Pro-inflammatory activity of Astronium fraxinifolium Schott on Lipopolysaccharide-stimulated RAW 264.7 cells

This study aimed to investigate the antioxidant and immunomodulating activities of ethanolic extract from the sapwood of Astronium fraxinifolium (EEAF) on Lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The constituents of the EEAF were analyzed by high-performance liquid chromatography (HPLC). Antioxidant activity of EEAF was evaluated by its capacity of inhibiting the production of free radical 2,2'-diphenyl-1-picrylhydrazyl and 2,2-azino-bis3-ethylbenzothiazoline-6-sulfonic acid. For the analysis of its immunomodulatory properties, Nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and transforming growth factor beta (TGF-β) levels were determined in supernatants from LPS-stimulated RAW 264.7 cells after treatment with the EEAF at different concentrations. Expression for mRNA of Cyclooxygenase-2 (COX-2) and Inducible nitric oxide synthase (iNOS), and detection of COX-2 protein were also analyzed. Caffeic acid, quercetin, followed by orientin and ρ-coumaric acid, were identified in the extract by the HPLC technique. The EEAF showed poor antioxidant activity when compared to the reference standard. NO, expression of COX-2 mRNA and COX-2 protein were found in high levels when LPS-stimulated cells were treated with the EEAF. Moreover, increased levels of TNF-α and low secretion of TGF-β were demonstrated in supernatants from LPS-stimulated cells treated with EEAF at different concentrations. In opposition to many different types of medicinal plants, the EEAF demonstrated a powerful pro-inflammatory capacity

Cytotoxicity and DNA damage in the neutrophils of patients with sickle cell anaemia treated with hydroxyurea

Hydroxyurea (HU) is the most important advance in the treatment of sickle cell anaemia (SCA) for preventing complications and improving quality of life for patients. However, some aspects of treatment with HU remain unclear, including their effect on and potential toxicity to other blood cells such as neutrophils. This study used the measurement of Lactate Dehydrogenase (LDH) and Methyl ThiazolTetrazolium (MTT) and the comet assay to investigate the cytotoxicity and damage index (DI) of the DNA in the neutrophils of patients with SCA using HU.In the LDH and MTT assays, a cytoprotective effect was observed in the group of patients treated, as well as an absence of toxicity. When compared to patients without the treatment, the SS group (n=20, 13 women and 07 men, aged 18-69 years), and the group of healthy individuals (AA) used as a control group (n=52, 28 women and 24 men, aged 19-60 years), The SSHU group (n=21, 11 women and 10 men, aged 19-63 years) showed a significant reduction (p<0.001) in LDH activity and an increase in the percentage of viable cells by the MTT (p<0.001). However, the SSHU group presented significantly higher DI values (49.57±6.0 U/A) when compared to the AA group (7.43 ± 0,94U/A) and the SS group (22.73 ±5.58 U/A) (p<0.0001), especially when treated for longer periods (>20 months), demonstrating that despite the cytoprotective effects in terms of cell viability, the use of HU can induce DNA damage in neutrophils.

A hidroxiuréia (HU) constitui o avanço mais importante no tratamento da anemia falciforme (AF) por prevenir complicações e aumentar a qualidade de vida dos pacientes. Entretanto, alguns aspectos do tratamento com HU permanecem obscuros, incluindo a sua ação e potencial toxicidade em outras células sanguíneas, tais como neutrófilos. Este estudo utilizou a mensuração da lactato desidrogenase (LDH) e do metil tiazoltetrazólio (MTT) e o ensaio do cometa para investigar a citotoxicidade e índice de dano (ID) ao DNA em neutrófilos de pacientes com AF em uso do medicamento. Nos ensaios de LDH e MTT, observou-se além de ausência de toxicidade, uma ação citoprotetora no grupo de pacientes tratados, Grupo SSHU (n=21, 11 mulheres e 10 homens, com idades entre 19-63 anos), quando comparados aos pacientes sem tratamento, Grupo SS (n=20, 13 mulheres e 07 homens, 18-69 anos), e grupo de indivíduos saudáveis (AA) usado como controle (n=52, 28 mulheres e 24 homens, 19-60 anos), com redução significativa (p<0,001) na atividade de LDH e aumento no percentual de células viáveis pelo MTT (p<0,001). Entretanto, o grupo SSHU apresentou valores de ID significativamente elevados (49,57±6,0 U/A), quando comparados ao grupo AA (7,43 ± 0,94U/A) e grupo SS (22,73 ±5,58 U/A) (p<0,0001), especialmente quando tratados por períodos mais longos (>20 meses), demonstrando que apesar dos efeitos citoprotetores quanto à viabilidade celular, o uso da HU pode induzir lesão ao DNA de neutrófilos.