Optimization of ultrasound-assisted extraction of polyphenols from globe artichoke (Cynara scolymus L.) bracts residues using response surface methodology.

BACKGROUND: The globe artichoke (Cynara scolymus L.) is a rich source of phenolic compounds which may be extracted by ultrasound technology and used as a medicinal alternative. The objective of this work was to determine the radiation amplitude (%), ethanol concentration (%), and time extraction (min) required to guarantee an elevated content of polyphenol compounds. METHODS: The optimal extraction conditions were assessed through the Box-Wilson design and by applying Composite Face Centered (CCFC) and total phenolic compounds (TPC) as the response variables. RESULTS: A quadratic model was adequate, with R2 = 0.993. The optimal conditions were a radiation amplitude of 97%, an ethanol concentration of 53%, and an extraction time of 9.7 min. The optimized extract of artichoke bracts (Cynara scolymus L.) showed a TPC of 25.13 (±0.030) mg GAE/g, an antioxidant activity DPPH of 39.79 (±0.014) mmol Trolox equivalents (TE), and an antioxidant capacity TEAC of 33.98 (±0.03) mmol Trolox equivalents. CONCLUSIONS: The results showed values closely related to the expected values, indicating that the models were well-developed.

Toxicological effects of particulate matter (PM2.5) on rats: Bioaccumulation, antioxidant alterations, lipid damage, and ABC transporter activity.

Previous studies have demonstrated the harmful effects of atmospheric pollutants on cardiac systems because of the presence of particulate matter (PM), a complex mixture of numerous substances including trace metals. In this study, the toxicity of PM2.5 from two regions, rural (PM2.5 level of 8.5 ± 4.0 µg m(-3)) and industrial (PM2.5 level of 14.4 ± 4.1 µg m(-3)) in Brazil, was investigated through in vivo experiments in rats. Metal accumulation and biochemical responses were evaluated after rats were exposed to three different concentrations of PM2.5 in saline extract (10× dilution, 5× dilution, and concentrated). The experimental data showed the bioaccumulation of diverse trace metals in the hearts of groups exposed to PM2.5 from both regions. Furthermore, mobilization of the antioxidant defenses and an increase in lipid peroxidation of the cardiac tissue was observed in response to the industrial and rural area PM2.5. Glutathione-S-transferase activity was increased in groups exposed to the 5× and concentrated rural PM2.5. Additionally, ATP-binding cassette (ABC) transporter activity in the cardiac tissue exposed to PM2.5 was reduced in response to the 5× dilution of the rural and industrial region PM2.5. Histological analysis showed a decrease in the percentage of cardiac cells in the heart at all tested concentrations. The results indicate that exposure to different concentrations of PM2.5 from both sources causes biochemical and histological changes in the heart with consequent damage to biological structures; these factors can favor the development of cardiac diseases.