RESUMO
In this study, a simple solid-phase extraction (SPE) approach by using activated attapulgite as sorbent was successfully developed for the determination of melamine in milk formula samples. Crucial factors impacting the extraction efficiency, including sample solvent, elution solvent, and sample loading volume, were investigated. Under the optimal extraction conditions, the sample loading volume was up to 200 mL and the adsorption capacity of the melamine gave rise to 1154 µg g(-1). Excellent linear calibration curves (r (2) > 0.999) were achieved, and then the limit of detection (S/N = 3) and the limit of quantification (S/N = 10) were found to be 0.15 and 0.5 ng mL(-1), respectively. The recoveries of the melamine spiked in four milk formula samples at three concentration levels ranged from 83.5 to 111.0 % with relative standard deviations (RSDs) less than 10.2 %. Furthermore, RSDs of batch to batch (n = 4) of the acidified attapulgite used in this developed method were in the range of 2.3â¼7.3 %. In comparison to the commercial Oasis MCX, the acidified attapulgite sorbent even outperformed (at least in terms of reproducibility) for melamine analysis in real food samples. Because of its simplicity, the newly developed SPE method based on acidified attapulgite nanoparticles should provide a promising tool for daily monitoring of doped melamine in milk formula or other complex matrices.
Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Compostos de Magnésio/química , Leite/química , Compostos de Silício/química , Extração em Fase Sólida/métodos , Triazinas/isolamento & purificação , Adsorção , Animais , Limite de Detecção , Triazinas/análiseRESUMO
BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver condition that typically arises in the middle and late stages of pregnancy. Short-chain fatty acids (SCFAs), prominent metabolites of the gut microbiota, have significant connections with various pregnancy complications, and some SCFAs hold potential for treating such complications. However, the metabolic profile of SCFAs in patients with ICP remains unclear. AIM: To investigate the metabolic profiles and differences in SCFAs present in the maternal and cord blood of patients with ICP and determine the clinical significance of these findings. METHODS: Maternal serum and cord blood samples were collected from both patients with ICP (ICP group) and normal pregnant women (NP group). Targeted metabolomics was used to assess the SCFA levels in these samples. RESULTS: Significant differences in maternal SCFAs were observed between the ICP and NP groups. Most SCFAs exhibited a consistent declining trend in cord blood samples from the ICP group, mirroring the pattern seen in maternal serum. Correlation analysis revealed a positive correlation between maternal serum SCFAs and cord blood SCFAs [r (Pearson) = 0.88, P = 7.93e-95]. In both maternal serum and cord blood, acetic and caproic acids were identified as key metabolites contributing to the differences in SCFAs between the two groups (variable importance for the projection > 1). Receiver operating characteristic analysis demonstrated that multiple SCFAs in maternal blood have excellent diagnostic capabilities for ICP, with caproic acid exhibiting the highest diagnostic efficacy (area under the curve = 0.97). CONCLUSION: Compared with the NP group, significant alterations were observed in the SCFAs of maternal serum and cord blood in the ICP group, although they displayed distinct patterns of change. Furthermore, the SCFA levels in maternal serum and cord blood were significantly positively correlated. Notably, certain maternal serum SCFAs, specifically caproic and acetic acids, demonstrated excellent diagnostic efficiency for ICP.
RESUMO
To investigate the antioxidative effect of astaxanthin on Nω-nitro-L-arginine methyl ester (L-NAME)-induced preeclamptic rats. Cell survival, the level of reactive oxygen species (ROS) and the changes in mitochondrial membrane potential (MMP) were examined in astaxanthin and H2O2-treated human umbilical vein endothelial cells (HUVECs). The preeclamptic Sprague-Dawley (SD) rat model was established by injection of LNAME and treatment with astaxanthin. The activities of malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide synthase (NOS) in serum were analyzed. Pathological changes were examined by hematoxylin and eosin (H&E) staining. The expression of nuclear factor (NF)κB, Rhoassociated protein kinase II (ROCK II), heme oxygenase1 (HO1) and caspase 3 in preeclamptic placentas were examined by immunohistochemistry. Astaxanthin significantly reduced H2O2induced HUVEC cell death, decreased ROS and increased MMP. Astaxanthin significantly reduced blood pressure and the content of MDA, but significantly increased the activity of SOD in preeclamptic rats. The urinary protein and the level of NO and NOS were also decreased. H&E staining revealed that the thickness of the basilar membrane was increased, while the content of trophoblast cells and spiral arteries were reduced following astaxanthin treatment. Immunohistochemistry results showed that the expression of NFκB, ROCK II and caspase 3 in preeclamptic placentas was significantly decreased after astaxanthin treatment, while HO1 expression was increased. In conclusion, astaxanthin inhibited H2O2induced oxidative stress in HUVECs. Astaxanthin treatment significantly improved LNAMEinduced preeclamptic symptoms and reduced the oxidative stress and inflammatory damages in preeclamptic placentas. Astaxanthin treatment may effectively prevent and treat preeclampsia.