluation of Oxidative Stress in Patients with Acute Lymphoblastic Leukemia: Experimental Evidence of the Efficacy of MDA as Cancer Biomarker in Young Patients

Acute lymphoblastic leukemia (ALL) is a fatal disorder in most cases and is the most common cancer in young patients. ALL features an uncontrolled proliferation and maturation arrest of lymphoid progenitor cells (lymphoblast) in the bone marrow. An increase of reactive species production occurs in ALL with an involvement of oxidative stress (OS) and cellular damage. However, there is a lack of information about variations in young patients. The biomarker widely used to measure the OS is the main product of lipid peroxidation, the malondialdehyde (MDA). This biomarker, when evaluated by a chromatographic method and the data analyzed by multivariate analysis with other biochemical parameters of ALL patient charts, shows the distinction of healthy and ALL patients, and a great correlation with the risk of disease.

Validation of a liquid chromatography ultraviolet method for determination of herbicide diuron and its metabolites in soil samples

Diuron is one of the most widely herbicide used worldwide, which can undergo degradation producing three primary metabolites: 3,4-dichlorophenylurea, 3-(3,4-dichlorophenyl)-1-methylurea, and 3,4-dichloroaniline. Since the persistence of diuron and its by-products in ecosystems involves risk of toxicity to environment and human health, a reliable quantitative method for simultaneous monitoring of these compounds is required. Hence, a simple method without preconcentration step was validated for quantitation of diuron and its main metabolites by high performance liquid chromatography with ultraviolet detection. Separation was achieved in less than 11 minutes using a C18 column, mobile phase composed of acetonitrile and water (45:55 v/v) at 0.86 mL min-1 and detection at 254 nm. The validated method using solid-liquid extraction followed by an isocratic chromatographic elution proved to be specific, precise and linear (R2 ˃ 0.99), presenting more than 90% of recovery. The method was successfully applied to quantify diuron and their by-products in soil samples collected in a sugarcane cultivation area, focusing on the environmental control.